WO2014114855A1

WO2014114855A1 - Control method and control device for driving mode transition in a hybrid vehicle

Info

Publication number: WO2014114855A1
Application number: PCT/FR2013/053206
Authority: WO
Inventors: Alexis MARCHYLLIE; Franck ZUMELLA; Yohan MILHAU
Original assignee: Peugeot Citroen Automobiles Sa
Priority date: 2013-01-22
Filing date: 2013-12-19
Publication date: 2014-07-31
Also published as: CN105073539A; EP2948354A1; FR3001188A1; FR3001188B1

Abstract

The invention concerns a hybrid vehicle, a device (CTL) for controlling the drive train of the hybrid vehicle and the control method for transitioning from a first drive mode to a second drive mode of the drive train. The invention comprises means for generating a time delay in order to force the transition at the end of the time delay, and to force the transition before the end of the time delay if a request is received from the driver by the control device, originating from an interface means (IHM2), for example the acceleration pedal. The invention applies to hybrid vehicles capable of operating in a plurality of drive modes with a view to improving the comfort of driving.

Description

CONTROL METHOD AND DEVICE FOR CONTROLLING A HYBRID VEHICLE FOR THE TRANSITION OF MOTORIZATION MODES

The field of the invention relates to hybrid vehicles and more specifically to a control method and the control device of the powertrain of the hybrid vehicle.

There are various types of electric, hydraulic, pneumatic, etc. motorized drive systems for motor vehicles. For example, a hybrid thermal-electric motor includes a heat engine coupled to an electric machine. The electric machine can function as an electric motor when it has a sufficient source of energy to power it and can also function as a generator of electrical energy when it is driven, usually by the engine , to supply energy to various on-board equipment of the vehicle, for example an energy accumulator, a voltage network or any other equipment requiring a power supply.

Depending on the degree of electrical hybridization with the engine, the powertrain may comprise one or more electrical machines. The term "powertrain" refers to the electromechanical elements involved in the propulsion or traction of the vehicle, ie the heat engine, the electric machines, the running gear and the control members for controlling these elements. In the case of a power train with several electrical machines, a main electrical machine coupled to the engine directly intervenes in the engine of the vehicle on the running gear of the vehicle, ie the front and / or rear axle either in electrical thermal hybridization or electrically alone. In the latter case, it is said that the hybrid vehicle has a 100% electric driving mode. When the electric motor provides torque in addition to the torque of the heat engine then the vehicle can have several modes of travel, for example a fuel economy saving running mode, a so-called sporty driving mode to provide high power in case driver demand, but this is done at the expense of consumption, and a driving mode with four-wheel drive to maximize handling. Generally, the vehicle has a powertrain operating mode selection device that allows the driver to choose from the various modes available. An example of such a selection device was the subject of the filing of the patent application FR2936450 by the applicant. To each of these modes corresponds a mapping of torque setpoint for the motorization means of the powertrain.

The torque setpoint at the wheel of a running gear depends on the driver setpoint and the speed of the vehicle but also on the active mode of operation of the powertrain. Therefore, a request from the operating mode change driver may result in a change in the torque setpoint to the wheel which may result in untimely acceleration or a torque jump. This modification of the torque setpoint is felt as a driving inconvenience during the transition of the operating mode.

It is known in the state of the art the document FR2928122 describing a control method of a powertrain of a hybrid vehicle in which the transition from a hybrid mode of operation to an electrical mode of operation is prevented during a predetermined time interval and, as a result of this time interval, as long as a situation likely to degrade the driving pleasure is detected.

However, this control method can become problematic when the mode of operation of the powertrain is a parameter selected by the driver. Indeed, if the driving license conditions are not met, the powertrain may remain frozen in an unwanted operating mode by the driver on the pretext that the transition between the modes of operation will be felt by the driver. However, this blockage in a mode of operation is not acceptable.

There is therefore a need to improve the control method of a powertrain to reduce the aforementioned inconvenience during the transition from a first mode of operation of the powertrain to a second mode of operation.

More specifically, the invention relates to a control method implemented by a control device of a hybrid vehicle powertrain for effecting the transition from a first motorization mode to a motor vehicle. second mode of motorization of said powertrain. According to the invention, the method comprises the following successive steps:

a step of detecting a transition request from the first motorization mode to the second motorization mode,

a step of initiating a delay triggered by the detection of the transition request to effect the transition at the end of the delay,

if a conductive request is received by the control device before the end of the transition, a step of controlling the parameters of the request with respect to predetermined conditions allowing the transition to make the transition before the end of the delay,

- After the transition, a wheel torque calculation step when the powertrain is configured in the second motorization mode.

According to a variant of the method, the conductive request is a wheel torque variation request.

According to a variant of the method, the driver request is a request configuring the control device so that the wheel torque calculation is independent of the motorization mode.

According to a variant of the method, the driver request is initiated by a vehicle interface means between a driver of the vehicle and the control device.

According to a variant of the method, the transition request is initiated by a vehicle interface means between a driver of the vehicle and the control device for selecting the motorization mode of the powertrain.

According to a variant of the method, the delay is a function of the motorization modes of the transition.

The invention also relates to a control device of a powertrain for a hybrid vehicle, the said powertrain being able to operate in at least a first and second motorization modes, comprising means for detecting a transition request of the first mode from motorization to the second motorization mode. According to the invention the control device also comprises a means for generating a delay when a transition request is detected to make the transition after the delay and means for triggering the transition before the end of the delay on receipt of the timer. a driver request. According to one variant, the means for triggering the transition is configured by an authorization function defining conditions with respect to parameters of the driver request that allow the transition before the timer expires.

The invention also relates to a hybrid vehicle comprising the said control device, and according to the invention it further comprises a first conductive interface means for selecting the motorization mode of the powertrain and for initiating the transition request and a second conductive interface means, for example an accelerator pedal, for initiating the driver request.

Thanks to the invention, the driving pleasure is improved during the transition of the drive modes of a hybrid vehicle. The transition is carried out during a rolling event during which the change of mapping of the torque setpoints is imperceptible or when this change of mapping does not impact the calculation of the setpoints of torque.

Other features and advantages of the present invention will appear more clearly on reading the following detailed description of embodiments of the invention given as non-limiting examples and illustrated by the appended drawings, in which:

- Figure 1 shows a diagram of a hybrid vehicle according to the invention.

FIG. 2 represents a diagram of a control device according to the invention.

The invention aims to improve the driving pleasure of a hybrid vehicle during a transition from one drive mode powertrain to another motorization mode.

Figure 1 shows more precisely the powertrain of a hybrid vehicle comprising the CTL control device according to the invention. This powertrain is said to be hybrid because it comprises a front train TRAV driven by a heat engine MTH and a rear train driven by a main electric machine (not shown in the diagram of Figure 1).

The heat engine MTH generates a drive torque for the front axle on receipt of a setpoint. The front train TRAV also includes a gearbox (not shown in Figure 1). The engine can be gasoline type, diesel, LPG (for liquefied petroleum gas) or, more generally, any other type of engine in this embodiment. The main electric machine generates a drive torque for the rear axle on receipt of a setpoint and acts mainly as an electric motor to assist the engine for the engine of the vehicle, or may even according to another engine mode participate alone in the mobility of the vehicle.

A secondary electrical machine MEL is coupled to the heat engine MTH, it can be driven by the heat engine MTH to generate electrical energy. The electric machine MEL then functions as a generator to transmit a quantity of electrical energy to various electronic equipment. The electric machine MEL can also provide torque to the front axle on receipt of a torque setpoint, thus acting as an electric motor, more generally in specific phases of rolling, for example at startup or to briefly assist the heat engine MTH.

In the embodiment shown in FIG. 1, a first piece of equipment is a first SOC energy accumulator forming part of a high voltage network of the vehicle. This first SOC energy accumulator, also called battery, can supply energy to the main electric machine so that it generates a drive torque for the rear axle. The battery may be a nickel or lithium-ion type technology, for example.

A second device is a DCDC voltage converter supplying a voltage network, more specifically a low voltage network, 12V being the voltage commonly used.

This network is a low-voltage network on which the cockpit equipment is powered, the vehicle computers and a second battery BAT low voltage energy. It is understood that other equipment can be connected to this voltage network. The BAT accumulator is used to store energy to power network equipment.

The powertrain also comprises the CTL control device, also called supervisor, having the role of intelligent electronic component to coordinate the MTH heat engine, the main electric machine, the MEL secondary electrical machine, the SOC accumulator, the DCDC converter and the BAT accumulator. This control device can be an ASIC type calculator ("Application-Specific Integrated Circuit" in English) to withstand high temperature and reliability constraints. The device control may consist of one or more calculators according to the strategy of decentralization of intelligence. For example, component-specific calculations can be performed at the component level itself. It is therefore understood that the control device of the invention is not limited to a single calculation component but can be one or more computers of the system, ASIC technology or other equivalent to perform the calculation functions. More specifically, the CTL control device performs the target calculations of the engine and electrical machines. These include calculations of torque setpoints. The functions performed in the context of the invention will be described more precisely in the following description.

Moreover, the powertrain presented in this embodiment allows the vehicle to drive in four distinct modes of motorization. A first mode, called auto mode, is a mode that minimizes fuel consumption, a second mode, called sport mode, is a mode that maximizes the performance of the vehicle at the expense of consumption, a third mode is a mode having four-wheel drive. to maximize the handling of the vehicle and a fourth mode is an all-electric driving mode. However, the invention can be applied to a powertrain that only allows the operation of a part of these modes of running or different running modes.

The hybrid vehicle also comprises interface means IHM1 and IHM2 between the driver of the vehicle and the CTL control device. These interface means have the function of communicating instructions between the driver and the control device. These instructions are communicated by means of data communication buses and interface devices such as screens, buttons and indicators.

A first interface means IHM1 is a means for selecting the drive mode of the hybrid vehicle. In one embodiment, this selection means is in the form of a wheel-type button accompanied by LEDs indicating the states of the motorization modes, for example an activated state or a motor mode that can not be activated. This interface means also allows the driver to communicate to the control device via a data bus its drive mode instruction. When the driver wishes to modify the motorization mode, for example to switch from a mode maximizing the Vehicle performance in an all-electric mode, that selects the desired drive mode and the interface means generates a drive mode transition driver request to the CTL control device. The CTL control device then processes this request to configure the operation of the powertrain and develop the wheel torque instructions.

A second HMI interface means 2 is a means for controlling the speed of the hybrid vehicle, such as, for example, the acceleration pedal, a speed regulator or a touch control screen. If the driver wishes to accelerate or slow down, it acts on the speed control means which then generates a driver request to the CTL control device via a data bus. The CTL control device then processes this driver request to develop the wheel torque setpoints.

In order to coordinate the entire powertrain to carry out the driver's instructions, the CTL controller develops functions to control the equipment. Among these functions, the CTL control device comprises:

- An interface function of the driver's will to collect information from the vehicle. This function is used to transmit the vehicle data to the CTL control device.

- A translation function of the will to accelerate the driver in a wheel torque setpoint. The CTL control device calculates the wheel torque needed to perform the driver instruction.

A function for calculating the organic limitations, more specifically the torque, the equipment of the engine, and in particular the heat engine

MTH and the main and secondary electrical machines MEL.

- A calculation function of the torque of each member to provide the wheel torque that the driver wants and distribution of couples between different suppliers of torque.

- A transmission function of a torque setpoint to the heat engine MTH.

- A transmission function of a torque setpoint to the secondary electrical machine MEL and a torque setpoint to the main electrical machine. Torque instructions for the MTH heat engine and electric machines depend on the driver's wishes, the motorization mode of the vehicle (sports, car, all electric etc.) and status data of electronic equipment including power supply. depends on the powertrain, especially the level of the amount of energy of the batteries.

For calculating the torque setpoints of the thermal engine MTH and electrical machines, the CTL control device has wheel torque calculation functions that depend on the motorization mode chosen. When the all-electric mode is active, only the main electric machine is driven to provide torque to the rear running gear, while in sport motorization mode all motorization means are controlled to provide torque to the running gear. The term "torque mapping" denotes the various wheel torque calculation functions for each motorization mode and for each of the powertrain motorization means, ie the MTH heat engine and the electric machines. A transition from piloting a first torque map to a second torque map can lead to accelerations or decelerations that can be felt by the driver.

To avoid this inconvenience the CTL control device implements a powertrain control method for performing the transition from one motorization mode to another motorization mode. Four or more modes of motorization can be controlled by the method and the control device according to the invention.

Following a driver request to change the drive mode, for example from auto mode to all-electric mode, a drive mode transition request is received by the control device. This request is issued for example from a button for selecting the motorization mode, such as the interface means IHM1. The CTL control device performs a step of detecting the transition request from the auto mode to the all-electric mode, then a step of initiating a delay triggered by the detection of the transition request to make the transition at the end of the transition. the delay.

However, if a driver request is received by the control device before the termination of the transition, the control device performs a step of triggering the transition from the auto mode to the all-electric mode before the end of the transition if the result of a control of the conditions allowing the transition is positive. This control step checks parameters of the driver request with regard to predetermined conditions indicating conditions favorable to the transition, ie conditions limiting driving inconvenience. The control function will be described later.

The driver request is initiated by an interface means IHM2 of the vehicle, for example a speed control means such as the accelerator pedal, the brake pedal or a speed controller. This driver request may have the effect of modifying the wheel torque setpoint. It is particularly advantageous to execute the wheel torque mapping transition during a wheel torque variation because the mapping transition is then imperceptible by the driver.

In another situation, the driving request may have the effect that the powertrain operates in a mode in which the transition has no impact on the calculation of the wheel torque.

Thus, thanks to the invention the transition of the motorization modes is triggered at a favorable time to improve driving pleasure. The driver request may be a torque setpoint change request to the wheel or a configuration request from the CTL control device so that the wheel torque calculation is independent of the motorization mode.

The transition from one motorization mode to another motorization mode has the effect of modifying the powertrain torque calculation map, the wheel torque calculation being in the majority of driving situations depending on the motorization mode. In addition, the timing allows not to prevent the transition if a condition of authorization of the transition does not appear.

The invention also relates to the control device of the powertrain. The functions specific to the invention are illustrated in FIG. 2. The control device comprises in particular a means 1 for generating the delay, when the control device detects the transition request M comprising data representing the active motorization mode and the motorization mode requested by the driver. This delay is necessary to force the transition at the end of a given time. The value of the delay is variable depending on the transition requested. The value of the delay before the transition initiated by a driver request depends on the source motor mode and target mode because each transition requires a specific configuration. One of the objectives of the strategy is to limit the torque gradients felt by the driver on simple change of motorization mode. The delay before the transition initiated by the driver request is even higher than the output torque difference of the source and target maps is high. Indeed, an increase in torque without action on the accelerator pedal is more problematic from a safety point of view than a decrease in torque. The delay is longer on a transition from an auto mode to a sport mode than on the inverse transition to maximize transition opportunities on the appearance of an authorization criterion.

The control device also comprises a means 2 for triggering the transition before the end of the delay on reception of one of the conductive requests C1 to C8 complying with at least one of the predetermined conditions. For this, the control device comprises calculation means 2 for executing an authorization function determining whether the transition can be authorized before the end of the delay under acceptable driving conditions. The driver request is an input data for this authorization function.

The authorization function includes several conditions for authorizing the transition. In this embodiment, these conditions make it possible to detect at least the following events named C1 to C8, and to execute the transition under conditions such that the transition of the motions mode is imperceptible to the driver, or when the drive mode is not a calculation data impacting the wheel torque setpoint. Among these events favorable to the transition of motorization mode, we can mention the following:

- C1 is a brake pedal support event: when a depressed brake pedal is detected, this event is interpreted as a driver will decrease speed, so the transition can take place without feeling driver.

- C2 is a foot throttle event: when the driver lifts his foot off the accelerator pedal, the torque demand is low regardless of the engine mode of the powertrain. The constant accelerator depression torque gradient generated by the transition is therefore imperceptible to the driver. - C3 is an event of strong depression of the accelerator pedal: the torque demand by the driver is high and is only slightly impacted by the transition of motorization mode.

- C4 is a speed regulator activation event: the torque setpoint sent to the engine no longer comes from the maps specific to the modes of the powertrain but is determined in speed regulation, the change of motorization mode therefore has no influence on the wheel torque.

- C5 is a lever position change event: the shift of the speed lever by the driver is translated as a request for changing the vehicle operating mode, the drive mode transition is then allowed.

- C6 is an activation ramping event: at low speed, the vehicle enters a rampage state recreating the rampage of an automatic gearbox. Thus, the wheel torque setpoint is regulated according to the speed of the vehicle, and regardless of the motorization mode. As when activating the cruise control, changing the drive mode has no influence on the wheel torque.

- C7 is an event with a high gradient of accelerator pedal displacement: in the event of a strong gradient of displacement of the accelerator pedal

(Depressing or lifting of the foot) the driver expects a change in the behavior of the vehicle, and the change in the wheel torque due to the drive mode transition is predictable.

- C8 is a low vehicle speed event: when the vehicle is stationary or close to a stop (for example a speed less than 3km / h), the GMP mode transition is immediately authorized.

The result of the authorization function is a data item or authorization message 3 for the wheel torque target calculation means. The calculation means comprise a variety of torque setpoint calculation functions dependent on a multitude of parameters such as the motorization mode, the driver request, the speed of the vehicle. Among these functions are also defined the maps of torque setpoints for each motorization mode. The invention applies to any type of hybrid vehicle that can operate in different modes of motorization and comprising means so that the driver can control these modes of motorization.

Claims

1. Control method implemented by a control device (CTL) of a hybrid vehicle powertrain for effecting the transition from a first motorization mode to a second motorization mode of said powertrain, characterized in that what it involves the following successive stages:

a step of detecting a transition request (M) from the first motorization mode to the second motorization mode,

if a driver request (C1 -C8) is received by the control device before the end of the transition, a step of controlling the parameters of the request with respect to predetermined conditions allowing the transition to make the transition before the end of the transition. delay,

2. The method of claim 1, wherein the conductive request is a request for variation of wheel torque.

3. Method according to claim 1, wherein the conductive request is a request configuring the control device so that the wheel torque calculation is independent of the motorization mode.

4. The method of claim 2 or 3, wherein the driver request is initiated by an interface means (IHM2) of the vehicle between a driver of the vehicle and the control device.

5. Method according to any one of the preceding claims, wherein the transition request is initiated by an interface means (IHM1) of the vehicle between a driver of the vehicle and the control device to select the drive mode of the powertrain .

6. Method according to any one of the preceding claims, wherein the delay is a function of the motorization modes of the transition.

7. Control device (CTL) of a powertrain for a hybrid vehicle, said powertrain being able to operate in at least a first and second modes of motorization, comprising means for detecting a transition request of the first mode of motorization to the second motorization mode, characterized in that it also comprises means (1) for generating a delay when a transition request (M) is detected to effect the transition at the end of the delay and a means (2) ) to trigger the transition before the end of the delay on receipt of a driver request (C1 -C8).

8. Device according to claim 7, wherein the means for triggering the transition is configured by an authorization function defining conditions with respect to parameters of the driver request (C1-C8) that allow the transition before the end of the delay. .

9. Hybrid vehicle characterized in that it comprises a control device (CTL) according to claim 7 or 8, and in that it further comprises a first conductive interface means (IHM1) for selecting the motorization mode powertrain and to initiate the transition request (M) and a second conductive interface means (IHM2), for example an accelerator pedal, to initiate the driver request (C1 -C8).