METHOD FOR MANAGING THE BRAKING OF A MOTOR VEHICLE

Abstract

The invention relates to a method for managing the braking of a motor vehicle, comprising an activation step (E1) of the driving mode when the predetermined wheel torque exceeds the first wheel torque setpoint, said second wheel torque setpoint being applied by the engine control unit; and a maintenance step (E2) of the driving mode when the driver applies force to said brake pedal, said speed control device being deactivated. Optionally, the method includes a deactivation step (E3) of the driving mode when the brake pedal depressment rate decreases to a predetermined threshold value. Figure 1

Description

Title of the invention: METHOD FOR MANAGING THE BRAKING OF A MOTOR VEHICLE

[0001] The invention relates to the management of braking in motor vehicles.

[0002] Prior art patent application EP3363696 is known, describing a speed control system with several disengagement modes selected by a brake pedal of an automated vehicle. The system comprises the brake pedal and a controller. Each disengagement mode is determined by the pressure exerted on the brake pedal, the duration of the pressure, or a combination of the pressure exerted on the brake pedal and the duration of the pressure. A first disengagement mode is the disengagement of the vehicle's acceleration control, while maintaining the vehicle's deceleration control. A second disengagement mode is the disengagement of both the vehicle's acceleration control and the vehicle's deceleration control. Another disengagement mode is the complete deactivation of the speed control system.The pressure applied to the brake pedal and / or the duration of brake pedal pressure is transmitted to the controller, which is responsible for providing a command to implement one of the disengagement modes. However, a drawback remains. When the vehicle is descending and / or heavily loaded, its speed may exceed the speed commanded by the cruise control system. Therefore, the driver will not exert the same force over the same duration to slow the vehicle down compared to driving on level ground. Similarly, when going uphill, the driver will not exert the same force and pressure duration to achieve the same braking effect as when going downhill, for example. The disengagement modes do not take into account the terrain on which the vehicle is traveling. They are therefore not suitable for all types of terrain.

[0003] The objective of the present invention is to remedy these drawbacks and to allow linear braking of the vehicle when the cruise control is deactivated by the driver.

[0004] To achieve this objective, the invention proposes a method for managing the braking of a motor vehicle, said vehicle having a determined wheel torque, said vehicle comprising a brake pedal and an engine control unit configured to regulate the determined wheel torque, said vehicle comprising a speed control device capable of determining an initial wheel torque setpoint when said speed control device is activated by the driver, said engine control unit being capable of activating a configured driving mode to issue a second torque command to the wheel, said second torque command to the wheel being lower than said first torque command to the wheel, characterized in that said method comprises the following steps: - a step of activating the driving mode when the determined wheel torque is greater than the first wheel torque setpoint, said second wheel torque setpoint being applied by the engine control unit; - a step of maintaining the driving mode when the driver exerts force on said brake pedal, said speed regulation device being deactivated.

[0005] Thanks to the invention, braking is linear because it is solely linked to the driver's will.

[0006] Advantageously, the brake pedal has a determined depressment rate, the depressment rate being 0% when the brake pedal is fully released, the depressment rate being 100% when the brake pedal is fully depressed, the method comprising a step of deactivating the driving mode when the depressment rate of the brake pedal decreases to a predetermined threshold value.

[0007] Thus, the speed regulation device is completely deactivated as soon as the driver fully releases the brake pedal.

[0008] Advantageously, the predetermined threshold value is equal to 0%.

[0009] Preferably, said speed control device is an adaptive speed regulator, a fixed speed regulator, a speed limiter or a speed limiting device.

[0010] The invention also relates to a computer program comprising instructions which, when said program is executed by a computer, lead the latter to implement the steps of the braking management process of a motor vehicle previously described.

[0011] Furthermore, the invention relates to a motor vehicle comprising an engine control unit configured to implement the motor vehicle braking management method described above.

[0012] Preferably, said vehicle is of the electric, hybrid or hydrogen type.

[0013] The invention will be further detailed by the description of a non-limiting embodiment, and on the basis of the attached figure illustrating the invention, in which [Fig.1] illustrates, in the form of a logic diagram, a method for managing the braking of a motor vehicle.

[0014] The invention relates to a method for managing the braking of a motor vehicle. Preferably, the motor vehicle is electric, hybrid, or hydrogen-powered. The vehicle has a brake pedal configured to have a specific deflection depth. The deflection depth varies between 0%, when the brake pedal is fully released, and 100%, when the brake pedal is fully depressed. The vehicle has a predetermined wheel torque. Furthermore, the vehicle includes an engine control unit configured to regulate this predetermined wheel torque. The wheel torque is positive when the vehicle accelerates and negative when the vehicle brakes. In addition, the vehicle includes a speed control system configured to determine an initial wheel torque setting when the driver activates the speed control system. For example, the speed control system is activated when the driver moves a lever located on the steering wheel. The primary function of the speed control system is to maintain a constant vehicle speed, regardless of the terrain.Thus, when the vehicle is traveling on a downhill slope, it is necessary to reduce the torque at the wheels to prevent acceleration that would be contrary to the driver's intent. Preferably, the speed control system is chosen from among adaptive cruise control, fixed cruise control, a speed limiter, or a speed restrictor. Adaptive cruise control, also known as adaptive cruise control (ACC), is a speed control system that, in addition to maintaining a constant driving speed, automatically adjusts the vehicle's speed according to the distance to the vehicle ahead. Fixed cruise control is also a system that maintains a constant speed, regardless of the position of other vehicles around it.A speed limiter is a device that allows the driver to set a maximum driving speed that the vehicle must not exceed. Unlike adaptive or fixed cruise control, the driver must manually maintain acceleration, but the system will prevent the vehicle from exceeding the preset speed. A speed limiter is a safety feature that restricts a vehicle's maximum speed to a predetermined value. This may be mandated by the manufacturer for safety reasons or activated voluntarily by the driver. The speed limiter is designed to prevent the risk of excessive speeds. As with prior art, the speed limiter deactivates when the driver presses the brake pedal. The engine control unit is capable of activating a driving mode configured to send a second torque command to the wheels.The second wheel torque setpoint is lower than the first wheel torque setpoint. During an activation step E1, the driving mode is activated when the determined wheel torque is greater than the first wheel torque setpoint so that the second wheel torque setpoint is applied by the engine control unit. During a hold step E2, the... The driving mode, and consequently the second wheel torque setting, is maintained when the driver applies force to the brake pedal, i.e., when the brake pedal depressment rate is strictly greater than 0%. Optionally, the method includes a step E3 for deactivating the driving mode when the brake pedal depressment rate decreases to a predetermined threshold value. The invention prevents the cancellation of the second wheel torque setting at the same time as the cancellation of the first wheel torque setting. Indeed, the second wheel torque setting is lower than the first wheel torque setting. When applied, the second wheel torque setting constantly reduces the vehicle's speed, i.e., braking.If the driver presses the brake pedal and the second wheel torque setting is canceled at the same time as the first wheel torque setting decreases, the braking associated with the second wheel torque setting is interrupted, which is contrary to the driver's intention to brake more. Thanks to the invention, maintaining the second wheel torque setting as long as the driver applies force to the brake pedal allows for linear braking, adapted to the driver's intent. Preferably, the second setting is completely canceled when the second pedal deflection decreases to a predetermined threshold value. Preferably, this predetermined threshold value is 0%. In other words, the brake pedal is fully released.

[0015] The invention also relates to a computer program configured to implement the method described above. Furthermore, the invention relates to a motor vehicle comprising an engine control unit configured to implement said method.

Claims

Demands

1. A method for managing the braking of a motor vehicle, said vehicle having a determined wheel torque, said vehicle comprising a brake pedal and an engine control unit configured to regulate the determined wheel torque, said vehicle comprising a speed control device capable of determining a first wheel torque setpoint when said speed control device is activated by the driver, said engine control unit being capable of activating a driving mode configured to issue a second wheel torque setpoint, said second wheel torque setpoint being lower than said first wheel torque setpoint, characterized in that said method comprises the following steps: - an activation step (E1) of the driving mode when the determined wheel torque is greater than the first wheel torque setpoint,said second wheel torque command being applied by the engine control unit; - a holding step (E2) of the driving mode when the driver applies force to said brake pedal, said speed regulation device being deactivated.

2. A method according to claim 1 characterized in that the brake pedal has a determined depressment rate, the depressment rate being 0% when the brake pedal is fully released, the depressment rate being 100% when the brake pedal is fully depressed, the method comprising a deactivation step (E3) of the driving mode when the depressment rate of the brake pedal decreases to a predetermined threshold value.

3. The method according to claim 2 characterized in that the predetermined threshold value is equal to 0%.

4. A method according to any one of claims 1 to 3 characterized in that said speed control device is an adaptive speed regulator, a fixed speed regulator, a speed limiter or a speed restrictor device.

5. A computer program comprising instructions which, when said program is executed by a computer, cause the computer to 6 to implement the steps of the braking management process of a motor vehicle according to any one of claims 1 to 4.

6. Motor vehicle comprising an engine control unit configured to implement the method of managing the braking of a motor vehicle according to any one of claims 1 to 4.

7. Vehicle according to claim 6 characterized in that said vehicle is of the electric, hybrid or hydrogen type.

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