The present invention relates to power controls for vehicles and, more particularly, to a power for a diesel powered vehicle.
It is common to use diesel combustion engines in various types of vehicles.
Presently, there is the desire to reduce the amount of carbon particles which come with the diesel exhaust when the diesel fuel is not entirely burned. Typically, the amount of carbon particles is engine load and engine RPM dependent. The fuel quality typically also has an influence, especially the sulfur percentage. Diesel engines are often already optimized to boost the entire burning of the diesel fuel by burning room design of the pistons and barrel heads. Nevertheless, there is often an amount of carbon particles in the exhaust which are coped with by additional means. Typically, there are carbon particle filters in use. The filter systems often employ several stages for archiving chemical modifications to the exhaust gases. The filters may also serve to reduce other undesired chemicals or to alter these to harmless chemical fumes. Solid remainings are undesired but may occur in these filter systems.
Two main classes of diesel carbon particle filter systems are in common use: deep bed filtering (“DBF”), which works by the principal of CRT (Continuously Regeneration Trap), and Wall-Flow (“WF”) principal. On WF the gases have to pass a porous material in which pores of carbon particles get stuck until becoming burned to a gas. A common material for these particle filters is silicium carbide. The main aspects are that the DBF does not add such high back pressure over run time of the filter of the WF type, but the efficiency of WF is typically greater. Since the WF is more complicated, it mostly becomes installed by OEMs during assembly, while DBF is a good choice for after market assembly. Especially on WF, the back pressure is caused by the particles choking the pores.
The burning of the particles (filter regeneration) can only take place when a certain temperature is given or certain chemical gases are increasingly present. Typically, the temperature, the presence of carbon particles accumulated in the filter and the presence of carbon burning gases act substitutional. When NO2 is present the carbon burning starts at lower temperatures such as around 250 degrees C. The burning produces NO and CO mainly and CO2 in parts. When using higher temperatures, O2 burning takes place. There the carbon burns to CO and CO2. NO, CO and CO2 are all gases which can pass the pores of the filters. Typically, the burning is controlled by the motor control system, which is supervising the exhaust gases by several temperature and lambda sensors and the pressure loss over the carbon particle filter.
The present invention provides a system that utilizes and controls vehicle inherent secondary systems to increase the mechanical load to the combustion engine for increasing the lost heat.
The system of the present invention thus may enhance filtering of exhaust gases of a vehicle combustion engine, such as via a control that is operable to utilize and control vehicle inherent secondary systems to increase a mechanical load to the combustion engine for increasing the lost heat.
Optionally, the lost heat may be mainly released to the exhaust gases, and/or the lost heat may be utilized to increase the heat of a carbon particle filter, and/or exhaust gases may flow through a carbon particle filter, which may be heated to its functional temperature, such as a temperature that is between about 250 degrees C. and about 800 degrees C.
The system may function in operation modes so that the inherent secondary systems are controlled in a manner/mode that it is substantially not perceptible to the vehicle occupants and/or bystanders.
The combustion engine may be controlled in a manner such that emitted torque is increased by the same amount as the torque discharged by the utilized or activated secondary systems. The secondary systems may be controlled in the operation manner/mode to maximize electrical power consumption, and/or to maximize mechanical discharged torque from the vehicle drivetrain. The secondary systems may be supervised by a master control to control the combined torque consumption and to prevent the secondary systems from damaging due to overload.
The secondary systems may comprise electrical switched or commuted current driver stages and driver controls and relays switched consumer or alternator (or commutator) driven actuators. The electrical commuted current driver stages may be controlled in opposite directions in short time durations so that the resulting force or momentum is near zero over time. The electrical commuted current driver stages may be controlled in a short cut mode.
These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings.
Engines, and in particular automotive diesel engines, produce as immediate exhaust a mixture of hot gases and solid particles, particularly solid carbon particles and the like. Passage of such particles out through a vehicle exhaust system is undesirable for a variety of environmental and health reasons. Thus, it is conventional to incorporate a particle filter or particle filtering means into a diesel vehicle exhaust system. The particle filter or screen functions to capture the particles so as to stop them from being exhausted out through the vehicle tail pipe. Of course, over a period of time (such as, for example, days or so), the particle filter or screen will begin to fill up or clog. Naturally, unless intervening means are provided, the screen or filter will become permanently clogged and cease to be useful. However, as the particle filter begins to fill up so as to be clogged with particles, the passage of gases therethrough is progressively impeded and thus a back pressure develops that impacts the operation/efficiency of the engine itself, leading to an increase in temperature of the exhaust gases up to a point that the exhaust gases can reach a temperature sufficient to burn off and thus de-clog the filter or screen.
During this period, however, the engine is not operating most efficiently and so automakers desire to have this out-of-normal operation mode be minimized. For example, automakers conventionally utilize catalytic materials/convertors in the formation/structure of the screen or filter so as to reduce the temperature at which the clogged material, such as carbon, can burn off to be converted to gas that can then exhaust through the tailpipe. Others, particularly in the after market, may spray the likes of additives and/or diesel fuel itself into the exhaust system between the engine and the clogged filter to enhance and accelerate burn off of clogged material.
A problem however can arise when the likes of city driving means that there can be a relatively short period between two sequential ignition cycles. A screen or filter may be nearly or fully clogged at the end of a particular urban journey. After sitting overnight in the cold during the likes of a winter night, the engine experiences a double inefficiency. Startup of the engine is from cold and the back pressure due to the presence of the clogged filter or screen adds to the inefficiency of the engine itself.
Thus, it would be desirable for the engine to work harder immediately on startup so that it correspondingly heats up faster and so that its exhaust gases immediately exiting the engine itself rise in temperature faster so as all the faster to get to the burn off temperature of the, for example, carbon particles, stuck at and clogging the screen or filter. Thus, in accordance with the present invention, and on occasions when this clogged filter situation is sensed or detected, electrical systems/accessories/loads of the vehicle are actuated so that they derive power from the engine itself and by so powering, the engine will rapidly heat up or get hot. Plainly, appropriate decisions need be made as to what items to so power. For example, an electrical horn would not be an appropriate item or system, nor would an electrical power window or electrical door lock/unlock be an appropriate system (these would either act unexpectedly or, when driven into a stall direction, disengage after about 0.5 seconds to limit or prevent electrical motor overload). A list of appropriate systems are discussed below.
Such electrical powered cooling fans typically use an electrical motor. However, to simply electrically actuate and turn on the electrical fan would be counter productive when trying to heat the engine. Thus, in accordance with the present invention, and as described below, the electrical motor of the fan may be powered in a non-synchronous manner such that the vanes or blades of the electrical motor generally stay stationary or at least minimally rotate. By so doing, the electrical motor of the cooling fan (that may be 200-1500 Watts) can help the rapid heat up of the engine in accordance with the present invention. These principles can be applied to any asynchronous motor, and preferably synchronous motor, utilized in the vehicle, such as, for example, a second motor, a pump unit or system, or the like. The accessory/system that is electrically powered during this special mode should not cause concern or bother to the occupant or driver of the vehicle (for example, actuation of an alarm or horn or audible accessory or actuation of a visual accessory that is viewable by the occupant or driver may not be appropriate during this heat up mode). The present invention thus provides a master system for controlling motors or accessories or the like to rapidly heat or increase the temperature of the engine during certain driving conditions to limit filter clogging and the like.
The overall power consumption of the electrical secondary systems may be in a range of from about 4 kW to about 8 kW or thereabouts for passenger vehicles or cars and from about 10 kW to about 25 kW or thereabouts for larger vehicles or trucks when controlled to maximum load. The maximum electrical load may be higher when using additional (uncommon) consumers such as extra resistors or the like. The consumer may be limited by the maximum power of the vehicles generator. Hybrid motors can produce up to about 200 kW in a generator mode. Typically, the short term (such as about 0.5 minutes to about 3 minutes or thereabouts) peak load of electrical commutated motors/generators may be up to about five times higher than the nominal (long term) load, limited by it's heat capacity and magnetic properties.
On engines with low NOx emissions or short range used vehicles, a self-evident method for carbon filter regeneration is to increase the exhaust gas temperature periodically. Often, this may be controlled by the engine control, triggered by an increased pressure loss over the carbon particle filter. It is known to inject and burn additional diesel fuel during the emission stroke. However, this adds to fuel consumption and since the fuel does not burn very efficient (no combustion) the temperature gain to the exhaust is not optimal.
The system of the present invention provides an enhanced filtering system that is efficient. To simplify the known systems by reducing the components and the complexity and to achieve a higher gain of the exhaust temperature by the additional used up fuel, the present invention or solution is to add the load to the combustion engine and to burn a higher amount of fuel preferably within a minimal period of time to increase the exhaust temperature called High Load Mode (HLM). The benefit will be that the fuel will be burned at a higher efficiency than injecting fuel during the exhaust stroke. Thus, the amount of fuel needed for a carbon particle filter regeneration cycle will be less. Another benefit of the present invention is that the diesel engine does not need to have a special mode for burning fuel during the exhaust phase (such as described in German Patent application DE1020005035168, which is hereby incorporated herein by reference in its entirety), which frees up engine and exhaust design limitations and eases the motor control.
Depart from
The additional load to the engine may be achieved by switching on electrical power consumers. Preferably, these will not become noticed by the driver and will not influence the driving properties of the vehicle. The electromagnetic (back-) force (momentum) of the electrical power generator increases, when the electrical consumption increases. Both powertrain consumers as well as interior and exterior vehicle accessories come into consideration. There may be different power and driving conditions that may limit the choice of consumer systems. Different modes may be necessary to match certain driving conditions.
For example, the system of the present invention may switch on or control or modulate one or more of the following secondary systems:
Additionally, known art electrical powered exhaust gas heating elements or heating elements in or at the carbon filter (such as, for example, resistors or coils or the like) may be switched on as additional electrical load in accordance with the present invention, with the side effect that it's consumed electrical power also adds to the heating of the Diesel filter, and it's heating power may be reflected in the loop control (-model) as well.
Additionally, systems may be known that are capable to add load to the combustion engine indirectly (or directly). In applications for hybrid vehicles (combustion engine plus electrical engine), the electrical engine may be controlled in a generator mode (known systems may control the generator highest at times when the engine is in a coasting mode (such as, for example, BMW's Efficient Dynamics system or the like), but unlike such systems, the system according to the present invention may work at times when the engine is on at a high load to peak load) or in a short cut mode (if it sustains that). Thus, it consumes mechanical energy from the drivetrain. The same can be done with combined starter generators, where its mechanical consumption is maximized when the maximal electrical generation is controlled.
Optionally, a more complex system of the present invention may additionally or alternatively use the vehicle's wheel brakes (such as at times when the clutch is closed) to add mechanical load to the combustion engine. In such an application, the brake temperature should be considered in a way that at all times a full brake application is still possible.
Optionally, a more complex system of the present invention may additionally or alternatively use a fly wheel of the vehicle which may also be capable to consume (or store) mechanical load from the combustion engine, typically in an area of about 20 KW to about 100 KW. The fly wheel may be coupled mechanically or electro-mechanically.
In order to not unsettle the driver, it is preferred that in all cases above and in any combinations thereof, the combustion engine is controlled in a way to balance the higher torque the vehicle's own systems consume in a way that the torque output to the vehicle's wheels is identical or substantially identical, so that, when the load is applied, it is not readily discernible to the driver of the vehicle so that it is as is no additional load has been switched on.
In
As an optional feature, this loop control may have an additional ‘Setpoint feed forward’ Function or Factor which acts to the system without delay. Typically, the ratio between ‘Setpoint feed forward’ signal w1′ and Control signal u is about 80 percent to 90 percent, by that the control has just to control 20 percent to 10 percent of the control deviation depending on the accuracy of the system description of FS1,FS2 and FM. In result the system's deviation, due to dynamically set point changes, is mostly eliminated. According to the invention, a controlled load caused by tuning electrically/electronically consumers may be applied to the engine system. The torque increase caused by (intentionally and non intentionally) applied ‘Electrical loads’ (y2=y2A+y2B+y2C+ . . . +y2n) act as additional mechanically drag on the electrical generator shaft, which diminishes the engines total torque output y by the drags total amount of momentum y2. That's why the ‘Electrical load’ acts subtractive to the sum point between Controlled system part one and two.
It may be enough to let the ‘Control’ react to torque decrease and increase over the output deviation e but the deviation and later compensation may be slightly noticeable (or hearable). Since that there is another optional path inserted to the control: The ‘Known disturbance feed back’ y2′ acts direct positively to the fuel throttle u for at least partially eliminating the consumed torque caused by the ‘Electrically load system’ before it comes to an output torque deviation. This is possible since the electrically load momentum y2 caused by the known amounts of consumer currents in the generator measured via the optional measuring systems (FM2A, FM2B, FM2C, . . . , FM2n) is well calculatable and/or modelable by its ‘n’ system's descriptions (FA, FB, FC, . . . , Fn) of any order (T1, T2 . . . Tm of Consumers A to n of
In the suggested control model of
Changes and modifications to the specifically described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law.
The present application claims the filing benefits of U.S. provisional applications, Ser. No. 61/837,369, filed Jun. 20, 2013; Ser. No. 61/793,558, filed Mar. 15, 2013; and Ser. No. 61/673,010, filed Jul. 18, 2012, which are hereby incorporated herein by reference in their entireties.
Number | Date | Country | |
---|---|---|---|
61837369 | Jun 2013 | US | |
61793558 | Mar 2013 | US | |
61673010 | Jul 2012 | US |