METHOD FOR MONITORING UNDESIRABLE MOVEMENT OF AN ELECTRIC OR HYBRID MOTOR VEHICLE

Abstract

The invention relates to a method for monitoring an undesirable movement of an electric or hybrid motor vehicle, said vehicle comprising at least one pedal, the vehicle comprising a speed sensor, said vehicle comprising a controller, characterized in that said method comprises a step of receiving (E1) a stopping instruction (C) by the controller; a step of determining (E2) a stopping distance (DA) as a function of said stopping instruction (C); a step of measuring (E3) a distance traveled (DP) by said speed sensor; a step of comparing (E4) the stopping distance (DA) and the distance traveled (DP); a step of detecting (E5) an undesirable movement by the controller when the distance traveled (DP) is greater than the stopping distance (DA). Figure 1

Description

Title of the invention: METHOD FOR MONITORING UNDESIRABLE MOVEMENT OF AN ELECTRIC OR HYBRID MOTOR VEHICLE

[0001] The invention relates to electric or hybrid motor vehicles, and more particularly to the occurrence of undesirable movements of these vehicles.

[0002] French patent application FR2994594 is known from the prior art, which describes a method for measuring the distance between a first point A and a second point B of a route by a self-propelled vehicle. The self-propelled vehicle comprises wheels enabling it to move, each wheel having a circumference. Furthermore, the invention relates to an odometer for said self-propelled vehicle. The odometer is a system for measuring the number of revolutions of a wheel moving on the ground by the movement of the vehicle. The odometer is embedded in said vehicle to deduce the distance traveled by said vehicle. The distance traveled is dependent on the circumference of the wheel. The odometer comprises an incremental encoder system coupled to said wheel. The encoder system delivers pulses in a given number per wheel revolution. In addition, the odometer comprises a detector capable of detecting markers.In said method, a first marker is placed at point A and a second marker is placed at point B. Finally, the odometer comprises a control unit capable of receiving the pulses emitted by said encoder system and a counting circuit for counting the number of pulses emitted. However, a drawback remains. The invention disclosed in the previously cited patent application makes it possible to know the distance traveled by a vehicle. However, there is no monitoring means for detecting a fault in the movement of the vehicle, i.e. an undesirable movement of said vehicle. The consequences of these undesirable movements are numerous: collision with another vehicle or an environment, the vehicle falling into a ditch or a body of water, driver anxiety, etc.

[0003] The objective of the present invention is to remedy these drawbacks and to detect unwanted movements.

[0004] To achieve this objective, the invention proposes a method for monitoring undesirable movement of an electric or hybrid motor vehicle, said vehicle comprising at least one pedal, said pedal being capable of having a depression rate as a function of a force exerted by a driver on said pedal, the depression rate determining a driving speed setpoint to be reached, said driving speed setpoint being zero when the depression rate is zero, said vehicle comprising a speed sensor configured to measure a speed of initial rolling, the initial rolling speed being less than a predetermined threshold value, said vehicle comprising a distance measurement sensor and a controller configured to collect and process the pedal depression rate, the rolling speed setpoint, the initial rolling speed measured by the speed sensor and the distance measured by the distance sensor, characterized in that said method comprises the following steps: - a step of receiving an instruction to stop the vehicle by the controller when the rate of sinking is zero; - a step of determining a stopping distance as a function of said stopping instruction by the controller, the stopping distance corresponding to the distance to be covered to bring the vehicle to a stop; - a step of measuring a distance traveled by the vehicle by said distance measuring sensor; - a comparison step between the stopping distance and the distance traveled by the controller; - a step of detection of unwanted movement by the controller as soon as the distance traveled is greater than the stopping distance.

[0005] Thanks to the invention, unwanted movements are detected.

[0006] Advantageously, during said determination step, the stopping distance is a constant or a series of constants determined relative to the initial rolling speed.

[0007] Alternatively, during said determining step, the stopping distance is dependent on the initial rolling speed.

[0008] Thus, the driver is accustomed to a stopping distance, depending or not on the speed at which he is driving, and the vehicle brakes if the stopping distance is exceeded. Thus, the driver is not surprised while driving.

[0009] Preferably, during the detection step, said controller activates a safe state blocking the movement of the vehicle as soon as the unwanted movement is detected.

[0010] Advantageously, said vehicle comprises service brakes and a parking brake, the activation of said safe state being effected by the actuation of the service brakes and / or the parking brake.

[0011] Preferably, said vehicle comprises an automatic gearbox, the activation of the safe state being carried out by activation of a parking locking device.

[0012] Preferably, said vehicle comprises an electric motor, the activation of the safe state being carried out by the application of an engine torque intended to control the stopping of said vehicle.

[0013] The vehicle is then immobilized to ensure the safety of the driver and potential passengers of said vehicle.

[0014] Preferably, said predetermined threshold value is equal to 7 km / h.

[0015] The invention also relates to a computer program comprising instructions which, when the program is executed by a computer, cause the latter to implement the steps of the method for monitoring undesirable movement of an electric or hybrid motor vehicle described above.

[0016] Furthermore, the invention relates to an electric or hybrid motor vehicle configured to implement the method for monitoring undesired movement of an electric or hybrid motor vehicle previously described.

[0017] The invention will be further detailed by the description of a non-limiting embodiment, and on the basis of the appended figure illustrating the invention, in which: [Fig.l] schematically illustrates, in the form of a flowchart, a method for monitoring unwanted movement of an electric or hybrid motor vehicle according to an embodiment of the present invention.

[0018] [Fig.l] schematically illustrates, in the form of a flowchart, a method for monitoring undesirable movement of an electric or hybrid motor vehicle. The vehicle has an initial driving speed lower than a predetermined threshold value. The initial driving speed is the speed at which said vehicle is traveling before stopping said vehicle is requested. Preferably, said predetermined threshold value is equal to 7 km / h. The vehicle comprises at least one pedal. The pedal actuates the powertrain. Indeed, the vehicle comprises an electric motor and a battery configured to store and distribute electrical energy to the electric motor. The pedal makes it possible to control the acceleration and braking, or even stopping, of the vehicle. When a driver presses said pedal, the electrical energy stored in said battery is transmitted to the electric motor.The initial driving speed is adjusted according to the amount of electrical energy supplied to the electric motor by said battery. Conversely, when the driver releases the pedal, the electrical energy is redirected from the electric motor to the battery. In the case of a hybrid motor vehicle comprising a thermal engine, in the context of thermal traction during which the thermal engine operates without the intervention of the electric motor, the role of the pedal is to control the amount of fuel entering the thermal engine and to adjust the intake of the air flow necessary for the combustion of said fuel. Thus, a driver is able to control the speed of movement of said vehicle by using the pedal. The pedal is capable of having a depression rate according to a force exerted by the driver on said pedal. The depression rate determines a driving speed setpoint to be reached.The rate of pedal depression is directly correlated to the driving speed setpoint desired by the driver. Thus, for example, when the pedal depression rate is 5%, it is interpreted as the driver's desire to reach an initial driving speed equal to 1 km / h. The relationship between the pedal depression rate and the driving speed setpoint is proportional or non-linear. When the depression rate is zero, the vehicle brakes until the vehicle stops. Indeed, the initial driving speed decreases until it becomes zero. In addition, the vehicle includes a speed sensor for measuring the initial driving speed and a controller configured to collect and process the pedal depression rate, the driving speed setpoint, the initial driving speed measured by the speed sensor and the distance measured by the distance sensor. In addition, the vehicle includes a distance measuring sensor.During a reception step E1, a stopping instruction C is received by the controller when the pedal depression rate is zero. During a determination step E2, the controller determines a stopping distance DA corresponding to the distance to be traveled to bring the vehicle to a stop. The stopping distance DA is a function of the stopping instruction C and the initial driving speed of the vehicle. In an alternative embodiment, the stopping distance DA is a predetermined constant or a series of constants determined with respect to one or more conditions, for example with respect to the initial driving speed. The objective is for the stopping distance of the vehicle to always be identical, or always identical for the same initial driving speed for example, and for the vehicle to brake before the driver reacts if said stopping distance DA is exceeded. Thus, the driver is not surprised.The stopping distance of the vehicle is made independent of the mass of said vehicle and of the slope. During a measurement step E3, the distance measuring sensor measures a distance traveled DP by the vehicle before it stops. During a comparison step E4, the stopping distance DA calculated during the determination step E2 and the distance traveled DP measured during the measurement step E3 are compared. When the distance traveled DP is less than or equal to the stopping distance DA, then this means that the vehicle has stopped moving at the appropriate time according to the driver's wishes, in accordance with the stopping instruction C. When the distance traveled DP is greater than the stopping distance DA, this means that the movement of the vehicle has not been interrupted in accordance with the stopping instruction C. Thus, we speak of unwanted movement. The unwanted movement takes place against the driver's wishes, i.e. against the stopping instruction C.Thus, when the traveled distance DP is greater than the stopping distance DA, the unwanted movement is detected by the controller during a detection step E5. Preferably, when said unwanted movement is detected during the detection step E5, said vehicle activates a safe state. The safe state blocks the movement of the vehicle when said unwanted movement is detected. Preferably, the vehicle . has service brakes and a parking brake and activation of the safe state is carried out by actuation of the service brakes and / or the parking brake. The service brakes are the main brakes for braking or stopping the vehicle via a brake pedal. The parking brake is a brake for immobilizing the vehicle when it is stationary. Advantageously, said vehicle has an automatic gearbox, activation of the safe state being carried out by activation of a parking lock device. The automatic gearbox is a type of transmission that automatically changes gears without driver intervention. The parking lock device is a safety feature designed to prevent the vehicle from moving when it is stationary.Preferably, said vehicle comprises an electric motor, the activation of the safe state being carried out by the application of an engine torque intended to control the stopping of said vehicle. The engine torque is a force emitted by the engine. This reduces the probability that the unwanted movement develops into a traffic accident. When the safe state is activated, said vehicle is therefore immobilized. To break this immobilization, it is necessary to stop and restart the vehicle's engine.

[0019] Furthermore, the invention relates to a computer program configured to implement said method for monitoring an undesirable movement of an electric or hybrid motor vehicle. The invention also relates to an electric or hybrid motor vehicle configured to implement said method previously described.

Claims

Claims

1. Method for monitoring an undesirable movement of an electric or hybrid motor vehicle, said vehicle comprising at least one pedal, said pedal being capable of having a depression rate as a function of a force exerted by a driver on said pedal, the depression rate determining a driving speed setpoint to be reached, said driving speed setpoint being zero when the depression rate is zero, said vehicle comprising a speed sensor configured to measure an initial driving speed, the initial driving speed being less than a predetermined threshold value, said vehicle comprising a distance measurement sensor and a controller configured to collect and process the pedal depression rate, the driving speed setpoint, the initial driving speed measured by the speed sensor and the distance measured by the distance sensor,characterized in that said method comprises the following steps: - a step of receiving (El) a stopping instruction (C) of the vehicle by the controller when the rate of sinking is zero; - a step of determining (E2) a stopping distance (DA) as a function of said stopping instruction (C) by the controller, the stopping distance (DA) corresponding to the distance to be traveled to reach the stopping of the vehicle; - a step of measuring (E3) a distance traveled (DP) by the vehicle by said distance measuring sensor; - a step of comparing (E4) the stopping distance (DA) and the distance traveled (DP) by the controller; - a step of detecting (E5) the undesired movement by the controller as soon as the distance traveled (DP) is greater than the stopping distance (DA).,

2. Method according to claim 1 characterized in that, during said determination step (E2), the stopping distance (DA) is a constant or a series of constants determined in relation to the initial rolling speed.

3. Method according to claim 1 characterized in that, during said determination step (E2), the stopping distance (DA) is dependent on the initial rolling speed.

4. Method according to any one of claims 1 to 3 characterized in that, during the detection step (E5), said controller activates a state safe blocking the movement of the vehicle as soon as unwanted movement is detected.

5. Method according to claim 4 characterized in that said vehicle comprises service brakes and a parking brake, the activation of said safe state being carried out by the actuation of the service brakes and / or the parking brake.

6. Method according to claim 4 or 5 characterized in that said vehicle comprises an automatic gearbox, the activation of the safe state being carried out by an activation of a parking locking device.

7. Method according to any one of claims 4 to 6, characterized in that said vehicle comprises an electric motor, the activation of the safe state being carried out by the application of an engine torque intended to control the stopping of said vehicle.

8. Method according to any one of claims 1 to 7 characterized in that said predetermined threshold value is equal to 7 km / h.

9. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to implement the steps of the method for monitoring undesired movement of an electric or hybrid motor vehicle according to any one of claims 1 to 8.

10. An electric or hybrid motor vehicle configured to implement the method for monitoring unwanted movement of an electric or hybrid motor vehicle according to any one of claims 1 to 8.

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