FR3010674A1 - BRAKE CONTROL SYSTEM FOR A HYBRID OR ELECTRIC VEHICLE COMPRISING A SPEED OR DISTANCE CONTROL - Google Patents

Abstract

Braking control system for a hybrid or electric vehicle having a machine delivering a braking torque by producing energy which is stored in accumulators, and control of regulation or limitation of its speed, or automatic regulation of the distance with a preceding vehicle, characterized in that in an operating mode, the control of speed regulation or limitation, or distance control, makes it possible to adjust the level of braking by the machine during a release of the accelerator pedal.

Description

The present invention relates to a braking control system for a hybrid or electric vehicle, as well as a hybrid or electric vehicle equipped with a braking control system for a hybrid or electric vehicle, and a hybrid or electric vehicle equipped with a braking control system. such a system. Hybrid vehicles using electrical energy, and electric vehicles, generally comprise a reversible electric machine that can deliver mechanical power for the traction of the vehicle, or apply a braking torque on the wheels while working as a generator, which makes it possible to recover kinetic energy from the vehicle by producing an electric current that recharges the batteries. [0003] Hybrid vehicles using other types of energy, such as hydraulic or pneumatic pressure, also generally include a machine capable of braking the vehicle and recharging the accumulators storing this energy. These vehicles further comprise a mechanical braking circuit controlled by the driver by means of a brake pedal, which acts mechanically on the wheels to brake them by the action of friction pads. A known braking control system for a hybrid electric vehicle, presented in particular by US-A1-20090029823, arranged in addition to the mechanical braking circuit, includes specific commands that allow when the driver releases the pedal of accelerator to apply by the electric machine a certain adjustable braking torque, in order to recover energy and recharge the batteries. It is realized whether the battery charge level accepts an additional charge, the equivalent of the engine brake usually produced by the engine, in a hybrid mode of operation where the engine is no longer driven by the drive wheels. However, this control system requires additional controls on the dashboard, which add complexity and additional costs. [000s] Another known brake control system for a hybrid vehicle uses shift paddles of a gearbox to give a positive or negative pulse which respectively decreases or increases the braking torque of the machine. electric when the accelerator pedal is released. However this solution is not applicable on vehicles with no control pallet of the gearbox. [001 0] Alternatively, another known braking control system uses a controlled electro-hydraulic device receiving the information of the pressure applied on the brake pedal, which is transformed by a program implemented by a computer to determining, according to the driver's request and the driving conditions, the distribution between the braking by the electric machine for recovering energy, and the braking with the mechanical braking circuit. It can thus be provided in case of release of the accelerator pedal and without actuation of the brake pedal, an electric braking equivalent to the engine brake, then during a slight pressure on the brake pedal more electric braking important, and during a pronounced support additional braking by the mechanical braking circuit. Moreover, when the batteries are full, the controlled device then achieves equivalent braking only with the mechanical braking circuit. This braking control system comprising the electrohydraulic device optimizes energy recovery, but it is complex, and has a high cost. In addition, the feel of the brake pedal is artificially realized, generally having an elastic feel, without biting braking, which can be unpleasant. The same problems arise for hybrid vehicles performing during braking, production and storage of energy other than electrical, such as hydraulic or pneumatic energy. The present invention is intended to avoid these disadvantages of the prior art. It proposes for this purpose a braking control system for a hybrid or electric vehicle having a machine delivering a braking torque by producing an energy that is stored in accumulators, a regulation control or limitation of its speed, or automatic regulation of the distance with a preceding vehicle, characterized in that in an operating mode, the control of regulation or limitation of the speed, or regulation of distance, makes it possible to regulate the braking level by the machine when releasing the accelerator pedal. An advantage of this control system is that it uses commands already existing on a large number of vehicles to achieve in addition the adjustment of the braking level when releasing the accelerator pedal, allowing an economical way of optimize the energy recovery, and adapt it to the wishes of the driver. One can in particular according to the habits of the different countries, to request a braking torque more or less important. The braking control system according to the invention may further comprise one or more of the following features, which may be combined with each other. Advantageously, the regulation or speed limitation control achieves a decrease in braking when the speed increase control is activated, and an increase in this braking when the speed decrease command is activated. Advantageously, the automatic distance control command achieves a decrease in braking when the distance reduction command is activated, and an increase in this braking when the request for increasing the distance is activated. Advantageously, the control system brakes the vehicle corresponding to several predefined deceleration levels of the vehicle. In particular, the control system may comprise three predefined deceleration levels. Advantageously, the control system comprises means for displaying the braking level requested by the driver. In particular the display means may use a power consumption indicator, indicating a level of energy produced by the braking. Advantageously, the highest braking level gives the vehicle a deceleration to maximize the recoverable energy by the GMP Hybrid. The invention also relates to a method of operating a control system comprising any one of the preceding characteristics, which when the accelerator pedal is released, systematically implements braking with a low level of braking. The invention further relates to a hybrid or electric motor vehicle having a machine delivering a braking torque by producing an energy that is stored in accumulators, and a control or regulation control of its speed, or automatic regulation of the distance with a previous vehicle, this vehicle comprising a brake control system delivered by the machine comprising any of the preceding characteristics. The invention will be better understood and other features and advantages will appear more clearly on reading the following description given by way of example, with reference to the accompanying drawings in which: - Figure 1 shows a command vehicle speed control and limitation system, used for a braking control system according to the invention; - Figure 2 shows as a function of time for this control system, different parameters during a release of the accelerator pedal; FIG. 3 shows a display on the dashboard of the state of the system; and FIGS. 4 to 6 present alternatively other commands that can be used for this system. Figure 1 shows a control and speed limitation of a vehicle, having at the end of a lever 2 placed behind the steering wheel, a rotary knob facing the driver 4 which controls in a "Cruise" position speed control, in a "Limit" position the speed limit, and in a "0" position the deactivation of these functions. The lever 2 further comprises an upper button 6 and a lower speed adjustment button 8 which give respectively positive pulses "Set +" or negative "Set-", to increase or decrease step by step. speed of regulation or limitation. The lever 2 finally comprises an end button 10 which allows in a "pause" position to temporarily disable the activated function, and in a "resume" position to return to the last request after a temporary neutralization of the function. For the application of this command to the braking control system according to the invention can be added to the rotary knob 4 an energy recovery position, called for example "Recup", or use the deactivation position " 0 ", to activate braking with energy recovery when releasing the accelerator pedal. [0032] An operation of the electric machine driven by the wheels of the vehicle is obtained to produce electrical energy stored in accumulators, or of another type of machine in the case of the recovery of a different energy. [0033] FIG. 2 successively presents a curve 20 giving the position of the accelerator pedal, a curve 22 giving the positive "+" or negative "-" pulses respectively on the upper 6 15 and lower 8 adjustment buttons. speed, and a vehicle acceleration curve expressed in m / s2. At time t0 the accelerator pedal 20 is released, the brake control system of the vehicle is implemented systematically with a low braking level "1", if the accumulators storing the energy produced 20 have a level of charge to receive this energy. The driver then adjusts the braking level of the vehicle by means of pulses on the upper and lower buttons 8, giving in this example successively a first negative pulse which increases braking to a mean level "2". a second negative impulse which raises it to a high level "3", a third positive impulse which decreases it to the average level "2" and a fourth positive impulse which reduces it to a low level "1". Advantageously, the high level of braking gives a deceleration of the vehicle to maximize the recoverable energy by the hybrid GMP (deceleration greater than or equal to 1m / s2), which is greater than the braking provided by the engine brake in the case of a drive by a heat engine. Thus, with the existing controls in the vehicle, an adjustment of the braking level occurring automatically during the release of the accelerator pedal, which can be adapted easily according to the driving circumstances and the driving habits, is thus inexpensively obtained with existing controls in the vehicle. driver, to ensure safety, comfort and a good level of energy recovery. [0038] FIG. 3 shows a display of the operation of the hybrid vehicle powertrain on the dashboard of this vehicle, comprising information on the general operation of the traction chain 30, and a power consumption indicator 32 comprising a circular dial in which is displayed a needle 36 which starts from 0 for a zero consumption, and can go up to 100%. Below zero consumption zero, the display comprises three levels of braking of the vehicle 34, low 1, medium 2 and high 3, corresponding to different energy recoveries presented in a negative manner on this dial of consumption of 'energy. The driver can see directly what level he has selected, to change it if necessary. FIG. 4 alternatively presents a lever 2 receiving various control knobs, which is actuated by moving it upwards along the "+" arrow or downwards along the "-" arrow, to obtain respectively an increase or a decrease in the regulated or limited speed of the vehicle. FIG. 5 alternatively presents a lever 2 which is actuated by moving it towards the front of the vehicle following the "+" arrow or rearward along the "-" arrow, to also obtain an increase or a decrease. speed. In the same manner these commands can be used to obtain an increase in the braking level by an action in the direction of the arrow "-", and a decrease in this level by an action in the direction of the arrow "+ ". Figure 6 shows an enlarged lever 42 which is on the side of the steering wheel 40, comprising various control buttons for activating functions of regulation and limitation of the vehicle speed, and automatic regulation the time taken to travel the distance between the preceding vehicle, according to the speed, and that distance which is measured by a detection means. The lever 42 is moved upwards along the arrow "Set +" or downwards along the arrow "Set-" to respectively increase or decrease the regulated or limited speed, and is moved to the forward following the arrow "Gap-" or rearward following the arrow "Gap +" to respectively reduce or increase the distance from the previous vehicle, automatically changing the speed. The movement of the lever 42 which controls the distance from the previous vehicle, can also be used to adjust the braking level in the case of the release of the accelerator pedal. Advantageously, a decrease in braking can be achieved when the "Gap-" distance reduction command is activated, and an increase in this braking when the request for increasing the "Gap +" distance is activated.

Claims (10)

CLAIMS1 - Braking control system for a hybrid or electric vehicle having a machine delivering a braking torque by producing an energy that is stored in accumulators, and a regulation or speed limitation control (2) , or automatic regulation of the distance with a previous vehicle (42), characterized in that in an operating mode, the regulation or speed limitation control, or distance control, to adjust the braking level by the machine when releasing the accelerator pedal. 2 - Control system according to claim 1, characterized in that the speed control or speed control (2) performs a decrease in braking when the speed increase control is activated, and an increase in this braking when the speed decrease command is activated. 3 - Control system according to claim 1, characterized in that the automatic distance control command (42) achieves a decrease in braking when the distance reduction control is activated, and an increase in this braking when the demand distance increase is activated. 4 - Control system according to any one of the preceding claims, characterized in that it performs a braking of the vehicle corresponding to several predetermined levels of deceleration of the vehicle. 5 - Control system according to claim 4, characterized in that it comprises three predefined deceleration levels. 6 - Control system according to any one of the preceding claims, characterized in that it comprises a display means (34) of the braking level requested by the driver. 7 - Control system according to claim 6, characterized in that the display means (34) uses a power consumption indicator (32), indicating a level of energy produced by the braking. 8 - Control system according to any one of the preceding claims, characterized in that the highest braking level corresponds to a deceleration greater than or equal to 1m / s2. 9 - A method of operating a control system according to any one of the preceding claims, characterized in that when the accelerator pedal (20) is released, it systematically implements braking with a low level of braking. 10 - Hybrid or electric motor vehicle having a machine delivering a braking torque by producing an energy that is stored in accumulators, and a control or regulation of its speed (2), or automatic regulation of the distance with a preceding vehicle (42), characterized in that it comprises a braking control system delivered by this machine comprising any one of claims 1 to 8.