FR2982910A1 - Method for controlling traction chain of e.g. hybrid vehicle, involves resetting injector during checking of deceleration of thermal engine, and controlling closing of clutch to couple engine and gear box for checking reaction of engine - Google Patents

Abstract

The method involves resetting an injector during checking of deceleration of a thermal engine (12). A quantity of fuel is injected into the engine. The quantity of the injected fuel in the thermal engine is controlled. The closing of a clutch (40) is controlled to couple the engine and a gear box (30) for checking the reaction of the engine. The variation of engine torque is determined with respect to the nominal torque corresponding to assumed quantity of the fuel. The thermal engine is carburized by the injector according to the action of a control device.

Description

BACKGROUND OF THE INVENTION The present invention relates to a traction chain control method for a vehicle, comprising an injector registration process. More particularly, the invention relates to a traction chain control method for a vehicle whose said traction chain comprises a thermal engine fueled by injectors following the control of an accelerator interface designed to be actuated by a driver. of the vehicle, a gearbox and a clutch interposed between said motor and said box for coupling or uncoupling. The method includes an injector recalibration process including a deceleration control step, wherein it is verified that the vehicle is in the deceleration phase by verifying that the accelerator interface is released by the driver. This method also comprises a step of injecting a supposed quantity of fuel and then a step of controlling the reaction of the engine with said supposed quantity of fuel.

An example of this kind of process is known from document FR2893362, applied to an automatic gearbox coupled to the engine via a clutch constituted by a hydraulic type torque converter. In this method, the step of controlling the reaction of the engine with the supposed quantity of fuel is carried out with sliding in the converter and measuring a variation of the speed of rotation of the engine. A problem is that this technique is not applied to engines and gearboxes that can be coupled by a friction-type clutch type clutch. Indeed, such a clutch alternately occupies an open position and a closed position, but it is not easy to operate by providing a slip to imitate the sliding of a hydraulic converter. In addition, for such an application, this type of sliding operation would need to be well controlled and the discs should be well dimensioned to avoid excessive wear of the clutch. The present invention is intended in particular to overcome the disadvantages of the prior art. To this end, the invention relates to a traction chain control method for a vehicle, said traction chain having a thermal engine fueled by injectors according to the control of an accelerator interface intended to be actuated by a driver of the vehicle, a gearbox and a clutch interposed between said motor and said box for coupling or uncoupling. This method comprises an injector recalibration process including a deceleration control step, during which it is verified that the vehicle is in the deceleration phase by checking that the accelerator interface is released by the driver. and on the other hand a step of injecting a supposed quantity of fuel then a step of controlling the reaction of the engine with said supposed quantity of fuel. The injector recalibration process includes, after the deceleration control step and prior to the injection step of the supposed amount of fuel, a clutch closure control step for coupling the engine and the engine. gearbox before checking the engine reaction. In one embodiment of the method according to the invention, the closing clutch control step is an inhibition of clutch opening during the energy recovery phase for a hybrid vehicle having an auxiliary motor in addition. of the engine, this auxiliary engine can be in energy recovery when the vehicle is in deceleration phase. In one embodiment of the method according to the invention, after the step of injecting the supposed quantity of fuel, the step of controlling the reaction of the engine with said supposed quantity of fuel comprises a step of measuring the torque. provided by this engine then a motor torque deviation determining step relative to the nominal torque corresponding to said supposed amount of fuel and then, following said gap, an injection calibration correction step. Furthermore, the invention also relates to a traction chain vehicle comprising a heat engine fueled by injectors following the action of a fuel supply control device connected to an accelerator interface provided to be actuated by a vehicle driver, a gearbox and a clutch interposed between the engine and said gearbox so as to couple or disengage them with the action of a clutch control device. In this vehicle, the fuel supply control device is adapted to control a process of resetting the injectors in a control method according to the invention. Other objects, features and advantages of the invention will become apparent from the following description of one of its embodiments, given by way of non-limiting example, with reference to the accompanying drawings. In the drawings: FIG. 1 is a schematic view from above of a motor vehicle for showing its hybrid power train architecture; - Figure 2 is a schematic diagram showing the system according to the invention can be implanted in the vehicle of Figure 1. In the different figures, the same references 5 designate identical or similar elements. Referring to the figures, reference numeral 10 designates an example of a hybrid type of motor vehicle. This vehicle comprises a diesel-powered traction chain 12 for driving the front wheels 14 of the vehicle and an electric-powered auxiliary motor 16 for driving the rear wheels 18. This architecture is given as a non-limiting example, any other architecture equivalent hybrid that can be considered. The type of engine, diesel or gasoline, is given by way of non-limiting example, as the type of auxiliary engine, electric or hydraulic or pneumatic. The engine 12 is supplied with fuel, gasoline or diesel, by injectors which periodically require a registration so that the vehicle in operation knows no drift detrimental to pollutant emissions resulting from the combustion of the fuel. The engine 12, diesel in the example taken into account, 25 has its operation which is controlled by a central unit 20, which is a unit of known type calculator. For the control of the injectors, a fuel supply control device 22 uses certain electronic and / or electrotechnical means in the central unit 20. An injector control connection 24 connects the injectors in a known manner to said device 22 of FIG. said central unit 20. Also knownly, the fuel supply control device 22 is connected to an injection pump. The heat engine 12 comprises, in known manner, a crankshaft output shaft, integral with a flywheel. Associated with the heat engine 12, the power train system comprises a gearbox 30 of conventional type with parallel shafts, including an input shaft and an output shaft for driving the front wheels 14 via a differential 32 and transmissions 34 to gimbals. The traction chain system also comprises a controlled clutch 40 of the conventional type with friction discs, interposed between the engine 12 and the gearbox 30. The clutch 40 is intended to couple or uncouple the flywheel and the input shaft of the gearbox following the action of a clutch control device 42. A clutch control link 44 connects the clutch control device 42 with the central unit 20 and its fuel supply control device 22. A torque control unit 46, also of known type, makes it possible to measure the torque delivered by the heat engine 12 to the gearbox 30 when the clutch is closed to couple said motor and the input shaft of said box. The torque control unit 46 is connected by a torque control link 47 to the central unit 20. The vehicle 10 has in its passenger compartment an accelerator pedal 48 constituting in a conventional manner an accelerator interface intended to be operated by a driver 49, drawn in Figure 1 with its seat 51 and the steering wheel 53 that it holds in hand. The accelerator pedal 48 is connected by an accelerator link 50 to the fuel supply control device 22 belonging to the central unit 20. The vehicle 10 comprises in the central unit 20 a hybridization supervisor 56 which is in hybridization connection 58 with the auxiliary motor 16 and which manages the synchronization of the actions of the engine 12 and said auxiliary engine.

The central unit 20 comprises a learning module 60 which is connected to the clutch control device 42. The training module 60 is used during the resetting of the injectors, using the clutch control link 44 and the injector control link 24. As the vehicle ages, the injector registration is performed periodically. Each registration is performed when the vehicle 10 is in rolling phase deceleration, the driver having raised his foot of the accelerator pedal 48 to give a zero load instruction for the engines, so that they do not deliver traction torque. The phases of rolling in deceleration, during which the driver does not require torque, are conducive to learning to reset the injectors. In the absence of the need for engine torque requested by the driver, the CPU 20 and its learning module 60 evaluate the torque produced by small amounts of fuel injected to apply a correction of operation if necessary. The hybrid traction system generally takes advantage of these deceleration phases to recover kinetic energy and transform it into electrical, hydraulic or pneumatic energy depending on the type of energy used by the auxiliary motor 16. In this case, to maximize the gain in kinetic energy, the power train will seek to uncouple the engine as soon as possible. This is normally to avoid the engine brake during which the kinetic energy is lost with regard to energy recovery. Hybridization supervisor 56 will modify the normal behavior of the power train when it should recover energy, making compatible on the one hand this energy recovery during deceleration phases and on the other hand learning while the clutch 40 is closed. Indeed, in normal operation with opening of the clutch 40 as soon as the driver sufficiently releases the accelerator 48 to put the vehicle 10 in deceleration, the learning module 60 does not have enough deceleration time available to perform the learnings of injector registration. If the registration was performed with the clutch 40 open, there would be a lack of occurrence of said resets.

The hybridization supervisor 56 and the central unit 20 will therefore use a setpoint modifying the normal behavior of the power train to prevent the opening of the clutch 40 when the vehicle is in deceleration phase and when the central unit 20 wishes that the heat engine 12 can benefit from learning the drifts of its injectors, in a registration operation. The opening of the clutch 40 will be delayed and a disruption of training time will occur relative to the normal control of the clutch. In the learning module 60 and the central unit 20, to implement an injector resetting process, the software strategy declares on the one hand that the vehicle 10 is decelerating during a control step of this state and on the other hand that an apprenticeship is then in progress. At the beginning of the injector recalibration process, during the vehicle deceleration phase control step, it is verified that the accelerator interface 48 is released by the driver. Hybridization supervisor 56 in any case supervises the behavior of the power train. In Figure 2, to better understand the process, there is shown the central unit 20, its fuel supply control device 22, its learning module 60 and its hybridization supervisor 56. A learning instruction 20P delivered by the central unit 20 generates a setpoint 20R clutch opening delay to the attention of the supervisor 56. The other interactions are indicated by the corresponding links, in particular the link 44 for controlling the clutch 42 passing a delayed opening instruction of the clutch. During the resetting operation, the clutch 40 is closed. A predetermined quantity of fuel injection is controlled by the learning module 60 and the central unit 20 via the injector control link 44.

The engine reacts to this fuel injection, and it produces a certain engine torque. The torque control unit 46 measures the effect produced by the injection and indicates to the CPU 20 and the training module 60 what is the actual amount of torque produced by the engine 12 when the determined amount of fuel is used by this engine. The learning module 60 determines the difference between the theoretical torque that should produce the engine responsive to the fuel quantity determined with respect to the actual torque produced by the engine when this quantity is controlled at the injection. It then calculates what correction, if any, has to be made to the fuel injection according to the reaction of the injectors during the registration training. Following said deviation, an injection calibration step is performed by correcting the nominal values. Advantageously, the amount of fuel injected during the injector registration process is low enough so that the driver and the other occupants of the vehicle do not perceive the corresponding torque call of the engine. Advantageously, when the injectors are supposed to start to behave differently from the nominal behavior defined for example when they are new, the registration process makes it possible to adapt the operation of the injection to the new characteristics of the injectors having a certain wear, for example . Advantageously, when calculating the torque produced by the heat engine 12, the engine brake resulting from the auxiliary motor 16 in the energy recovery mode is known by the central unit 20 and its hybridization supervisor 56. Thus, the recovery energy does not disturb the data collected by the torque control unit 46 associated with the clutch 40 between the heat engine 12 and the gearbox 30. The registration activation conditions are no longer met when this learning operation is complete. The opening inhibition of the clutch 40 is then deactivated. The training module 60 informs the hybridisation supervisor 56 and the rest of the central unit 20 acting on the control of the heat engine 12, the clutch 40, and the gearbox 30. The usual behavior of the clutch 40 starts again, in particular its opening if necessary, just like the usual control of the heat engine 12, in particular during the deceleration phases. Advantageously, the step of measuring the torque supplied by the motor and then the step of determining the deviation of the engine torque from the nominal torque corresponding to the said supposed quantity of fuel constitutes a step of controlling the reaction of the engine with the said supposed amount of fuel. This reaction control can alternatively be carried out by any equivalent method based on any means equivalent to the torque control unit. In any case, it is then necessary to perform a registration, which may also be called an injection calibration correction, if the differences in the behavior of the engine in response to said injection have significant differences with respect to the nominal values which must then be corrected. After the deceleration control step by checking that the accelerator interface 48 is released by the driver, the injector registration process can be summarized in that it comprises a clutch closure control step 40 to couple the engine 12 and the gearbox 30 and then a step of injecting a supposed amount of fuel and then a step of controlling the reaction of the engine to said supposed amount of fuel. In addition, the step of controlling the reaction of the engine 12 with the supposed quantity of fuel comprises a step of measuring the torque supplied by this engine and then a step of determining the deviation of the engine torque from the nominal torque corresponding to said said amount of fuel and then, following said deviation, an injection calibration correction step. Finally, the closing control step of the clutch 40 ensures inhibition of clutch opening. In the case of a hybrid vehicle as represented by having the auxiliary motor 16 in addition to the heat engine 12, the closing control step of the clutch 40 is a clutch opening inhibition during the recovery phase. energy. Said auxiliary motor may be in energy recovery when the vehicle is in the deceleration phase. Advantageously, the resetting process as described above is carried out in the context of a relatively economic friction-type clutch type traction chain system. This system simply comprises a thermal engine fueled by injectors following the action of a fuel supply control device adapted to be connected to an accelerator interface intended to be actuated by a driver of the vehicle, a gearbox and a clutch interposed between the engine and said gearbox so as to couple or disengage them with the action of a clutch control device. This system has its fuel supply control device that can control an injector resetting process requiring the injection of an assumed amount of fuel when the fuel supply control device is informed that the interface of accelerator is released by the driver. This system further comprises a torque control unit which is connected to the fuel supply control device and controls the torque supplied by the engine to be operated when the fuel supply controller performs the registration process during which the clutch control device clutch coupling. This traction chain system has been described as part of a hybrid vehicle. It can also be a non-hybrid vehicle, not shown in the figures, a control in in to implement the method described above. In this non-hybrid vehicle, the controlled clutch is associated for example with a gearbox with parallel shaft architecture supporting gears each having a fixed gear and a idler gear. In this case of the application of the method for a non-hybrid vehicle embodiment, it is a question of not controlling the clutch opening to change a report if a registration process is in progress. If the clutch must still be open during this process, for example if a gear change is to be performed imperatively, then the registration is not taken into account.

Claims (4)

REVENDICATIONS1. A traction chain control method for a vehicle (10), said drivetrain having a combustion engine (12) supplied with fuel by injectors following control of an accelerator interface (48) arranged to be actuated by a driver (49) of the vehicle, a gearbox (30) and a clutch (40) interposed between said engine (12) and said gearbox (30) for coupling or decoupling thereof, comprising an injector resetting process comprising firstly a deceleration control step, during which it is verified that the vehicle (10) is in the deceleration phase by checking that the accelerator interface (48) is released by the driver, and secondly a step of injecting a supposed quantity of fuel then a step of controlling the reaction of the engine (12) with said supposed quantity of fuel, characterized in that the injector resetting process comprises, after the step of co deceleration control and prior to the injection step of the supposed amount of fuel, a closing clutch control step (40) for coupling the engine (12) and the gearbox (30) prior to the control of the engine reaction. 2. Method according to the preceding claim, characterized in that the closing clutch control step (40) is an inhibition of clutch opening in the energy recovery phase for a hybrid vehicle (10) having an auxiliary motor (16) in addition to the heat engine (12), this auxiliary motor can be in energy recovery when the vehicle is in the deceleration phase. 3. Method according to any one of the preceding claims, characterized in that, after the step of injecting the supposed quantity of fuel, the step of controlling the reaction of the engine (12) to said supposed quantity of fuel comprises a step of measuring the torque supplied by this motor and a step of determining the motor torque deviation with respect to the nominal torque corresponding to said supposed quantity of fuel and then, following said gap, an injection calibration correction step. 4. A traction chain vehicle comprising a heat engine (12) supplied with fuel by injectors following the action of a fuel supply control device (22) connected to an accelerator interface (48) provided for be actuated by a vehicle driver, a gearbox (30) and a clutch (40) interposed between said engine and said gearbox so as to couple or decouple them with the action of a clutch control device (42), the fuel supply control device (22) being adapted to control an injector resetting process in a control method according to any of the preceding claims.