CONTROL OF SLIDING STATE DETECTORS OF A VEHICLE'S THERMAL AND ELECTRICAL ENGINE COUPLING DEVICE

Abstract

A control method is implemented in a vehicle, on the one hand, comprising first and second drive machines, respectively thermal and electric, designed to be coupled via a coupling device having slipping and closed states. The first drive machine is controlled in terms of speed or torque depending on whether the coupling device is detected in the slipping or closed state. On the other hand, the method employs a learning strategy consisting of inducing a chosen slip of the coupling device during torque transmission between the first and second drive machines in order to estimate the torque actually transmitted by the coupling device. This method includes a step (10-20) in which, during the learning strategy, any detection of the slipping state of the coupling device is prevented so that the first drive machine remains controlled in torque mode. Figure 3

Description

Title of the invention: CONTROL OF SLIDING STATE DETECTIONS OF A COUPLING DEVICE BETWEEN THE THERMAL AND ELECTRICAL ENGINES OF A VEHICLE Technical field of the invention

[0001] The invention relates to vehicles comprising a powertrain (or PMT) comprising first and second drive machines respectively thermal and electric and suitable for being coupled via a coupling device, and more specifically the control of the detections of the sliding state of such a coupling device. State of the art

[0002] Certain vehicles, possibly of the automobile type, comprise a powertrain (or PWM) including first and second drive machines, respectively thermal and electric, designed to be coupled via a coupling device having sliding and closed states (such as, for example, a clutch). It should be noted that in such a PWM, the output of the second (electric) drive machine is generally coupled to a gearbox, possibly a dual-clutch (or DCT) gearbox.

[0003] In the powertrains described above, the first drive machine is controlled by speed or torque depending on whether the coupling device is detected in its sliding or 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 precisely controlled, the powertrains described above may employ a learning strategy (sometimes called "Micro Slip Learning" (or MSL)) which consists of inducing a selected slip of the coupling device during torque transmission between the first and second drive machines, in order to estimate the torque actually transmitted by the coupling device. This learning strategy, which is triggered frequently (for example, every 10 km), is intended to correct any deviation.

[0005] When the learning strategy is activated during vehicle operation, the slip induced at the coupling device is detected, and therefore the latter is considered to be in its sliding state, which leads to a change in the control mode of the first (thermal) engine. Indeed, it switches from torque control (to ensure regulation of torque) to a speed control (to ensure speed regulation). This can induce an acoustic annoyance when the speed regulation phase is interrupted, and / or longitudinal annoyances of the vehicle during the state transitions of the coupling device (shocks).

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

[0007] In particular, it proposes for this purpose a control method intended to be implemented in a vehicle comprising a powertrain (or PMT), on the one hand, having first and second drive machines respectively thermal and electric and suitable for being coupled via a coupling device having sliding and closed states, the first drive machine being controlled in speed or 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 torque transmission between the first and second drive machines, in order 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 by torque to ensure its torque regulation, which makes it possible to avoid an acoustic annoyance or a longitudinal annoyance of the vehicle.

[0010] For example, in the process step, when the detection of the sliding state results from a torsion angle, measured in the coupling device, exceeding 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 process step, the second threshold can, for example, be between 120% 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 suitable for implementing a control method of the type presented above, in a vehicle comprising a powertrain (or PWM), on the one hand, comprising first and second drive machines respectively thermal and electric and suitable for being coupled via a coupling device having sliding and closed states, the first driving machine being controlled in speed or 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 torque transmission between the first and second driving machines, in order to estimate a torque actually transmitted by the coupling device, in order 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 PWM), on the one hand, having first and second drive machines respectively thermal and electric and suitable for being coupled via a coupling device having sliding and closed states, the first drive machine being controlled in speed or 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 torque transmission between the first and second drive machines, in order to estimate a torque actually transmitted by the coupling device.

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

[0014] The invention also proposes a vehicle, possibly of the automobile type, comprising a control device of the type presented above and a powertrain (or PMT), on the one hand, comprising first and second drive machines respectively thermal and electric and suitable for being coupled via a coupling device having sliding and closed states, the first drive machine being controlled in speed or 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 torque transmission between the first and second drive machines, in order 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 drive machine, and possibly a dual clutch. Brief description of the figures

[0016] Other features and advantages of the invention will become apparent upon examination of the detailed description below, and attached drawings, on which:

[0017] [Fig.1] schematically and functionally illustrates an example of an embodiment of a vehicle comprising a control device according to the invention and a powertrain comprising first and second drive machines, respectively thermal and electric and coupled via a coupling device, and associated with a supervisory computer,

[0018] [Fig.2] schematically and functionally illustrates an example of an embodiment of a supervisory computer comprising an example of an 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 DC2 control device, intended to allow control of the detections of the sliding state of a DC1 coupling device ensuring the coupling / decoupling between first MM1 and second MM2 drive machines respectively thermal and electric and forming part of a powertrain (or GMP) equipping a vehicle V and having an AMG type learning strategy.

[0021] In what follows, vehicle V is considered, by way of non-limiting example, to be an automobile. For example, it is a car, as illustrated in [Fig. 1]. However, the invention is not limited to this type of vehicle. It relates to any type of vehicle comprising a powertrain with a drive unit having first and second drive machines, respectively thermal and electric, suitable for coupling via a coupling device, and having an AMG-type learning strategy. Thus, it relates to land vehicles (commercial vehicles, motorhomes, minibuses, coaches, trucks, motorcycles, road maintenance vehicles, construction equipment, agricultural machinery, and trains, for example), aircraft, and boats.

[0022] A vehicle V comprising a DC2 control device according to the invention, a GMP transmission chain comprising a first thermal drive machine MM1 and a second electric drive machine MM2, coupled via a DC1 coupling device, a CS supervisory computer, and a main (or "traction" or "power") battery BP, is schematically represented in [Fig.1].

[0023] As illustrated, the transmission chain also includes, here, an AM drive shaft, a BV gearbox, and an AT transmission shaft.

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

[0025] The first (thermal) drive machine MM1 comprises a crankshaft (not shown) which is fixedly attached to the drive shaft AM in order to drive the latter (AM) in rotation. This first drive machine MM1 is designed to operate at a first speed to provide a first torque, which is a function of a first torque setpoint, for example determined by the CS supervisory computer, for at least one set Tl of drive wheels of the vehicle V.

[0026] For example, and as illustrated but not limited to [Fig. 1], the axle T1 can be located in the front PVV section of the vehicle V. It is preferably, and as illustrated, coupled to the AT driveshaft via a differential (here, the front one) DV. However, in an alternative, this axle T1 could be the one referenced as T2, which is located in the rear PRV section 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 computer CM1.

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

[0029] For example, the main (or power or traction) battery BP can be of the cellular type. In this case, it comprises 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. However, this is not mandatory. It could alternatively be of the 48 V or 600 V type, for example.

[0030] The first drive machine MM1 can be coupled to / decoupled from this second drive machine MM2 by the coupling device DC1, which can be 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 could be a hydraulic clutch. But it could be of another type.

[0031] This first drive machine MM1 is controlled in terms of speed or torque by the second machine computer CM2 depending on whether the coupling device DC1 is detected in its sliding or 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 threshold, if chosen.

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

[0033] The gearbox can, for example, be a dual-clutch (or DCT) gearbox, as illustrated non-limitingly in [Fig. 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 subsets of ratios (for example 1, 3 and 5, and 2, 4, 6 and possibly 7).

[0034] The first APS1 and second APS2 secondary primary shafts are driven in rotation 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 which they receive from the main primary shaft APP from the GMP.

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

[0036] In order for the DC1 coupling device to be precisely controlled, the powertrain also has an AMG (Micro Slip Learning) type learning strategy consisting of inducing a chosen slip of the DC1 coupling device during a torque transmission between the first MM1 and second MM2 drive machines, in order 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 supervisory 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 demand (driver).

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

[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 for this purpose comprises at least one PR1 processor, for example a digital signal processor (or DSP), and at least one MD memory. This control device DC2 can therefore be implemented as a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software"). For example, it could be a microcontroller.

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

[0041] In the example illustrated, but not limited to, Figures 1 and 2, the DC2 control device is part of the CS supervisory computer. However, this is not mandatory. Indeed, the DC2 control device could comprise its own dedicated computer, which could then be coupled to the CS supervisory computer, or it could be part of another computer embedded in the vehicle V and performing at least one other function, such as, for example, the first machine computer CM1.

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

[0043] Step 10-20 of the process includes a substep 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 driving of the first driving 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 the learning strategy is activated during a vehicle V driving phase, the slip induced at the level of the coupling device DC1 can no longer be detected due to the second threshold s2 being temporarily used. As a result, the coupling device DC1 is not considered to be in its slipping state, which prevents the change in the control mode of the first drive machine MM1 (it remains torque-controlled by the first machine computer CM1 to ensure its torque regulation). Therefore, there is no longer any risk of acoustic or longitudinal disturbance of the vehicle V during the state transitions of the coupling device DC1, since there is no interruption of the torque regulation phase.

[0045] For example, in substep 10 of step 10-20, when the detection of the sliding state results from a torsion angle (measured in the coupling device DC1) greater than the first threshold (if chosen), any detection of the sliding state of the coupling device DC1 can be prevented (for example, the control device DC2 can trigger the prevention of) by imposing, during the learning strategy, a second threshold s2, chosen strictly greater than this first threshold (if), instead of the latter (if). 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 substep 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 si and 200% of the first threshold si (i.e., s2 between l,2*sl and 2*sl). As an illustrative example, this second threshold s2 can be equal to 150% of the first threshold si. But other values ​​for the 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 [Fig.3], step 10-20 of the process may also include a substep 20 in which, as soon as the end of the learning strategy is signaled, one (for example the control device DC2) allows the immediate reuse of the first threshold if.

[0048] It should be noted that, alternatively, instead of replacing the first threshold si with the second threshold s2 at the very beginning of substep 10, it would be possible to temporarily prohibit the detection of the sliding state of the coupling device DC1 or the consideration of the detected sliding state as soon as one has been informed of the imminent launch of the learning strategy.

[0049] It should also be noted, as illustrated but not limited to [Fig. 2], that the CS supervisory computer (or the DC2 control device computer) may also include a mass memory MME, in particular for storing information indicating that a learning strategy is about to begin, as well as any intermediate data involved in all its calculations and processing. Furthermore, this CS supervisory computer (or the DC2 control device computer) may also include an IE input interface for receiving information indicating that a learning strategy is about to begin, for use in calculations or processing, possibly after having been shaped and / or demodulated and / or amplified, in a manner known per se, by means of a PR2 digital signal processor.Furthermore, this CS supervisory computer (or the DC2 control device computer) may also include an IS output interface, in particular to deliver each message intended to prevent any detection of the sliding state of the DC1 coupling device during the learning strategy (for example by requesting the replacement of the first threshold si by the second threshold s2), and each possible message intended to allow the detection of the sliding state of the DC1 coupling device again after the learning strategy (for example by allowing the use of the first si again).

[0050] It should 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 such as electronic circuits (or hardware), such as the PR1 processor, is suitable for implementing the control method described above for controlling the detections of the sliding state of the DC1 coupling device in vehicle V.

Claims

Demands

1. A control method for a vehicle (V) comprising a powertrain i) having first (MM1) and second (MM2) drive machines, respectively thermal and electric, adapted to be coupled via a coupling device (DC1) having sliding and closed states, said first drive machine (MM1) being driven in speed or torque depending on whether said coupling device (DC1) is detected in the sliding or closed state, and ii) having a learning strategy consisting of inducing a chosen slip of said coupling device (DC1) during a torque transmission between said first (MM1) and second (MM2) drive machines, in order 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,We prevent any detection of the sliding state of said coupling device (DC1) 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. Product: A computer program comprising a set of instructions which, when executed by processing means, is suitable for implementing the control method according to any one of claims 1 to 3, in a vehicle (V) comprising a powertrain i) having first (MM1) and second (MM2) thermal and electric drive machines respectively, suitable for being coupled via a coupling device (DC1) having sliding and closed states, said first drive machine (MM1) being driven in speed or torque depending on whether said coupling device (DC1) is detected in the sliding or closed state, and ii) having a learning strategy consisting of inducing a chosen slip of said coupling device (DC1), during a torque transmission between said first (MM1) and second (MM2) drive 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. A control device (DC2) for a vehicle (V) comprising a powertrain i) having first (MM1) and second (MM2) drive machines, respectively thermal and electric, adapted to be coupled via a coupling device (DC1) having sliding and closed states, said first drive machine (MM1) being driven in speed or torque depending on whether said coupling device (DC1) is detected in the sliding or closed state, and ii) having a learning strategy consisting of inducing a chosen slip of said coupling device (DC1), during a torque transmission between said first (MM1) and second (MM2) drive machines, in order 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 perform 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) having first (MM1) and second (MM2) drive machines, respectively thermal and electric, adapted to be coupled via a coupling device (DC1) having sliding and closed states, said first drive machine (MM1) being driven in speed or torque depending on whether said coupling device (DC1) is detected in the sliding or closed state, and ii) having a learning strategy consisting of inducing a chosen slip of said coupling device (DC1), during a torque transmission between said first (MM1) and second (MM2) drive machines, 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 drive machine (MM2).

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

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

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