METHOD FOR ACTIVATING A HYBRID POWERTRAIN WITH PARALLELIZATION OF TASK

Abstract

The invention relates to a method for activating a hybrid powertrain (10) of a motor vehicle, comprising, following detection of a request for activation of said hybrid powertrain (10) by a driver, - a step of closing electrical contactors of the traction battery (19), - a step of activating the DC / DC converter (26), - a step of diagnosing the low-voltage electrical network (27), - a step of activating the alternator-starter (20), - a step of activating the rotating electrical machine (15) of the electrical transmission device (12), and - a step of starting the internal combustion engine (11), - the step of diagnosing the low-voltage electrical network (27) and the step (109) of starting the internal combustion engine (11) being carried out at least partially simultaneously with each other. Figure 2.

Description

Title of the invention: METHOD FOR ACTIVATING A HYBRID POWERTRAIN WITH TASK PARALLELIZATION

[0001] The present invention relates to a method for activating a hybrid powertrain with task parallelization. The invention finds a particularly advantageous application with two- or four-wheel drive hybrid automotive vehicles.

[0002] In a manner known per se, a hybrid powertrain of a motor vehicle may comprise an electric transmission device comprising a dual-clutch gearbox and a rotating electric machine, an alternator-starter, a heat engine, and an electrical system composed in particular of a direct-direct converter (or DC / DC converter) and a traction battery.

[0003] As illustrated in [Fig. 1], the activation sequence of such a motorcycle group propulsion unit consists of a first step 100 of waking up the powertrain computers following an opening of the driver's door. After waking up the computers, the method then comprises a step 101 of activating a mechanical part of the gearbox 16 consisting of pressurizing a hydraulic circuit making it possible to control the opening and closing of the various clutches of the gearbox 16.

[0004] The next step 102 of this sequence is the detection of the driver's request for activation of the powertrain. During a step 103, the closing of a clutch coupling the thermal engine and the electric machine of the electric transmission device is carried out at the same time as the activation of the electrical system.

[0005] The activation of the electrical system is composed of 3 main steps: the first step 104 being the closing of the contactors of the traction battery, the second step 105 being the activation of the DC / DC converter and the third step 106 being the carrying out of a diagnosis of a low voltage electrical network of the motor vehicle.

[0006] Once the electrical system is activated, it is the turn of the alternator-starter and the electrical machine of the electrical transmission device to be activated respectively during steps 107 and 108.

[0007] A final step 109 consists of starting the thermal engine using both the alternator-starter and the electrical machine of the electrical transmission device. The starting of the thermal engine is carried out in two steps: a first step 109a consists of tensioning the alternator-starter belt in order to limit its deformation; gradation over time and a second step 109b consists of starting the thermal engine by means of the alternator-starter and the rotating electrical machine of the electrical transmission device.

[0008] Such a powertrain activation sequence is, however, long to implement, since almost all of the steps are carried out in series, i.e. one after the other. In addition, carrying out the diagnosis of the low-voltage electrical network is a particularly long step of the order of a second, as is the closing of the traction battery contactors and the activation of the DC / DC converter, which is of the order of 800 ms.

[0009] The fact that the starting of the thermal engine is carried out at the very end of the sequence generates a lack of understanding on the part of the driver, insofar as a significant latency time, of the order of 2 seconds, between the start request made by the driver and the start of the starting of the thermal engine will be felt.

[0010] The invention aims to effectively overcome this drawback by proposing a method for activating a hybrid powertrain of a motor vehicle comprising an electric transmission device provided with a dual-clutch gearbox and a rotating electrical machine, an alternator-starter, a heat engine, and an electrical system composed in particular of a traction battery and a DC / DC converter electrically connected between a low-voltage electrical network and a high-voltage electrical network, said method comprising, following detection of a request to activate said hybrid powertrain from a driver, - a step of closing the electrical contactors of the traction battery, - a step of activating the DC / DC converter, - a diagnostic stage of the low voltage electrical network, - a step of activating the alternator-starter, - a step of activating the rotating electrical machine of the electrical transmission device, and - a thermal engine start-up step, - the low voltage electrical network diagnostic step and the thermal engine starting step being carried out temporally at least partially simultaneously with each other.

[0011] The invention thus makes it possible, by parallelizing the performance of the diagnosis of the low-voltage electrical network and the starting of the thermal engine, to reduce the latency between the request for activation of the powertrain and the start of starting the thermal engine. The invention therefore reduces the overall activation time of the powertrain and improves the responsiveness of the vehicle to the driver.

[0012] According to one implementation of the invention, the step of closing a clutch ac coupling the heat engine and the rotating electrical machine is carried out at least partially at the same time as an activation of the electrical system.

[0013] According to one implementation of the invention, as soon as the electrical contactors of the traction battery are closed, the step of activating the alternator-starter and the step of activating the rotating electrical machine of the transmission device are carried out temporally at least partially simultaneously with each other.

[0014] According to one implementation of the invention, the step of activating the DC / DC converter is carried out temporally at least partially simultaneously with the step of activating the alternator-starter and the step of activating the rotating electrical machine of the electrical transmission device.

[0015] According to one implementation of the invention, the step of diagnosing the low-voltage electrical network is carried out partially simultaneously with the step of activating the alternator-starter and the step of activating the rotating electrical machine of the electrical transmission device.

[0016] According to one implementation of the invention, the step of starting the thermal engine is carried out as soon as the rotating electrical machine and the alternator-starter are activated.

[0017] According to one implementation of the invention, the step of starting the heat engine comprises a step of tensioning a belt of the alternator-starter and a step of starting the heat engine by means of the alternator-starter and the rotating electrical machine of the electrical transmission device.

[0018] According to one implementation of the invention, said method further comprises a step of activating a second rotating electrical machine installed on a rear wheel set of the motor vehicle.

[0019] According to one implementation of the invention, the step of activating the second rotating electrical machine is carried out at the same time as the activation of the alternator-starter and the rotating electrical machine.

[0020] According to an implementation of the invention, prior to the detection of a request for activation of said hybrid powertrain from a driver, said method comprises a step of waking up computers.

[0021] The invention will be better understood upon reading the following description and examining the accompanying figures. These figures are given only for illustrative purposes but in no way limit the invention.

[0022] [Fig.l], already described, is a time diagram of the different stages of a method of activating a hybrid powertrain according to the state of the art;

[0023] [Fig.2] is a schematic representation of a powertrain implementing a method for activating a hybrid powertrain according to the invention;

[0024] [Fig.3] is a time diagram of the different stages of the method of activating a hybrid powertrain according to the invention.

[0025] [Fig. 2] shows a hybrid powertrain 10 of a motor vehicle comprising a heat engine 11 and an electric transmission device 12 mounted on a wheel set 13, in particular a front wheel set.

[0026] The electric transmission device 12 comprises a rotating electric machine 15 and a dual-clutch gearbox 16 comprising two clutches K1, K2 for changing gear ratios. The rotating electric machine 15 is arranged at the input of the dual-clutch gearbox 16. The gearbox 16 comprises an input shaft 16.1 and an output shaft 16.2. The output shaft 16.2 of the gearbox 16 is connected to the wheels via a differential and a lowering axle (not shown).

[0027] Furthermore, a clutch KO for connecting and disconnecting the heat engine 11 is capable of selectively connecting the heat engine 11 to the input shaft 16.1 of the gearbox 16 when said clutch KO is in the closed state and of isolating the heat engine 11 from the input shaft 16.1 of the gearbox 16 when said clutch KO is in the open state. For this purpose, the clutch KO is arranged between the heat engine 11 and the rotating electrical machine 15. The isolation of the heat engine 11 from the input shaft 16.1 of the gearbox 16 and therefore from the wheels is required in particular when the vehicle is operating in a pure electric driving mode. The clutch KO is associated with a flywheel 17.

[0028] The rotating electrical machine 15 is mounted between the clutch KO and the gear change clutches K1, K2 of the gearbox 16. The rotating electrical machine 15 can be connected to the input shaft 16.1 of the gearbox 16 via a belt or chain reduction unit 18.

[0029] The rotating electrical machine 15 is capable of transforming electrical energy from a traction battery 19 into mechanical energy to provide traction for the vehicle. The rotating electrical machine 15 is also capable of operating in a generator mode in which the rotating electrical machine 15 transforms mechanical energy into electrical energy making it possible to recharge the traction battery 19, in particular during a regenerative braking phase.

[0030] The heat engine 11 is associated with an alternator-starter 20. The alternator-starter 20 can be coupled with the heat engine 11 on the accessories front by means of a motion transmission device 22 with pulley and belt. An air conditioning compressor 23 can also be mounted on the accessories front.

[0031] The rotating electrical machine 15 and the alternator-starter 20 are electrically connected to the traction battery 19 on a high-voltage electrical network 25. The high-voltage electrical network 25 has an operating voltage of 48 Volts, or even a voltage several hundred volts higher. The traction battery 19 is associated with electrical contactors allowing selectively connecting elec electrically or electrically isolate the traction battery 19 from the high voltage electrical network 25 and the electrical loads connected to it.

[0032] A DC / DC converter 26 (or DC / DC converter) makes it possible to transform the voltage of the high-voltage electrical network 25 into a voltage compatible with a low-voltage electrical network 27. This low-voltage electrical network 27 comprises a low-voltage battery 28. The low-voltage electrical network 27 has an operating voltage of 12 Volts. On-board equipment 30 such as a lighting system, a human-machine interface of the touch-screen tablet type for example, window or seat actuators, or any other low-voltage equipment on board the vehicle are electrically connected to the low-voltage electrical network 27. The DC / DC converter 26 and the traction battery 19 are part of an electrical system referenced 32. An oil pump 31 of the gearbox 16 is also electrically connected to the low-voltage electrical network 27.

[0033] The method for activating the hybrid powertrain 10 is described below, with reference to [Fig. 3]. This method comprises a first step 100 of waking up the computers of the powertrain following an opening of the driver's door. The method then comprises a step 101 of activating a mechanical part of the gearbox 16 consisting of pressurizing a hydraulic circuit making it possible to control the opening and closing of the various clutches KO, K1, and K2 of the gearbox 16.

[0034] The next step 102 of this sequence is the detection of a request for activation of the powertrain 10 by the driver. At the time of detection of this request for activation of the powertrain, the closing of the clutch KO coupling the heat engine 11 and the rotating electrical machine 15 of the electric transmission device 12 is carried out during a step 103 at least partially at the same time as an activation of the electrical system 32.

[0035] The activation of the electrical system 32 is composed of 3 main steps: the first step 104 being the closing of the contactors of the traction battery 19, the second step 105 being the activation of the DC / DC converter 26 and the third step 106 being the carrying out of a diagnosis of the low voltage electrical network 27 of the motor vehicle. In this case, step 104 and at least part of step 105 are carried out at the same time as step 103 of closing the clutch KO.

[0036] As soon as the contactors of the traction battery 19 are closed (end of step 104), the alternator-starter 20 and the rotating electrical machine 15 are activated respectively during a step 107 and a step 108. Steps 107 and 108 are carried out temporally at least partially, preferably completely, simultaneously with each other.

[0037] In parallel, the electrical system 32 continues its activation by activating the DC / DC converter 26 during step 105 and by carrying out the diagnosis of the low-voltage electrical network 27 during step 106. In this case, step 105 of activating the DC / DC converter 26 is carried out temporally at least partially simultaneously with steps 107 and 108. Step 106 of diagnosing the low-voltage electrical network 27 is carried out partly simultaneously with steps 107 and 108.

[0038] As soon as the rotating electrical machine 15 and the alternator-starter 20 are activated (end of steps 107 and 108), the method comprises a step 109 consisting of starting the heat engine 11. The starting of the heat engine 11 is carried out in two steps: a first step 109a consists of tensioning the belt of the alternator-starter 20 in order to limit its degradation over time and a second step 109b consists of starting the heat engine 11 by means of the alternator-starter 20 and the rotating electrical machine 15.

[0039] Step 106 of diagnosing the low-voltage electrical network 27 and step 109 of starting the thermal engine 11 are carried out temporally at least partially simultaneously with each other. In other words, the two steps 106 and 109 are carried out at least during a common time period TL. The period T1 begins at the end of steps 107 and 108.

[0040] A variant of this sequence makes it possible to activate a rotating electrical machine (not shown) installed on the rear wheel set of the vehicle. The activation of this rotating electrical machine is then carried out during a step 110. Preferably, step 110 is carried out at the same time as the activation of the alternator-starter 20 and the rotating electrical machine 15 (steps 107 and 108). Step 110 begins at the end of the step of closing the electrical contactors of the traction battery 19.

Claims

Claims

1. Method for activating a hybrid powertrain (10) of a motor vehicle comprising an electric transmission device (12) provided with a dual-clutch gearbox (16) and a rotating electrical machine (15), an alternator-starter (20), a heat engine (11), and an electrical system (32) composed in particular of a traction battery (19) and a DC / DC converter (26) electrically connected between a low-voltage electrical network (27) and a high-voltage electrical network (25), said method comprising, following detection of a request to activate said hybrid powertrain (10) from a driver, - a step (104) of closing electrical contactors of the traction battery (19), - a step (105) of activating the DC / DC converter (26), - a step (106) of diagnosing the low-voltage electrical network (27), - a step (107) activation of the alternator-starter (20),- a step (108) of activating the rotating electrical machine (15) of the electrical transmission device (12), and - a step (109) of starting the thermal engine (11), characterized in that the step (106) of diagnosing the low-voltage electrical network (27) and the step (109) of starting the thermal engine (11) are carried out temporally at least partially simultaneously with each other.,

2. Method according to claim 1, characterized in that a step (103) of closing a clutch (KO) coupling the heat engine (11) and the rotating electrical machine (15) is carried out at least partially at the same time as an activation of the electrical system (32).

3. Method according to claim 1 or 2, characterized in that as soon as the electrical contactors of the traction battery (19) are closed, the step (107) of activating the alternator-starter (20) and the step (108) of activating the rotating electrical machine (15) of the transmission device are carried out temporally at least partially simultaneously with each other.

4. Method according to any one of claims 1 to 3, characterized in that the step (105) of activating the DC / DC converter (26) is carried out temporally at least partially simultaneously with the step (107) of activating the alternator-starter (20) and the step (108) of activating the rotating electrical machine (15) of the electrical transmission device (12).

5. Method according to any one of claims 1 to 4, characterized in that the step (106) of diagnosing the low voltage electrical network (27) is carried out partially simultaneously with the step (107) of activating the alternator-starter (20) and the step (108) of activating the rotating electrical machine (15) of the electrical transmission device (12).

6. Method according to any one of claims 1 to 5, characterized in that the step (109) of starting the thermal engine (11) is carried out as soon as the rotating electrical machine (15) and the alternator-starter (20) are activated.

7. Method according to any one of claims 1 to 6, characterized in that the step (109) of starting the heat engine (11) comprises a step (109a) of tensioning a belt of the alternator-starter (20) and a step (109b) of starting the heat engine (11) by means of the alternator-starter (20) and the rotating electrical machine (15) of the electrical transmission device (12).

8. Method according to any one of claims 1 to 7, characterized in that it further comprises a step (110) of activating a second rotating electrical machine installed on a rear wheel set of the motor vehicle.

9. Method according to claim 8, characterized in that the step (110) of activating the second rotating electrical machine (15) is carried out at the same time as the activation of the alternator-starter (20) and the rotating electrical machine (15).

10. Method according to any one of claims 1 to 9, characterized in that prior to the detection of a request for activation of said hybrid powertrain (10) from a driver, said method comprises a step of waking up computers.

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