FR2818935A1 - DEVICE AND METHOD FOR STARTING A MOTOR VEHICLE - Google Patents

Abstract

A device and method for controlling the start of a motor vehicle comprising a clutch control for closing the force transmission link between the engine (50) of the vehicle and at least one wheel (80, 90) thereof, a slope maintenance system, an installation for detecting the position of the pedals (10) for detecting the end of the actuation of the brake pedal, a motor control installation which, if the end of the brake is detected actuation of the brake pedal, controls the motor to create a preload torque. The clutch control is adapted to control the force transmission linkage between the engine and at least one wheel (80, 90) of the vehicle so that the pre-stress torque is applied to at least one wheel of the vehicle when the load is detected. end of brake pedal actuation.

Description

The present invention relates to a control device

  to start the starting of a motor vehicle.

  The invention also relates to a method of implementing

  work of such a starting device.

  In many systems for controlling the power of internal combustion engines, present in a vehicle, the position of the accelerator pedal is no longer transmitted directly to the throttle flap of the internal combustion engine of the vehicle by a mechanical connection. . Instead, the throttle flap is generally controlled using an electric actuator through an electronic control unit. In such systems, the driver of the vehicle uses the accelerator pedal to determine a setpoint signal to the electronic control unit which indicates the

  power to the internal combustion engine.

  According to document DE 197 26 214 Ai, there is known a combined control system for an assisted clutch and the engine

internal combustion of the vehicle.

  According to document DE 197 26 214 Ai, the assisted clutch and the internal combustion engine of the vehicle form part of the transmission line. In the presence of a predetermined operating state, in particular in the field of low vehicle speeds, such as for example starting from a standstill, the assisted clutch and the internal combustion engine of the vehicle are controlled so that the position the accelerator pedal predetermines the acceleration or speed of the vehicle. While in general, apart from the starting operation, the transmission line controls the power or the torque supplied according to the position of the accelerator pedal, according to document DE 197 26 214 A1, during the operation of the accelerator pedal controls acceleration or speed. This allows a more comfortable starting of the

vehicle from stop.

  In addition, automatic braking systems are known which prevent the vehicle from moving forward or backward after the driver has stopped operating the accelerator pedal. These systems are called suppressing creeping movements, slope maintenance systems or starting assistance systems. A slope retention system is a system that makes it possible to avoid the forward or backward movements of a vehicle. Slope-keeping systems are usually used in combination with automatic gearboxes. They include a sensor detecting the movement of a vehicle wheel, a calculation installation and a

  signal transmission as well as a brake installation.

  Such a slope maintenance system is for example described in document US 5,415,467. According to this document, the system applies brake pressure to the wheel brake cylinders even if the driver stops applying pressure on the brake pedal. brake to keep the vehicle stationary. Wheel sensors detect any movement of the wheels and supply signals corresponding to the i0 movement to the computing unit. The calculation unit then emits a signal for a signal transmission installation; this in turn sends an actuation signal to the brake system. The calculation installation determines the output signal from the input signals supplied by the wheel sensors, an input signal from a brake pedal actuation sensor and a signal from input of a sensor detecting an actuation of the accelerator pedal. The calculation system thus controls the brake pressure in the wheel brake cylinders until the driver actuates the accelerator pedal. If between the moment when the driver stops applying the brake pedal and until the moment when the driver actuates the brake pedal again, the vehicle begins to move forward or to reverse, the wheel sensors detect the movement and the computation installation controls the installation

  of brake; in this case, it is a hydraulic installation

  locking (ABS system) so as to increase the braking torque applied to the wheels. As soon as the driver actuates the accelerator pedal and thus indicates that he wants to get the vehicle out of the stop position, the brake pressure in the wheel brake cylinders

  thus decreases the braking torque applied to the wheels.

  Other slope holding systems are known which are described in documents GB 2 314 596 and US 4 415 467. In such slope holding systems, when a preselected longitudinal speed of the vehicle is detected, this automatically increases the force of braking, regardless of driver intervention. This is done by increasing the brake pressure in the wheel brake cylinders. The brake pressure and thus the braking torque applied to the wheels is maintained until a start command is received as

  for example actuation of the accelerator pedal.

  In the systems described above, there is nevertheless a difficulty if the driver actuates the accelerator pedal, at least at the start the brake system cuts the movement of the vehicle or brakes it. In addition, this deteriorates the behavior of the vehicle during acceleration, because at least at the start, the acceleration is cut or decreased. This results in slower and more

slack of the vehicle.

  In addition, an elasticity of the entire transmission line, which is frequently increased by one or more mass flywheels, and of play in the vehicle transmission line, which still exists due to manufacturing tolerances, results in vibrations and noises, generated by the application of the engine torque to the accelerated transmission line very quickly, until the elasticity and the clearance are exceeded, and braked abruptly when the elasticity and the clearance are compensated and that the resistance of the wheels is applied to the

transmission line.

  The object of the present invention is to develop a starting control device as well as a starting method offering a

better vehicle behavior.

  To this end, the invention relates to a device of the type defined above, characterized in that it comprises - a clutch control for closing the force transmission link between the engine of the vehicle and at least one wheel of that -this, - a slope maintenance system, - an installation for detecting the position of the pedals for detecting the end of actuation of the vehicle brake pedal, and - an engine control installation, which when detected the end of actuation of the brake pedal, controls the engine to generate a prestressing torque, - the clutch control controlling the force transmission link between the engine and at least one wheel of the vehicle so that the pretensioning torque is applied to at least one vehicle wheel if the pedal position detection system detects the end of

  actuation of the vehicle brake pedal.

  The invention also relates to a starting control device for controlling the starting of a motor vehicle, characterized in that it comprises: - a clutch control for closing the force transmission link between a flywheel and at least a vehicle wheel, - a slope retention system, and - a pedal position detection installation for detecting the end of the actuation of the vehicle brake pedal, - the clutch control controlling the power link between the flywheel and at least one wheel of the vehicle so as to apply a pretensioning torque to at least one wheel of the vehicle, if the installation for detecting the position of the pedal detects the end of

  io actuation of the vehicle brake pedal.

  The invention also relates to a method of starting a motor vehicle using a clutch control to close a force transmission link between the vehicle engine and at least one wheel thereof, and with a slope maintenance system according to which the end of the actuation of the vehicle brake pedal is detected and if the end of the actuation of the brake pedal is detected, the engine generates a prestressing torque which controls the connection force transmission between the engine and at least one vehicle wheel by the clutch control so that the pretensioning torque is

applied to at least one wheel.

  The invention also relates to a method of starting a motor vehicle with a clutch control to close the force transmission link between a flywheel and at least one wheel of the vehicle and a slope-maintaining system according to which it is detected the end of the actuation of the brake pedal and if this end of actuation is confirmed, the force transmission link between the flywheel and at least one wheel is controlled by the clutch control so as to apply to the minus one wheel a couple of

  preload stored in the flywheel.

  The present invention advantageously allows better behavior when starting the vehicle from a standstill. In addition, the invention advantageously makes it possible to eliminate the annoying vibrations in the transmission line and the noises which they generate. In addition, the invention advantageously allows rapid acceleration of the vehicle to

from the stop.

  According to other advantageous characteristics of the device, - the slope maintenance system is designed to maintain a minimum braking torque on at least one wheel if the installation for detecting the position of the pedals detects the end of actuation of the vehicle brake pedal; - the pedal position detection system is designed so that, after having entered the end of actuation of the brake pedal, it captures the actuation of the accelerator pedal, and the slope retention system is designed to decrease the minimum torque gradually over a predetermined period of time if the pedal position detection system detects the end of actuation of the accelerator pedal; the pedal position detection system is designed to detect a degree of actuation of the accelerator pedal and the engine control system is designed to determine a setpoint torque as a function of the degree of actuation of the pedal. accelerator pedal and a torque for neutralizing the minimum braking torque, this torque for neutralizing the minimum braking torque having the same module as the minimum braking torque, and the engine is controlled to generate an overall starting torque, the amplitude corresponds to the sum of the neutralization torques, minimum braking torque and the setpoint torque, if the pedal position detection installation detects actuation of the accelerator pedal; - the pretensioning torque is large enough to exceed the clearance of the force transmission link between the vehicle engine and at

minus one wheel.

  The present invention will be described below with the aid of exemplary embodiments represented diagrammatically in the appended drawings, in which: FIG. 1 is a block diagram of an exemplary embodiment of a start-up control installation according to the invention, - Figure 2 shows a timing diagram representing the curve of the torque applied to the wheels as a function of time in the embodiment of Figure 1, - Figure 3 shows a flow chart of the example of operation of the start control installation of the

figure 1.

  Figure i shows a block diagram of a start control installation according to the present invention. Reference 10 designates a device for detecting the position of a pedal which detects the actuation of the accelerator pedal and that of the brake pedal. When the driver of the vehicle actuates the accelerator pedal, the detection installation 10 supplies an acceleration signal 12 to a control installation 20 of the internal combustion engine. If the installation for detecting the position of a pedal 10 detects actuation of the brake pedal, it emits a brake signal 14 to the installation for controlling the ABS system 30 (installation or system for controlling the brake anti-blocking). The control installation 20 of the internal combustion engine and the control system of the ABS system 30 communicate by connections 22, 32 shown diagrammatically. Via the connections 22, 32, the control installation 20 of the internal combustion engine, a control installation 30 of the ABS system exchange information concerning for example the desired acceleration, the brake pressure applied to the brake cylinders of the wheels and the engine torque applied to the wheels. The internal combustion engine control installation 20 controls a throttling installation, the injectors, the fuel injection and the adjustment of the ignition angle of the internal combustion engine 50 by corresponding output signals. These signals are transmitted to the engine at

  internal combustion 50 by a link 26 shown diagrammatically.

  The internal combustion engine 50 is connected by a crankshaft 55 to a flywheel 56 and a clutch 57. The clutch 57 connects the engine to

  internal combustion 50 at gearbox 60.

  Reference 58 designates the connection between a crankshaft angle sensor not shown and the control installation 20 of the internal combustion engine. The link 58 transmits the rotational speed of the crankshaft to the control installation 20 of the internal combustion engine. The control installation 20 of the internal combustion engine is connected by a link 24 to a clutch control installation 40. The clutch control installation 40 determines whether there is a force transmission between the driven side of the clutch 57 and the output side of the clutch 57 by means of sensors not shown transmitting a corresponding signal by a link 42 to the clutch control installation 40. Instead of this installation of sensors, one can also provide an installation determining the clutch force which determines the force applied by the clutch from the position of the clutch and of the engine torque. The clutch control installation 40 is also connected by a link 44 to an actuation installation 46 such as for example a servomotor or a hydraulic actuator. The actuating installation 46 controls the clutch 57 to have a force transmission between the engine side of the clutch 57 and the output side of this same clutch 57. In other words, the actuating installation 46 controls the clutch 57 1o to make a connection between the flywheel 56 connected itself by the crankshaft 55 to the internal combustion engine 50 and the gearbox to open or close this connection. As the gearbox 60 is connected to the wheels 80, 90 by the transmission line 65, by closing the clutch 57, a force transmission connection is made between the

  iS internal combustion engine 50 and at least one of the wheels 80, 90.

  The transmission line 65 comprises a rotation speed sensor (not shown) which emits an output signal 48 as a function of the rotation speed of the transmission line 65 at the clutch control installation 40. The references 81 and 82 designate respectively the shown wheel brake installations associated with the wheels 80, 90. The reference 70 designates the hydraulic unit of the ABS system connected to the wheel brake installations 81, 91 and applying a

  brake pressure at wheel brake systems 81, 91.

  Reference 83 designates a speed sensor which detects the speed of a wheel 80 and provides a signal

  corresponding to the clutch control installation 30.

  The ABS control system 30 is connected by a link 73 to the unit

ABS 70 hydraulic system.

  The hydraulic unit of the ABS 70 system includes a

  pressure establishment installation 72 such as a pump.

  The installation 72 is connected by a modulator valve 74 to the wheel brake installation 81 of the wheel 80. The pressure establishment installation 72 is also connected by another modulation valve 75 to

  the wheel brake installation 91 of the wheel 90.

  Via the link 73, the ABS control installation 30 supplies control signals to the hydraulic unit of the ABS system 70 relating to at least one of the brake pressures applied by the wheel brake installations 81, 91 of the hydraulic unit of the ABS system 70 for the pressure build-up installation 72 and the modulation valves 74, 75. The hydraulic unit 70 is equipped with the pressure build-up installation 72 for applying brake pressure to the installations wheel brake 81, 91, to modify it from the value predetermined by the control system 30 of the ABS system; this value is predetermined by the link 73 and it is then increased

  or decreased. This assembly achieves the slope maintenance system.

  If the driver operates the vehicle's brake pedal,

  below a certain speed threshold equal for example to 10 kilometers-

  lo hour, the hydraulic unit 70 detects the brake pressure applied by the wheel brake system 81, 91 and thus the braking torque applied to the wheels 80, 90. The detection of the braking torque ends when the vehicle is stopped. The detected torque values are

  transmitted by link 73 to the ABS control installation 30.

  The ABS 30 control system detects a maximum value of the

torque values entered.

  If the driver now stops applying the brake pedal, the control system 30 of the ABS system controls the hydraulic unit 70 via the link 73 so that the hydraulic unit 70 applies a minimum braking pressure to the brake systems of wheels 81, 91, to apply a minimum torque to the wheels 80, 90. This torque is minimum, and corresponds to the minimum value of the braking torques entered when braking the vehicle, multiplied by a coefficient

  predetermined preferably between 0.1 and 0.9.

  To maintain the minimum braking torque of the wheels, 90, the hydraulic unit 70 of the ABS system blocks by controlling the modulation valves 74, 75, the brake pressure applied during actuation to the wheel brake installations 81; this means that the brake pressure is maintained. If the blocked brake pressure is not sufficient, the pressure setting installation 72 of the hydraulic unit 70 increases the brake pressure applied to the installations

wheel brake 81, 91.

  In addition, the control system 30 of the ABS system is designed so that if the speed sensor 83, after actuation of the brake pedal and before actuation of the accelerator pedal detects a rotation of a wheel 80, it transmits signals to the hydraulic unit 70 so that this hydraulic unit 70 increases the minimum torque by the installation of pressure establishment 72 for

  prohibit movement of the vehicle in both directions.

  The control installation 20 of the internal combustion engine preferably controls the internal combustion engine 50 so that, after the driver has finished actuating the brake pedal, the internal combustion engine 50 generates a prestressing torque. This prestressing torque can also be obtained with the energy accumulated in the flywheel 56. The prestressing torque is transmitted by means of the clutch 57 actuated by the actuating installation 46 by the control installation clutch 40, by

  through the gearbox 60 to the transmission line 65.

  If, after having removed his foot from the brake pedal, the driver actuates the accelerator pedal, this releases the wheel brake systems 81, 91. This release does not occur suddenly, however, the control installation 30 of the ABS system controls the hydraulic unit 30 of this same ABS system so that the brake pressure applied to the wheel brake installations 81, 91 is reduced to obtain a ramp-like curve (descending) from the

  brake pressure and thus the braking torque applied to the wheels 80, 90.

  In a short time, preferably in less than 0.2 to 1.5 seconds, the braking torque will be completely neutralized. The gradient of the decrease in braking torque depends on the amplitude of the actuation of the accelerator pedal or on the gradient of this actuation. During the decrease of the braking torque, the clutch control installation 40 controls the actuation installation 46 of the clutch 57 so that the torque developed by the internal combustion engine 50 or that stored in the flywheel 56 either applied by the gearbox 60 to the transmission line 65 and thus to the wheels 80, 90 and is increased as a function of the gradient of the decrease in braking torque

  and the starting torque requested from the accelerator pedal.

  This eliminates the play in the connection between the internal combustion engine 50 or the flywheel 56 and the wheels 80, 90 as well as the spring elasticity of the entire transmission line. In addition, by eliminating this play which still exists due to manufacturing tolerances, vibrations are eliminated when the vehicle is started. The prestressing of the transmission line reduces the vibrations in the connection between the internal combustion engine 50 or its flywheel 56 and the wheels 80, 90, which could produce a tilting or a pitching effect when the vehicle is started, because among other things the spring constant of the transmission line 65 increases with the applied force. The reaction is also reduced, which guarantees a smooth start. This situation will

  described below with reference to Figure 2.

  FIG. 2 shows a diagram schematically plotting the curve of the braking torque applied to the wheels 80, 90, as a function of time. On the abscissa in the diagram of FIG. 2, time has been represented. The reference 130 designates a graph in solid lines representing the curve of the braking torque applied to the wheels 80, 90 as a function of time. The reference 140 designates by a dotted line, the curve of the braking torque requested by the brake pedal in

  function of time. Reference 150 corresponds to a line curve-

  points, representing the torque transmitted by the internal combustion engine 50 and the clutch 57 to the transmission line 65, as a function of time. The reference 160 denotes in dashed lines the curve of the engine torque requested by the driver via the pedal.

  accelerator, as a function of time.

  In the time interval to-t2, the vehicle is stopped.

  During this time, the ABS control installation 30 controls the hydraulic unit 70 of the ABS system so that the forward movement and the backward movement of the vehicle are blocked independently of this.

  whether or not the driver operates the brake pedal.

  At time to, the driver takes his foot off the brake pedal and at time ti, he completes the actuation of the brake pedal completely. This is shown in graph 140 by the corresponding curve of the braking torque. If the driver takes his foot off the brake pedal, the installation for entering the position of the pedal 10

  transmits the brake signal 14 to the control system 30.

  The control installation 30 thus acts on the hydraulic unit 70 to maintain the minimum braking torque by the wheel brake installations 81, 91. The braking torque of the wheels 80, 90 remains according to the embodiment of the FIG. 2 at the level which results from the braking curve before the instant to, after the driver has stopped actuating the brake pedal. At time to ', the braking torque no longer decreases as requested by the driver, but remains at the minimum torque determined previously. At time t 1, the ABS control installation 30 emits a signal via the connections 22, 32 to the control installation 20 of the internal combustion engine. Upon receipt of this signal, the installation of

  control 20 acts on the internal combustion engine 50 so that it

  this generates the predetermined prestressing torque. Then, the control installation 20 emits a signal transmitted by the line 24 to the clutch control installation 40; the latter then controls the installation, the actuation 46 by the link 44; the clutch 57 is thus actuated, that is to say closed so that the prestressing torque is transmitted by the internal combustion engine 50 by the flywheel 56, the clutch 57,

  the transmission 60 and the transmission line 65 to the wheels 80, 90.

  As shown in graph 150, the torque applied by the internal combustion engine 50 and the clutch 57 to the transmission line 65, increases sharply after time tl until it reaches the pretensioning torque. The prestressing torque then remains maintained until time t2. If necessary, the prestressing torque transmitted to the gearbox 60 by the internal combustion engine can be reduced by adjusting the clutch torque 57 using the installation of

  clutch control 40 and the actuating installation 56.

  The prestressing torque is large enough to overcome the play and the elasticity in the connection between the internal combustion engine 50 and the wheels 80, 90. This is how the prestressing torque is chosen, for example, so that the torsion damper springs provided in the connection between the internal combustion engine 50 and the wheels 80, 90 and the entire transmission line are tensioned. The pretensioning torque is less than the torque of

  braking applied to the wheels 80, 90, during the time interval t-t2.

  This ensures that the entire transmission line going from the internal combustion engine 50 to the wheels 80, 90 is prestressed and that nevertheless the vehicle remains stationary. The prestressing torque thus guarantees the prestressing of the transmission line between the internal combustion engine 50 and the wheels 80, 90 and the establishment of a torque.

  between the wheel brake systems 81, 91 and the engine bearings.

  In a variant of this exemplary embodiment, the prestressing torque is generated by rotational energy stored in the flywheel 56 between the internal combustion engine and the clutch 57. Then it is not necessary, to overcome the game in the transmission line between the flywheel 56 and the wheels 80, 90, to increase the motive power supplied by the internal combustion engine. Advantageously, this allows an operation of the internal combustion engine optimized from the point of view of consumption.

  At time t2, the driver actuates the accelerator pedal. Then, the installation for inputting the position of the pedals 10 emits the acceleration signal 12 to the control installation 20 of the internal combustion engine. Then, the control installation 20 transmits a signal via the links 22, 32 to the control installation 30 of the ABS system; this signal indicates that the accelerator pedal has been pressed. Then, the control installation 30 acts on the hydraulic unit 10 70 of the ABS system so that the brake pressure applied to the wheel brake installations 81, 91 gradually decreases until time t3. Thus, the braking torque applied to the wheels 80, 90 gradually decreases from time t2 to time t3 o it is practically zero. If in the time interval t2-t3, the vehicle is accelerated, to ensure that the vehicle is actually accelerated according to the position of the accelerator pedal, a motor torque is applied to the wheels 80, the module of which is greater than that of the engine torque predetermined by the accelerator pedal and is necessary to overcome the braking torque applied at this time to the wheels 80, 90. This procedure is

  described in more detail below.

  To smooth the transition from the time interval t2-t3, the control system 30 of the ABS system is designed to determine the neutralization torque of the minimum braking torque, necessary to overcome the braking torque applied to the wheels 80, 90 in the time interval t2-ta. This evaluated value of the torque is transmitted to the control installation 20 of the internal combustion engine. After receiving the acceleration signal 12, the control installation 20 determines a setpoint torque as a function of the position of the accelerator pedal. The setpoint torque determined on the basis of the position of the accelerator pedal is then increased by the amplitude of the value of the evaluated torque, transmitted by the control installation 30 of the ABS system to the control installation 20 of the internal combustion engine. In other words, the control installation 20 of the internal combustion engine determines from the position of the accelerator pedal and the evaluated value of the torque of the control installation 30 of the ABS system, an engine torque overall necessary to reach the acceleration requested by the accelerator pedal in the interval between times t2 and t3, although in this interval t2-t3, braking torque remains applied to the wheels 80, 90. The maximum value of overall engine torque determined by the control installation 20 of the internal combustion engine is the maximum of the engine torque that the control installation 20 of the internal combustion engine can request. This procedure will be described with the help of the graphs 150, 160 of

Figure 2.

  At time t2, the torque applied by the internal combustion engine 50 is greatly increased by means of the clutch 57 and the gearbox 60 to the transmission line 65. At time t2, the torque applied to the wheels 80, 90 by the transmission line 65 exceeds the braking torque applied to the wheels 80, 90, so that the vehicle sets in motion at time t2. The greater the increasing slope of the engine torque (slope represented by graph 150), the more rapid will be the decrease in braking torque as shown in graph 130 and thus the shorter will be the period t2-t2 ', necessary for the vehicle to set in motion after actuating the accelerator pedal. In the present exemplary embodiment, the control installation 20 of the internal combustion engine, the control installation 30 of the ABS system and the control installation 40 of the clutch are designed so that according to the conditions in which it is found the motor vehicle, the increase in engine torque and the decrease in braking torque are controlled to minimize the period t2-t2 '. At time t2., The engine torque applied by the transmission line to the wheels 80, 90 reaches a value which corresponds to the sum of the amplitudes of the engine torque requested at this time by the driver via the foot pedal. accelerator and braking torque applied at this instant to the wheels 80, 90. After the instant t2 ", the curve of the torque applied by the transmission line 65 to the wheels 80, corresponds to the sum of the amplitudes of the driving torque requested by the driver by the accelerator pedal and the braking torque applied to the wheels 80, 90; in other words, this corresponds to

  the addition of graphs 130 and 160.

  At time t3, the braking torque applied to the wheels 80 is practically zero, so that the wheels 80, 90 receive only the

engine couple.

  Instead of the gradual curve in the form of a ramp of the braking torque in the time interval t2-t3, it is also possible to design the control system 30 of the ABS system so that after having reached a predetermined minimum speed , the gradient of the ramp increases and thus the time during which a braking torque is

  applied to the wheels 80, 90 decrease.

  The installation for inputting the position of the pedals 10, the control installation 20 for the internal combustion engine, the control installation 30 for the ABS system and the clutch control installation 40 are preferably constituted by computing facilities. It is also possible to carry out such

  installations in the form of EPLD.

  FIG. 3 shows a flowchart which gives an example of the operation of the control installation object of the

figure 1.

  After starting in step S10, the processing proceeds to step S12 in which the control system 30 of the ABS system determines whether the system for detecting the position of the pedals 10 emits the braking signal 14. Then, the processing continues until step S14 in which the control system 30 of the ABS system asks whether the brake pedal has been released or not. If the interrogation in step S14 shows that the brake pedal remains applied, the processing returns to

step S12.

  If in step S14, it is determined that the brake pedal has been released, the processing continues at step S16 in which the control system 30 of the ABS system controls the hydraulic unit 30 of this ABS system to apply a minimum braking torque at the wheels 80, 90. This minimum braking torque can be as indicated above, ie a minimum torque depending on a maximum torque applied during the previous braking operation below a speed threshold or the braking torque can be applied depending on the actuation of the brake pedal by the

  driver while the vehicle stops at wheels 80, 90.

  In step S16, the control system 30 of the ABS system further determines using the speed sensor 80 whether the vehicle is moving or not. If the control installation 30 finds that the vehicle is moving, this installation 30 controls the hydraulic unit 70 of the ABS system so that the pressure establishment installation 72 increases the brake pressure applied to the wheel brake installations. 81, 91 and thus the torque applied to the wheels 80, 90. This achieves the

  regulation of the braking torque applied to the wheels 80, 90.

  The control system 30 of the ABS system emits in step S16 a signal to the control system 20 of the engine

  internal combustion. This signal indicates that the brake pedal has been released.

  Then, the processing continues with step S18.

  In step S18, the control installation 20 of the internal combustion engine controls the engine 50 so that the latter creates the l0 prestressing torque transmitted via the crankshaft 55 and the flywheel 56 to the engine side of the clutch 57. In addition, the control installation 20 emits a signal to the clutch control installation 40. On receipt of this signal from the control installation 20 of the internal combustion engine, the installation of clutch control 40 controls the actuating installation 46 so that this installation 46 controls the clutch 57 in order to apply the prestressing torque applied to the engine side of the clutch 57 in order to transmit it to the outlet side of the clutch 57 The pretensioning torque is thus applied to the gearbox 60 which transmits it

  by the transmission line 65 to the wheels 80, 90.

  The clutch control installation 40 can also be designed to regulate the actuation installation 46 on the basis of the output signal of the speed sensor 48 of the transmission line 65 so that the torque transmitted from the side clutch 57 motor at the clutch 57 output side is minimized so that only the minimum torque necessary to overcome the play and elasticity is applied to the connection between the internal combustion engine 50 and the wheels, 90 per via the gearbox to the transmission line and thus finally to the wheels 80, 90. This preferably makes it possible to reduce the stress on the gearbox 60 and the transmission line 65, which lengthens the duration of life of these facilities. The

  processing then continues with step S20.

  In step S20, the control installation 20 of the internal combustion engine determines whether the installation 10 detecting the position of the pedals emits the acceleration signal 12. Then the processing continues with step S22 during which in the control installation 20 of the internal combustion engine, it is asked whether the accelerator pedal is actuated, that is to say depressed or not. If in step S22, it is noted that the accelerator pedal is not depressed, the processing continues

until step S16.

  If in step S22, it is noted that the pedal

  accelerator has been pressed, processing continues with step S24.

  In step S24, the control system 30 of the ABS system transmits the evaluated value of the braking torque applied to the wheels

  , 90 to the control installation 20 of the internal combustion engine.

  This evaluated value is preferably determined using characteristics fields or update tables on the basis of the 1o braking torque set during the stopping of the vehicle, for example by actuation.

  of the brake pedal by the driver.

  In step S24, the control installation 20 of the internal combustion engine, using the acceleration signal 12 which indicates the driver's acceleration desire and the evaluated value of the torque of the control installation 30 of the system ABS, emits a control signal to the internal combustion engine 50 so as to achieve the acceleration of the vehicle requested by the position of the accelerator pedal, although at least at the start a braking torque remains applied to the wheels 80, 90, for example by adding the engine torque requested by the position of the accelerator pedal with the evaluated value

  of the torque of the control system 30 of the ABS system.

  Then the processing continues until the end of step S26.

  The processing described in FIG. 3 is executed cyclically during the operation of the vehicle. This guarantees that in the interval t2 to t3 according to FIG. 2, the components of the torque generated by the internal combustion engine 50, necessary to overcome the braking torque applied to the wheels 80, 90 by the hydraulic unit 70 of the ABS system. ,

gradually decrease.

Claims (15)

CLAIMS) Starting control device for controlling the starting of a motor vehicle, characterized in that it comprises - a clutch control (40, 46) for closing the force transmission link (55, 56, 57, 60, 65) between the engine (50) of the vehicle and at least one wheel (80, 90) thereof, - a slope maintenance system (30, 70, 72, 74, 75, 81, 83, 91 ), - an installation for detecting the position of the pedals (10) for detecting the end of the actuation of the vehicle brake pedal, and - an engine control installation (20), which when the end is detected actuation of the brake pedal, controls the motor (50) to generate a prestressing torque, - the clutch control (40, 46) controlling the force transmission link (55, 56, 57, 60, 65) between the engine (50) and at least one wheel (80, 90) of the vehicle so that the pretensioning torque is applied to at least one wheel (80, 90) of the vehicle s i the pedal position detection installation (10) detects the end of actuation of the vehicle brake pedal.   2) start control device according to claim 1, characterized in that the slope maintenance system (30, 70, 72, 74, 75, 81, 83, 91) is produced to maintain a minimum braking torque on at minus a wheel (80, 90) if the installation for detecting the position of the pedals (10) detects   the end of actuation of the vehicle brake pedal.   3) Start control device according to claim 2, characterized in that the installation for detecting the position of the pedals (10) is designed so that after having grasped the end of the actuation of the brake pedal, it grips the accelerator pedal, and the grade hold system (30, 70, 72, 74, 75, 81, 83, 91) is designed to decrease the minimum torque gradually over an interval of predetermined time if the device for detecting the position of the pedals   (10) detects the end of actuation of the accelerator pedal.   4) Start control device according to claim 3, characterized in that the installation for detecting the position of the pedals (10) is designed to detect a degree of actuation of the accelerator pedal and the control installation (20) of the engine is designed to determine a setpoint torque as a function of the degree of actuation of the accelerator pedal and a torque for neutralizing the minimum braking torque, this torque for neutralizing the minimum braking torque having the same module the minimum braking torque, and the motor is controlled to generate an overall starting torque, the amplitude of which corresponds to the sum of the neutralization, minimum braking torque and setpoint torque, if the detection installation of the pedal position (10) detects the actuation of the accelerator pedal.   5) Start control device according to any one of claims 1 to 4,   characterized in that the prestressing torque is large enough to exceed the clearance of the force transmission link (55, 56, 57, 60, 65) between the motor (50)   of the vehicle and at least one wheel (80, 90).   6) Starting control device for controlling the starting of a motor vehicle, characterized in that it comprises: - a clutch control (40, 46) for closing the force transmission link (55, 56, 57 , 60, 65) between a flywheel (56) and at least one wheel (80, 90) of the vehicle, - a slope maintenance system (30, 70, 72, 74, 75, 81, 83, 91), and - a pedal position detection installation (10) for detecting the end of actuation of the vehicle brake pedal, - the clutch control (40, 46) controlling the force link (55, 56, 57, 60, 65) between the flywheel (56) and at least one wheel (80,) of the vehicle so as to apply a prestressing torque to at least one wheel (80, 90) of the vehicle, if the installation of pedal position detection (10) detects the end of pedal actuation vehicle brake.   7) Start control device according to claim 6, characterized in that the slope maintenance system (30, 70, 72, 74, 75, 81, 83, 91) is designed to maintain a minimum braking torque on at minus a wheel (80, 90) if the installation for detecting the position of the pedals (10) detects   the end of actuation of the vehicle brake pedal.   8) Device according to claim 7, characterized in that 1o the position detection installation of the pedals (10) is designed so that after entering the end of operation of the brake pedal, it captures the actuation of the accelerator pedal and the slope maintenance system (30, 70, 72, 74, 75, 81, 83, 91) is designed to gradually decrease the minimum torque in a predetermined time interval if the detection installation ( 10) detects the end of   actuation of the accelerator pedal.   9) Device according to claim 8, characterized in that the installation for detecting the position of the pedals (10) is designed to detect a degree of actuation of the accelerator pedal and the installation for driving control ( 20) is provided for determining a setpoint torque corresponding to the degree of actuation of the accelerator pedal and a torque for neutralizing the minimum braking torque, the torque for neutralizing the minimum braking torque having the same module as the torque minimum braking, and the vehicle engine (50) is controlled to generate an overall starting torque, the module of which corresponds to the sum of the neutralization torque of the minimum braking torque and the setpoint torque if the detection installation (10) finds that the accelerator pedal is actuated.    ) Device according to any one of claims 6 to 9,   characterized in that the prestressing torque is large enough to exceed the clearance in the force transmission connection (55, 56, 57, 60, 65) between the   engine flywheel (56) and at least one wheel (80, 90).   11) Method for starting a motor vehicle using a clutch control (40, 46) to close a force transmission link (55, 56, 57, 60, 65) between the engine (50 ) of the vehicle and at least one wheel (80, 90) thereof, and with a slope maintenance system (30, 70, 72, 74, 75, 81, 83, 91)   according to which the end of the actuation of the brake pedal of the vehicle is detected and if the end of the actuation of the brake pedal is detected, the motor (50) generates a prestressing torque which controls the link of the 1o transmission force (55, 56, 57, 60, 65) between the engine (50) and at least one wheel (89, 90) of the vehicle by the clutch control (40, 46) to   that the pretensioning torque is applied to at least one wheel (80, 90).   12) Method according to claim 11, characterized in that when the end of the actuation of the brake pedal is detected, it is maintained using the slope maintenance system (30, 70, 72, 74, 75 , 81, 83, 91), at least a minimum braking torque applied to the less to a wheel (80, 90).   13) Method according to claim 12, characterized in that after having detected the end of the actuation of the brake pedal, the actuation of the accelerator pedal is detected and if this actuation is observed, the torque is gradually reduced minimum in one   predetermined time interval.   14) Method according to claim 13, characterized in that the degree of actuation of the accelerator pedal is detected and if the pedal is actuated, a target torque is determined as a function of the degree of actuation of the pedal d accelerator and a torque for neutralizing the minimum braking torque, this torque for neutralizing the minimum braking torque having the same module as the minimum braking torque and the engine (50) generates an overall starting torque whose module is equal to the sum of the neutralization torque, the torque   minimum braking pressure and setpoint torque.    ) Method according to any one of claims 11 to 14,   characterized in that the prestressing torque is large enough to exceed the clearance in the force transmission link (55, 56, 57, 60, 65) between the vehicle engine (50) and at least one wheel (80, 90 ). 16) Method for starting a motor vehicle with a clutch control (40, 46) to close the force transmission link (55, 56, 57, 60, 65) between a flywheel (56) and at least a wheel (80, 90) of the vehicle and a slope maintenance system (30, 70, 72, 74, 75, 81, 83, 91)   according to which the end of actuation of the brake pedal is detected and if this end of actuation is confirmed, the transmission link of S5 force (55, 56, 57, 60, 65) between the flywheel ( 56) and at least one wheel (80, 90) by the clutch control (40, 46) so as to apply to at least one wheel (80, 90) a prestressing torque stored in the flywheel (56).   17) Method according to claim 16, characterized in that if the end of the actuation of the brake pedal is detected, using the slope maintenance system (30, 70, 72, 74, 75, 81, 83, 91), we   maintains a minimum braking torque on at least one wheel (80, 90).   18) Method according to claim 17, characterized in that after having detected the end of the actuation of the brake pedal, the actuation of the accelerator pedal is detected and if the accelerator pedal is actuated, gradually decreases the torque   minimum in a predetermined time interval.   19) Method according to claim 18, characterized in that a degree of actuation of the accelerator pedal is detected and if the accelerator pedal is actuated, a reference torque corresponding to the degree of actuation of the actuator is determined. accelerator pedal and a torque for neutralizing the minimum braking torque, this torque for neutralizing the minimum braking torque having the same amplitude   that the minimum braking torque, and using the drive (50) a global starting torque is generated, the amplitude of which is equal to the sum of the neutralization torque, the minimum braking torque and the setpoint torque .    ) Method according to any one of claims 16 to 19,   characterized in that the prestressing torque is large enough to exceed the clearance lo in the force connection (55, 56, 57, 60, 65) between the flywheel (56) and at least one wheel (80, 90).