MOTOR VEHICLE COMPRISING SPEED LIMITING SYSTEMS FOR REVERSE AND FORWARD MOTION, AND PROCESSES ON THE BASIS OF SUCH A VEHICLE

Abstract

The invention relates to a motor vehicle (V) comprising: - a powertrain (PW) having a first configuration enabling forward movement and a second configuration enabling reverse movement; - a first speed limiter system (SLS1) connectable to the powertrain (PW) when it is in the first configuration to limit the vehicle's speed; - a second speed limiter system (SLS2), different from the first speed limiter system (SLS1), connectable to the powertrain (PW) when it is in the second configuration to limit the vehicle's speed. The invention also relates to a method based on such a vehicle. Figure 1

Description

Title of the invention: MOTOR VEHICLE COMPRISING SPEED RESTRICTION SYSTEMS FOR THE REVERSE AND FORWARD GEAR, AND METHOD BASED ON SUCH A VEHICLE

[0001] The invention relates to the field of systems for limiting and regulating the speed of motor vehicles.

[0002] Currently, the prior art proposes various types of speed limitation and regulation modules (or functions) in motor vehicle powertrain control systems. These include: - adaptive cruise control used as a speed and distance regulator between vehicles; - cruise control; - the speed limiter; - speed restriction; - etc.

[0003] The speed restriction function aims to restrict the maximum speed of the motor vehicle for organic constraints.

[0004] This speed restriction function is active regardless of the direction of travel.

[0005] A maximum speed limitation is required on certain powertrains to limit the speed when reversing (to 30km / h for example for certain vehicles).

[0006] Unfortunately, such a limitation would not be relevant for forward motion.

[0007] A workaround is used via a calibration of the maximum speed limitation. However, the maximum engine speed limitation function is intended to protect the component from over-revving, and therefore from its destruction. It is not intended to meet a need for limiting / regulating vehicle speed.

[0008] Furthermore, variations in acceleration generate jolts when approaching the calibrated target value. These disturbances are perceptible to the driver, and cause discomfort and inconvenience.

[0009] Furthermore, this degrades control of the vehicle when reversing under full load, which can be detrimental to safety.

[0010] Another solution is a calibration dependent on the vehicle's V1000, but the calibration is not transversal.

[0011] The calculation of the V1000 is dependent on the gear ratios of the gearbox and the developed wheels. Thus, it is necessary to check and adapt for each vehicle, the consistency between calibration and the need for limitation.

[0012] Furthermore, the speed control is not set to achieve comfortable driving, and may not cover all life situations.

[0013] In the context of an electrified powertrain, the control of the vehicle speed via a maximum target results from an imposed maximum torque, but there is no speed regulation strictly speaking.

[0014] The solution is not robust: the torque calibration value is adapted to the vehicle concerned under the conditions of vehicle mass at half payload, and for a 0% slope (flat ground).

[0015] This torque value is therefore no longer suitable for different mass conditions (example MT AC) and also for slope conditions other than 0%, to maintain the regulation value of the speed target.

[0016] Furthermore, this is open-loop control that is highly dependent on the precision of the torque structure.

[0017] An objective of the present invention is to remedy the defects of the prior art, and in particular to propose a precise, robust, comfortable and configurable speed limiting solution specifically for forward or reverse travel.

[0018] To achieve this objective, the invention proposes a motor vehicle comprising: - a powertrain having a first configuration allowing forward gear to be implemented, and a second configuration allowing reverse gear to be implemented; - a first speed restriction system connectable to the powertrain when it is in the first configuration to restrict the speed of the vehicle; - a second speed limiting system, different from the first speed limiting system, connectable to the powertrain when it is in the second configuration to limit the speed of the vehicle.

[0019] Advantageously, the invention proposes a specific clamping solution for forward movement, and a second specific clamping solution for reverse movement. These solutions appear precise, robust and comfortable.

[0020] Furthermore, there is no longer any need to divert a function not initially intended to provide the speed restriction service.

[0021] Furthermore, this allows better control of over-acceleration (or "jerk" in English, i.e. the derivative of acceleration) to address vehicle stability issues.

[0022] According to a variant, the first speed limiting system and / or the second speed limiting system implements closed-loop speed regulation.

[0023] This allows for precise regulation.

[0024] According to one variant, the powertrain uses two drive wheels.

[0025] This makes it possible to adapt the invention to two-wheel drive vehicles.

[0026] According to one variant, the powertrain implements four-wheel drive.

[0027] This makes it possible to adapt the invention to four-wheel drive vehicles.

[0028] The invention further relates to a speed limiting method for a motor vehicle according to the invention, characterized in that it comprises the following steps: - a step of speed restriction in forward gear by means of the first speed restriction system when the powertrain is in the first configuration; and - a step of speed restriction in reverse gear by means of the second speed restriction system when the powertrain is in the second configuration.

[0029] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the attached [Fig.l] which schematically illustrates a motor vehicle according to a preferred embodiment of the invention.

[0030] The invention relates to a motor vehicle V of the type comprising a GMP powertrain. The GMP powertrain may or may not comprise an automatic gearbox.

[0031] The GMP powertrain has a first forward gear configuration allowing forward gear to be implemented.

[0032] The GMP powertrain further has a second reverse gear configuration allowing reverse gear to be implemented.

[0033] According to the invention, a motor vehicle V further comprises a first speed restriction system BVI, and a second speed restriction system BV2 different from the first speed restriction system BV1.

[0034] The first speed restriction system BV1 is connectable to the powertrain GMP when it is in the first configuration to restrict the speed of the vehicle when moving forward.

[0035] The second speed restriction system BV2 can be connected to the GMP powertrain when it is in the second configuration to restrict the speed of the vehicle in reverse.

[0036] Thus, the restriction is made by means of the first speed restriction system BV 1 when the vehicle is in forward gear, or by means of the second speed restriction system BV 1 when the vehicle is in reverse gear.

[0037] The current mechanism uses any vehicle speed, and the reverse speed restriction is based on recognition of the direction of travel requested by the driver. This makes it possible to calibrate the vehicle speed value to the desired limitation (30 km / h for example) for this direction of travel.

[0038] The speed regulation is closed loop

[0039] In the case of an electric, hybrid, or hydrogen type motor vehicle, the invention makes it possible to avoid going to the high speeds that the vehicle could reach, because the electric machine would allow the vehicle to reach very high speeds.

[0040] The invention remains compatible with standard vehicle systems, in particular other speed restriction systems (safety restriction present in the event of a fault, restriction limiting the general speed of the vehicle, for example to 180 km / h).

[0041] The invention is compatible with two-wheel drive and four-wheel drive architectures.

Claims

Claims

1. Motor vehicle (V) comprising: - a powertrain (GMP) having a first configuration allowing forward gear to be implemented, and a second configuration allowing reverse gear to be implemented; - a first speed limiting system (BV1) connectable to the powertrain (GMP) when it is in the first configuration to limit the speed of the vehicle; - a second speed limiting system (BV2), different from the first speed limiting system (BV1), connectable to the powertrain (GMP) when it is in the second configuration to limit the speed of the vehicle.

2. Motor vehicle (V) according to claim 1, characterized in that the first speed limiting system (BV1) and / or the second speed limiting system (BV2) implements closed-loop speed regulation.

3. Motor vehicle (V) according to any one of claims 1 to 2, characterized in that the powertrain (GMP) uses two drive wheels.

4. Motor vehicle (V) according to any one of claims 1 to 2, characterized in that the powertrain (GMP) uses four drive wheels.

5. Speed ​​limiting method for a motor vehicle (V) according to any one of claims 1 to 4, characterized in that it comprises the following steps: - a step of limiting the speed in forward gear by means of the first speed limiting system (BV1) when the powertrain (GMP) is in the first configuration; and - a step of limiting the speed in reverse gear by means of the second speed limiting system (BV2) when the powertrain (GMP) is in the second configuration.

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