Method and device for managing the operation of a combustion engine and / or of an electric motor of a motor vehicle provided with a positive-clutch gearbox

Abstract

The invention relates to a method for managing the operation of a combustion engine (2) and / or of an electric motor (3) of a motor vehicle (1) provided with a positive-clutch gearbox (4) driven by the combustion engine (2) and the electric motor (3), wherein the method is implemented by a computer device (100) on board the vehicle. The invention also relates to a device (100) implementing such a method, as well as to a motor vehicle (1) comprising such a device.

Description

DESCRIPTION TITLE: Method and device for managing the operation of a thermal engine and / or an electric motor of a motor vehicle equipped with a dog gearbox Technical field of the invention

[0001] The present invention relates to the field of computer and electronic systems on board motor vehicles for managing their operation, in particular hybrid motor vehicles equipped with dog gearboxes. The invention relates in particular to a method for managing the operation of a thermal engine and / or an electric motor of a motor vehicle equipped with a dog gearbox driven by said thermal engine and said electric motor, said method being implemented by a computer device on board the vehicle. The invention also relates to a device implementing such a method, as well as a motor vehicle which has such a device on board. The invention applies to motor vehicles such as land motor vehicles, in particular cars. State of the prior art

[0002] Some hybrid motor vehicles (i.e. with a hybrid thermal and electric engine) are equipped with a dog gearbox which is driven jointly by a thermal engine and at least one electric motor, one or more dogs of the gearbox being thus driven by the thermal engine while one or more others are driven by the electric motor.

[0003] In such a vehicle, an action carried out by the driver on the vehicle's accelerator pedal is therefore interpreted by the vehicle's computers in order to manage the operation of the gearbox, in particular in function of an operating strategy that establishes one or more gearbox ratios to be engaged based on a value of the requested vehicle torque. Similarly, some computers manage the operation of engines, in particular based on torque instructions that are also determined based on the requested torque.

[0004] However, during complex gear changes, the computer that manages the operation of the gearbox breaks these changes down into one or more simpler transient gear changes. And in order to achieve these elementary gear changes, ramps for decreasing or increasing the torque of the engines are established. In addition, compensation for the torque differences of the actuators whose torque varies is carried out to achieve the elementary transitions using the remaining actuators in order to maintain optimal gear change quality. This strategy is identified by the concept of balancing or, in English, torque balancing. Generally, these variation ramps are as fast as possible to guarantee optimal responsiveness of the gearbox.

[0005] However, when changing gears, the vehicle may not be able to provide the torque requested by the driver via the accelerator pedal or, equivalently, by a cruise control computer or driver assistance system. This phenomenon mainly occurs when one of the engines is in the synchronization phase in preparation for the next dog clutch. And it is when a final gear of the gearbox is engaged that all the engines converge towards the requested torque. This then generates a strong acceleration of torque delivery. However, as much as this phenomenon is appreciable during frank acceleration requests, it generates discomfort when gentle acceleration is requested. Summary of the invention

[0006] The invention aims to overcome this problem. In particular, it aims to provide a solution for, in a hybrid vehicle equipped with a dog gearbox, improving the comfort of the vehicle during requests for gentle acceleration while maintaining optimal performance during requests for sharp acceleration. By this means, the invention aims to improve the comfort and performance of hybrid motor vehicles equipped with dog gearboxes.

[0007] In order to achieve these objectives, the invention relates, according to a first aspect, to a method for managing the operation of a heat engine and / or an electric motor of a motor vehicle equipped with a dog gearbox driven by said heat engine and said electric motor, said method being implemented by a computer device on board the vehicle and comprising the steps of: i) determining whether a first condition is met or whether a second condition is met, said first condition being met when it is established that a value of the torque of the requested vehicle increases from a first initial value without exceeding a pre-established threshold value, said second condition being met when it is established that the value of the torque of the requested vehicle increases from a second initial value while exceeding the threshold value;ii) obtaining data characterizing an operating strategy of said gearbox which is established as a function of said requested vehicle torque value; iii) determining whether a third condition is met, said third condition being met when it is established that said strategy involves a transition between an initial ratio of said gearbox which is engaged at the moment when the requested vehicle torque value begins to increase and a final ratio of said gearbox which must be engaged to provide the requested vehicle torque value; and iv) managing the operation of said heat engine and / or said electric motor as a function of data characterizing a first torque setpoint; when said first condition and said third condition are met or according to data characterizing a second torque setpoint when said second condition and said third condition are met, said first torque setpoint defining, between the engagement of said initial gear of said gearbox and the engagement of said final gear of said gearbox, at least a first variation between the first initial value and a first intermediate value greater than the first initial value and less than the value of the torque of the requested vehicle followed by a second variation between the first intermediate value and the first initial value, then, as soon as said final gear of said gearbox is engaged, a third variation between the first initial value and the value of the torque of the requested vehicle, said second torque setpoint defining,between the engagement of said initial gear of said gearbox and the engagement of said final gear of said gearbox, at least a fourth variation between the second initial value and a second intermediate value lower than the value of the requested vehicle torque followed by a fifth variation between the second intermediate value and the second initial value then, as soon as said final gear of said gearbox is engaged, a sixth variation between the second initial value and the value of the requested vehicle torque, said first variation and said third variation being less sudden than said fourth variation and said sixth variation.,

[0008] Alternatively, said first variation and said third variation may be equally sudden.

[0009] According to another variant, said fourth variation and said sixth variation can be as sudden as each other.

[0010] According to yet another variant, said first variation, said second variation, said third variation, said fourth variation, said fifth variation and said sixth variation may be linear.

[0011] According to yet another variant, said second variation and said fifth variation may be instantaneous.

[0012] According to yet another variant, said at least one initial ratio of said gearbox may not be able to provide the value of the torque of the requested vehicle.

[0013] According to a second aspect, the invention relates to a device for managing the operation of a thermal engine and / or an electric motor of a motor vehicle equipped with a dog gearbox driven by said thermal engine and said electric motor, the device comprising at least one information processing unit, comprising at least one processor, and a data storage medium, which are configured to implement a method as described above.

[0014] According to a third aspect, the invention relates to a computer program comprising program code instructions for executing the steps of a method as described above when said program is executed by at least one processor.

[0015] According to a fourth aspect, the invention relates to a medium usable in a computer on which a program as described above is recorded.

[0016] According to a fifth aspect, the invention relates to a motor vehicle which has a device as described above. Brief description of the figures

[0017] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended figures, in which:

[0018] [Fig. 1] is a schematic illustration of a motor vehicle according to the invention;

[0019] [Fig. 2] is a functional diagram of a device according to the invention;

[0020] [Fig. 3] is a flowchart of the steps of a method according to the invention; and

[0021] [Fig. 4] illustrates the implementation of at least one step of the method according to the invention. Detailed description of the invention

[0022] Figure 1 schematically illustrates a motor vehicle 1 according to the invention. It is a hybrid vehicle comprising a heat engine 2 and at least one electric motor 3 which jointly drive a dog gearbox 4. Thus, some dogs of the gearbox 4 are driven by the heat engine 2, while other dogs are driven by the electric motor 3. According to a preferred embodiment, the heat engine 2 drives four dogs, so as to produce four gearbox ratios, while the electric motor 3 drives two dogs, so as to produce two gearbox ratios.

[0023] To manage the operation of these different elements, the vehicle 1 according to the invention preferably incorporates a first computer 5 which manages the operation of the gearbox 4, being configured in particular to determine, as a function of a value of the torque of the requested vehicle, an operating strategy of the gearbox 4 which, as will be seen below, establishes ratios of the gearbox 4 over time.

[0024] A second computer 6 manages the operation of the thermal engine 2, in particular being configured to determine a torque setpoint, i.e. a temporal distribution of torque values, as a function of a value of the requested vehicle torque.

[0025] A third computer 7 similarly manages the operation of the electric motor 3, also being configured to determine a torque setpoint based on a value of the requested vehicle torque.

[0026] A fourth computer 8 is configured to determine a value of the requested vehicle torque as a function of an action performed on the accelerator pedal of the vehicle, an action which is detected and measured by means of an appropriate sensor (not shown), or as a function of an instruction transmitted by a cruise control 9 or a driving assistance system 10 of the vehicle 1.

[0027] Finally, the vehicle 1 according to the invention advantageously incorporates a device 100 for managing the operation of a thermal engine and / or an electric motor of a motor vehicle equipped with a dog gearbox driven by said thermal engine and said electric motor, as described below, which implements a method for managing the operation of a thermal engine and / or an electric motor of a motor vehicle equipped with a dog gearbox driven by said thermal engine and said electric motor, as briefly summarized below and described in detail below.

[0028] When implementing the method, the device 100 according to the invention determines whether the value of the requested vehicle torque, which is established by the fourth computer 8 as a function of an action performed by the driver on the accelerator pedal of the vehicle 1 or of an instruction transmitted by the cruise control 9 or the driving assistance system 10, increases from a first initial value without exceeding a pre-established threshold value or, on the contrary, if it increases by exceeding the threshold value. At the same time, it determines whether an operating strategy of the gearbox 4, which is established by the first computer 5, involves a transition between an initial ratio of said gearbox which is engaged at the moment when the value of the requested vehicle torque begins to increase and a final ratio of said gearbox gears that must be engaged to provide the requested vehicle torque value. And it is according to these determinations, i.e. the type of acceleration requested, sharp or gentle, and the operating strategy of the gearbox 4, that the device 100 according to the invention then manages the operation of the thermal engine 2 and / or the electric motor 3 according to a first torque setpoint or a second torque setpoint, which advantageously define more or less sudden torque variations. Thus, the operation of the thermal engine 2 and / or the electric motor 3 is managed differently depending on whether a request for sharp or gentle acceleration occurs while a gear change is necessary. This makes it possible to maintain optimal performance in the event of sharp acceleration while maintaining comfort in the event of gentle acceleration.

[0029] In Figure 2 is illustrated a block diagram of the device 100 according to the invention for managing the operation of a heat engine or an electric motor of a motor vehicle equipped with a dog gearbox driven by said heat engine and said electric motor. It is essentially a computer device, which comprises at least one information processing unit 101, comprising one or more processors, a data storage medium 102, on which is recorded in particular a program which comprises program code instructions for the execution of the steps of the method according to the invention described later, and an input and output interface 103 allowing the reception and transmission of data.

[0030] Preferably, the device 100 according to the invention is integrated into an independent computer and it interacts via its input and output interface 103 and by means of a wired communication network of the vehicle (e.g. CAN, Ethernet, MOST, etc.) - shown by the arrows in Figure 1 - with the second computer 6, the one that manages the operation of the thermal engine 2, and with the third computer 7, the one that manages the operation of the electric motor 3. Alternatively, the device 100 according to the invention is part partially or fully of one or other of these calculators. Thanks to these means, the device 100 according to the invention can therefore, in particular, determine a current value of the torque of the vehicle 1, and it can obtain data characterizing a value of the torque of the requested vehicle by interacting with the fourth calculator 8. It can also manage the operation of the thermal engine 2, by interacting to do this either with the second calculator 6 or directly with the thermal engine 2, and it can also manage the operation of the electric motor 3, either by interacting with the third calculator 7 or directly with the electric motor 3.

[0031] According to the invention, all the elements described above combine to enable the implementation of a method for managing the operation of a heat engine and / or an electric motor of a motor vehicle equipped with a dog gearbox driven by said heat engine and said electric motor, as described below in connection with figures 3-4.

[0032] Figure 3 illustrates by means of a flowchart the steps of the method according to the invention.

[0033] According to a first step 301 of the method according to the invention, the device 100 according to the invention determines whether a first condition is fulfilled or whether a second condition is fulfilled, said first condition being fulfilled when it is established that a value of the torque of the requested vehicle increases from a first initial value without exceeding a pre-established threshold value, said second condition being fulfilled when it is established that the value of the torque of the requested vehicle increases from a second initial value while exceeding the threshold value.

[0034] In other words, the device 100 according to the invention first determines whether the situation is one of a gentle acceleration request or a frank acceleration request. Such an acceleration request is produced when the driver presses the accelerator pedal and, in the same way, if it is the cruise control 9 or the driving assistance system 10 which generates an equivalent instruction. And, in these cases, the requested torque increases more or less significantly. Thus, the device 100 according to the invention advantageously focuses during this first step 301 on determining whether we are in the case where the phenomenon of convergence of the engines described in the preamble is acceptable, when we have a request for frank acceleration, or, on the contrary, if this phenomenon will be the cause of discomfort in the case of a request for gentle acceleration.

[0035] To implement this first step, the device 100 according to the invention interacts with the fourth computer 8 in order to obtain the value of the torque of the requested vehicle, which the latter establishes as a function of an action performed on the accelerator pedal of the vehicle 1 or of an instruction generated by the regulator 9 or the driving assistance system 10. Similarly, it obtains the current value of the torque of the vehicle 1 by also interacting with this same computer. Concerning the threshold value, for example between 800 Nm and 1500 Nm, it has preferably been recorded on the data storage medium 102 of the device 100 according to the invention at the time of the design of the vehicle.

[0036] Then, according to a second step 302 of the method according to the invention, the device 100 according to the invention obtains data characterizing an operating strategy of the gearbox 4 which is established as a function of the value of the torque of the requested vehicle. Thus, the device 100 according to the invention seeks during this step to obtain, by interacting for this purpose with the first computer 5 which manages the operation of the gearbox 4, an operating strategy of the gearbox 4, which the first computer 5 establishes as a function of the value of the torque of the requested vehicle which is transmitted to it by the fourth computer 8. This operating strategy defines one or more ratios of the gearbox 4 which must be engaged to satisfy the value of the torque of the requested vehicle. Preferably, the operating strategy defines at least two ratios of the gearbox 4, a first ratio for the thermal engine 2 and a second ratio for the electric motor 3. In other words, the operating strategy of the gearbox 4 establishes, in connection with at least one instant subsequent to the current instant, at least one ratio of the gearbox 4.

[0037] Then, according to a third step 303 of the method according to the invention, the device 100 according to the invention determines whether a third condition is met, considering that this is the case when it establishes that the operating strategy involves a transition between an initial ratio of the gearbox 4 which is engaged at the moment when the value of the torque of the requested vehicle begins to increase and a final ratio of the gearbox 4 which must be engaged to provide the value of the torque of the requested vehicle. In other words, the device 100 according to the invention determines whether a change of ratio of the gearbox 4 is necessary to satisfy the value of the torque of the requested vehicle.

[0038] According to a fourth step 304 of the method according to the invention, the device 100 according to the invention manages the operation of the thermal engine 2 and / or the electric motor 3 as a function of data characterizing a first torque setpoint when the first condition and the third condition are met or as a function of data characterizing a second torque setpoint when the second condition and said third condition are met, the first torque setpoint defining, between the engagement of said initial gear of said gearbox and the engagement of said final gear of said gearbox, at least a first variation between the first initial value and a first intermediate value greater than the first initial value and less than the value of the torque of the requested vehicle followed by a second variation between the first intermediate value and the first initial value, then,as soon as said final ratio of said gearbox is engaged, a third variation between the first initial value and the value of the requested vehicle torque, said second torque instruction defining, between the engagement of said initial ratio, of said gearbox and the engagement of said final gear of said gearbox, at least a fourth variation between the second initial value and a second intermediate value lower than the value of the torque of the requested vehicle followed by a fifth variation between the second intermediate value and the second initial value then, as soon as said final gear of said gearbox is engaged, a sixth variation between the second initial value and the value of the torque of the requested vehicle. Advantageously, said first variation and said third variation are less sudden than said fourth variation and said sixth variation.

[0039] To implement this step, the device 100 according to the invention interacts with the second computer 6 and / or the third computer 7, by transmitting to it a command to use the first torque setpoint or the second torque setpoint to manage the operation of the corresponding engine(s). Alternatively, it manages by itself the operation of the thermal engine 2 and / or the electric motor 3 according to the first or second torque setpoint.

[0040] For greater clarity, Figure 4 shows graphs illustrating the implementation of the fourth step of the method according to the invention. The top graph illustrates the implementation of this step when the device 100 according to the invention has established that the first and third conditions are met, i.e. when gentle acceleration is requested (the threshold value th is not exceeded), while the bottom graph illustrates the implementation of this step when the device 100 according to the invention establishes that the second and third conditions are met, i.e. when sharp acceleration is requested (the threshold value th is exceeded).

[0041] According to the example illustrated, it is considered that the operating strategy of the gearbox 4 which was determined by the first computer 5 as a function of the variation in torque requested involves two ratios intermediate between the initial gear engaged at the time when the increase in the requested torque occurs and the final gear to be engaged to provide the requested torque value. On both graphs, a dotted line indicates the change in the requested torque, a solid line indicates the torque setpoint used to manage the operation of the thermal engine 2 and / or the electric motor 3 and a thinner solid line indicates the torque achieved.

[0042] We see on the top graph that the first torque setpoint defines at least a first variation between the initial value CO when an initial ratio RO of the gearbox 4 is engaged and a first intermediate value higher than the first initial value and lower than the value of the requested vehicle torque, followed by a second variation between the first intermediate value and the first initial value, preferably an instantaneous (or almost instantaneous) return to the initial value CO. This same torque variation ramp is repeated between each intermediate ratio R1->R2 and R2->R3. Finally, as soon as said final ratio R3 of said gearbox 4 is engaged, the one which will make it possible to provide the requested torque, the first torque setpoint defines a third variation between the first initial value CO and the value of the requested vehicle torque. As we see, the slope of this last ramp is not very significant.This allows comfort to be maintained in the event of a request for gentle acceleration.

[0043] Conversely, we see on the bottom graph that the second torque setpoint similarly defines at least a fourth variation between the second initial value Cl when an initial ratio R 0 of the gearbox 4 is engaged and a second intermediate value higher than the second initial value and lower than the value of the torque of the requested vehicle, followed by a fifth variation between the second intermediate value and the second initial value, in other words an instantaneous (or almost instantaneous) return to the second initial value Cl. Several similar torque variation ramps are then repeated between each intermediate ratio RI, R2 and R3, with values intermediate torque values ​​reached at each gear change preferentially increasing. Finally, as soon as the final gear R3 is engaged, the second torque setpoint defines a sixth variation between the second initial value Cl and the value of the requested vehicle torque, but the slope of this last ramp is in this case much greater. In other words, the first variation and the third variation defined by the first torque setpoint are less sudden than the fourth variation and the sixth variation defined by the second torque setpoint. This is how optimal performance is maintained in the case of a frank acceleration request.

[0044] Preferably, the first variation and the third variation are equally sudden. Similarly, the fourth variation and the sixth variation are equally sudden. Furthermore, the second variation and the fifth variation are instantaneous. Furthermore, the first variation, the second variation, the third variation, the fourth variation, the fifth variation and the sixth variation are linear.

[0045] Therefore, by means of the method and device according to the invention described above, a solution is provided for, in a hybrid vehicle equipped with a dog gearbox, improving the comfort of the vehicle during gentle acceleration requests while maintaining optimal performance during sharp acceleration requests. By this means, the invention improves the comfort and performance of hybrid motor vehicles equipped with dog gearboxes.

Claims

CLAIMS:

1. Method for managing the operation of a heat engine (2) and / or an electric motor (3) of a motor vehicle (1) equipped with a dog gearbox (4) driven by said heat engine (2) and said electric motor (3), said method being implemented by a computer device (100) on board the vehicle, characterized in that said method comprises the steps of: i) determining whether a first condition is met or whether a second condition is met, said first condition being met when it is established that a value of the torque of the requested vehicle increases from a first initial value without exceeding a pre-established threshold value, said second condition being met when it is established that the value of the torque of the requested vehicle increases from a second initial value while exceeding the threshold value;ii) obtaining data characterizing an operating strategy of said gearbox (4) which is established as a function of said requested vehicle torque value; iii) determining whether a third condition is met, said third condition being met when it is established that said strategy involves a transition between an initial gear of said gearbox (4) which is engaged at the moment when the requested vehicle torque value begins to increase and a final gear of said gearbox (4) which must be engaged to provide the requested vehicle torque value;and iv) managing the operation of said thermal engine (2) and / or said electric motor (3) as a function of data characterizing a first torque setpoint when said first condition and said third condition are met or as a function of data characterizing a second torque setpoint when said second condition and said third condition are met, said first torque setpoint defining, between the engagement of said initial ratio of said gearbox and the engagement of said final ratio of said gearbox, at least a first variation between the; first initial value and a first intermediate value greater than the first initial value and less than the value of the requested vehicle torque followed by a second variation between the first intermediate value and the first initial value, then, as soon as said final gear of said gearbox is engaged, a third variation between the first initial value and the value of the requested vehicle torque, said second torque setpoint defining, between the engagement of said initial gear of said gearbox and the engagement of said final gear of said gearbox, at least a fourth variation between the second initial value and a second intermediate value less than the value of the requested vehicle torque followed by a fifth variation between the second intermediate value and the second initial value then, as soon as said final gear of said gearbox is engaged,a sixth variation between the second initial value and the value of the requested vehicle torque, said first variation and said third variation being less sudden than said fourth variation and said sixth variation., 2. Method according to claim 1, characterized in that said first variation and said third variation are both equally sudden.

3. Method according to one of the preceding claims, characterized in that said fourth variation and said sixth variation are both equally sudden.

4. Method according to one of the preceding claims, characterized in that said first variation, said second variation, said third variation, said fourth variation, said fifth variation and said sixth variation are linear.

5. Method according to one of the preceding claims, characterized in that said second variation and said fifth variation are instantaneous.

6. Method according to one of the preceding claims, characterized in that said at least one initial ratio of said gearbox does not make it possible to provide the value of the torque of the requested vehicle.

7. Device (100) for managing the operation of a thermal engine (2) and / or an electric motor (3) of a motor vehicle (1) equipped with a dog gearbox (4) driven by said thermal engine (2) and said electric motor (3), characterized in that said device comprises an information processing unit (101), with one or more processors, and a data storage medium (102), which are configured to implement a method according to any one of the preceding claims.

8. Computer program comprising program code instructions for executing the steps of a method according to any one of claims 1 to 6 when said program is executed by at least one processor.

9. Computer-readable medium, characterized in that a program according to claim 8 is recorded therein.

10. Motor vehicle (1), characterized in that said vehicle carries a device (100) according to claim 7.

Images