Engine control method adapted to a hybrid architecture with drive by the electric motor alone

Abstract

A control method implemented in a computer (70) of a motor vehicle, said vehicle comprising both an electric motor (40) and an internal combustion engine (10), the electric motor (40) being powered by at least one battery (30) and configured to drive the wheels (50) of the motor vehicle, and the internal combustion engine (10) being decoupled from the wheels (50) of the motor vehicle and configured to drive an electric generator (20) which powers said battery (30), the method comprising the following steps: - receiving a synchronization error detection signal (Err), and detecting an operating mode of the internal combustion engine (10); - if it is confirmed that the internal combustion engine (10) is in a reduced operating mode, starting a time counter;- when the time counter has reached a predetermined time threshold (Thd1), generation of a synthetic command (C) for resetting the fault status, intended to reset, to a state signaling an absence of fault, a fault status of each of the at least one associated angular position sensor. Figure for the abstract: Figure 5.;

Description

Title of the invention: Motor control method adapted to a hybrid architecture with drive by the electric motor alone Technical field

[0001] The invention relates to the automotive field and more particularly to a method and a device for engine control adapted to a hybrid architecture with drive by the electric motor alone. State of the art

[0002] So-called hybrid motor vehicles are known in the prior art, i.e. motor vehicles equipped with an electric motor and a thermal combustion engine, both of which participate directly or indirectly in the propulsion of the vehicle.

[0003] The invention is more particularly applicable in a hybrid architecture with drive by the electric motor alone. In such an architecture, the wheels of the vehicle are driven by the electric motor, which is powered by a battery. The internal combustion engine is decoupled from the wheels of the vehicle. On the other hand, it is configured to drive an electric generator, which powers said battery. Thus, the electric motor only participates indirectly in the propulsion of the vehicle and the driving of the wheels, via an action on the charge of the battery powering the electric motor.

[0004] In a manner known per se, in an internal combustion engine, one or more cylinders are made in an engine block and delimit with a cylinder head and pistons (one piston for each cylinder) respective combustion chambers. For each combustion carried out in the internal combustion engine, the corresponding piston is moved and rotates a crankshaft. To control the gas flows entering and leaving each combustion chamber, valves are provided each time and the opening and closing of these valves are controlled by at least one camshaft. To know the position of the pistons in the internal combustion engine, it is usual to use, on the one hand, a sensor associated with a toothed target rotating with the crankshaft, and, on the other hand, a sensor associated with a toothed target rotating with a camshaft. Knowledge of this position is essential for proper operation of the internal combustion engine.The term "engine synchronization" refers to the determination of this position. Said synchronization is implemented by an engine synchronization unit, defined in a computer which includes one or more processor(s) as well as one or more memory(s). The engine synchronization unit receives data as input. sensor from the cam sensor (sensor associated with the toothed target rotating with the camshaft) and the crankshaft sensor (sensor associated with the toothed target rotating with the crankshaft), and outputs the engine synchronization information. The engine synchronization unit preferably belongs to a computer dedicated to controlling the internal combustion engine. Said computer, called an engine control computer, comprises one or more processors as well as one or more memories. It is configured to manage the entire process of controlling the internal combustion engine based in particular on sensor data and external commands reflecting a user's wishes.

[0005] The cam sensor and the crankshaft sensor both form angular position sensors associated with the internal combustion engine. It may happen that the engine synchronization method does not make it possible to determine the desired engine position, for example because at least one of said angular sensors is defective. In this case, the engine synchronization unit generates a signal for detecting an error in the synchronization of the internal combustion engine. In the following, this is simply referred to as an error detection signal. Such a signal may also be generated when the desired position could not be successfully determined within a given time, despite having intact angular sensors. This is then referred to as a false error detection. In any event, said error detection signal indicates a possible fault on at least one angular position sensor associated with the internal combustion engine.

[0006] Each of the angular position sensors associated with the internal combustion engine corresponds to a respective parameter called fault status, which can take at least two values, or states, associated respectively with an absence of fault and a presence of fault (possible or proven) on the sensor concerned. Each of said fault statuses is stored in a memory, on board in use on the motor vehicle, for example a memory of the engine control computer.

[0007] Upon receipt of the error detection signal, the engine control computer controls an update of at least one of said fault statuses. More particularly, the engine control computer controls a switch from a state associated with an absence of fault to a state associated with a presence of fault, of the fault status of at least one of the angular position sensors associated with the internal combustion engine.

[0008] The engine control computer then controls a switch in the operating mode of the internal combustion engine, from a normal operating mode to a reduced operating mode.

[0009] Reduced engine operating mode, or "limp home" mode, refers to a restricted, or limited, or reduced operating mode in which the internal combustion engine has its maximum rotational speed limited to a value well below normal. Reduced engine operating mode is intended, in an architecture equipped only with an internal combustion engine, to allow the user to drive slowly to a nearby breakdown location.

[0010] As explained above, the error detection signal may reflect a false error detection, rather than a genuine failure of an angular position sensor. It is therefore provided to be able to reset the fault statuses and switch the combustion engine back to its normal operating mode. If it were a false error detection, engine synchronization can this time be carried out without difficulty, no error detection signal will be generated, and the internal combustion engine will remain in its normal operating mode. If it were a genuine sensor failure, a sensor failure diagnosis will be confirmed, and the internal combustion engine will again be switched to the reduced operating mode, this time until a maintenance operation is confirmed.

[0011] In a purely thermal architecture, only a restart of the internal combustion engine, using a physical key stroke performed by the driver, makes it possible to reset these fault statuses to a state indicating an absence of fault, thus allowing a new engine synchronization attempt to be made and a return to normal operating mode of the internal combustion engine. Indeed, the physical action on the key generates a transition at the level of a key signal, which in turn generates an action not only on the starter of the internal combustion engine, but also on the engine control software, including a reset of the fault statuses.

[0012] On the other hand, in a hybrid architecture as described in the introduction, the thermal combustion engine is generally started not in response to a physical action on the key and a transition at the level of a key signal, but in response to a request by a computer configured to control a start of the thermal combustion engine under certain predetermined conditions such as a high torque request at the level of the vehicle drive or a request to charge the battery. This request, or restart request, generates an action on the starter of the internal combustion engine, but not on the engine control software. Thus, said restart request is not accompanied by a reset of the fault statuses.

[0013] The invention originates from the identification of a flaw in the control of a hybrid type motorization system as described in the introduction, in which the wheels are driven by the electric motor alone.

[0014] The objective of the invention is to propose improved control of a hybrid type motorization system as described in the introduction, in which the wheels are driven by the electric motor alone. Statement of the invention

[0015] This objective is achieved with a control method implemented in a computer of a motor vehicle, said vehicle comprising both an electric motor and an internal combustion engine, the electric motor being powered by at least one battery and configured to drive the wheels of the motor vehicle, and the internal combustion engine being decoupled from the wheels of the motor vehicle and configured to drive an electric generator which powers said battery, the method comprising the following steps implemented when the wheels are driven by the electric motor: a) receiving a synchronization error detection signal, signaling a possible fault on at least one angular position sensor associated with the internal combustion engine; (b) in response to said reception, detecting an operating mode of the internal combustion engine; (c) if it is confirmed in step (b) that the internal combustion engine is in a reduced operating mode, starting a time counter; dl) detecting that the time counter has reached a predetermined time threshold; and e) when at least one predetermined condition is met, including said detection that the time counter has reached the predetermined time threshold, generating a synthetic fault status reset command, intended to reset, to a state signaling an absence of fault, a fault status of each of the at least one associated angular position sensor, said fault status being able to take a state signaling an absence of fault or a state signaling a presence of fault.

[0016] The inventors have in fact noticed that, when the internal combustion engine has been switched into the reduced operating mode, this can result in a situation in which: 1 / The internal combustion engine is switched to its reduced operating mode. It then stops recharging the battery that powers the electric motor, or performs a slow recharge. The most problematic case is of course the case where the internal combustion engine stops recharging the battery entirely. This can happen if a fault is diagnosed, rightly or wrongly, on all the angular position sensors available for engine synchronization. In this case, all the angular position sensors associated with the internal combustion engine have their respective fault status(es) which has been switched to a state indicating the presence of a fault. This can happen in a situation in which the vehicle only has a single angular sensor to perform engine synchronization. It can also occur in a case where one of the first angular sensors is faulty. defective, but nevertheless provides a noisy signal wrongly considered as an intact signal, so that it is the second of the angular sensors that is wrongly considered as defective. In this case, at the next start of the internal combustion engine (without resetting the fault statuses), the second angular sensor remains considered (wrongly) as defective, the first angular sensor is this time recognized as defective, so that ultimately all the angular sensors dedicated to engine synchronization are considered as defective, leading to the situation in which the internal combustion engine stops recharging the battery entirely. 2 / The electric motor continues to drive the vehicle's wheels, drawing power from the battery. The battery will thus gradually discharge, since recharging using the combustion engine is prevented or limited. 3 / It may then happen that the electric motor continues to drive the vehicle's wheels until the battery is completely discharged, or until it is discharged below a threshold below which the battery is insufficiently charged to allow the vehicle to be restarted after the engines have completely switched off. 4 / This then leads to a blocking situation, in which the internal combustion engine can only leave its reduced operating mode, in the prior art, by restarting the internal combustion engine. However, such a restart is made impossible by the battery being too low. In this situation, the vehicle quickly becomes blocked, since the battery charge level is insufficient to power the electric motor, and the battery cannot be recharged since the internal combustion engine is blocked in its reduced operating mode.

[0017] The invention therefore finds its origin in the identification of the possibility of such a situation.

[0018] As detailed above, the invention is particularly advantageous when a failure is diagnosed, rightly or wrongly, on the entire angular position sensor(s) available for engine synchronization. When the engine synchronization uses two angular sensors (cam sensor and crankshaft sensor), the probability of such an event is quite reduced. In certain configurations, however, the engine synchronization uses a single angular sensor. In the event of failure of this single angular sensor, the failure therefore affects the entire angular position sensor(s) available for engine synchronization. However, the probability of failure of a single sensor is obviously much higher than the probability of simultaneous failure of two independent sensors.It is therefore understood that the invention is more particularly applicable in this type of configuration, in which the motor synchronization uses a single angular sensor.

[0019] The invention is also based on the observation that, more than the request to restart the internal combustion engine, it is the resetting of the fault parameters which truly allows the return to normal operating mode.

[0020] It is thus proposed, in the invention, to count down the time elapsed from a switch in the operating mode of the internal combustion engine, from a normal operating mode to a reduced operating mode. This time countdown uses the time counter mentioned in step c).

[0021] As soon as it is detected that this elapsed time has reached a predetermined time threshold, it is proposed to generate a synthetic fault status reset command, intended to reset, to a state indicating an absence of fault, the fault status of each of the angular position sensors used for engine synchronization. This is referred to as a synthetic fault status reset command, as opposed to a so-called real reset command, generated with the restart of the internal combustion engine. In the case of a synthetic command, only the fault statuses are affected by the command.

[0022] Said predetermined time threshold is calibrated so that the synthetic command is generated early enough, and in any event before the battery charge level has reached a critical threshold below which a “manual” restart, by operating the starter, is no longer possible.

[0023] Said synthetic control is configured to control a reset, to a state signaling an absence of fault, of the failure status of each of the angular position sensors used for engine synchronization. The synthetic control is generated without action on the starter. Throughout the text, the starter designates the electric starter of the internal combustion engine.

[0024] In a purely thermal architecture (drive using the internal combustion engine alone), a physical action on the vehicle's starter key generates a transition at the level of a key signal. We can speak of a "key off / key on" command to designate this transition of the key signal. The "key off / key on" command generates a command on the starter of the internal combustion engine, called a request to restart the internal combustion engine. The request to restart the internal combustion engine is accompanied by a reset request at the level of the engine control software, including a command to reset the fault statuses. In the invention, a command to reset the fault statuses, called synthetic, is proposed.

[0025] The synthetic command is identical to the fault status reset command which is generated in response to a physical action on the vehicle's ignition key, in a purely thermal architecture. It is noted that, in the hybrid architecture according to the invention, the same "key off / key on" command is generated in the event of a physical action on the vehicle's ignition key, with the same consequences, particularly in terms of resetting the fault statuses. Consequently, the synthetic command according to the invention is also identical to the fault status reset command which is generated in response to a physical action on the vehicle's ignition key, in the hybrid architecture according to the invention. One of the differences is that said synthetic command is not generated in conjunction with an action on the starter, but in response to the detection of a certain state of the time counter.

[0026] The invention thus makes it possible to restart the thermal combustion engine. If the detection of failure on the angular position sensor(s) was a false detection, the thermal combustion engine will return to its normal operating mode and allow the battery supplying the electric motor to be efficiently recharged. This avoids ending up in the blocking situation described above.

[0027] In other words, the invention aims to avoid using the battery until it is completely discharged. The invention proposes to generate a synthetic signal allowing a return to normal operation of the internal combustion engine, after the latter has switched to reduced operating mode and before the battery level falls below a certain limit threshold.

[0028] Advantageously, the method comprises, in parallel with steps a) to e), at least one iteration of a step of issuing a request to restart the internal combustion engine, and said request results in a restart accompanied by successful synchronization of the internal combustion engine after resetting the respective fault statuses using the synthetic control. Such a restart request is preferably generated by a computer, or control unit, configured to control a start of the thermal combustion engine under certain predetermined conditions such as a high torque request at the vehicle drive or a battery charging request. This request, or restart request, generates an action on the starter of the internal combustion engine, but not on the engine control software.Thus, the said restart request is not automatically accompanied by a reset of the fault statuses.

[0029] Preferably, the synthetic fault status reset command is identical to an actual fault status reset command generated when a user manually operates a starter of the motor vehicle.

[0030] Advantageously, the method further comprises the following step, implemented after step dl): d2) detection of a current state of charge of the battery supplying the electric motor, and comparison with a predetermined charge threshold.

[0031] The at least one predetermined condition of step e) may further include determining mination that the battery state of charge is below the predetermined charge threshold.

[0032] Advantageously: the method comprises, in parallel with steps a) to e), at least one iteration of a step of transmitting a request to restart the internal combustion engine (as described above); said request results in a restart accompanied by successful synchronization of the internal combustion engine after resetting the respective fault statuses using the synthetic command; and the method further comprises a count of a number of restart requests issued from step a), the at least one predetermined condition of step e) further including the determination that the number of requests is greater than a predetermined request threshold, and the generation of the synthetic command being implemented regardless of the current state of charge of the battery.

[0033] The invention also covers a computer for a motor vehicle, configured to implement a method according to the invention.

[0034] The invention also covers a motor vehicle comprising both an electric motor and an internal combustion engine, the electric motor being powered by at least one battery and configured to drive the wheels of the motor vehicle, and the internal combustion engine being decoupled from the wheels of the motor vehicle and configured to drive an electric generator which powers said battery, said vehicle further comprising a computer according to the invention. Description of figures

[0035] Other characteristics and advantages of the invention will become apparent from reading the description which follows. This is purely illustrative and must be read in conjunction with the appended drawings in which:

[0036] [Fig-1] [Fig.l] schematically illustrates the drive system of the wheels of a motor vehicle in which the method according to the invention is implemented;

[0037] [Fig.2] [Fig.2] schematically illustrates a method according to a first embodiment of the invention;

[0038] [Fig.3] [Fig.3] schematically illustrates a method according to a second embodiment of the invention;

[0039] [Fig.4] [Fig.4] schematically illustrates a method according to a third embodiment of the invention; and

[0040] [Fig.5] [Fig.5] schematically illustrates the wheel drive system of [Fig.l], as well as a computer according to the invention.

[0041] Detailed description of at least one embodiment

[0042] [Fig.l] schematically illustrates the system 100 for driving the wheels 50 of a motor vehicle in which the method according to the invention is implemented.

[0043] The system 100 comprises an internal combustion engine 10, which rotates an electric generator 20. The electric generator 20 is configured to convert mechanical energy supplied by the internal combustion engine 10 into electrical energy.

[0044] The electric generator 20 is mounted between the internal combustion engine 10 and a battery 30, so that the electrical energy generated recharges said battery 30.

[0045] Said battery 30 is configured to power an electric motor 40, which rotates an axle comprising a transverse axis and two drive wheels 50 of the motor vehicle. It is of course understood that [Fig.l] is a schematic illustration, so that not all the details of the embodiment are necessarily illustrated. In particular, any mechanical reducers between the electric motor 40 and the axle are not illustrated.

[0046] Thus, the internal combustion engine 10 is decoupled from the axle and the wheels 50. Its role is simply to drive the electric generator 20, to contribute to recharging the battery 30 of the electric motor 40.

[0047] A method according to a first embodiment of the invention is then described with reference to [Fig.2].

[0048] The method comprises the following steps, implemented when the wheels 50 are driven by the electric motor 40, itself powered by the battery 30. The method is implemented by a processing unit defined in a computer as described below, which comprises one or more processor(s) as well as at least one memory. The computer forms, for example, an engine control computer as mentioned in the introduction.

[0049] Step El: In the first step E1, the processing unit receives a synchronization error detection signal, signaling a possible fault on at least one angular position sensor associated with the internal combustion engine 10. Such an error detection signal is provided by an engine synchronization unit of said motor vehicle, configured to determine an angular position of a shaft of the internal combustion engine using a signal provided by at least one angular position sensor as described in the introduction (cam sensor and / or crankshaft sensor). Said engine synchronization unit is configured to generate an error detection signal when the signals provided by the at least one angular position sensor do not allow it to determine, within a given time, the desired angular position. Preferably, the engine synchronization unit belongs to the control computer engine as mentioned above. In [Fig.2], this step El is represented by the diamond marked with the sign "Err?", symbolizing the question about the detection or not of a synchronization error.

[0050] In a manner known per se, upon receipt of the error detection signal, at least one fault status as described in the introduction is switched from a state signaling an absence of fault to a state signaling a presence (possible or proven) of fault. In an advantageous embodiment, the error detection signal considered concerns all of the angular position sensors dedicated to engine synchronization. Such an error detection signal results in a switch of fault status affecting all of said sensors.

[0051] Furthermore, and in the method according to the invention, when such an error detection signal is received, step E2 is implemented (see arrow marked with a “Y”). Otherwise, the processing unit remains waiting for the reception of such an error detection signal (see arrow marked with an “N”).

[0052] Step E2: Step E2 consists of detecting a current operating mode of the internal combustion engine 10. In other words, it is a matter of determining whether, in response to the detection of a synchronization error, the internal combustion engine has been switched (by the control unit of the internal combustion engine 10) from a normal operating mode to a reduced operating mode. Said switching may be linked indirectly only to the detection of a synchronization error, the synchronization error causing a switch of the fault statuses mentioned above, which then causes the change of operating mode of the internal combustion engine. In [Fig. 2], this step E2 is represented by the diamond marked with the sign "Mode?", symbolizing the interrogation on the current operating mode of the internal combustion engine 10.

[0053] When it is confirmed in step E2 that the internal combustion engine 10 is in the reduced operating mode, step E3 is implemented (see arrow marked with a “Y”). Otherwise, the processing unit remains waiting for such confirmation (see arrow marked with an “N”).

[0054] Step E3: Step E3 consists of starting a time counter Tstop, as soon as it is confirmed that the internal combustion engine 10 is in the reduced operating mode. In [Fig.2], this step E3 is represented by a rectangle marked with the sign "Tstop".

[0055] Step E4: Step E3 is then followed by a step E4 (see arrow marked with a “Y”) of detection that the time counter Tstop has reached a predetermined time threshold Thdl. In [Fig.2], this step E4 is represented by the diamond marked with the sign “Tstop > Thdl? », symbolizing the monitoring of the value taken by the meter and its comparison with the Thdl threshold to identify that said threshold has been reached.

[0056] The time threshold Thdl is advantageously between one minute and sixty minutes, more preferably between one minute and ten minutes, for example five minutes.

[0057] As soon as it is detected in step E4 that the time counter Tstop has reached the time threshold Thdl, step E5 is implemented (see arrow marked with a “Y”).

[0058] Optionally, the method further comprises the detection of a manual command to restart the internal combustion engine (the “key off / key on” command mentioned above). If such a command is detected, the time counter T stop is reset (see arrow marked with an “N” emerging from block E4). Indeed, said manual command to restart the internal combustion engine is accompanied by a reset of the fault statuses, making it unnecessary to continue implementing the method according to the invention.

[0059] Step E5: Step E5 consists of generating a synthetic command for resetting the fault statuses, configured to reset, to a state signaling the absence of a fault, the respective fault status(es) of each of the angular position sensor(s) used for engine synchronization. As explained above, this or these fault status(es) have been switched to a state signaling the presence of a fault, upon receipt of the synchronization error detection signal. In [Fig.2], this step E5 is represented by the oval marked with the sign “CS”, symbolizing the transmission of a synthetic command.

[0060] As detailed below, said synthetic command generation may be subject to the verification of additional conditions. In any event, a necessary condition for it to be generated is that the time counter Tstop has reached the time threshold Thdl. In other words, step E5 is implemented when at least one predetermined condition is met, including the detection that the time counter Tstop has reached the predetermined time threshold Thdl.

[0061] The synthetic command is sent to a control unit of the internal combustion engine, which can be defined in the same computer as the processing unit implementing the method according to the invention. This synthetic command is similar to a real command for resetting the fault statuses, generated by a computer of the motor vehicle when a user manually operates the start key of the motor vehicle. Thus, the synthetic command generated in the method according to the invention makes it possible to deceive the control unit of the internal combustion engine 10. From the point of view of the fault statuses of the angular sensors dedicated to engine synchronization, everything happens as if the motorization of the vehicle had been stopped and then restarted, while in reality during all this time the vehicle continued to be driven by the electric motor 40.

[0062] As detailed in the introduction, the method according to the invention is more particularly applicable in a situation in which: - due to a synchronization error of the thermal combustion engine 1, a failure of the entire angular position sensor(s) used for said engine synchronization was wrongly detected; - in response, the failure statuses of said sensors were switched to a state signaling the presence of a failure, and the thermal combustion engine 10 was switched to its reduced operating mode, in which it does not recharge, or does not sufficiently recharge, the battery 30.

[0063] In such a situation, it may happen that, with the vehicle continuing to run for a long period, the battery 30 discharges completely, or at least below a limit threshold below which the starter of the thermal combustion engine cannot be activated. In such a situation, the vehicle may then find itself in a blocking situation, in which the battery 30 is insufficiently charged to be able to restart the vehicle, and in which the thermal combustion engine 10 is blocked in an operating mode in which it cannot contribute to recharging said battery.

[0064] The invention makes it possible to avoid reaching this blocking situation, by ensuring that the thermal combustion engine quickly leaves its reduced operating mode when possible (i.e. when at least one failure detection on the angular sensors is a false detection).

[0065] A method according to a second embodiment of the invention is then described with reference to [Fig. 3]. The method of [Fig. 3] will only be described for its differences relative to the method of [Fig. 2].

[0066] In the method of [Fig.3], as soon as it is detected in step E4 that the time counter Tstop has reached the time threshold Thdl, a step E4' is implemented (see arrow marked with a "Y").

[0067] Step E4': Step E4' consists of detecting a state of charge of the battery 30, and comparing this state of charge with a predetermined charge threshold Thd2. In [Fig.3], this step E4' is represented by the diamond marked with the sign "SOC < Thd2?", symbolizing the monitoring of the state of charge of the battery and its comparison with the threshold Thd2 to identify that said threshold has been reached.

[0068] The charge level is expressed as a percentage, where 100% corresponds to a fully charged state of the battery 30 and 0% corresponds to a fully discharged state of the battery 30.

[0069] The time threshold Thd2 is advantageously between 10% and 50%, more preferably between 10% and 20%, for example 15%.

[0070] As soon as it is detected in step E4' that the state of charge of the battery is lower than the threshold Thd2, step E5 as described above (generation of the synthetic command) is implemented (see arrow marked with a "Y").

[0071] Thus, the generation of the synthetic command is not conditioned solely on the lapse of a predetermined duration from a switch to the reduced operating mode of the internal combustion engine. The generation of the synthetic command is further conditioned on a current state of charge of the battery 30.

[0072] In certain cases, the state of charge of the battery 30 is already below the threshold Thd2 when the time counter Tstop reaches the time threshold Thd1. In this case, step E5 is implemented immediately.

[0073] In other cases, the state of charge of the battery 30 is greater than the threshold Thd2 when the time counter Tstop reaches the time threshold Thd1. In this case, step E5 will only be implemented when the state of charge of the battery falls below the threshold Thd2.

[0074] A method according to a third embodiment of the invention is then described with reference to [Fig. 4]. The method of [Fig. 4] will only be described for its differences relative to the method of [Fig. 3].

[0075] In this embodiment, the method according to the invention further comprises at least one iteration of a step of transmitting a request to restart the internal combustion engine 10. These restart requests are transmitted in parallel with the implementation of the steps of the method according to the invention, and from the detection of a synchronization error as mentioned with reference to step EL As detailed above, such a restart request is preferably generated by a computer, or control unit, configured to control a start of the thermal combustion engine under certain predetermined conditions such as a high torque request at the level of the vehicle drive or a battery charging request.

[0076] Each restart request includes a command to activate the starter of the internal combustion engine. The engine restart request is accompanied by engine synchronization attempts. If necessary, there may be several engine synchronization attempts during a single attempt to restart the internal combustion engine. Each restart request that results in a failed restart attempt is followed by the transmission of a new restart request. As soon as a restart request results in a restart accompanied by successful synchronization of the internal combustion engine 10, these requests stop being issued (at least until the next engine shutdown or synchronization failure). Restart requests are not, by default, accompanied by a reset of the fault statuses.

[0077] For the restart request to result in a restart accompanied by successful synchronization, the failure statuses must all be in the state indicating no failure.

[0078] In the embodiment of [Fig.4], an additional step E4 is proposed.

[0079] Step E4”: The method of [Fig.4] includes an additional step E4' ' of: counting a number of restart requests RS issued from step EL In other words, we count a number of failed engine restart attempts from step El, and comparison with a request threshold Thr3 to detect when said number of requests reaches said request threshold Thr3.

[0080] In [Fig.4], this step E4'' is represented by the diamond marked with the sign "RS > Thd3?", symbolizing the monitoring of the number of requests and its comparison with the threshold Thd3 to identify that said threshold has been reached.

[0081] The counting of the number of restart requests RS is initiated at the same time as the start of the counter Tstop, and continues until a restart of the internal combustion engine has been successfully carried out. In other words, the counting uses a counter which is incremented with each failed restart and which is reset as soon as a restart succeeds. The counting is implemented in parallel with the steps of the method according to the invention.

[0082] The comparison with the request threshold Thr3 to detect when said number of requests reaches the threshold Thr3 is implemented at the end of step E4', if it is detected that the state of charge of the battery is greater than the charge threshold Thd2 (see arrow marked with an "N").

[0083] For reasons of readability of the figure, step E4'' illustrated in [Fig.4] corresponds more specifically to the comparison with the request threshold Thr3 to detect when said number of requests reaches the threshold Thr3.

[0084] When it is detected in step E4'' that the number of requests reaches the threshold Thr3, step E5 as described above (generation of the synthetic command) is implemented (see arrow marked with a "Y"). As long as this number of requests is lower than the threshold Thr3, it is the state of charge of the battery which has priority for the possible generation of a synthetic command C (see arrow marked with an "N").

[0085] Thus, step E5 is implemented as soon as a number of failed attempts to re engine start has reached a predetermined threshold value Thd3, even if the battery charge level is higher than the predetermined threshold value Thd2.

[0086] The threshold Thd3 is advantageously between 2 and 8, more preferably between 2 and 3, for example equal to 3.

[0087] [Fig.5] finally illustrates, in a schematic manner, the wheel drive system of [Fig.l], as well as a processing unit 70 defined in an engine control computer 80, configured to implement a method according to the invention.

[0088] The engine control computer 80 comprises at least one processor provided with at least one memory storing instructions which, when executed by the at least one processor, implement the method according to the invention. The processing unit 70 designates the resources (memory and processor) of the computer 80 dedicated to the implementation of the method according to the invention. The processing unit 70 comprises in particular at least one memory space storing the time threshold Thl, as well as, where appropriate, the thresholds Th2 and Thd3. The processing unit 70 also incorporates the time counter Tstop as described above. The time counter Tstop is configured to determine a quantity relating to a duration elapsed from a predetermined instant.

[0089] The processing unit 70 is configured to receive data from a control unit 60 of the internal combustion engine 10, and to provide the synthetic command C as described above.

[0090] The control unit 60 is defined in a computer which comprises at least one processor provided with at least one memory, here the engine control computer 70. Said data from the control unit 60 comprise the synchronization error detection signal, referenced “Err”, as well as information relating to the operating mode of the internal combustion engine, referenced “Mode”. Where appropriate, they may further comprise a number of failed engine restart attempts (see embodiment illustrated with reference to [Fig.4]).

[0091] In certain embodiments, the computer 80 comprises at least one input interface, configured to receive a state of charge data item, referenced SOC, relating to a current state of charge of the battery 30.

[0092] Other embodiments and variants of the invention may be implemented without departing from the scope of the invention, for example with different threshold values ​​Thd1, Thd2 and / or Thd3.

Claims

Claims

1. A control method implemented in a computer (70) of a motor vehicle, said vehicle comprising both an electric motor (40) and an internal combustion engine (10), the electric motor (40) being powered by at least one battery (30) and configured to drive the wheels (50) of the motor vehicle, and the internal combustion engine (10) being decoupled from the wheels (50) of the motor vehicle and configured to drive an electric generator (20) which powers said battery (30), the method comprising the following steps implemented when the wheels (50) are driven by the electric motor: a) reception (El) of a synchronization error detection signal (Err), signaling a possible fault on at least one angular position sensor associated with the internal combustion engine (10); b) in response to said reception, detection (E2) of an operating mode of the internal combustion engine (10);c) if it is confirmed in step b) that the internal combustion engine (10) is in a reduced operating mode, starting (E3) a time counter; dl) detecting (E4) that the time counter has reached a predetermined time threshold (Thdl); and e) when at least one predetermined condition is met, including said detecting that the time counter has reached the predetermined time threshold (Thdl), generating (E5) a synthetic fault status reset command (C), intended to reset, to a state signaling an absence of fault, a fault status of each of the at least one associated angular position sensor, said fault status being able to take a state signaling an absence of fault or a state signaling a presence of fault.;

2. Control method according to claim 1, characterized in that it comprises, in parallel with steps a) to e), at least one iteration of a step of transmitting a request to restart the internal combustion engine (10), and in that said request results in a restart accompanied by successful synchronization of the internal combustion engine (10) after resetting the respective fault statuses using the synthetic control (C).

3. Control method according to claim 1 or 2, characterized in that the synthetic fault status reset command (C) is identical to an actual fault status reset command, generated when a user manually operates a motor vehicle starter.

4. Control method according to any one of claims 1 to 3, characterized in that it further comprises the following step, implemented after step dl): d2) detection (E4') of a current state of charge (SOC) of the battery (30) supplying the electric motor (40), and comparison with a predetermined charge threshold (Thd2).

5. Control method according to claim 4, characterized in that the at least one predetermined condition of step e) further includes the determination that the state of charge of the battery is lower than the predetermined charge threshold (Thd2).

6. Control method according to claim 5, characterized in that: the method comprises, in parallel with steps a) to e), at least one iteration of a step of issuing a request to restart the internal combustion engine (10); said request results in a restart accompanied by successful synchronization of the internal combustion engine (10) after resetting the respective fault statuses using the synthetic command (C); and the method further comprises a count of a number of restart requests issued from step a), the at least one predetermined condition of step e) further including the determination that the number of requests is greater than a predetermined request threshold (Thd3), and the generation of the synthetic command (C) being implemented regardless of the current state of charge of the battery (30).

7. Computer (70) for a motor vehicle, configured to implement a method according to any one of claims 1 to 6.

8. A motor vehicle comprising both an electric motor (40) and an internal combustion engine (10), the electric motor (40) being powered by at least one battery (30) and configured to drive the wheels (50) of the motor vehicle, and the internal combustion engine (10) being decoupled from the wheels (50) of the motor vehicle and configured to drive an electric generator (20) which powers said battery (30), said vehicle further comprising a computer (70) according to claim 7. 18