Control of detections of the sliding state of a coupling device between combustion and electric prime movers of a vehicle

Abstract

The invention relates to a control method implemented in a vehicle, comprising first and second prime movers – combustion and electric, respectively – able to be coupled via a coupling device having sliding and closed states, the first prime mover being operated under speed control or torque control depending on whether the coupling device is detected in the sliding or closed state; also having a learning strategy that consists in causing a selected sliding of the coupling device, during a torque transmission between the first and second prime movers, to estimate a torque actually transmitted by the coupling device. This method comprises a step (10-20) wherein, during the learning strategy, the sliding state of the coupling device is prevented from being detected so that the first prime mover continues to be operated under torque control.

Description

DESCRIPTION TITLE: CONTROL OF DETECTIONS OF THE SLIDING STATE OF A COUPLING DEVICE BETWEEN THERMICAL AND ELECTRIC DRIVE ENGINES OF A VEHICLE The present invention claims priority from French application No. 2401078 filed on 05.02.2024, the content of which (text, drawings and claims) is incorporated herein by reference. Technical field of the invention

[0001] The invention relates to vehicles comprising a powertrain (or GMP) comprising first and second thermal and electric motors respectively and capable of being coupled via a coupling device, and more precisely the control of the detections of the sliding state of such a coupling device. State of the art

[0002] Some vehicles, possibly of the automobile type, comprise a powertrain (or GMP) comprising first and second thermal and electric driving machines respectively and capable of being coupled via a coupling device having sliding and closed states (such as for example a clutch). It will be noted that in such a GMP the output of the second (electric) driving machine is generally coupled to a gearbox, possibly with a double clutch (or DCT (“Dual-Clutch Transmission”)).

[0003] In the GMPs presented above, the first prime mover is controlled in speed or torque depending on whether the coupling device is detected in its sliding state or its closed state. For example, the detection of the sliding state of the coupling device may result from the fact that the torsion angle measured in the latter is greater than a chosen threshold.

[0004] In order for their coupling device to be controlled precisely, the GMPs presented above may have a learning strategy (sometimes called "Micro Slip Learning" (or MSL)) which consists of causing a chosen slip of the coupling device, during a torque transmission between the first and second prime movers, to estimate a torque actually transmitted by the coupling device. This learning strategy, which is triggered frequently (for example every 10 km), is intended to recalibrate any dispersion.

[0005] When activating the learning strategy in a vehicle rolling phase, the slip caused at the coupling device is detected and therefore the latter is now considered to be in its sliding state, which results in a change in the control mode of the first (thermal) prime mover. Indeed, we move from torque control (to ensure torque regulation) to speed control (to ensure speed regulation). This can cause acoustic discomfort when the speed regulation phase is interrupted, and / or longitudinal discomfort of the vehicle during state transitions of the coupling device (shocks).

[0006] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0007] For this purpose, it proposes in particular a control method intended to be implemented in a vehicle comprising a powertrain (or GMP), on the one hand, comprising first and second respectively thermal and electric motors and capable of being coupled via a coupling device having sliding and closed states, the first motor being controlled in speed or in torque depending on whether the coupling device is detected in the sliding or closed state, and, on the other hand, having a learning strategy consisting of causing a chosen slip of the coupling device, during a transmission of torque between the first and second motors, to estimate a torque actually transmitted by the coupling device.

[0008] This control method is characterized by the fact that it includes a step in which, during the learning strategy, any detection of the sliding state of the coupling device is prevented so that the control of the first driving machine remains in torque.

[0009] Thus, during a learning strategy the coupling device cannot be considered to be in its sliding state, and therefore the first driving machine remains driven in torque to ensure its torque regulation, which makes it possible to avoid acoustic inconvenience or longitudinal inconvenience of the vehicle.

[0010] For example, in the method step, when the detection of the sliding state results from a torsion angle, measured in the coupling device, greater than a first chosen threshold, any detection of the sliding state of the coupling device can be prevented by imposing during the learning strategy a second chosen threshold, strictly greater than the first threshold, in place of the latter. In this case, in the method step, the second threshold can, for example, be between 120% of the first threshold and 200% of the first threshold.

[0011] The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing a control method of the type presented above, in a vehicle comprising a powertrain (or GMP), on the one hand, comprising first and second respectively thermal and electric prime movers and capable of being coupled via a coupling device having sliding and closed states, the first prime mover being controlled in speed or in torque depending on whether the coupling device is detected in the sliding or closed state, and, on the other hand, having a learning strategy consisting of causing a chosen slip of the coupling device, during a transmission of torque between the first and second prime movers, to estimate a torque actually transmitted by the coupling device,to control the detections of the sliding state of the coupling device.,

[0012] The invention also proposes a control device intended to equip a vehicle comprising a powertrain (or GMP), on the one hand, comprising first and second thermal and electric prime movers respectively and capable of being coupled via a coupling device having sliding and closed states, the first prime mover being controlled in speed or in torque depending on whether the coupling device is detected in the sliding or closed state, and, on the other hand, having a learning strategy consisting of causing a chosen slip of the coupling device, during a transmission of torque between the first and second prime movers, to estimate a torque actually transmitted by the coupling device.

[0013] This control device is characterized by the fact that it comprises at least one processor and at least one memory arranged to carry out the operations consisting, during the learning strategy, in triggering a prevention of any detection of the sliding state of the coupling device so that the control of the first motor machine remains in torque.

[0014] The invention also proposes a vehicle, possibly of the automobile type, and comprising a control device of the type presented above and a powertrain (or GMP), on the one hand, comprising first and second thermal and electric prime movers respectively and capable of being coupled via a coupling device having sliding and closed states, the first prime mover being controlled in speed or in torque depending on whether the coupling device is detected in the sliding or closed state, and, on the other hand, having a learning strategy consisting of causing a chosen slip of the coupling device, during a transmission of torque between the first and second prime movers, to estimate a torque actually transmitted by the coupling device.

[0015] For example, the powertrain may also include a gearbox coupled to an output of the second driving machine, and possibly with a double clutch. Brief description of the figures

[0016] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0017] [Fig. 1] schematically and functionally illustrates an exemplary embodiment of a vehicle comprising a control device according to the invention and a GMP transmission chain comprising first and second motor machines, respectively thermal and electric and coupled via a coupling device, and associated with a supervision computer,

[0018] [Fig. 2] schematically and functionally illustrates an exemplary embodiment of a supervision computer comprising an exemplary embodiment of a control device according to the invention, and

[0019] [Fig. 3] schematically illustrates an example of an algorithm implementing a control method according to the invention. Detailed description of the invention

[0020] The invention aims in particular to propose a control method, and an associated control device DC2, intended to allow control of the detections of the sliding state of a coupling device DC1 ensuring the coupling / decoupling between first MM1 and second MM2 respectively thermal and electric motor machines and forming part of a powertrain (or GMP) equipping a vehicle V and having an AMG type learning strategy.

[0021] In the following, it is considered, by way of non-limiting example, that the vehicle V is of the automobile type. It is for example a car, as illustrated in Figure 1. But the invention is not limited to this type of vehicle. It relates in fact to any type of vehicle comprising a GMP transmission chain comprising first and second motor machines, respectively thermal and electric and capable of being coupled via a coupling device, and having an AMG type learning strategy. Thus, it relates to land vehicles (utility vehicles, camper vans, minibuses, coaches, trucks, motorcycles, construction machinery) roads, construction machinery, agricultural machinery, and trains, for example), aircraft and boats.

[0022] Figure 1 schematically shows a vehicle V comprising a DC2 control device according to the invention, a GMP transmission chain comprising a first thermal motor MM1 and a second electric motor MM2, coupled via a DC1 coupling device, a supervision computer CS, and a main (or “traction” or “power”) battery BP.

[0023] As shown, the drive train also includes, here, an AM drive shaft, a BV gearbox, and an AT drive shaft.

[0024] The operation of the transmission chain (and therefore of the GMP) is supervised by a CS supervision computer.

[0025] The first (thermal) prime mover MM1 comprises a crankshaft (not shown) which is fixedly secured to the engine shaft AM in order to drive the latter (AM) in rotation. This first prime mover MM1 is capable of operating according to a first speed to provide a first torque, which is a function of a first torque setpoint, for example determined by the supervision computer CS, for at least one train T1 of drive wheels of the vehicle V.

[0026] For example and as illustrated non-limitingly in Figure 1, the train T1 can be located in the front part PW of the vehicle V. It is preferably, and as illustrated, coupled to the transmission shaft AT via a differential (here front) DV. But in a variant this train T1 could be that referenced T2 which is located in the rear part PRV of the vehicle V.

[0027] It should be noted that the control of the operation of the first driving machine MM1 is ensured by a first machine calculator CM1.

[0028] The second (electric) prime mover MM2 is capable, when supplied with electrical energy by the main battery BP, of operating at a second speed to provide for at least the train T 1 a second torque defined by a second torque setpoint, for example determined by the supervision computer CS.

[0029] For example, the main battery (or power or traction battery) BP can be of the cellular type. In this case, it includes electrical energy storage cells, possibly electrochemical (such as lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd cells). Also, for example, this main battery BP can be of the 450 V type. But this is not an obligation. Indeed, it could alternatively be of the 48 V or 600 V type, for example.

[0030] The first prime mover MM1 can be coupled to / decoupled from this second prime mover MM2 by the coupling device DC1 which can be placed in an open state (for total decoupling), a sliding state (for partial coupling), and a closed state (for total coupling). For example, this coupling device DC1 can be a hydraulic circuit clutch. But it could be of another type.

[0031] This first driving machine MM1 is controlled in speed or in torque by the second machine computer CM2 depending on whether the coupling device DC1 is detected in its sliding state or its closed state. For example, the detection of the sliding state of the coupling device DC1 may result from the fact that the torsion angle measured in the latter (DC1) is greater than a first chosen threshold s1.

[0032] Furthermore, the second driving machine MM2 is coupled to the main input shaft APP of the gearbox BV to transmit to it its second torque and / or a third torque delivered by the coupling device DC1 when it is in its sliding or closed state and depending on the first torque delivered by the first driving machine MM1. In this type of GMP, the second driving machine MM2 is therefore physically interposed between the coupling device DC1 and the gearbox BV.

[0033] The gearbox BV may, for example, be a dual-clutch (or DCT) gearbox, as illustrated non-limitingly in Figure 1. In this case, it comprises first APS1 and second APS2 secondary primary shafts, first E1 and second E2 clutches, and first SP1 and second SP2 sub-parts dedicated respectively to first and second sub- sets of ratios (e.g. 1, 3 and 5, and 2, 4, 6 and possibly 7).

[0034] The first APS1 and second APS2 secondary primary shafts are rotated by the main primary shaft APP and are coupled respectively to the first E1 and second E2 clutches in order to transfer to them the torque they receive from the main primary shaft APP coming from the GMP.

[0035] It should be noted that the BV gearbox could be of a different type than a double clutch.

[0036] In order for the DC1 coupling device to be controlled precisely, the GMP also has an AMG (Micro Slip Learning) type learning strategy consisting of causing a chosen slip of the DC1 coupling device, during a torque transmission between the first MM1 and second MM2 driving machines, to estimate the third torque actually transmitted by the DC1 coupling device. For example, this learning strategy can be triggered (or activated) every 10 km, for example on the order of the CS supervision computer.

[0037] The vehicle V also includes here an accelerator pedal PA (or similar) which allows the driver to signal his desire to accelerate, which then serves to define a torque request (driver).

[0038] As mentioned above, the invention notably proposes a control method intended to enable the control of the detections of the sliding state of the coupling device DC1.

[0039] This (control) method can be implemented at least partially by the control device DC2 (illustrated at least partially in Figures 1 and 2) which comprises for this purpose at least one processor PR1, for example a digital signal processor (or DSP), and at least one memory MD. This control device DC2 can therefore be implemented in the form of a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software"). For example, it can be a microcontroller.

[0040] The MD memory is RAM in order to store instructions for the implementation by the processor PR1 of at least part of the control method. The processor PR1 may comprise integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. An integrated (or printed) circuit is understood to mean any type of device capable of carrying out at least one electrical or electronic operation.

[0041] In the example illustrated non-limitingly in Figures 1 and 2, the control device DC2 is part of the supervision computer CS. But this is not obligatory. Indeed, the control device DC2 could include its own dedicated computer, which can then be coupled to the supervision computer CS, or could be part of another computer on board the vehicle V and providing at least one other function, such as for example the first machine computer CM1.

[0042] As illustrated non-limitingly in Figure 3, the (control) method, according to the invention, comprises a step 10-20 which is implemented each time the GMP of the vehicle V is in operation and therefore provides torque to the main input shaft APP of the gearbox BV.

[0043] Step 10-20 of the method comprises a sub-step 10 in which, during the learning strategy (and therefore as soon as the latter begins), any detection of the sliding state of the coupling device DC1 is prevented (for example the control device DC2 triggers the prevention of) so that the control of the first motor machine MM1 remains in torque, and therefore that it (DC1) continues to be subject to torque regulation by the first machine computer CM1.

[0044] Thanks to the invention, when activating the learning strategy in a rolling phase of the vehicle V, the slip caused at the coupling device DC1 can no longer be detected due to the second threshold s2 temporarily used. As a result, the coupling device DC1 is not considered to be in its sliding state, which prevents the change in the control mode of the first driving machine MM1 (it remains in fact controlled in torque by the first machine computer CM1 to ensure its torque regulation). There is therefore no longer any risk of acoustic or longitudinal discomfort of the vehicle V during state transitions of the coupling device DC1, since there is no interruption of the torque regulation phase.

[0045] For example, in sub-step 10 of step 10-20, when the detection of the sliding state results from a twist angle (measured in the coupling device DC1) greater than the first threshold s1 chosen, it is possible to prevent (for example the control device DC2 can trigger the prevention of) any detection of the sliding state of the coupling device DC1 by imposing during the learning strategy a second threshold s2 chosen, strictly greater than this first threshold s1, in place of the latter (s1). It will be understood that the replacement of the first threshold s1 by the second threshold s2 is carried out at the very beginning of sub-step 10, as soon as the control device DC2 has been informed of the imminent launch of the learning strategy.

[0046] Also for example, in step 10-20 the second threshold s2 can be between 120% of the first threshold s1 and 200% of the first threshold s1 (i.e. s2 between 1,2*s1 and 2*s1). As an illustrative example this second threshold s2 can be equal to 150% of the first threshold s1. But other values of second threshold s2 can be used. For example, this second threshold s2 can be chosen during the development or testing phase of a vehicle similar to vehicle V.

[0047] Also for example, and as illustrated non-limitingly in Figure 3, step 10-20 of the method can also comprise a sub-step 20 in which, as soon as the end of the learning strategy is signaled, one (for example the control device DC2) authorizes the immediate reuse of the first threshold s1.

[0048] It will be noted that as a variant, instead of replacing the first threshold s1 with the second threshold s2 at the very beginning of sub-step 10, it would be possible to temporarily prohibit the detection of the sliding state of the coupling device DC1 or the taking into account of the detected sliding state as soon as one has been informed of the imminent launch of the learning strategy.

[0049] It will also be noted, as illustrated non-limitingly in Figure 2, that the supervision computer CS (or the computer of the control device DC2) may also comprise a mass memory MME, in particular for storing the information signaling that a learning strategy is going to start, as well as any intermediate data involved in all its calculations and processing. Furthermore, this supervision computer CS (or the computer of the control device DC2) may also comprise an input interface IE for receiving the information signaling that a learning strategy is going to start, to use it in calculations or processing, possibly after having shaped and / or demodulated and / or amplified it, in a manner known per se, by means of a digital signal processor PR2.In addition, this supervision calculator CS (or the calculator of the control device DC2) can also comprise an output interface IS, in particular to deliver each message intended to prevent any detection of the sliding state of the coupling device DC1 during the learning strategy (for example by requiring the replacement of the first threshold s1 by the second threshold s2), and each possible message intended to allow the detection of the sliding state of the coupling device DC1 again after the learning strategy (for example by authorizing the use of the first s1 again).

[0050] It will also be noted that the invention also proposes a computer program product (or computer program) comprising a set of instructions which, when executed by processing means of the electronic circuit (or hardware) type, such as for example the processor PR1, is capable of implementing the control method described above to control the detections of the sliding state of the coupling device DC1 in the vehicle V.

Claims

CLAIMS

1. Control method for a vehicle (V) comprising a powertrain i) comprising first (MM1) and second (MM2) thermal and electric prime movers respectively and suitable for being coupled via a coupling device (DC1) having sliding and closed states, said first prime mover (MM1) being controlled in speed or in torque depending on whether said coupling device (DC1) is detected in the sliding or closed state, and ii) having a learning strategy consisting of causing a chosen slip of said coupling device (DC1), during a transmission of torque between said first (MM1) and second (MM2) prime movers, to estimate a torque actually transmitted by said coupling device (DC1), characterized in that it comprises a step (10-20) in which, during said learning strategy,any detection of the sliding state of said coupling device (DC1) is prevented so that said control of the first driving machine (MM1) remains in torque.

2. Method according to claim 1, characterized in that in said step (10-20), when said detection of the sliding state results from a torsion angle, measured in said coupling device (DC1), greater than a first chosen threshold, any detection of the sliding state of said coupling device (DC1) is prevented by imposing during said learning strategy a second chosen threshold, strictly greater than said first threshold, in place of the latter.

3. Method according to claim 2, characterized in that in said step (10-20) said second threshold is between 120% of said first threshold and 200% of said first threshold.

4. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the control method according to one of claims 1 to 3, in a vehicle (V) comprising a powertrain i) comprising first (MM1) and second (MM2) thermal and electric motors respectively and capable of being coupled via a coupling device (DC1) having sliding and closed states, said first driving machine (MM1) being controlled in speed or in torque depending on whether said coupling device (DC1) is detected in the sliding or closed state, and ii) having a learning strategy consisting of causing a chosen sliding of said coupling device (DC1), during a transmission of torque between said first (MM1) and second (MM2) driving machines, to estimate a torque actually transmitted by said coupling device (DC1), to control the detections of the sliding state of said coupling device (DC1).

5. Control device (DC2) for a vehicle (V) comprising a powertrain i) comprising first (MM1) and second (MM2) thermal and electric prime movers respectively and suitable for being coupled via a coupling device (DC1) having sliding and closed states, said first prime mover (MM1) being controlled in speed or in torque depending on whether said coupling device (DC1) is detected in the sliding or closed state, and ii) having a learning strategy consisting of causing a chosen slip of said coupling device (DC1), during a transmission of torque between said first (MM1) and second (MM2) prime movers, to estimate a torque actually transmitted by said coupling device (DC1), characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to carry out the operations consisting, during said learning strategy,to trigger a prevention of any detection of the sliding state of said coupling device (DC1) so that said control of the first driving machine (MM1) remains in torque.,

6. Vehicle (V) comprising a powertrain i) comprising first (MM1) and second (MM2) thermal and electric prime movers respectively and suitable for being coupled via a coupling device (DC1) having sliding and closed states, said first prime mover (MM1) being controlled in speed or in torque depending on whether said coupling device (DC1) is detected in the sliding or closed state, and ii) having a learning strategy consisting of causing a chosen slip of said coupling device (DC1), during a transmission of torque between said first (MM1) and second (MM2) prime movers motors, to estimate a torque actually transmitted by said coupling device (DC1), characterized in that it further comprises a control device (DC2) according to claim 5.

7. Vehicle according to claim 6, characterized in that said powertrain comprises a gearbox (BV) coupled to an output of said second prime mover (MM2).

8. Vehicle according to claim 7, characterized in that said gearbox (BV) is a double clutch gearbox.

9. Vehicle according to one of claims 6 to 8, characterized in that it is of the automobile type.

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