Patent Application
20220144058
This application is a modified improvement of two applications filed by the above-named inventor—application Ser. No. 15/911,627, filed Mar. 5, 2018; and application Ser. No. 16/399,194, filed Apr. 30, 2019, which was published Nov. 21, 2019 (2019/0351895 A1)—to fit all electric-vehicles, e.g., cars, trucks buses and semi-trailers; and application Ser. No. 17/352,411, filed Jun. 21, 2021, as a modification of application Ser. No. 16/399,194 to fit all railway vehicles.
When the world population was just about one-billion, and nature was able to replenish man-made pollution, Nicolaus August Otto (1832-1891) invented in 1862 the four-stroke piston engine; and in 1885 Gottlieb Daimler (1834-1900) and Karl Friedrich Benz (1844-1929) instigated the piston-engine automobile era (
This disclosure is a radical modification of the traditional, mechanical engineering model of traction, steering and braking systems. Countless billions of dollars spent on autonomous vehicles (AV) R&D to pursue human sensing physiology while driving a vehicle, when the world is sinking into a pollution disaster scenario of ‘no-return.’ Engineers, scientists, and politicians dedicated insufficient concerns and funds, to improve and regulate EVs efficiency to combat global pollution; forgetting that most electricity production is from coal, oil, and natural gas, and half (about 45%) of global CO2 emission comes from the production of electricity.
This disclosure provides an advanced solution to reduce EVs pollution by up-to 60% while providing a seamless driving and handling of any EV, autonomous EVs, buses, heavy-duty trucks, and semi-trailers by spreading the traction and steering task among verity of differently designed electric motors, independently propelling, and steering—with electronic means—each individual wheel independently, while integrating a scalable traction system with the steering system, by pursuing the four Pedi motoric of the fastest animals on the planet (
The general idea in the current transportation industry transformation-years is that electric vehicles need to be re-engineered from scratch. It should be transformative because EVs are completely different animals. Trying to build an electric, driver-less vehicle based on traditional, mechanical propulsion and steering developed in the 19th century; and applying electronic architecture developed in the 1980s is like trying to build a spaceship on the foundations of the Wright brother's flying-machine. This is certainly not where the transportation industry is heading.
About two decades ago, traditional manufacturers and startups constructed the first EVs by merely replacing the ICE (internal combustion engine) with an electric motor-totally ignoring the enormous difference of energy-density between gasoline and Li-ion batteries. Gasoline energy density is 12.7 kWh/Kg about 42 times the energy-density of Li-ion battery that is just 0.3 kWh/Kg. Gasoline efficiency of about 24% reduces the effective energy-density reaching the wheels to 3.048 kWh/Kg; while Li-Ion battery efficiency to wheels averages 92% (0.28 kWh/Kg), and the ratio gasoline/Li battery is reducing to about 11. The only way to close the gasoline/battery energy-density gap is to design EVs with superior efficiency, which are the objectives of this disclosure.
The second major objective to consider before designing an EV is the exponential demand for electric energy. At the end of 2020 there were 8.5 million EVs worldwide. Bloomberg cautious estimate predicts that at the end of 2030, the number of EVs will grow exponentially, reaching 116 million by marking a leap of 1,365% in less than a decade, which will increase the world electricity demand by 8,500 TWh. Other's opinion is that the EVs number will grow much faster for 3 reasons:
4. Most manufacturers will stop manufacturing piston engines between 2025 and 2035. Between 2025 and 2030 people will buy much more EVs because they will realize that nobody will buy their piston engine as a used vehicle, which will deter banks to give a loans to ICE cars.
5. Governments around the globe will impose higher taxes on fuel to combat pollution and to prevent people from using piston engine vehicles; and
6. The purchase price and maintenance of EV will be so much cheaper than piston engines vehicles that will lure people to buy EVs.
With the shortage of electricity supply to 8.5 million EVs today, the big question is how to provide electricity to 116 million EVs in 2030? Big electric traction-motors with large battery pack will not contribute to the atmosphere clean-up since the majority of electric-energy is produce from coal, oil, and natural-gas. Current OEMs claim to be “zero” EVs, are:
Tesla Model S, with 515 Hp motors, and with 2.3 metric tons curb weight; Volvo Polstar 2, 408 Hp, W/2.4 tons; Lexus LF-30, 536 Hp, W/2.4 tons; Mustang Mach-E, 459 Hp, W/2.4 tons; Mercedes EQC, 408 Hp, W/2.5 tons; Audi E-Tron Quattro, 408 Hp, W/2.5 tons; and Porsche Taycan, 680 Hp, W/2.3 tons.
It does not take a rocket scientist to figure-out that these vehicles are unnecessarily too heavy in every aspect, with average electric-energy consumption of 4 Km/kWh, while lighter and more efficient EVs perform above 8 Km/kWh. Governments will eventually impose penalties, similar to EPA CAFE (Corporate Average Fuel Economy) standards to enforce manufacturers to fabricate EVs with smaller traction-motors and with smaller battery-packs to boosting efficiency and consume up to 60% less electricity.
This application is pursuing nature's 2.5 billion-years of selective evolution where only the best ‘motion technology’ survived. EVs should be built different from ICE vehicles by first, eliminating obsolete mechanical components, and second, by designing a scalable tractive power system for superior efficiency, integrated with all-wheel steering system which leverage synergies between plurality of differently designed, and individually controlled electric traction-motors and all-wheel electric steering-motors, under the management of a holistic, digitized control-system, to consume the least electric-energy, yet maneuvering as powerful EV; while meeting the mobility prerequisites of the autonomous vehicle era, and safely dealing with any cyber threats.
Additionally, this disclosure is radically modified, to digitally communicate with the multi-sensing-analog-information obtained—with variety of cameras, ultrasonic sensors, long & short-range radars, and LiDAR systems—in autonomous vehicles. This disclosure provides the answer to a seamless driving and handling of any EV, autonomous EVs, buses, heavy-duty trucks, and semi-trailers by spreading the traction and steering task among verity of differently designed electric motors, independently propelling, and steering each individual wheel—with electronic means—while integrating a scalable traction system with the steering and braking systems, by pursuing the four Pedi motoric of the fastest animals on the planet (
The holistic controller in this disclosure monitors a variety of analog information collected from plurality of sensors; translates the analog sensory data into digital data, with which it can be applies to all kinds of electric traction and steering-motors and to electric brake-calipers to:
Electric Power Steering (EPS) is today the standard fitment in most vehicles. However, autonomous driving poses challenges to the steering technology manufacturing community:
, First, once a vehicles starts to operate without a driver, steering systems will expect to cater loss-of-assist mitigation in order to provide a safety net as, and when, the EPS power-pack fails to provide assistance for the vehicle steering. This will therefore force steering suppliers to migrate from fail safe systems3 to fail operational systems for steering. However, the major obstacle for the steering suppliers is NHTSA [National Highway Transportation and Safety Administration] regulatory compliance, which manufacturer are expecting modifications to accommodate AVs steering functionality. The scalable, integrated traction, steering and braking concept of this disclosure should be adopted as the ultimate future technology of choice because: 3 A fail-safe or fail-secure device is one that, in the event of a specific type of failure, responds in a way that will cause no harm, or at least a minimum of harm, to other devices or to personnel.
(iii) currently there is no effective mechanical solution for AV steering as this disclosure is; and
(iv) this disclosure triggers the elimination of EPS and all conventional, mechanical steering gears below the driver's steering-wheel.
In other words: while opposing wheels in an electronic-axle are activated with different tractive-power, and different speed; and while all wheels are steered in different angles because the distance of each wheel from the geometric center is different, it is obvious that a differential, electronic-controlled tractive-power will take-over the power-steering function, while integrating the traction in the electric all-wheel steering process, which will provide an exceptional stability and maneuverability without comparison.
autonomous driving does not require humans to drive the vehicle, in which case the use of steering wheel is made redundant. This then allows OEMs and steering suppliers to concentrate on technologies that will help either eliminate the steering wheel or allow the steering to retract to the dashboard if not required. The bottom line: OEMs realized that steer-by-wire must be the system of choice.
In short; this disclosure attempts to indoctrinate the taboos in mechanical engineering perceptions because, the inventor's philosophy is that EVs have to be contemplated as a completely new animal and not as a machine. Robots in the industry, should be classified as machines because robots are carrying-out one or at the most extremely limited, repetitive, pre-programmed functions. Yet an EV operates under constant changing driving conditions. Every driving mode is different from the previous one or the next one, which compels to sustain complex multi-objective optimization algorithm to calculate all operatives for the next move in milliseconds.
Level-Five AVs collapses the traditional, redundant steering wheels, yet the sophisticated cameras, ultrasonic sensors, long & short-range radars, and LiDAR systems digital data is connected to the wheels with mechanical differentials, mechanical steering linkages and hydraulic brake systems, developed in the 19th century. There is no engineering sense in having sophisticated sensory systems in autonomous vehicles—providing exclusively sensing information of the environment around the vehicle—while translating the digital information to the wheels, with a 130-year-old, obsolete mechanical-technologies. The analog sensory information received by the AV's ECU is converted to digital system, with which it can poorly communicate with mechanical gears that propel, steer and decelerates the wheels.
This disclosure provides a frog-leap towards prevention of the catastrophic global pollution that is reaching a point-of-no-return. System 10 infra provides an efficient and seamless driving and handling of any EV, or AV, by spreading the traction and steering functions among plurality of differently designed electric traction and steering-motors, to propel and steer each wheel independently, while the electric brake-calipers decelerate each wheel independently, with a sophisticated digitized electronic systems.
A holistic controller is configured at the center stage of the overall management since the holistic controller is accomplishing every logic associated with excellent and safe handling; electing the most efficient alternatives for traction, steering, and braking, by utilizing plurality of Multi-Objective Optimization Design (MOOD) procedures simultaneously and employing Evolutionary Multi-objective Optimization (EMO). The main purpose to elect a holistic processes was to take all the steps in the MOOD procedure into a centralize account:
(vi) meet all government pollution requirements;
(vii) reduce the battery-pack size by up to 50%;
(viii) reduce excessive electricity [in today electric trucks & buses] spending;
(ix) establish alternate energy solutions; and
(x) reduce the massive maintenance and repair expenditures.
The supremacy of humanity materialized about 5,500-years ago with the invention of the wheel, which outperformed evolution since there are no wheels in any known species. Yet, the first most efficient mobility emerged 5,300-years later when on Jun. 12, 1817, Karl von Drais (1785-1851) realized the first self-propelled machine when he travelled through the streets of Mannheim, Germany with his Laufmaschine, the “running machine,” the first bicycle. Human muscles create a super-efficient propulsion since it is the direct result of close-to-perfection human muscle motoric physiology. The lower part of the brain—with “algorithm” precision—activates the exact muscle-fibers, with the electric degree of intense that is just necessary to propel the bicycle's pedals. Then, the pedal rotation is transferred to the rear wheel, to accomplish the best efficiency in any given load condition, which is the gist of this disclosure. The nanotechnology in the molecular level—engaging the precise electro-chemical process that excites the exact number of Actin and Myosin proteins needed to perform precision contraction of the muscle—is not yet worked-out in vitro; yet it eventually will become the leading technology in future science because, every bio-technology utilized in lighting, television, and in a long list of products, makes it many-time-over superior and efficient, compared with any other technologies.
The reason the industry needed 130 years to look at a vehicle as an quadruped animal, is first because the convenience of cheap fuel, and
, because the dogma taught in engineering schools that only mechanical components in machines is dependable. The turning point emerged when AV researchers realized the necessity to pursue human physiology ‘perception of the environment’ while driving a vehicle to produce AVs. However, the current “end-product” of a multi-billion-dollar AV-research, is translating the ‘environment perception’ into the traditional mechanical traction, steering, and braking which is on the way to be obsolete.
Visiting Thomas Alva Edison's Museum in Fort Myers Fla., man can witness the “old timer” philosophy of ‘power transfer’ when one electric motor-actuates several ‘consumers’ with one leather belt. In the past—and unfortunately also in the present transportation industry—one crankshaft actuated since 1885 all “consumers” in ICE vehicles: the crankshaft rotates a camshaft with belt or chain, to activate the valves; water pump; oil pump; power-steering pump; alternator; pollution air pump; ignition distributor shaft; AC compressor; transmission and differentials to mechanically synchronize most power into only two wheels.
In system 10 as depict in
The first philosophy rule behind this disclosure is the notion that traction, steering and braking should complement each other, which is the only way to perform any perfect and stable mobility. Traditional automobile engineering, and new EVs, are constructed with traction, steering, and braking with no coordination between the three systems. It is obvious that propelling the wheels with one system and steering the same wheels with another is an imperfect arrangement, especially when it is conducted with mechanical means.
The philosophy rule is to centralize and digitize-control of all components with exclusively electronic means, for precision integration of the traction into the steering and braking process; providing EVs a ‘cheetah-like’ maneuverability; a precise computed scalable traction for outstanding efficiency; and in AVs the ability to translate the perception of the environment around the vehicle into digitized vehicle mobility.
The philosophy rule is to split power between plurality of electric traction-motors, to follow the steps of evolution where thousands muscle-fibers are involved in motoric procedures, yet super-efficient precision is arrived at, only when the brain—the holistic controller—actuates only those, elected muscle fibers [e.g., electric traction-motors] that are necessary to sufficiently do the job. Therefore, coupling, de-coupling and precision rotation of plurality of small electric traction-motors while steering all wheels, and unevenly actuating brake calipers to manage wet and ice roads is the ultimate approach to achieve optimization of super-efficient mobility.
The philosophy rule is that one electric traction-motor can do limited undertaking. Add another electric traction-motor for different task, add sensors, and further relationship becomes possible. Yet, gradually adding more, differently designed electric traction-motors configured to different specifications and to different assignment, with individual, electronically controlled, coupling, and de-coupling clutches, then the number of complex inter-relationships grows exponentially.
The philosophy rule teaches us that complex systems are accommodating substantial number of elements that operate in coordination with one another, flinching new modes of actions. This disclosure exhibits simple forms of coordination between traction steering and braking, which results from interaction of multiple electric-motors and electric brake-calipers in a non-linear behaviour. Complexity of multiple-component in non-linear system could never be predicted from just computing a single component and adding it up. Human precision motoric is typically acquired during incredibly early age and becomes programmed in the lower brain with association to the cortex. Later on, most motoric undertakings are performed subconsciously through interactions of millions of neurons. The same “specific learned motoric sequence” in humans—with reliance on GPS's (
The philosophy rule is to move into digitized controls and to discard the obsolete traditional mechanical traction, steering and braking gears. This will result in drastic reduction in weight, in manufacturing cost, and at the same time boost efficiency, precision maneuverability and safety, which will extend the EV driving-range, reduce components wear, and fulfil all AV engineering demands by translating analog data collected from cameras, radars, LiDAR and variety of sensors into a digital information, with which the holistic controller can utilize to precisely maneuver the traction-motors, the steering-motors, the electric brake-calipers and all other management undertakings.
The philosophy rule is to completely electrify the trucking industry and pave the road to autonomous heavy-duty trucks and semi-trailers that will drive on highways during night-time to prevent road-congestion during the day. There is a wide consensus among manufacturers that—parallel to the enormous transition in the electrification of light-duty vehicles—the trucking and buses industry has to be revolutionized as well. Diesel engines in trucks, semi-trucks and buses are to become obsolete for the extensive pollution of NOx and CO2 emission, which are a respiratory health detriments. The damage to the environment and the expenditure of health-care will always exceed by far the unsupported claims of the trucking industry that manufacturing and operating electric semi-trailer is much more expensive than diesel. Unsupported arguments as presented infra with supported calculations.
This disclosure is obviously not following the steps of engineering schools which support the notion that “bigger is always better.” In fact, up to last decade, automobile industry only rated vehicles by how fast they go from 0 to 60 mph; totally ignoring efficiency and pollution while neglecting the rest 99.9999% of the time traveled. It makes no technological, economical, or environmental sense to continuously operate an EV with a single or dual, 175 to 200 HP electric traction-motors when this level of power is needed only for the first few seconds of forward-motion start and during accelerations that last also only seconds.
It took ICE engineers about 100-years to register that the classic 350 CID (5,735 cc) Chevy engine could be downsized to 122 CID (2,000 cc), and while equipped with a turbo charge system (2018 Camaro)—which is only engaged for intervals of seconds at forward-motion start and during accelerations—could produce the same pep as a 350 CID engines, thus pollutes 300% less, and consumes 60% less fuel.
As part of the development of AVs; most vigorous R&D are in the artificial intelligence (AI) technologies, which is nothing but a computer science that pursues human sensory perception of the environment. The holistic controller receives the sensory information, but it cannot apply this information directly to the vehicle mechanical steering gears or to the vehicle transmission or differentials that propels the wheels. In order to provide the holistic controller a form of traction and steering management abilities, electric motors have to be installed to activate the different mechanical gears. Getting rid of mechanical gears while propelling, steering, and decelerating each wheel individually ‘by wire,’ is what nature decided to be the best mobility in the fastest animal on the planet (
Manufacturers require about 5-years to develop a new model, which makes it especially important to predict how the transportation industry will look like in the next 10-years. To follow government regulations and meet CAFE (Corporate Average Fuel Economy) requirements, the majority of the manufacturers specific intent is to electrify by 2035 their entire vehicle portfolios.
A different approach to EVs manufacturing is presented in
The right column in
This observation brought the inventor to the conclusion that larger motors are more efficient than smaller motors when moving stationary, or heavy-weight vehicles; and therefore, the best efficiency solution may be a plurality of—relatively small electric—traction-motors, coupled to and de-coupled from the wheels, according to a scheme derived from the holistic controller computed algorithms to satisfy the changing tractive-power requirements.
As for heavy-duty electric trucks, this disclosure achieved 23% better efficiency results than the Tesla semi-trailer (
(iii) Tesla's semi-trailer utilizes the same conventional steering as diesel semi-truck, which attributes to 22% inefficiencies of wheel-dragging. Integrating the traction in the steering process, while steering the articulated trailer two rear-axles will improve efficiency by about 20%; and
(iv) Distributing 10 electric traction-motors along the tractor and the trailer; and de-coupling selected electric traction-motors will improve the efficiency by additional 20-40% on the low side.
In most cases, the decision how to design a vehicle does not begin in the engineering department. The decision is made in the new vehicle showroom by sale personal, providing the information what sells. New-car customers are not interested in efficiency; top interest is the look of the vehicle, the pep, and the price, which is usually what makes a sale. To meet buyers' demands, the manufacturers listed in
There is a huge gulf in opinions about EVs design among manufacturers. Most of the manufacturers believe that the only factor to become more efficient is an improved battery to increase the driving range and the rest of the EV has to be manufactured with the same, traditional die-cutting because, traditional manufacturers refuse to accept the fact that EV manufacturing is eventually going to evolve as a ‘computer on wheels’ piece of equipment. EV chassis and bodies will be built by robots, and the electric motors and digital computers—which are not traditional vehicles manufacturing components—will be manufactured by subcontractor. When this stage evolves, it will indicate the start of a revolution in the transportation industry, with the main concern—how to deal with the huge unemployment the EV era generated.
The size of the battery-pack; the contribution to the vehicle weight and the contribution to manufacturing cost—and how the subject disclosure will contribute to reduce the size of battery-packs, and at the same time improve efficiency—is the core issue in this disclosure. A rigorous and thorough analysis considering battery metrics as well as vehicle design's parameters was done to decide how to reduce the weight, cost, and size of the battery-packs. Since personal vehicles are designed with no weight-limitations, the following battery-pack evaluations is concentrating in semi-trucks—since the size of energy-storage needed is more than five-times larger than in personal vehicles, although the equations presented infra are applicable to any EV.
The average payload carried by diesel semi-trucks is up to 17,300 Kg. The starting point is the fact that Class 8 semi-trailer has to comply with federal requirements of 36,364 Kg GVW; consisting of (i) semi-tractor 8,600 Kg; (ii) empty trailer 6,200 Kg; (iii) battery pack weight; and (iv) the size of the payload. The semi-truck empty weight Wv is about 14,800 Kg. Cummins X-15 engine and transmission weight about 1,750 Kg; and the differential gears about 400 Kg. Then, a diesel semi-trailer ‘empty weight’ without gears is about 12,650 Kg. Four-motors in Tesla's semi-truck weight 35 Kg.×4=140 Kg. and four differentials about 200 Kg. Then, the Tesla electric semi-trailer empty weight Wv should be considered as: 12,990 Kg. The only variable to determine the payload is the battery-pack weight Wbp:
(WLoad)=Wt−(Wbp+Wv)=36,364 Kg.−(Wbp+12,990 Kg); then: Eq. 1.0
W
Load=23,374 Kg.−Wbp when: Eq. 1.1
Wbp is the battery-pack weight; and WLoad is 23,374 Kg permissible load-battery-pack weight. Theoretically, a reduced battery-pack weight increases the permissible load.
P: energy, battery-pack size depends on the energy density in Wh/kg. A new nickel-rich cathode enables storage of 560 Wh/kg (0.56 kWh/kg), is configured with the best energy-density, which is more than double the leading battery used in current EVs made by Panasonic (LiFePO4 model NCR18650B), which contains specific energy density of 243 Wh/kg. However, even the best Lithium batteries contain lower energy-density than petrol 12,889 Wh/kg, and hydrogen 39,443 Wh/kg. But battery-to-wheels efficiency is 90%, which includes battery discharge efficiency of 95% and electric drive-train efficiency over 90%, e.g., batteries propelling electric traction-motors are several times over more efficient than IC engines, with 24% gasoline and 28% diesel power that reaches the wheels. In hydrogen fuel-cell efficiency is only 36% that reach the wheels. The current fuel-cell technology is actually not serving the environment since hydrogen is produced from oil and natural gas (!) Clean hydrogen production via water electrolysis (P size in kWh, the vehicles have to meets dynamic requirements as presented in Eq. 2.0:
Each of the above parameters is cast as truncated multivariate Gaussian Distribution (truncated within the limits of future projections and known max/min values as depict in
Based on distributions of variables, a standard simulation test considering the mean values of an output, the distribution of output values, and the minimum/maximum output values brought the following results:
(iv) an average annual distance traveled by a Class 8 diesel semi-trucks is 75,000 miles. 52-weeks and 6-days a week driving, translates into an average drive of about 250 miles/day, which is accurate statistics for more than 80% of semi-trucks travel. Since average semi-trucks speed is about 45 mph, driving 270 miles takes six-hours. Then, battery-pack size, weight, cost, and maximum payload capacity for electric, Class-8 truck is conducted with 480 Km driving ranges, and optional 960-mile range.
(v) after driving 480 Kms, a driver should stop after six-hours; spend 30 minutes charging the batteries to 80% capacity with Mega-charger at 7-cents/kW and complete the rest 480 Km with another 6-hour drive, which is little above the ‘Federal Motor Carrier Safety Administration Rules’ in which: semi-trailer driver can drive up to 11-hours after being off duty for 10 or more consecutive hours.
(vi) the trucking industry arguments that diesel trucks have a 1,450 Km range in one fueling is not a valid argument because this distance requires 20-hours driving, in violation of federal law. Therefore, the only weight-values considered for the required battery-pack is for 480- and 960-Kms range. For light-duty vehicles, any battery-pack may be utilized—there is no weight limits.
Tesla claims its electric semi-truck achieves 2 miles/kWh. This is correct when driving downhills. Tesla's tractor power-train consists of 4×192 kW electric traction-motors and gear-assemblies taken from Tesla's model 3. EPA test records confirms that Tesla Model 3 with a single 192 kW motor achieves about 6 Km/kWh with about 1,773 Kg curb weight, and =0.36. Tesla's semi-truck definitively produces lower than 3.2 Km/kWh results because:
(iv) coefficient of drag accounts to 16% of energy loses in Class 8 semi-trucks. Model 3 =0.23 while Tesla's semi-truck has
=0.36, which is the result of 57% increase in drag for having frontal area of about 7.2 m2, causing an efficiency decrease to about 1.6 Km/kWh.
(v) Tire-drag and rolling-resistance accounts to 22% of energy loses in Class 8 semi-trucks. Assuming a fully loaded semi with 36,364 Kg distributes the weight equally on all 18-wheels, then each wheel carries about 2,000 Kg. Class 8 semi-truck has two steered-tires in the very front and 16 dragged-tires that will massively decrease efficiency by multiple tires rolling-resistance. With a tires rolling resistance coefficient Crr=0.0063, utilizing SAE J1269 standard test as defined by the Society of Automotive Engineers, the tires rolling resistance of the semi-truck will decrease efficiency to about 1.02 Km/kWh.
(vi) Class 8, diesel semi-truck's engine accounts to 59% of energy loses will not be considered; instead, an evaluation how this disclosure will improve electric semi-tucks efficiency is presented infra. All other variables listed in Eq. 2, were not considered because their influence on efficiency is fractional.
Applying the EP energy results to 480- and 960-Km traveled distance; then fully loaded semi-truck will consumes 470 kWh, and 940 kWh, respectively. The battery-pack weight calculations are set forth as follows:
To calculate limit payload, the above weights are inserted in Eq. 1:
W
Load=23,374 1,930˜21,500 Kg, with a 470-kWh battery-pack; Eq. 1.1
W
Load=23,374 3,870˜19,500 Kg, with a 940-kWh battery-pack. Eq. 1.2
CostP. the battery-pack cost: After calculating the battery-pack required energy and weight for Class 8 semi-trailer, the cost is given as follows:
P=×
kWh Eq. 4.0
The cost of batteries based on the price available in the market is assumed to have a current mean value of $100/kWh.
P=470 kWh×$100=$47,000 for 480 Km range; and Eq. 4.1
P=940 kWh×$100=$94,000 for 960 Km range. Eq. 4.2
For beyond current Li-ion batteries, it is assumed to be at mean cost of $80/kWh with a minimum value of $50/kWh (see Bloomberg's BNEF estimate in
Silicon is leading in battery research for two peerless advantages:
(iv) It is the third most common element after hydrogen and oxygen; and
(v) crystalline silicon anode has a theoretical specific capacity of 3,600 mAh/g; approximately ten times that of graphite anodes (372 mAh/g) in Li-ion batteries. Future Silicon Nano-Technology [to overcome swelling and rupturing problems] with 700 Wh/kg and up to 1.0 kWh/kg or better specific density might be available that could reduce the battery-pack energy EP to 470 kWh and 940 kWh respectively; reduce the battery-pack weight to 470 Kg, and 940 Kg, respectively; and the cost to $470 and $970, respectively.
(vi) Magnesium could also become a viable alternative to overcome the safety and energy density limitations faced by current lithium-ion technologies.
Past experience teaches us that in 1967, the first digital wrist-watch, model CEH-1020, introduced with a retail price of couple hundred US dollars. Today, better digital watches are selling in dollar stores. This is the prognosis for the battery manufacturing community, and in the EV manufacturing turf in particular. The vehicle chassis will be manufactured by robots; the electric traction-motors; DC-DC converters, and the DC to AC inverters will be produced in multi-million units that will slash the EV's prices to the level of vehicle prices in the early 1980s. In fact; in certain vehicle categories, today's EV prices are already lower than the current price of vehicles with IC engines.
The future social and economic considerations-especially the availability, and monopoly of the rare-earth elements that are crucial to EV manufacturing-were evaluated before drafting this disclosure since automobiles in particular, are devices of culture and behavior, not just economics. Both culture and behavior can change quickly for the following reasons:
(vi) Because automobile personal ownership is a bad investment since it is in use less than 10% of the time and depreciate in value rapidly; automobile ownership expected to decline dramatically also because the world population is moving into cities, leading to augmentation of public transportation, and the car-sharing programs. A car shared by 5-10 people will be running 5-10 times longer, and less vehicles may be produced. In addition to focusing on reduction in the price of battery manufacturing, and increase in the batteries kW/Kg ratio, e.g., increase in energy density to extend the driving range, manufacturers should develop EVs that can withstand the rigors of near-constant driving and have much longer driving range on a single charge.
(vii) Shared vehicles will reduce the desire for personal “options” which usually makes 20-30% of new vehicles price. Another decline in price may be expected in the manufacturing of energy storage devices which makes more than 30% of the vehicle retail price today. Eventually, the future, average EV retail prices may be stretched from below $20,000 to about $30,000. This excludes manufacturers who retail EVs for much more than $40,000, since their sales depend heavily on $7,500 Federal Tax Credit, state, and local incentives; and on selling CAFE credits to other manufacturers. Those benefits may be no longer available in the future.
(viii) Before purchasing a new car, the first consideration—which includes lending institutions' top concern—is the projected resale value after 3, 4 or 5 years of the loan. Empirical tests prove that fast-charging procedures—which may be the MO—will shorten battery life. Since the battery-pack makes more than 30% of a new EV price; after 3, 4 or 5 years, when the batteries may be replaced, the vehicle batteries value will entail more than 75% of the entire used vehicle. Therefore, new vehicles with large battery-packs would have exceptionally low resale value as a used-car.
(ix) When the EV industry reaches production of 20-30 million BEVs/year, soaring demand for Lithium, Cobalt, Nickel and other rare earth metals such as: neodymium magnet Nd2Fe14B, samarium magnet [cobalt SmCo5]—with magnetic field exceeding 1.4 Teslas—could be monopolized by China since it controls 90% of the world mining of those elements. This monopoly—especially when China logged 60% of global EV sales [Bloomberg]—will skyrocket prices to levels that would lead to dis-economy. Minimizing, or totally giving up the use of rare earth magnets is one of the goals of this disclosure.
(x) Massive quantities of battery hazardous waste disposal are another reason to produce efficient EVs with small battery-packs, or find an alternatives in the bio-technology, which demonstrates impressive recycling and efficiency results.
IC engines waste into heat most of the energy they produce; only 28% in diesel and 20% of the energy in gasoline engines reach the wheels.
Most electric-motors are designed to run at 50% to 100% of their rated load; maximum efficiency is usually near 75% of the rated load. The specific example of Motor #3 in
Unfortunately, the drive-trains design in most EVs listed in
VW demonstrated in 2009 how far efficiency can go with the experimental XL-1 hybrid vehicle, first presented in the 2013 Geneva automobile show. In addition to its super-aerodynamic (Cd=0.189); its light-weight carbon-fiber reinforced polymer (CFRP) which facilitates only 1,749 Lb (795 Kg) curb weight, and its hybrid propulsion of two pistons, 800 cc diesel engine, producing 50 HP with an electric-motor that adds 27 HP; the XL-1 brings about an impressive efficiency of 280 to 313 mpg, more than twice the average current EVs. In full power mode, the XL-1 can run 125 mph. The achievement of the XL-1 inspired the inventor to record the subject disclosure by virtue of the fact that if the XL-1 is able to cruise in a windless highway at 62 mph (100 km/h) with just 8.3 HP, which supports the inventor philosophy supra that 175-200 HP electric traction-motors that operate at all times must be extremely inefficient.
Synchronous motor is rated with better efficiency than induction motor attributable to their permanent magnets in the rotor, while induction motors consume part of the electric energy to create the magnetic field in the rotor. Yet, synchronous motors have “side effects” and high price that diminishes their efficiency benefits. Synchronous-motors are expensive; they overheat, which calls for an extensive water-cooling system, especially with 175 to 200 HP and larger motors. Torque ripple and rotor skew produces annoying vibrations, similar to the annoying vibrations in high compression IC engines. Manufacturing synchronous motors with Neodymium is expensive, and depends on monopolized supply, which could lead to dis-economy.
Induction motors are amazingly simple, require no ‘rare-earth-elements,’ are robust, air-cooled, and cost a fraction of synchronous motors. Tesla's best-selling model S, originally equipped with induction-motors, was reported on March 2019 in the German magazine “Das Elektroauto & E-Mobilitats-Portal” that TeslaModel S listed by “Schwake” [German Blue Book] as a three-year-old with 60,000 kilometers “at a considerable 60% residual value [the Model S has had an induction-motor], while Porsche Panamera stood at 57.4% residual value.”
In spite of induction-motors' lower-efficiency, when distributing power among four-pairs of induction-motors as depict in
Electric traction-motors operate above 90% efficiency because mechanical losses during transmission of power to the wheels as in IC-engines no longer exist, which predicts that EVs are enormous potential in reducing transportation's energy demand. EVs will play a significant role in the future of personal mobility and a leading role in transformation of energy; especially after car-sharing will become the norm. But to achieve the energy turnaround, battery EVs (BEVs) must be much more efficient.
There are all kind of Intelligent Motor Controllers (IMC) in the market, and in patent application process, to justify an EV design with a single electric traction-motor, claiming to have solved efficiency problems in electric motors by utilizing microprocessors to monitor motor load and accordingly match the motor torque to the motor load—maybe in laboratory testing. The process is reducing or increasing the voltage to the AC terminals and at the same time lowering or elevating the current to bring the motor to operate within its ‘High-Efficiency Range.’ Unfortunately, IMC provides limited efficiency improvement for a single electric traction-motors because, for substantial part of traveled-time, EVs are operating under low load conditions; and electric-traction-motors operate extremely inefficient at low and at high RPM (see
If emulating human physiology to create AI (artificial intelligence) is so widespread today, then why human's and certain mammals' motoric physiology is not implemented in manufacturing EVs?
A Cheetah could reach speeds of over 115 Km/h by using both rear Pedi, and front Pedi to achieve an extremely fast sprint forward. However, the Cheetah's precise operation is different than horse galloping that put into motion one Pedi at a time. A slow-motion video of running Cheetah establishes that both rear Pedi hit the ground at the same time while the front Pedi hit the ground most of the time at the same time. Yet, in maneuvering [steering], other than straight-forward, the Cheetah hit the ground with the front Pedi in an extremely fast sequence, one after the other to steer its body as needed. When turning to the right, the Cheetah hits the ground with the front left Pedi harder to force a turn to the right, as matched in this disclosure: when the driver steers to the right, the left-side electric traction-motors turn the left-side wheels faster than the right-side to assist the steering without EPS (electric power steering) as described infra. Because Cheetahs were “operational” millions years before Karl Benz put the first automobile on the road in 1885, this observation deduces that for much better power distribution and stability, the rear wheels better be equipped with more powerful, identical electric traction-motors on each side; since EVs are manufactured with rigid chassis, a holistic controller may provide uneven speed distribution to the left and to the right wheels to force a turn without EPS.
In principle, the decisive difference between this disclosure and other EV designs is the notion that in order to achieve the best efficiency possible, not all electric motors have to be engaged in the traction and steering at all times. It took engineers decades to realize that running power-steering pump, or hydraulic pump all the time is extremely inefficient. Today's norm is EPS that assist in the steering process only when the driver moves the steering-wheel. Hydraulic pumps are replaced by electric motors or powerful solenoids. If all muscles, in humans and animals, would be in motion all the time, when only the legs were used to take a walk, humans and animals would be sleeping every 2-hours to “charge their batteries.” The concept of this disclosure is a design of plurality of distinctively designed electric traction-motors, coupled to wheels almost only in their highest efficiency range of operation as depict in
This intricate mechanism is designed to preserve small portions of energy in the battery-pack that adds-up, especially when a vehicle is driven for hours. The additional energy saved by running the vehicle in highly efficient procedure, may go a long way.
It is evaluated and proven that three fundamental factors affect the efficiency in vehicles with IC engines: 12% for the vehicle's aerodynamics; 22% for the tires rolling-resistance; and 59% for the IC engines inefficiency in transmitting the power to the wheels. Aerodynamics is a vehicle design issue—affected in particular by the EV frontal area—which is not a part of this disclosure. The design of this disclosure drastically reduces the 22% tire rolling resistance, tire dragging, and the inefficiencies of electric traction-motors in certain loads and speeds. In addition, it will dramatically improve heavy-duty vehicles maneuverability and overcome the manufacturing cost barrier of electric semi-trailers, by significantly reducing the battery-pack size and the vehicle weight, while increasing the payload capacity.
The concept that electric traction-motors operate above 90% efficiency is only partially correct because it only materializes under specific loads and during specific angular speeds as depicted in
The big advantage of electric traction-motors over IC engines is the ability to design infinite electric traction-motors to fit a mixture of specifications to efficiently cover cruising speed from forward-motion start to the top-rated speed of the vehicle. The industry world-wide utilizes exclusively electric power; and therefore, the number of IC engines in the industry are fractional because of their high pollution rate, narrow torque output, narrow efficiency range, low durability, and high maintenance cost for having multiple moving parts. IC engines were manufactured for their extremely low price, and high energy content of gasoline. Yet, the wider range of efficiency in electric traction-motors is not enough to operate an EV with a single electric traction-motor because it cannot operate efficiently without a transmission across the range of zero to 90 mph and under variable loads. Manufacturers who built EVs with a single motor introduced in the model years 2020 EVs with 2-motors in
In EVs with a single electric traction-motor, most driving-modes after forward-motion start are inefficient. The solution must be a distribution of the vehicle's power demand—in different driving modes—between electric traction-motors designed with different ‘high-efficiency range of operation.’ While driving through changing load and changing speed, controller 100 (
Controller 100 management begins the forward motion-start with all electric traction-motors—with 100 kW power in System 10—to accelerate the vehicle from zero to 60 mph in less than 5 seconds, which solves the deficient maneuverability problem of EVs No. 1, 2 and 4 in FIG. 3. Yet, seconds after forward-motion start, controller 100 de-couples selected electric traction-motors because at this point the vehicle gained sufficient kinetic energy to proceed efficiently with only 2 or 4 electric traction-motors. De-coupling electric traction-motors promotes efficiency, prevents overheating, and components wear out. One of tractive-power setup in system 10 may be with the following electric traction-motor (100 kW total):
Trace 150 in
However, that electric traction-motors 53, 54 and 57, 58 are not “pairs” although they operate the same joint shaft. Electric traction-motors 53, 54 and 57, 58 may be constructed with distinctive design and different specification. Electric traction-motors 53, 54 and 57, 58 that are on the right side of the vehicle is “paired” with electric traction-motors 51, 52 and 55, 56 that are on the left side of the vehicle, respectively. Because electric traction-motors pairs have the same design and specification, they are engaged in propulsion at the same time except in precision steering modes—for example in tight parking conditions—when controller 100 disables the electric traction-motors of one wheels, and slowly activates the other three wheels, using the non-operating wheel as pivoting axis.
Controller 100 may elect to de-couple electric traction-motors 53, and/or 54—or any other electric traction-motors in system 10—when:
(iv) their engagement in traction of the EV is not necessary at specific point and time; and when the EV is operating in a speed range that is not in the specific electric traction-motors' ‘high-efficiency range of operation;’
(v) controller 100 may elect to engage alternative electric traction-motors with higher or lower torque or power rating to meet the power demand during changing speed, while maintaining efficiency at optimum; and
(vi) during regenerative mode, controller 100 may be configured to couple all electric traction-motors that are not coupled to promote faster deceleration; maximum gain in converting most of the vehicle's kinetic energy into electric energy; supply the bucked voltage to the respective energy storage units 14, 16; and promote efficiency, getting by without, or with effortless use of the electric brake-calipers, which also curtails wear and tear of the braking-pads.
In
Relaying on Einstein's theory, the electronic-clutches operative-sequence of coupling and de-coupling of individual electric traction-motors, illustrated in
(vi) utilizing multi-objective optimization algorithm, controller 100, may couple to wheels electric traction-motors 53, 54 if the algorithm provides that electric traction-motors 53, 54 efficiency rating is the least energy use-up in a specific driving mode, and at the same time the traction-motors meet system 10 tractive-power demand.
(vii) since revolutions of the permanently attached discs 87a, 87b is constantly monitored by speed sensor 88; and, since disc 86a, 86b RPM information is provided to controller 100 via close-loop feedback-mechanism through sensor 88a, 88b; and because electric traction-motors 53, 54 are not under load, controller 100 may spin electric traction-motors 53, 54 in a fraction of a second to revolutions that precisely match the revolution of disc's 87a, 87b.
(viii) controller 100 may then actuate the three-solenoid-sets 81a, 81b, triggering a pull-back of locking-latches 83a, 83b, which causes the releases of the electronic-clutch's circular gear 84a, 84b.
(ix) a large coupling-spring 85a, 85b, between the disc and the electric traction-motor thrusts the already rotating motor-side disc 86a, 86b forward, to couple the motor-side disc with the permanently attached wheel-side disc 87a, 87b while both discs are rotating at precisely the same angular speed. At this point, rotational power is transferred from a coupled electric traction-motor to the wheel. The two discs are configured with dog-teeth, claws-teeth or any other means of concave indentation and convex projections that fits perfectly tight one into the other when they are coupled.
(x) at the same time, controller 100 actuates electric traction-motors 53, 54 through DC to AC voltage inverters 43, 44, and with the appropriate voltage, current and frequency modulation, satisfies the torque, power, and RPM demand for optimal traction in every mode of operation within the integrated AWD and AW-steering of a vehicle.
When electronic-clutches have to be de-coupled as presented in
To overcome the sluggish start as mentioned supra with EVs No. 3, 4 and 5 in
Three systems, as detailed below, is integrated into one system for much better vehicle dynamics, stability, and exceptional handling and efficiency:
Two traditional engineering concepts in current EVs are the paramount contribution to vehicles inefficiencies:
(iii) transfer power from electric traction-motors to the wheels via traditional transmissions and differentials;
(iv) utilizing 130 years old mechanical steering only in the front wheels, while the rear wheels are dragged.
EPA motor vehicle's Federal Test Procedure driven on a dynamometer, is not a real-world driving environment since in the real world, vehicles do not drive only straight forward as on a dynamometer. The scenario of mechanical steering inefficiency is unaccounted for because during steering procedures on the road, three tires are dragged in different degrees, especially the two rear ones, and especially in short-radii steering. Cd [Coefficient of drag] and the vehicle weight are entered into the dynamometer calculations, yet the consideration that are ignored are four tires side-slip in their contact-patch, the deformation that affects all four tire carcasses, caused by cornering shear-stress-forces and rear wheels dragging. The energy lost in mechanical steering affects EVs efficiency the same way it affects IC engine vehicles, which dramatically curtails the driving range; while additionally, wheel dragging diminishes life expectancy of tires.
A layout of a traditional fixed rear-wheel suspension (
Since traditionally only the front wheels are steered, a layout of front-wheel suspension (
The fact that AWD (all-wheel drive) systems provides partial solutions for better dynamics and road stability improvement, was the first choice by EV manufacturers who utilized one electric traction-motor in the rear axle, coupled via differentials to both rear wheels, and one electric traction-motor in the front axle, coupled via differentials to both front wheels. However, both electric traction-motors coupled to the wheels at all times when the vehicle is in motion. AWD systems that improve vehicle dynamics is manufactured in limited numbers for their economic expense, and massive mechanical components that caused the vehicle to ‘gain weight,’ which called for bigger IC engines and transmissions. However, traditional AWD systems faded away, for being heavy, costly, and inefficient.
The next step in improving stability and efficiency in EVs is the incorporation of a single electric traction-motor inside the wheel. Protean Electric in Michigan claims to improve stability and efficiency in EVs by incorporating a single electric traction-motors inside the wheel, as represented in
(iv) connecting two or four different electric traction-motors, one on each wheel is an innovative idea. However, after the first few seconds, when the vehicle gained sufficient kinetic energy, the electric traction-motors cannot be disconnected to keep traction within ‘high-efficiency range’ as depict in
(v) considering that the wheel's disc-brake, and brake-caliper is also located inside each wheel, then during braking procedure, the brake-calipers may release a huge amount of heat that might damage and curtail the life expectancy of the electric traction-motors;
(vi) constructing an EV with only two or four electric traction-motors, e.g., one or two pairs of electric traction-motors, is not desirable because,
It is definitely possible to design electric traction-motors that can cover efficient operation in a 45 mph range. Yet such electric traction-motors will perform inefficient before and after the narrow 45 mph efficiency ranges-of-operation. In addition, the electric traction-motor must be much larger than the electric traction-motor in system 10, such as: synchronous motors must be utilized, with all the attachments, and with higher production and maintenance costs.
A sophisticated, mechanical AWD architecture manufactured by Audi, a subsidiary of VW, assists the steering by activating the brake calipers. However, this ‘Quattro’ system (
Audi engineered an advanced version of the Quattro. It is a hybrid AWD system (
The concept of making a vehicles steer better by actuating all four wheels has inspired engineers since World War II, when the US Army experimented with all-wheel-steering jeeps. Currently, BMW utilizes ‘Integral Active Steering’ featured on the 7-Series and 5-Series; Infiniti (in their G and M cars), the 2014 Acura RLX; Renault (on the Laguna); and currently the GM Hummer and Tesla's Cyber Truck “crab-mode” steering make use of this technology.
In 2014, Infiniti Q50 introduced the first “steer-by-wire” vehicle, meaning there is no mechanical connection between the steering-wheel in the driver hands and the wheels on the street. “Turning the steering wheel sends just electronic signals to the steering-force-actuator, which sends data to the electronic control unit, which forwards it to the steering angle actuator, which turns the wheels” [according to Nissan specs information]. Steering response is quicker and more precise than in a mechanical setup. It also keeps the vibrations from the road from annoying the driver and improves the car's active lane control system. Electronic control includes a car's lane control system, which steps in when the driver drifts out of his lane. The system can adjust steering by electronic means, which is unfeasible with mechanical gears. ‘Steer by wire’ cuts the vehicle's weight since no mechanical gears are utilized, and there is no need of an EPS system, which boost efficiency; make it easier and cheaper to produce a left- and right-hand drive versions of cars; it's an easy jump to systems that can be used by handicaps drivers; it reduces maintenance cost, and creates designing AVs a lot easier.
‘Steer by Wire’ option is not welcomed by all drivers because:
(iv) the additional cost for such system.
(v) for 130 years, sitting at the steering-wheel stands in a figurative sense also for exercise of power. The driver has his vehicle under control over the steering wheel, and he can tear around in extreme situations. It is about being deprived of obedience of sheet metal to the driver's command. It takes years to get rid of human's control syndromes.
(vi) subconscious fear that between steering wheel and wheels on the street no solid connection exists, and steering order transmitted only by data cables.
Safety concerns have slowed the adoption of steer-by-wire technologies. Mechanical systems can and do fail, but conservative regulators, under the influence of insurance company lobbyists, see them as being more dependable than electronic systems. However, time have changed because the automobile industry is experiencing technological transition never materialized in such a degree since 1885. Manufacturers are foisting autonomous driving technologies, which will eventually eliminate most, if not all mechanical components utilized in today's vehicles. Traction and steering “by-wire” is the next step toward that age. In the coming age of self-driving cars, NHTSA would certainly certify AW-steering and AW-drive ‘by wire’ since in today's advanced technologies, a problem is electronically detected before it materializes. Hence, AWD propulsion and AW steering “by-wire” should be safer than any mechanical system
Back to evolution; most living species are controlling their motoric “by wire” (brain-neurons-muscles). Humans are at the top of the list for their muscle control precision (speech, piano and violin playing.) However, motoric “by-wire” was also utilized by very primitive species that no longer exist, including dinosaurs who lived over hundred million years ago and moved their huge bodies with muscles actuated “by wire.” If it were not safe during 2.5 billion years of evolution, species who carry motoric “by-wire” would have disappeared and replaced by species with better systems. It did not materialize, which makes NHTSA's arguments that “steer by wire” is unsafe without merit; considering steer-by-wire—approved by FAA—is the norm in aviation for decades. A pilot cannot stop in midair to fix his steering.
The instant disclosure is getting to full efficiency requires solutions that can scale; designed from the ground up to scale both economically and environmentally while addressing the essential attributes of efficiency, maneuverability, and safety. The scalable system presented in this disclosure can be used in a variety of vehicle types for the movement of goods and people, making it perhaps the most efficient and versatile driving solution available today; it is a scalable tractive-power system, integrated with all-wheel electronic steering and electric braking systems, which may be applied to any class of vehicles—with two or more wheels—and in infinite configurations. The wide-ranging aspects of this disclosure suggest that EV manufacturers should throw-out all mechanical gears utilized in traditional transportation engineering; skip the design stage of manufacturing EVs in admixture with IC engines; and design vehicles only with electric motors for traction and steering, with electric brake-calipers, while utilizing battery-pack, ultra-capacitors, fly-wheels, fuel-cells and photovoltaic cells as energy storage and production source.
This disclosure comprises of plurality of differently designed electric traction-motors, that may be configured as a single electric traction-motor coupled to the wheel via a driveshaft, or two electric traction-motors sharing a joint shaft in series, coupled to the wheel via a driveshaft, which may comprise the basic traction assembly that propels each wheel individually, with or without reduction gears; connected with or without a drive-shaft directly to each, independently propelled wheel instead of a speed changing transmission and/or a differential assembly. Each electric traction-motor may have its own individual, bidirectional DC-DC converter; and may have its own DC to AC bidirectional inverter. Utilizing DC motor in any section of the design, then no inverter is necessary. To secure precise, while variable torque and angular speed of each individual electric traction-motor coupled to the wheels, the holistic controller may actuate all or less than all electric traction-motors to reach fast response from forward-motion start to the top-rated speed. However, after gaining sufficient kinetic energy, the holistic controller may de-couple selected electric traction-motors, and in any given speed and load, actuate the electric traction-motors, designed to operate most efficient in a specific load and speed ranges.
Coupling and decoupling electric traction-motors in and out of the vehicle tractive system is achieved with electronic-clutches attached to selected electric traction-motor. If one or more electric traction-motors utilizes no electronic-clutches (
A four-wheel maneuvering and steering system comprises of four individually controlled electric systems, where each system assigned to specific wheel. Each individual electric steering-motors installed on the vehicle's frame and connected via a tie-rod and a wheel-position sensor to the steering-knuckle of each wheel. Each wheel-position sensor acts also as a traditional tie-rod-end, while continuously monitoring and transmitting to the controller the instant wheel-angle.
During steering procedures, the holistic controller integrates the traction into the steering systems by applying different speed and different torque to opposing wheels to perfect the steering process while replacing the power-steering system. Each wheel-position sensor, in any given point and time, sends ‘by wire’ a continuous, precise information about the instant position of each wheel, with which information the holistic controller computes the precise, mostly different, angle and speed for each wheel during any speed and load conditions. Simultaneously, the holistic controller actuates each steering-motor to bring each individual wheel to the precise computed angle to precisely meet the driver elected steering angel received from the steering-wheel sensor.
The holistic controller receives information from multiple sensors; process the information received, and precisely, in conformity with the program stored in the holistic controller, execute, and coordinate the integration of the tractive-system with the steering and braking systems. This logical operation of all four wheels transpires by actuating precise power, torque, speed, and proper angle of each wheel—rather than only two wheels in the front or the rear—to accomplish an overall traction stability with no-wheel-dragging, and thus, enhanced maneuverability, safety, and maximum efficiency.
This disclosure supersedes the safety and stability benefits of mechanical AWD and AW-steering while abolishing the “side-effects” of imperfect handling control; poor stability and ill-maneuverability; excess weight; poor efficiency; excessive tire wear; and high manufacturing cost caused by multiple obsolete mechanical gears, especially in heavy duty trucks and buses. In addition, with electronically controlled torque, and speed, and while precise positioning of each wheel, the vehicle performance results in a superb performance, which resembles a ‘Cheetah-like’ super-efficient model, by consuming the least energy for better efficiency, and at the same time satisfying propulsion demands. This form of precise calculated energy consumption would provide much longer driving range in one charge, and with up to 60% smaller battery pack, 50% off manufacturing cost; and 30% less weight.
Various other features and advantages are made apparent from the following detailed description and drawings.
The drawings illustrate embodiment presently contemplated for conducting the invention. In the drawings:
Various other features and advantages will be made apparent from the following detailed description and drawings.
The embodiment of the present disclosure is described herein. It is to be understood, however, that the disclosure embodiment can take various and alternative forms. The figures are not necessarily to scale; certain features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiment that are not explicitly illustrated or described. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular application or implementation.
Referring now to the drawings wherein like reference numerals are used to identify identical components in the various views.
In various embodiment of this invention, the AWD traction segment of system 10 configured to be incorporated into diverse types of vehicles. The electric traction-motors in system 10 (
In energy storage units 14, 16, within system 10, sensors 30, 40 may be provided to monitor and compute the state-of-charge of energy storage units 14, 16. According to one embodiment, sensors 30, 40 may include voltage and current sensors configured to measure the voltage and current of first and second energy storage units 14, 16 during operation of system 10.
According to various embodiment, first and second energy storage units 14, 16 may include one or more energy storage or energy producing devices such as batteries, ultra-capacitors, flywheels, photovoltaic cells, fuel cell or a combination of all five components, in various percent of their representation within each energy storage units 14, 16. Other embodiment may be where energy storage units 14, 16 incorporate ultra-capacitors with numerous capacitor-cells couple to one another, where every single capacitor-cell may have a capacitance between 500 and 3000 Farads—or greater. Ultra-capacitors offer nearly instantaneous power bursts during periods of peak power demand, therefore they may be implemented as a secondary energy source that complements the primary batteries sources that suffer fast deterioration when repeatedly providing quick bursts of power; and since traditional battery energy storage have problems supporting high-power features—such as frequent start-stop vehicle uses, especially at lower temperatures—a secondary energy source with ultra-capacitors may be utilized to overcome this limitation.
In different embodiment, first and second energy storage units 14, 16 may be with high power battery-packs, with density more than 500 Wh/Kg. Other embodiment may be where energy storage units 14, 16 integrate high density batteries detailed above, in combination with ultra-capacitors.
In other embodiment, first and second storage units 14, 16 are a low-cost lithium-ion batteries. Alternatively, first and second storage units 14, 16 may comprise of a Silicon or Magnesium-anodes in Lithium-Sulfur battery; Sodium metal hybrid battery; a Sodium Sulfur battery; a Nickel metal hybrid battery; a Zinc-air battery, a Lead-Acid, or any other combinations of low-constituent battery.
The scalable traction in system 10 may include: four bi-directional DC-DC converters 21, 22, 23 and 24, as integral components of the propulsion of the front wheels; and four bi-directional DC-DC converters 25, 26, 27 and 28, as integral components of the propulsion of the rear wheels, which are coupled across the positive DC link 20 and link 29 in the front and the rear bi-directional DC-DC converters respectively. The negative link begins in energy storage units 14, 16, and coupled on the negative side of each component in system 10.
System 10 may include front left bi-directional DC-DC converters 21, 23 may connect across the positive and the negative DC link with DC bus 31 that may connect to voltage sensor 35 to monitor the bus voltage. Bi-directional DC-DC converters 22, 24, 25, 27, 26 and 28 may maintain the same set-up as bi-directional DC converters 21, 23 respectively; that is, DC bus 32, 33 and 34 may connect in parallel with a separate voltage sensor 36, 37, 38 to monitor the voltage in DC bus 32, 33 and 34, respectively.
To reduce the number of components in system 10; a different embodiment may fit where the front and rear energy storage units 14, 16 may be equipped with specific batteries that the respective bi-directional DC-DC converters may be left out. This will simplify production and reduce overall production cost. In such embodiment, a solenoid provides to selectively couple energy storage units 14, 16 to the respective DC bus.
All bi-directional DC-DC converters 21, 22, 23, 24, 25, 26, 27 and 28, when in use, is configured to convert one DC voltage to another DC voltage, either by bucking or boosting the DC voltage. According to one embodiment, each bi-directional DC-DC converter 21, 22, 23, 24, 25, 26, 27 and 28 includes an inductor coupled to a pair of electronic switches and coupled to a pair of diodes. Each switch coupled to a respective diode, and each switch/diode pair forms a respective half phase module. Switches may be isolated gate bipolar transistors (IGBT), metal oxide semiconductor field effect transistors (MOSFET), silicon carbide (SiC) MOSFET, gallium nitrite (GaN) devices, bipolar junction transistors (BJT), and metal oxide semiconductor-controlled thyristors (MCT).
In system 10, both energy storage units 14, 16 coupled via DC bus 31, 32, 33 and 34 to all electric traction-motors or any other combination of partial loads. The holistic controller may actuate any number of electric traction-motors in any driving procedure, speed, or load conditions, using multi-objective optimization algorithm to determine which of the electric traction-motors configurations would consume the least Kw in any given driving procedure to reach the best, most efficient traction.
In one embodiment of system 10, each DC to AC inverter 41, 42, 43, 44, 45, 46, 47 and 48 includes six half phase modules that are paired to form three phases, with each phase is coupled between the positive DC links 20, 29 of the DC bus 31, 32, 33 and 34 and the overall negative links of system 10.
Each electric traction-motors 51, 52, 53, 54, 55, 56, 57, and 58 includes a plurality of winding coupled to respective phases of its respective DC-to-AC voltage inverter 41, 42, 43, 44, 45, 46, 47 and 48. The arrangements and design of electric traction-motors 51, 52, 53, 54, 55, 56, 57, and 58 is limitless. Electric traction-motors 51, 52, 53, 54, 55, 56, 57, and 58 may either be a variety of AC motors, DC motors, fraction motors, and/or generators. It contemplates thus, that three-phase inverters 41, 42, 43, 44, 45, 46, 47 and 48 described herein may utilize any number of phases in alternative embodiment.
According to other embodiment, system 10 could be configured as genuine electric traction, steering and braking system. Alternatively, system 10 could be configured in a hybrid electric vehicle (HEV) traction system, which also includes an IC engine [not shown], coupled to electric traction system by mean of shared transmission [not shown]. System 10 could be configured in as fuel cell electric vehicles (FCEV) propulsion system, which also includes fuel cell [not shown] that may be coupled to distinctive design of energy storage unit 14, 16.
Traction, steering and braking system 10 may include geared power-transmissions [not shown in detail], 65, 66, 67 and 68 coupled to four joint shafts 61, 62, 63 and 64 that may be shared by two electric traction-motors when actuated by controller 100. The four-geared power-transmissions 65, 66, 67 and 68 [not shown in detail], may be constructed as single or multi-gear drive assemblies; toothed belt drive; chain drive assemblies or combinations thereof, according to innumerable embodiment. According to other embodiment, four geared power-transmissions 65, 66, 67 and 68 [not shown in detail], may be configured as electronic-variable transmission (EVT) that couples the outputs joint shafts 61, 62, 63 and 64 of electric traction-motors 51, 52, 53, 54, 55, 56, 57, and 58 to an internal planetary gear [not shown]. In operation, electric traction-motors 51, 52, 53, 54, 55, 56, 57, and 58, may be operated interchangeably over their specific high-efficiency range of bi-directional speed, torque, and power commands to minimize energy loss and maintain high degree of overall system efficiency while system 10 is operating in either charge depleting (CD) or charge sustaining (CS) mode of operation.
The power outputs of four geared power-transmissions 65, 66, 67 and 68 are coupled directly to each corresponding driveshaft 71, 72, 73 and 74 of the vehicle since no differentials are necessary in this electric AWD traction, steering and braking of system 10.
Controller 100 that runs and operates System 10 is connected to all eight bi-directional DC-DC converters 41, 42, 43, 44, 45, 46, 47 and 48 by control lines 15, 17. In one embodiment, control lines 15, 17 may include a real or virtual communication data link that conveys the voltage commands to the respective bi-directional DC-DC converters 21, 22, 23, 24, 25, 26, 27 and 28. Through appropriate control of switches in the front bi-directional DC-DC converters 21, 22, controller 100 is configured to boost voltage of first energy storage unit 14 to higher voltage and to supply the higher voltage to DC bus 31, 32 during the various modes of propulsion. Likewise, through appropriate control of switches in the front bi-directional DC-DC converters 23, 24, controller 100 is configured to boost voltage of first energy storage unit 14 to higher voltage and to supply the higher voltage to DC bus 31, 32 during various traction procedures. In the same way, through appropriate control of the switches in the rear bi-directional DC-DC converters 25, 26 controller 100 is configured to boost voltage of second energy storage unit 16 to higher voltage and to supply the higher voltage to DC bus 33, 34 during various traction procedures. Likewise, through appropriate control of the switches in the rear bi-directional DC-DC converters 27, 28 controller 100 is configured to boost voltage of second energy storage unit 16 to higher voltage and to supply the higher voltage to DC bus 33, 34 during the various Traction procedures.
Additionally, during charging or during regenerative mode of operation, controller 100 is configured to control switching bi-directional DC-DC converters 21, 22, 23 and 24 in the front of the vehicle; and bi-directional DC-DC converters 25, 26, 27 and 28 in the rear of the vehicle to buck voltage of DC bus 31, 32 in the front and DC bus 33, 34 in the rear and supply the bucked voltage to the respective first and second energy storage units 14, 16.
System 10 may be implemented in infinite configurations. To fit this scalable, integrated all-wheel electric traction, steering, and braking in any vehicle, the variables may include the number and design of the electric traction-motors, the power and torque rating, and the design of the algorithms inside the logic data base of holistic controller 100. System 10, as depict in
In all traction, steering and braking procedures, controller 100 is coupled individually to all four DC to AC voltage inverters 41, 42, 43 and 44 in the front of the vehicle through control lines 49. Controller 100 is also configured to control the half phase modules of the front DC to AC voltage inverters 41, 42, 43 and 44 to convert the DC voltage on DC bus 31, 32 to AC voltage for supply individually to each electric traction-motors 51, 52, 53 and 54, as part of the front propulsion. In forward-motion start, in changing speed, in acceleration or deceleration, or in any change of load, controller 100 may increase or decrease the voltage and increase or decrease the frequency modulation in selected DC to AC inverters 4142, 43 and 44, through lines 49, with which the revolutions—in electric traction-motors 51, 54 or 52 and 53, or in all four electric traction-motor together—are boosting or bucking to increase or decrease the speed of the vehicle.
Similar operation takes place through control line 50. Controller 100 is configured to control the half phase modules of the rear DC to AC voltage inverters 4546, 47 and 48 to convert the DC voltage on DC bus 33, 34 to AC voltage for supply to electric traction-motor 55, 56, 57 and 58 as part of the rear propulsion. In forward-motion start, in changing speed, to acceleration or deceleration, controller 100 may increase or decrease the voltage and increase or decrease the frequency modulation in selected DC to AC inverters 45, 46, 47 and 48, through lines 50, with which the revolutions—in electric traction-motors 55, and 58 or in electric traction-motors 56, and 57 or all four electric traction-motors together—are boosting or bucking to increase or decrease the speed of the vehicle. DC to AC inverters, and electric traction-motors may be different in size and specifications. Nevertheless, controller 100 MO does not change thus, it may be programmed to fit all kind of specifications, utilizing machine learning procedures.
In a regenerative [charge sustaining] mode, controller 100 is configured to control DC to AC voltage inverters 41, 42, 43 and 44 in front of the vehicle through control lines 49 to invert an AC voltage received from its corresponding electric traction-motors 51, 52, 53 and 54 into a DC voltage to be supplied to DC bus 31, 32. Similar condition of operation takes place through control line 50 in the rear of the vehicle, which may contain the same configuration as the front of the vehicle.
During operation, controller 100 receives continuous feedback from plurality of sensors, while transmitting control commands to other components within the Traction, steering and braking operation. In this instance of system 10, holistic controller 100 receives via control line [not shown], specific feedback from voltage sensors 35, 36 coupled in parallel to DC bus 31, 32; and from energy storage unit sensor 30 via control line 18. Controller 100 also receives via control line [not shown], specific feedback from voltage sensors 37, 38 coupled in parallel to DC bus 33, 34; and from energy storage unit sensor 40 via control line 19.
The steering capacity of system 10 is configured to be incorporated into various embodiment, in miscellaneous types of vehicles, including but not limited to, automobiles, light-duty trucks, delivery trucks, buses, semi-trailers, commercial and industrial vehicles such as mining and construction equipment, marine craft, aircraft, off-road vehicles, material transport vehicles and personal carrier vehicles.
According to the embodiment of the present invention, at some point during vehicle steering—as pre-programmed in the data base—the holistic controller 100 may apply various speeds and load to the left and to the right wheels; and simultaneous, activate all four-electric steering-motors, to position each individual wheel 90° to the turning center, which is the core of this integrated traction, steering and braking disclosure, as depicted in
To achieve the precise steering maneuver—which is to steer and propel all 4-wheels at the same time—controller 100 is conducting the following steering steps:
(vi) the electric traction-motors that are coupled to the wheels should operate all the time in their optimal range of operation.
(vii) the electric traction-motors should be integrated in the vehicle steering and braking, for better efficiency, stability, and much better handling. Integration of traction, steering and braking will also dispose-of the power steering system, and other redundant mechanical unnecessary gears, to reduce weight, improved efficiency, and lower production cost.
(viii) during low-speed steering, all four wheels may be positioned perpendicular to the turning-center to eliminate wheel dragging (see
(ix) in velocities above 50 Km/h, the rear-wheels are positioned at the same directions as the front wheels, not necessarily at the same angle. The exact rear-wheels angle may be determined with empirical testing since it depends on the vehicle's wheelbase, the distance between the left-side and right-side wheels, the vehicle weight, center of gravity, and purpose of the vehicle; and
(x) in multi-wheel-vehicles, AW-steering will stabilize the vehicle and improve efficiency to a greater extent than light duty vehicles with four-wheels. When changing the steering angle of the front axle, the longitudinal axis of the vehicle must be taken into consideration and stored in controller 100 data base, to provide individual, and accurate steered angle for each steerable wheel along the vehicle and the trailer. This will also comply with NHTSA's new FMVSS 136 for semi-trailer and certain buses with GVWR of 26,000 Lb. [about 12,000 Kg], which will reduce untripped-rollovers, and mitigates severe understeer or oversteer conditions that usually leads to loss of control.
Steering a vehicle begins when the driver or the Autonomous Vehicle (AV) ECU elects to change the direction of the vehicle.
If one contact leaflet is defective, broken, disconnected or malfunctioning, controller 100 may be programmed to utilize the last and/or the next leaflet reading—which may be just 1° difference between the leaflets—to keep the wheel within safe range of only 1.66% error; and activate specific warning signal to alert the driver of the malfunctioning leaflet. This fail-assist maneuver complies with NHTSA's “fail operational systems” for steering (
The steering-sensor configuration in
In the embodiment of system 10, steering-sensor 90, comprises of sixty leaflets, thirty for the right turns, and thirty for the left turns. Each leaflet represents a specific angle [in degrees], which is pre-programmed in the data base of controller 100. However, in different configurations, a leaflet may represent any angle; and the number of leaflets on each side of the steering-wheel sensor may be elected to fit specific vehicle's applications.
The integration of the electric traction-motors in the steering of the vehicle begins when the driver moves the steering-wheel to a position other than 0°[straight forward]. In AVs, it begins when the ECU initiates a specific turning mode. As a part of system 10, the vehicles schematics in
Turning gradually steering-wheel sensor 90 [in
(v) controller 100 (
Simultaneously, the front-right wheel speed may be reduced, remain unchanged or increased (see
(vi) the same steering procedure follows when controller 100 actuates the front-left electric-steering-motor 111b in steering assembly 110a to gradually bring the front-left wheel to 20.1°. Controller 100 then continuously receives electronic information about the changing position of the left-front wheel from wheel-position sensor 115a. When wheel-position sensor 115a informs controller 100 that the left-front wheel reached the angle of 20°; controller 100 stops steering-motor 115a.
Simultaneously, the front-left wheel speed—in case where the front-right wheel's speed remains unchanged—will be gradually increased to 43.6 mph to make a perfect turn without a standard EPS (see
(vii) controller 100 actuates the rear-right electric steering-motor 111d in steering assembly 110d to gradually bring the rear-right wheel to 330°. Controller 100 then continuously receives electronic information about the changing position of the right-rear wheel from wheel-position sensor 115d. When wheel-position sensor 115d informs controller 100 that the right rear wheel reached the angle of 330°; controller 100 stops electric steering-motor 111d.
Simultaneously, the rear-right wheel speed may be reduced, remain unchanged or increased. It usually matches the front-right wheel's speed (see
(viii) the same procedure follows when controller 100 actuates the left-rear electric steering-motor 1l1c in steering assembly 110c to gradually bring the rear-left wheel to 340°. Controller 100 then continuously receives electronic information about the changing position of the left-rear wheel from wheel-position sensor 115c. When wheel-position sensor 115c informs controller 100 that the right-rear wheel reached the angle of 340°; controller 100 stops electric steering-motor 111c.
Simultaneously, the rear-left wheel speed—in case where the front-right wheel's speed remains unchanged—will be gradually increased to 43.6 mph to match the front-left wheel speed (see
Since at 30° steering the right wheels' turning center has only a radius of about 10′, a 70 Km/h or even 50 Km/h velocity is not realistic because it may knock the vehicle off balance. While the relationship between speed and turning angle could be empirically determined for each vehicle or computed by using wheel-base measurements, weight distribution and center of gravity; in the 70 Km/h turn, the controller is configured to execute control logic stored in a data base associated with the stability of the vehicle. Controller 100 can determine the highest permissible speed at 30° turning mode that will keep the specific vehicle velocity below the speed that might endanger the vehicle stability (see
Beside the safety issue, without the ‘overturn prevention system,’ drivers would nervously apply the braking-system, trying to stabilize the vehicle and in the process drive down efficiency. In view of stability benefits—while the traction system engages in the steering and braking process—a vehicle could easily manage lateral acceleration of 0.07 g in 30° turning procedure without to push-down the braking pedal. The same applies to AVs because every time brake pads are applied; it cuts down in the vehicle efficiency.
Steering assemblies as depicted in
To push or pull the wheels to the proper angle, system 10 embodiment utilizes a large ball-bearing screw 112 as a device for converting the rotation of the electric steering-motor 111 into linear motion of the outer tie rods 113. To minimize friction in ball-bearing screw 112, bearing balls 114 are captured between the nut 118 and the ball-bearing screw-threads. Since controller 100 determines how far the outer tie rod 113 needs to travel to bring the wheel to the elected angle, electric-steering-motor 111 turns large ball-bearing screw 112 and applies axial force through outer tie rod 113 directly to the modified into wheel-position sensor-outer tie rod end 115. Rotor 116 in the electric traction-motors rotates a shaft that is configured with direct gear 117, or with toothed belt drive wheel [not shown], or with chain drive [not shown] or with any other form of power transmission to nut 118, which rotates and moves large ball-bearing screw 112 forward and backwards.
System 10 is configured with four wheel-position sensors 115 attached to each wheel's steering knuckle-arm to accomplish the same function as a mechanical tie-rod end, yet, at the same time, the wheel-position sensors monitor, and transmit by electronic means the continuous wheel-position angles to controller 100.
A wheel-position sensor may in fact be configured as a miniature version of steering sensor 90 and may also be constructed that way. Pointer 121 is fixed to the axle of center-gear 120, which is meshed with the teeth of side-gear 124 and said side-gear is meshed with teeth molded inside wheel-position sensor housing 115. When nut 118 rotates; outer tie rod 113 is following the axial movement of screw 112 to the left or the right, triggering a change in the angle between outer tie rod 113 and knuckle steering arm 126, which is proportional to the change in the wheel's angle, e.g., in relation to 0°. The proximate result is the rotation of cylinder 125 inside wheel-position sensor's housing 115 that triggers the movement of the toothed area 123, molded inside the wheel-position sensor housing, which initiates the following chain reaction: movement of toothed area 123 rotates toothed side-gear 124, which rotates center-gear 120, which causes the movement of pointer 121, that sends by electronic means the instantaneous ‘change of position’ information to controller 100.
In situations where any of the wheel-position sensors is totally ‘out-of-order,’ controller 100 may be programmed to apply the reading of the opposite side wheel-position sensor, interpolate the readings to fit the defective side and apply the interpolation to keep the vehicle in safe driving conditions and notify the driver by electronic means about the location and the cause of the malfunction. In AVs, a flushing-light and a buzzer will make the passengers aware of the malfunctioning device. This fail-assist maneuver complies with NHTSA's “fail operational systems” for steering (
The myth that mechanical steering is safer than electronic steering is no longer factual. It was vastly demonstrated supra that digital controls can monitor, compute, and actuate EV's gears in milliseconds, giving rise to precision in electronic steering, which translates also into safety; including but not limited to, electronic malfunction warning systems—as described in steering section [0110] supra—with which it can correct defects by electronic means, and notify the driver/owner of AV that the vehicle has malfunction, and what needs to be repaired (
Heavy-duty trucks, buses and semi-trailers are widely used for transportation of goods and people due to their low operation cost per weight; and, since the world population is moving into cities, public transportation is expected to increase dramatically leading to increased number of buses for inside the city and inter-cities transportation. So far, inherent to these class of vehicles, only electrification—in particular with this disclosure—will solve the vehicles' two paramount nuisances and complications they trigger off:
(iii) a massive pollution of CO2 and NOx that triggers health detriments to living organisms, and diminishes the green-house gases in the atmosphere; and
(iv) extremely poor maneuverability. Drivers are shortcoming when they have to steer their heavy-duty trucks, buses, and semi-trailers inside an urban areas to deliver goods or transport passengers.
The future semi-trailer's business is projected to be autonomous; well, the only way to bring about autonomous mobility for semi-trailers is when traction and steering systems with digitized electronic means while the energy source could be batteries, ultra-capacitors, flywheel, photovoltaic-cells, and fuel-cells, all of which provide electric power from various sources. Traditional diesel engines in buses, heavy-duty and semi-trucks should be abandoned.
Current electric semi-trucks need improvements to be economic viable, and profitable. It is not sufficient to just replace the diesel engine with four electric traction-motors and propel the same traditional rear-wheels of the tractor; or lower the tractor nose for better coefficient of drag, and continue to steer with the same traditional, mechanical system where only the two very front-wheels of the tractor are steering a 58′-feet long vehicle. Interpreting system 10 as depict in all
(i) superior efficiency; (ii) longer range; (iii) uniform distribution of traction power and weight along a 58′-feet long vehicle; (iv) remarkable maneuverability; (v) zero NOx pollution, and minuscule CO2 pollution [electricity production in power plants emits much lower CO2]; (vi) reduction in battery-pack seize, weight, and cost; (vii) lower manufacturing cost and (viii) 40% reduction in operating expenses compared to diesel heavy-duty trucks and semi-trailers.
The philosophy of the disclosure is to spread the tractive-power and steering to all, or all wheels along any heavy-duty vehicle for a balanced distribution of the tractive-power, and the steering. Two or three rear axles in the articulated trailer may be propelled and steered to assist the semi-tractor at forward-motion-start and in any acceleration or uphill drive.
Steering an articulated vehicle, with only the front two-wheels is a massive obstacle not only to the semi-trailer driver, but also to all other drivers on the road as presented in
Low-speed multi-wheel vehicle maneuverability was always a problem in resolving the amount of space required by the vehicle to make a turn as depicted in
Steering and propelling the trailer rear-axles; this disclosure design for heavy-duty and articulated vehicles will eventually provide better result than just improve steering when the traction is integrated in the steering process:
(vii) it will result in dramatic improvement in the vehicle maneuverability, at low and high speeds, minimize off-tracking and a total swept path width, and overall, much better stability at any speed range because individual traction of each wheel causes equal power distribution along a 58′ feet long tractor and trailer.
(viii) in low-speed steering modes, aligning the rear wheels of the trailer—at 60° to 90° to the turning center (see
(ix) 58′ Semi-trucks are much longer than cars, then the radii to the turning-center would be much longer too, developing smaller speed differences between the left and the right wheels as is noticeable in passenger cars. Rear-wheel propulsion and steering will dramatically increase tire-grip on the road; and put a stop to the trailer when the tractor stops, which will prevent a quite common accident in semi-trailers roll-overs.
(x) propelling the left and the right side of the tractor and the trailers wheels with different speed will perfect stability, ease maneuverability, and would eliminate the need of power-steering system altogether; and
(xi) as in system 10, the controller, or the autonomous semi-trailer ECU may de-couple specific electric traction-motors when reaching sufficient kinetic energy—especially in highway driving, which is more than 90% of semi-trucks driving—to save electric energy, which results in extended driving range.
(xii) after evaluating the driver's desired steering angle, and the topographic GPS data, the holistic controller computes the specific tractive-power for each wheel, while computing the angle-position of each steerable-wheel. Then, the holistic controller may compute and evaluate, which of the ten or twelve electric-traction-motors along the semi-trailer has to couple to wheels; and in what angle each wheel has to be steered in every point and time of mobility, which is much more sophisticated task than in a 4WD passenger car, yet it is much closer to perfect mobility.
The design of various electric traction-motors may secure that the vehicle never stops because power distribution among plurality of various electric traction-motors will eventually eliminate mechanical break-downs because, even though one or a couple of electric traction-motors may malfunction, the rest will suffice to keep the vehicle running, which is a top priority, especially in the trucking industry to deliver goods on time. Utilizing induction motors will eliminate the necessity of water-cooling system and overheating because of the smaller size and substantial number of the electric traction-motors in this disclosure, compared with the giant electric traction-motors in today's electric tracks. The energy losses through to heat is much smaller, which support better efficiency.
To steer heavy-duty vehicles, and especially semi-trailers with maneuverability of 4-wheel vehicles as described in
To steer all wheels in the same direction as the front wheels, the four or eight wheels at the rear axles of the semi-tractor—that are not steered in the basic configuration (see
The method of steering these wheels differs from the previous, traditional approach where each individual wheel steered by pushing or pulling the steering-knuckle of the wheel.
It is obvious from the
Each and every time when a traditional class 8 semi-trailer is changing lanes, steering the two front wheels of the semi-tractor is dragging the 16-wheels behind; when the driver steers to the left lane, and after passing the slow-driving vehicle, when the driver steers back to the right lane. Adding the 36.5 metric tons on top of the dragged wheels and the wasted energy becomes a significant factor in the reduction of the driving range.
Manufacturing and maintenance cost computations is a particularly critical issues when operating trucking business. Purchase price of a new, standard diesel eighteen-wheeler semi-tractor and trailer is about $170,000 where, standard semi-tractor with diesel engine cost about $130,000; and standard trailer for 18-wheeler, cost about $40,000. Adding steerable rear-wheels system will cost additional $20,000; total $190,000. All estimates are on the low-side.
The same new semi-tractor without diesel engine, transmission, drive-shafts, and differentials; exhaust system; water-cooling system, pollution prevention system; power-steering system; starting system; alternator charging system; hydraulic-brakes system; and air-conditioning system will cost about $40,000. Then, the trailer cost about $40,000, and all together about $80,000.
To manufacture eighteen-wheeler semi-tractor and trailer according to this disclosure, with electric integrated traction, steering, and braking may include in general: (i) stripped tractor and trailer $80,000; (ii) 10 electric traction-motors; eight 50 kW induction-motors $960 [@ $200] and two 100 kW induction motors $1,400 [@ $700]; (iii) adding; 6 electronic-clutch mechanisms [4 induction motors, two in the tractor and two in the trailer may be connected to the wheels at all times] $1,800; (iv) six steering electric traction-motors $3,000 [@ $500]; (v) 10 DC to DC converters $1,000 [@ $100]; 10 DC to AC inverters $1,000 [@ $100]; (vi) digital system-controller with all wiring at $4,000; (vii) 10 electric-brake systems $2,000 [@ $200] brakes won't be as powerful as in semi-trailers with diesel-engine since regenerative braking by 10 induction motors will do most of the job and evenly distributed along the tractor and trailer; and (viii) air-conditioning system $1,800; total without the battery-pack is about $97,000˜$100,000.
Under previous considerations in [0037], the battery-pack weight and cost in [0040] have a decisive role in designing electric buses, heavy-duty trucks, and semi-trailers. Using Tesla semi's specifications as computed supra that for 480 Km range the battery-pack will cost $47,000 in today's $100/kWh price, and $23,500 when kWh price will reach $50/kWh in 2024 (see
Maintenance cost of a semi-trailer with this disclosure will be significantly lower than diesel semi-trailer. Average annual distance traveled by Class 8 diesel semi-trucks is about 75,000 miles; and the average efficiency is 6.5 miles per gallon, with yearly consumption of 75,000/6.5=11,540 gallons within a price of $3.90/gal, annual cost of fuel is about $45,000.
Semi-trailer with this disclosure and with the efficiency of 0.75 miles/kWh will consume 100,000 kWh to drive 75,000 miles; with $0.07/kWh commercial price of electricity=$7,000 and with 90% efficiency, annual ‘fuel’ cost=$7,700, which is $37,300 less than semi-truck with diesel engine. 3-years just fuel savings will buy a new electric semi-trailer. The additional expenses with diesel semi-trucks, such as tires replacement, engine lubrication and maintenance, are not available in e-semi-trailers because induction-motors are maintenance-free. The battery-pack replacement is due after 1,000,000 K/m, depending on the charging methods.
The modularity in assembling components of this disclosure is another advantageous aspect that could ease fitting this disclosure in any vehicle type.
Attributable to Modularity of the Design, this disclosure further simplifies, and lowers manufacturing cost.
It should be understood that in certain embodiment electronic controller may include conventional processing apparatus known in the art, and capable of executing pre-programmed instructions stored in associated memory, all performed in accordance with the functionality described herein. To the extent that the methods described herein are embodied in software, the resulting software may be stored in an associated memory where so described, may also constitute the means for performing such methods. Implementation of certain embodiment of the invention, where done so in software, would require no more than routine application of programming skills by one of ordinary skill in the art, in view of the foregoing enabling description. Such a controller be of the type having both ROM, RAM, a combination of non-volatile memory so that the software can be stored and yet allow storage and processing of dynamically produced data and/or signal.
