The present invention relates to a bimodal, preferably electrically powered, traffic system, one of the modes being conventionally controlled by the driver and the other being highly automated, comprising:
The deployment of autonomous traffic in motor vehicles is currently facing a legal problem due to the fact that the legal responsibility in case of an accident is transferred from the driver to the manufacturer (and his suppliers). Indeed, most traffic accidents are currently of human origin and the driver is mainly responsible.
All current autonomous vehicle concepts are based on a “contactless” technology including sensors and electronic control systems, of “automotive” reliability, which are therefore not immune to failure (computer bug, blackout, etc.) and therefore most manufacturers limit themselves to level 3 driving aids requiring, on the part of the driver, constant vigilance in order to regain control of the vehicle and thus relieve the manufacturer of responsibility in the event of an accident in autonomous mode due to a malfunction of the “contactless” trajectory control system.
However, it is not disputable that drowsiness at the wheel remains one of the first causes of accidents on freeways and level 3 autonomous driving, by removing the need for the driver to keep his car permanently in the lane, does not go in the direction of reducing the monotony inherent to driving on a separate roadway such as a freeway or expressway, at sustained speed.
In the current state of traffic and travel speeds, a loss of visual cues such as a missing marking line or an unexpected interruption of the non-contact guidance system, even if only for a few tenths of a second, can lead to a runaway or a collision.
Although the aeronautical industry has developed electrical systems with a very high level of reliability, these systems are too costly for a car and above all require periodic maintenance programs with a high level of quality that is difficult to reconcile with routine maintenance as perceived by the driver of a car today. Indeed, if one only counts a few hundred thousand aircraft in the world, there are more than a billion vehicles on the road today, i.e. more than 5,000 times more!
It is therefore not surprising that all serious projects of autonomous cars “without immediate vigilance” are limited today to very low speeds (in traffic jams for example) to minimize the consequences of accidents or are oriented towards shared vehicles belonging to operators, who are the only ones able to cover the high acquisition cost and to ensure rigorous maintenance. In addition, the electric propulsion of conventional motor vehicles, despite the significant improvements it brings in the areas of atmospheric pollution and noise, comes up against a problem of weight for on-board energy storage.
In fact, 100 kg of lead-acid batteries are needed to store the equivalent energy of one liter of gasoline, weighing 700 grams. Although lithium-ion technology has quadrupled the mass capacity of batteries over the last twenty years, from 40 Wh/kg to more than 150 Wh/kg, the autonomy is still insufficient and represents an obstacle to the electrification of the automobiles fleet in developed countries.
On the other hand, the manufacturing and recycling of these batteries represents a substantial environmental impact that is contrary to the ecological objectives set for the coming decades of the 21st century.
Numerous studies have been carried out on the possibility of recharging vehicles without contact while driving on the basis of magnetic induction, but due to the distance between the transmitter and the receiver, the efficiency drops and the cost of the infrastructure remains prohibitive for widespread deployment.
Moreover, long-distance travel is increasingly taking place on dual roadways, expressways or freeways with separate roadways.
It is an object of the present invention to provide a dedicated track on the central side of separate traffic lanes for one of the side wheel assemblies of vehicles forming a mechanical lane keeping device having a “gutter” shape by the cooperation of two side surfaces located one on the bottom of the “cast-in-place” crash barrier that generalizes and the other on the lateral face of a continuous rail anchored in the roadway bordering said dedicated track.
This dedicated track, which advantageously uses the dead space between the crash barrier and the continuous marking line delimiting the fast-traffic lane, called the roughened zone, which does not encroach on the existing traffic lanes, allows for safe highly automated traffic, for equipped vehicles, sharing the roadway in a laterally staggered manner with the existing traffic, in order to allow for an economically viable transition to a progressive deployment of a highly automated traffic mode.
In his application PCT/FR93/00486, which was published in WO 94/26573, the applicant already demonstrated the safety advantages of such a guided traffic with all the side wheels running in a “gutter”. But, the described device required either the interruption of a side wall of the “gutter” to allow the entry and the exit of the wheels laterally, or a frontal entry and exit as in the “O-Bahn” system, which equips certain buses in ADELAIDE in AUSTRALIA since the Nineties, taking again the principle of the “Tracline 65” project experimented in the Eighties in Birmingham in England. Indeed, the interruption of a side wall poses a safety problem in case of failure of the steering system or in case of emergency braking in a zone where the side wall is interrupted.
The present invention provides a new solution for entering and exiting the dedicated track “gutter” by providing a means for laterally crossing the internal side surface by the side wheel assembly, at a sustained speed (which may be the current maximum speed in most countries on freeways). Advantageously, retractable rollers placed on the axle stubs of the side wheels of one of the side wheel assemblies, allow to momentarily relieve the load on the side wheels, by taking support on the extension of the roadway when the said side wheels are in line with the gutter for the purpose of landing, without impact, and extracting the said side wheel assembly, also at sustained speed.
The main function of this device lies in the existence, for the equipped vehicle running with a side wheel assembly in the gutter, of an emergency mechanical lateral guidance to control its trajectory in case of emergency mode due to a failure of the primary steering system in highly automated mode. As a result, the highly automated traffic mode according to the invention allows the vehicle to enter and exit laterally at any point of the shared infrastructure and this at a higher speed than in the case where it would have to enter the network through a specific entrance gate as it is the case in the “O-Bahn” system.
Thanks to these essential means of the invention, there is no longer a privileged entry/exit zone on the dedicated track that can be entered or left at any point. Advantageously, this exclusive dedicated track can be bordered directly by the “Jersey” type crash barrier or other lane separation wall of a divided roadway, the side surface bordering the roadway being carried by the lower part of the “Jersey” wall, thus advantageously using the unobstructed strip located between the “Jersey” wall and the continuous white marking line delimiting the lane.
It is thus understood that, even when installed on the left-hand side of a separate roadway (in the case of right-hand drive), this track dedicated to vehicle guidance retains all its characteristics so that the infrastructure thus modified can also be used by existing driver-controlled vehicles, thus greatly facilitating the introduction of the system and leaving the way open for a more or less rapid increase in the number of vehicles equipped according to the invention without requiring major initial investments.
Advantageously, the side wheels can be equipped with height-adjustable suspensions whose height varies in synchronization with the movement of the wheels to minimize body roll. The height of the suspension of the other side wheels can be adjusted in order to eliminate body roll when entering and exiting the runway of the dedicated track according to the invention, which will thus become transparent for the driver and the passengers.
By continuously measuring the lateral distance of the vehicle with respect to the side surfaces bordering the “gutter”, by one or more sensors placed in front of the front wheel, a servo-control of the vehicle's steering can thus maintain the front wheels in the center of the dedicated track, thus offering a simplified mode of highly automated driving that does not require visual detection of the marking lines. Although the measurement of this distance can be acquired continuously by several sensors, advantageously placed in front of the front wheel, measuring the lateral position of the vehicle with respect to the side surfaces bordering the dedicated track, a failure of this distance detection system is always possible and in this eventuality the contacts between the sidewalls of the tires, or the edges of the rims in the case of a flat tire, with the side surfaces of the “gutter” will be able to maintain the trajectory of the vehicle until an emergency stop. The vehicle can then exit the gutter by turning its front wheels at a standstill, and be able to free the dedicated track. This is the procedure for manual exit from the “gutter” that will be used by any vehicle that is not equipped and that by accident finds itself with all of its side wheels in the gutter. It is obvious to the man skilled in the art that in order to minimize failures, an obligation of close periodic control of the guidance and emergency braking devices will be put in place by the authorities.
The object of the present invention is then to provide electric mobility with a dynamic very low voltage power charge, arranged along the traffic lanes, from which each vehicle can be supplied with a voltage of less than 50 V AC and 120 V DC in order to comply with safety standards. It is reminded that although lower than the 400 V, the standard voltage of the battery pack, the very low safety voltage of 120 V DC still allows each 100 V block of the battery pack to be charged successively by switching, the batteries being composed of voltage elements of only a few volts.
In a preferred embodiment, the “Jersey” wall has above the first lateral guiding surface on each side a “third rail” connected to one of the poles of a very low voltage source and the vehicle has a lateral sliding shoe in order to ensure the electrical charge of the vehicle while driving, the other pole, connected to the rail, being picked up by a brush or any other known device
Indeed, in an advantageous way in terms of global energy efficiency (i.e. taking into account not only the energy to propel the car, but also to extract the raw materials from the mines and to transform them for its manufacture and that of its batteries), the present invention makes it possible to substantially limit the capacity and thus the weight of the on-board battery pack, thus reducing the quantity of C02 generated for its production. Moreover, the very low voltage of 120 V DC collected directly by sliding/rolling contact allows to supply directly the motor in autotransformer mode, without passing by the batteries, the latter being used only to supply the temporary additional energy or to recover the excess energy due to the ascents/descents and the changes of speed imposed by the profile of the roadway in highly automated traffic mode.
Finally, the present invention aims at reducing the current congestion of the network by allowing the “platooning” of several vehicles while mitigating the danger of such a system, which in essence reduces the distances of the vehicles in the platoon, by an on-board emergency braking device.
During the PATH (Partners for Advanced Transit and Highways) program tests in the 1990s, a 20% gain in aerodynamic drag was calculated if the vehicles were driven at a distance of 1 m, but this configuration led to difficulties in the control system and in particular to a risk of collision between the vehicles in the “platoon” in the event of emergency braking.
To alleviate this problem, according to the invention, an emergency braking caliper, allowing a deceleration of up to several g, is attached to the rear of the vehicle, preferably behind the rear wheel, to allow it to engage and disengage from the rail during entry and exit of the highly automated mode according to the invention. This device advantageously allows maximizing the reaction time for the management of ephemeral or permanent obstacles that may be on the track by substantially decreasing the braking distance, which may thus be of the same order or less than the 2 seconds prescribed for the current speeds on fast lanes or freeways. Consequently, the emergency braking device according to the invention increases the time allocated to the analysis of the nature of the obstacle and also avoids the degradation of braking performance in wet or icy weather.
Advantageously, this braking system will be associated with a telescopic bumper placed in the front bumper of the vehicles which operates by inertia, as on heavy towed trailers, by mechanically activating the emergency brake caliper, in emergency mode, in the event of failure of the on-board control system or total “black-out”.
The invention advantageously makes it possible to increase the traffic flow without necessarily requiring the creation of additional lanes on the roadway as is the case today, and thus represents a substantial economic and environmental interest.
Thus, instead of having to widen a freeway to two times three lanes when peak traffic exceeds 4,000 vehicles/hour, the invention will make it possible to increase the flow to more than 6,000 vehicles/hour at sustained speed, and this for a fraction of the cost necessary to create a third lane.
Then the rail, which offers:
By allowing a highly automated serene driving, due to the presence of the guidance system in emergency mode by mechanical contact, private individuals as well as professionals will be able to make road trips without having to maintain constant vigilance, thus bringing gains in terms of safety.
This will allow both individuals and professionals to travel on the road without having to maintain constant vigilance, thus saving productive time while working on other tasks for professionals or saving leisure time in the case of personal travel.
The traffic system for motor vehicles, comprises on the side of a traffic lane a dedicated track, in the form of a “U” shaped gutter, receiving in highly automated driving one of the side wheel assemblies of a vehicle and comprising:
The means for laterally crossing the internal side surface may be a ramp, generally gently sloping perpendicular to the direction of travel, which connects the roadway to the upper end of the internal side surface.
The means for laterally crossing the internal side surface may be obtained by placing the running surface of the dedicated roadway at a lower height than the roadway.
The lateral crossing means of the internal side surface may be obtained by the combination of:
The upper end of the internal side surface comprises an auxiliary rolling surface, substantially parallel to the roadway surface and the front wheel of the side wheel assembly is equipped with an auxiliary support means capable of, while traveling at cruising speed, to temporarily relieve the load of the front wheel by taking support on the auxiliary rolling surface, the auxiliary support means being retractable by movement between a high position, where it preserves the ground clearance of the vehicle, and a low position where its lower contact point is substantially at the same height as the point of contact of the front wheel with the roadway. The auxiliary support means includes at least one roller mounted on a support arm hinged to the front wheel axle stub of the side wheel assembly and the internal side surface and the auxiliary running surface are carried by a continuous rail.
The rail has a third, ledge-like surface substantially parallel to and below the auxiliary rolling surface, the third surface and the auxiliary surface being pinchable by an emergency brake caliper connected to the vehicle structure to generate a braking force, by friction on the rail, that can reach a high value of more than 1 g in an emergency, independently of the coefficient of adhesion between wheel and road.
The side wheel assembly may be equipped with variable height suspensions and the heights of the suspensions:
Forward of the side wheel assembly, a sensor measures the lateral distance between the side wheel assembly and the outer side surface of the dedicated track and controls the vehicle steering device to maintain the side wheels of the side wheel assembly generally centered on the dedicated track while driving.
A “third rail”, powered by a pole of an electrical source, is positioned above and recessed from the outer surface of the dedicated track, with the return to the source provided by the conductive continuous rail, and known means are provided in the vehicle for establishing an electrical connection while driving by sliding/rolling shoe with the “third rail” and the continuous rail.
The yaw torque generated during emergency braking between:
A method for moving in and out of a freeway motor vehicle travel mode at a sustained speed to a highly automated travel mode, comprising a “U” shaped gutter dedicated track positioned at the edge of the freeway, capable of receiving a side wheel assembly of the motor vehicle by “vertical landing” for entry and “vertical extraction” for exit, the side wheel assembly being equipped with rollers fixed, in a vertically retractable manner, to the inner faces of the wheel spindles, the lower part of the rollers being, in the lowered position, substantially at the height of the wheel-road contact, comprising the steps:
to enter:
This Method is completed in the case where at least the side wheel assembly is equipped with height adjustable suspensions in that the steps for:
Other characteristics and advantages of the invention will be apparent from the description given below of an example of its implementation. Reference will be made to the appended drawings among which:
Light vehicles D and heavy vehicles E travel on lanes 11 and 12 in a conventional manner, under the control of their drivers, who keep their vehicles substantially centered on the lanes.
The light vehicles F1 to F6 circulate astride the marking line 4b or 4c in a “platoon” and in a highly automated way, in pseudo 4/5 mode (according to the SAE standard commonly defined by the authorities and the car manufacturers), without requiring any particular vigilance from their drivers, the vehicles F moving astride the marking lines 4b or 4c.
On the rail 27, a gently sloping ramp 34 having substantially the height of the rail 27, formed of ramp segments is attached to the rail 29 attachment flange.
Accordingly, the substantially vertical side surfaces 23 and 31 serve as side edges, in a emergency mode, to keep the side wheels on the track by contact between the side wheel tire sidewalls 35 and 36, or the rim edge in the event of a flat tire, and the side surfaces 23 and 31. This emergency mode only occurs in case of failure of the steering control device (not illustrated) which is already fitted to certain cars with a type 3 automated driving mode. Advantageously, this steering control device is simplified, not requiring optical recognition, and being able to operate with simple lateral distance telemetry, by ultrasonic sensors 33 for example, to keep the front wheel 35 of the vehicle centered on the running surface 22 in highly automated driving mode according to the invention.
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With the high emergency braking capacity, greater than 1 g, independent of the tire/pavement adhesion conditions because the brake caliper 40 pinches the rail 27, the vehicles F1, F2, F3 and F4, F5, F6 can advantageously group together in a platoon with a distance of less than 1 m between vehicles as illustrated in
Vehicles grouped in this way can nevertheless leave the platoon at any time by means of a communication device between the vehicles of the “Wi-Fi”, “Bluetooth” or similar type. Indeed, before a split-lane junction, and not a simple exit that will in any case require a resumption of the conventional traffic mode, if the vehicle needs to take the right-hand branch, it will have to leave the highly automated traffic mode and will only be able to re-engage the highly automated traffic mode when it has entered the right-hand branch. The vehicle wishing to leave the platoon informs the vehicles in front and behind, which will automatically reduce or increase their speed to re-establish the required 2-second separation distance. For example, in the case of a speed of about 120 km/h, it will take about ten seconds to re-establish this regulatory distance allowing the exit of the platoon and the highly automated traffic mode according to the invention. When a large portion of the traffic is in the highly automated traffic mode according to the invention, and if the side lines are well detectable, a vehicle also equipped with level 3 autonomous driving will be able to carry out, without the driver's intervention, but under his vigilance, the maneuver of disengagement of the wheels 35 and 36 from the gutter 21 before the junction, then the change of lane to take the right branch of the junction in free mode, and then the re-engagement in the gutter 21 of the right branch. Reference beacons located on these junction zones can help the basic autonomous system, since it is level 3, to locate the vehicle precisely in relation to the infrastructure in case of reduced visibility (night, rain, fog, etc.).
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The previously described devices of the invention, allowing the lateral entry and exit of the highly automated traffic mode according to the invention on a road infrastructure in cohabitation with vehicles circulating in free mode, are particularly advantageous for solving the problem posed by the entry and exit of dedicated lanes, exclusively reserved for light vehicles, as illustrated in
The description and the drawings illustrate “right-hand” traffic, but it will be obvious to the person skilled in the art that this system is also valid for “left-hand” traffic. Also, the highly automated mode of driving is not restricted to electromobility or hybrid propulsion, and it is conceivable that ICE vehicles could take advantage of the benefits of highly automated driving and platooning in areas where electrification of the road will not be economically viable.
A substantial advantage of augmented road mobility, according to the invention, is that a transition from free-running to highly automated traffic according to the invention can be achieved on existing infrastructure without heavy investment.
When a substantial proportion of the vehicle fleet is equipped to travel in highly automated traffic mode, and because of the small width of the footprint of a guided traffic lane according to the invention, which allows for reduced infrastructure dimensions as illustrated in
Another substantial advantage of augmented road mobility according to the invention is the reduction of the size of the battery of “100% electric” vehicles, which will now be able to limit themselves to a capacity necessary to cover a distance of less than 100 km between recharges, representing a division by a factor of 3 to 5 of the weight of the batteries, with an impact on the weight, the cost, the need for reinforcement of the vehicle of thermal design and the environmental impact that the size of the latest generation of batteries imposes on “free circulation” electro mobility.
It goes without saying that the devices according to the invention can be adapted to other lane-separated road configurations, in particular single-lane roads in each direction, other forms of gutters and rails or to other vehicle structures, and the examples just given are only particular illustrations and in no way limit the fields of application of the invention.
Filing Document | Filing Date | Country | Kind |
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PCT/IB2021/051187 | 2/12/2021 | WO |