WO2012175890A1

WO2012175890A1 - On-board system for controlling the speed of a vehicle, and operating method

Info

Publication number: WO2012175890A1
Application number: PCT/FR2012/051430
Authority: WO
Inventors: Jean-François Forzy; Serge Vallee; Philippe Laporte-Galaa; Philippe PICQUENARD
Original assignee: Renault S.A.S.
Priority date: 2011-06-22
Filing date: 2012-06-22
Publication date: 2012-12-27
Also published as: FR2976887A3

Abstract

The invention relates to the operation of an on-board system (100) for controlling the speed of a vehicle, which includes transmitting adjustment signals (S) to a control module (12) of the drive device (13) and/or of the braking device (14) of the vehicle, said signals (S) being modulated according to a set value (V) specified to the system by the driver during a step in which the driver applies an action onto a man/machine interface (11), characterised in that said set value is representative of a desired increase or reduction in speed of the vehicle when the action of the driver on the man/machine interface (11) is shorter than a duration T, said set value being representative of the desired acceleration or deceleration of the vehicle when the action of the driver on the man/machine interface (11) is no shorter than the duration T. The invention also relates to an on-board system and to a motor vehicle.

Description

ON-VEHICLE SPEED CONTROL SYSTEM AND METHOD OF OPERATION

Technical field of the invention

The invention relates to the field of controlling the speed of a motor vehicle.

The subject of the invention is more particularly a method and an onboard system providing such control. Regulating signals are generated for controlling a motorization device and / or a vehicle braking device.

State of the art

An on-board system for controlling the speed of a vehicle may, for example, provide a servo-control of the vehicle speed to regulate and maintain the vehicle at a speed as close as possible to a set speed, despite the variations in driving conditions of the vehicle. vehicle. For this purpose, the servo system provides the transmission of speed regulation signals to at least one control module of the vehicle operator device. The regulation signals are a function of the periodic comparison between the reference speed and the actual speed of movement of the vehicle.

Conventionally, the driver has at his disposal a two-position control to turn off or turn on the servo system. When the system is turned on, it is first in a first state in which the speed control function is not operative. When the driver has driven his vehicle to the speed he wishes to maintain thereafter, he presses a first button, which allows the system to memorize the set speed and to enter a second state in which the speed control is activated. In the second state, the first button and a second button respectively allow the driver to change the set speed in increments or decrements. It is also possible acting momentarily on the accelerator pedal, for example to double a vehicle, then release the pedal so that the speed of the vehicle stabilizes again at the set point. The return to the first state is automatic by a change of position of the start control, or by a stress, even very lightly, on the brake pedal.

It is therefore not possible, in a simple and immediate manner, to adjust its pace to changes in speed of the surrounding flow. Indeed, an action on the brake pedal disables the regulation and therefore requires to reactivate it then manually.

However, the deactivation of the servo system is felt by the occupants of the vehicle so much stronger that the power delivered by the drive device is important. At steady speed, the torque supplied to the drive wheels balances the different driving resistances, essentially the slope, the rolling resistance and the aerodynamic resistance. By deactivating the regulation, the engine torque immediately becomes almost zero, which breaks this balance abruptly. The resistance to progress then print the vehicle deceleration all the more important that the torque delivered by the drive device at the time of deactivation was high.

With a command of the servo system where the only parameter accessible to the driver is the target speed, there is therefore no progressiveness in the deceleration that generates the deactivation of the regulation, while in many cases the driver only wish to slow down very slightly, for example to keep a reasonable distance from the vehicle in front of it.

It is certainly generally possible to act on the means of increment or decrement of the target speed to modify the speed reference without have to disable and then reactivate the regulation. Thus, a solution for making the slowdown more gradual consists in controlling the speed of the vehicle with the means of decrementing the target speed by provisionally imposing a lower setpoint.

This solution, which is frequently used, however, remains poorly ergonomic. This is in particular due to the fact that the means of increment and decrement of the set speed are inherently uncomfortable: they do not allow the driver to select in a single operation the appropriate speed, and it is necessary for him to act repeatedly on these means to achieve the desired slowdown.

Furthermore, the effects of the acceleration or deceleration are not immediate and extend beyond the manipulation of the command, until the desired speed, according to a specific law.

This situation is uncomfortable for the driver who performs these operations and for the occupants for the reasons mentioned above. Although it may be satisfactory for automatic cruise control on the motorway, where the situation is generally clear, it is also unsafe, particularly in the case of heavy traffic or urban driving. This is all the more true because of the current incapacity of the servo system to act on the braking device of the vehicle. More advanced control systems may consist of implementing a regulation action on the braking device of the vehicle. In this case, it is known to equip the vehicle with means for measuring distances and / or speed of vehicles or obstacles preceding it. These means, based on radar, optical or other techniques, in particular allow to perform an automatic speed control of the vehicle according to the traffic. They are generally qualified in the English literature by the acronym ACC corresponding to the expression "Automative Cruise Control". US5634446 discloses such a solution.

However, an ACC solution is very expensive and poses the problem of returning the driver to the control loop when the system is beyond its operating limits. Moreover, the acceleration and deceleration parameters, over which the driver has no influence, may not be adapted to the driver's expectations (for example, an acceleration that is too high compared to a desired economical driving ...).

It is moreover known, for example from the document US2003 / 0209376, a speed control system from a desired acceleration or deceleration by the driver of the vehicle and materialized by a push-type cursor, the position of the cursor reflecting the setpoint acceleration or deceleration.

Object of the invention

The object of the present invention is to overcome the disadvantages of speed controllers based solely on a speed reference value, while improving the accuracy and ergonomics of speed controllers based on a setpoint acceleration or deceleration, without complicating the control, while maintaining design simplicity, safety, comfort, and a controlled cost. A first aspect of the invention relates to a method of operating an on-board system providing a control of the speed of a vehicle, comprising the transmission of control signals to a control module of the motorization device and / or the control device. braking of the vehicle, said signals being modulated according to a set value specified in the system by the driver during a step in which the driver applies an action on a man-machine interface, characterized in that said setpoint value is representative of an increase or desired speed reduction for the vehicle when the action by the driver on the man-machine interface is less than a duration T, said setpoint being representative of the desired acceleration or deceleration for the vehicle when the action by the driver on the human-machine interface is greater than or equal to the duration T.

The acquisition of the setpoint during the action by the driver on the human-machine interface may comprise a step in which an intensity value of this action is determined.

The intensity value of the action may comprise a displacement amplitude of a mobile control element of the man-machine interface. The intensity value of the action may include a force exerted on a control element of the man-machine interface.

The intensity value of the action can control the increment or decrement of the set value in a discrete or progressively continuous manner.

The absolute value of the set value can be limited to a predetermined value.

The on-board system can provide a control of the speed of the vehicle, the regulation signals comprising a speed reference value of the vehicle.

A second aspect of the invention relates to an on-board system providing a control of the speed of a vehicle, comprising an interface with the driver, characterized in that the interface comprises means allowing the driver to specify the system with a set value. representative of a desired increase or decrease in speed for the vehicle when the action by the driver on the interface is shorter than a duration T, said setpoint being representative of the acceleration or deceleration desired for the vehicle when the action by the driver on the human-machine interface is greater than or equal to the duration T.

The interface may include a control element arranged near the steering wheel of the vehicle, the intensity of the action exerted on the element achieving the acquisition of the set value. The system may comprise a position sensor of the control element, the setpoint being a function of the displacement amplitude of the control element, or a force sensor exerted on the control element, the value setpoint depending on the force exerted on the control element.

The system may comprise a control module of a motorization device and / or a vehicle braking device, the system being configured to ensure servocontrol of the vehicle speed by a transmission of control signals to the control module , including a setpoint value of the vehicle speed, modulated according to the setpoint.

Finally, a third aspect of the invention relates to a motor vehicle comprising an embedded system as mentioned above.

The command implementing a modulation of the regulation signals as a function of a setpoint representative of the acceleration or deceleration desired for the vehicle by the driver allows the latter not only to vary the speed of the vehicle but also to adjust in real time, at will, the amount of speed variation (in other words acceleration or deceleration) with respect to time. The driver thus has a direct influence on the acceleration and deceleration of the vehicle. Such a control has the effect of allowing the driver to adapt fluidly to revolution in the speed of the traffic in which the vehicle is traveling.

In addition, when the driver sees the speed of the vehicle stabilize at a value close to that desired, a pulse on the control member then makes it possible to send a speed incrementation or decrementation instruction, which allows a finer adjustment of the set speed.

Thus, the present invention makes it possible to adjust the target speed by an intuitive control based on the acceleration or deceleration controlled by the driver via the man-machine interface, this adjustment being adjusted by a pulse type control allowing optimize the setting of the set speed. This combines the advantages of an acceleration control, like the accelerator pedal, which provides a speed in the definition of the speed setpoint, the advantages of speed control, finer and precise , to adjust the speed of t1 setpoint obtained by the command in acceleration.

Brief description of the drawings

Other advantages and features will emerge more clearly from the following description of particular embodiments of the invention given as non-restrictive examples and shown in the accompanying drawings, in which:

FIG. 1 is a diagram of an embodiment of a speed control system according to the invention,

Figures 2 to 4 illustrate the state graphs of three embodiments of speed control systems according to the invention.

Description of preferred modes of the invention An embodiment of an onboard system 100 providing a speed control of a motor vehicle is described below with reference to FIG. The term "control" corresponds to a modulation or regulation of the speed of the vehicle by management, control, steering, adapted. This is for example a system 100 ensuring a servocontrol of the speed of the vehicle and which mainly comprises a man-machine interface 1 1 and a control device 16.

The interface 1 1 is configured to allow manual entry by the driver. By a P action for a duration ti, that the driver can gradually dose on the interface 1 1, the driver specifies to the servo system 100 a set value V.

The description which follows treats, in a first step, the case where the duration ti of actuation is greater than or equal to a duration T paramétrable. The value of T can vary from one type of vehicle to another, or even from one geographical location to another, the principle being to differentiate, by this value T, a "pulse" type operation, an " continued ". For example, it is possible to set the value of T less than 1 s, and preferably less than 500 ms.

Either of which a duration ti of actuation greater than the duration T. The setpoint value V is then representative of either the acceleration or the desired deceleration for the vehicle by the driver. The interface 1 1 has the function of translating the action P it undergoes into a corresponding reference value V. For example, the absolute value of the set value increases at the same time as the value of the action P, proportionally or in step with the design of the assembly. More specifically, the interface 1 1 is designed so that the action P that the driver manually dose can translate the set value selectively acceleration or deceleration. It includes a means control variable provided on the steering wheel of the vehicle itself or at least close to it, a manual dosage by the gradual action P achieves the acquisition of the set value V. The action P dosed by the driver and measured by the interface 1 1 can translate the acquisition of a positive setpoint value V acceleration or conversely a negative setpoint value V deceleration. For this purpose, the interface 1 1 is structured so as to allow the driver to specify that the action P that dose is a desire to accelerate or otherwise decelerate the vehicle. The control means can thus take the form of a single command (for example a button pivoting on either side of a rest position) whose operating direction allows the selection between the acceleration mode or the deceleration, or the form of a dual command with two independent buttons each assigned to either the acceleration mode or the deceleration mode. Once the selection is made between the deceleration or acceleration mode, the proportioning of the action P makes it possible to modulate the setpoint value V respectively during deceleration or acceleration.

In other words, the acquisition of the setpoint value V is done by application by the driver of a mechanical action on the human-machine interface and determination, at the level of the system, particularly at the interface, of the value intensity of this action. The intensity value of the action may comprise a displacement amplitude of a mobile control element of the man-machine interface and / or a force exerted on a control element of the man-machine interface.

The control device 16 comprises a regulation module 10 and a control module 12.

The regulation module 10 receiving the setpoint value V from the interface 1 1 when the system is in a first activated operating mode, sends regulation signals S for example in speed to a control module 12 which issues commands O1 steering towards the device motor 13 and / or control commands 02 to the braking device 14, the latter comprising for example an electronic stability device ESP programmed and which ensures the braking of the vehicle. The control commands 01 and 02 are elaborated and transmitted by the control module 12 as a function of the regulation signals S that it receives. In the case where the onboard system 100 is a speed control system, the signals S comprise the desired desired speed of the vehicle, around which must be enslavement. The regulation signals S for their part are modulated according to the reference value V representative of the acceleration or deceleration desired for the vehicle specified in system 100 by the driver. In particular, in the case where the onboard system 100 is a speed control system, the target speed can be directly modulated in real time as a function of the setpoint value V in acceleration / deceleration. Finally, the drive device 13 and the braking device 14 are controlled, by means of the control device 16, from the setpoint value V reflecting the desire for acceleration or deceleration of the driver. During regulation, the regulation signals S are modulated by the control device so that the mechanical action resulting from the orders O1 and / or 02 of the motorization and braking devices 13, 14 is a function of the setpoint value V and that this mechanical action makes it possible to achieve the acceleration and deceleration parameters sought by the driver via his action P. The motorization device 13 of the vehicle is for example an internal combustion engine, but could also be another type, for example electric or hybrid type. In response to the regulation signals S, the motorization and / or braking devices 13, 14 act on motor actuators or brakes. The regulation signals S result in maintaining the speed of movement of the vehicle in the absence of action P, or in increasing it in the form of a vehicle acceleration adjusted by a dosage of the action P of the driver such that the set point V becomes positive, or the decrease thereof in the form of a deceleration of the vehicle adjusted by a dosage of the action P such that the set value V becomes negative. On the other hand, when the system 100 is in a second inactivated mode of operation, the regulation module ceases to send regulation signals S to the control module 12. Suitable means are thus provided for selectively enabling or disabling the control function. control, for example by means of a speed control, these means being made available to the driver of the vehicle at the driving position.

The motorization and / or braking devices 13, 14 transmit mechanical forces in the form of positive and negative pairs respectively to the wheels 15 in connection with the ground. The rotation speed thereof, read by any known and adapted means, is retransmitted in the form of a measurement result R to the control device so that it can ensure the speed control of the vehicle. This control can in particular go through a speed-controlled type of control performed by a continuous comparison between a setpoint speed and the actual measured speed R, the servo setpoint speed being itself possibly established and modulated according to the value setpoint V acceleration or deceleration if necessary for the case where the embedded system 100 is a speed control system. If there is no set point value V, the set speed recorded in the control system remains constant. In general, the regulation signals S are established by the regulation module 10 as a function of the result of the speed regulation which is carried out.

That the variable control means of the interface 1 1 comprises one or more buttons, it can include in both cases a movable element on which is intended to be applied the action P of the driver. In a first embodiment, this control means may comprise a position sensor of the movable element, the adjustment of the manual dosage then being a function of the displacement amplitude measured by the position sensor from a release position. By coming to occupy a driving position under the effect of the action P of the driver, the value of the stroke (of the angular type for the case of a single command button, of rectilinear type in the case of two buttons of independent control) of movement of the movable element reflects the standard of the desired value V desired by the driver, the choice between acceleration or deceleration being further indicated at the interface 1 1 (either by the choice of the direction moving the movable element for the case of a single control button, or by the choice between two separate movable elements in the case of two independent control buttons). In a second embodiment, this control means may comprise a force or gauge sensor capable of measuring the manual force exerted on the movable element, the adjustment of the manual dosage being a function of the force measured by the sensor. For example, the force measured by the sensor is a function of the action P applied by the driver. Overall, the force sensor has the function of measuring the force required to depress the button (s) of the control means. This measured force is approximately equal to the restoring force towards the position of release or rest applied to the button (s) after its (their) solicitation (s) to a depression position. The value of the force measured reflects the standard of the desired value V desired by the driver, the choice between acceleration or deceleration being also indicated at the interface 1 1 (either by the choice of the direction of movement of the movable element for the case of a single control button, or by the choice between two separate movable elements in the case of two independent control buttons). The basic structure of the gauge is, however, designed to withstand forces far greater than the restoring force to the original position of the button or the control in general. However, in case of support leading to the destruction of the gauge, a predefined degraded mode takes over with an indication to the driver of a malfunction of the device.

In summary, in the case where the control means comprises a single button, a lack of action P implies that the button is in the release position, the control device 16 controls the drive device 13 or the braking device 14 of the vehicle to maintain the current speed of the vehicle. When the button is positioned in a first direction of movement (for example by tilting), the control device 16 controls the motorization device 13 or the braking device 14 of the vehicle to reduce the current speed of the vehicle, the level of this reduction. being a function of either the position of the movable element of the button or the value of the measured force applied to it. When the button is instead positioned in a second direction of movement (for example by tilting in the opposite direction relative to the first direction of movement), the control device 16 controls the motorization device 13 of the vehicle to increase the current speed of the vehicle , the level of this increase being a function of either the position of the movable element of the button or the value of the measured force applied to it.

In the case where the control means comprises two separate buttons each having a movable member, a lack of action P on both buttons implies that they are in the release position. The control device 16 then controls the motorization device 13 or the braking device 14 of the vehicle to maintain the current speed of the vehicle. When the movable element of one of the two buttons is pressed, the control device 16 controls the operator device 13 or the device of braking 14 of the vehicle to reduce the current speed of the vehicle, the level of this reduction being a function of either the position of the movable element of the button pressed or the value of the measured force applied to it. When the movable element of the other button is pressed, the control device 16 controls the motorization device 13 of the vehicle to increase the current speed of the vehicle, the level of this increase being a function of the position of the movable element the button pressed is the value of the measured effort applied to it. From the foregoing, it is understood that the acquisition of the set value V comprises a step in which the driver performs a manual dosing (via the action P) on a variable control means arranged near the steering wheel of the vehicle, the term "close" including the possibility that the control means is carried by the steering wheel itself. The dosage is achieved by adjusting either the displacement amplitude of a movable member of the variable control means, or the manual effort exerted thereon. This manual dosage can control the increment or decrement of the set value V discretely or in a progressively continuous manner.

In one embodiment, the absolute value of the setpoint value V can be limited to a predetermined value. Such a possibility can be effective to avoid the shaking movements of the vehicle when controlling the motorization device 13 and that of the braking device 14. The expression "jolt" here means a variation of the acceleration or deceleration as a function of time. For example beyond a set limit value approximately equal to +/- 3m / s ^2, the bias of the vehicle by the driver during acceleration or deceleration can be done only from the accelerator pedal and brake.

On the other hand, the controlled decelerations of small amplitude avoid any output of the system 100 from its control or regulation function, unlike the the prior art. On the other hand, the invention simplifies the system state logic while involving a reduced number of manual commands.

In the case where the actuation duration ti is less than the duration T, the support, which can be described as discrete or impulse, then corresponds to an adjustment of the current speed, for example with the prescribed speed. . The signals sent are then increments or speed decrements, in steps of +/- 2 km / h for example. Figures 2 to 4 illustrate the state graphs of three embodiments of a control according to the invention.

The first embodiment of Figure 2 corresponds to a basic design of the control. The system 100 varies between a first inactivated state of operation E1 and a second activated state of operation E2. The transition from the state E1 to the state E2, symbolized by the arrow F1, can be made from the activation to a "on" position of a central switch. In the state E1, the regulation function that can ensure the system 100 is inactive. On the contrary, the transition from the state E2 to the state E1 may consist of a deactivation of the central switch to a "stop" position (arrow F2), even a slight biasing of the brake pedal (arrow F3 ), or else by placing the gearbox in the neutral position. When the system 100 occupies the state E2 and the speed regulation function is operative, the biasing of the control means of the interface 1 1 for example at the "plus" and "minus" buttons respectively controls the increment and the decrement of the reference value V. This command from the state E2 is symbolized by the arrow F4 in FIG. 2, with an automatic return to the state E2. The second embodiment provided in FIG. 3 is a variant of that of FIG. 2, comprising an additional function called "waiting". Since a first inactive state of operation E4, the transition to a second operating state pending E5, symbolized by the arrow F5, is controlled by a start of the system 100, for example by activation to a "on" position of a central switch. In the state E4, the regulation function that can ensure the system 100 is inactive. On the contrary, the transition from the state E5 to the state E4 can consist of a deactivation of the central switch to a "stop" position (arrow F6). When the system 100 occupies the state E5, it remains on standby but the speed regulation is still inoperative, waiting for a complementary order to move to a third operating state activated E6. To switch on the speed control system after switching on the system 100 by activating the central switch to the "on" position, the driver of the vehicle must act on a specific push-button (arrow F7). The transition from the state E6 to the state E5 can consist of a solicitation even of small amplitude of the brake pedal (arrow F8), or even by setting up the gearbox on the neutral position. On the contrary, the deactivation of the central switch to the "off" position (arrow F9) from the state E6 controls the passage of the servo system to the state E4. When the system 100 occupies the state E6 and the speed regulation function is operative, the biasing of the control means of the interface 1 1 for example at the "plus" and "minus" buttons respectively controls the increment and the decrement of the setpoint value V. This command from the state E6 is symbolized by the arrow F10 in FIG. 3, with an automatic return to the state E6. It may be advantageous if the push button controlling the transition from the waiting state E5 to the activated state E6 is constituted by the "plus" button of the control means of the interface.

The third embodiment provided in FIG. 4 is a variant of that of FIG. 3, comprising an additional function called "recovery". All references equivalent to the embodiment of Figure 2 are shown in Figure 4 for the sake of clarity. On the other hand, unlike the operation described with reference to FIG. 3, the fact that the brake pedal has a small amplitude since the activated state E6 controls the passage of the brake pedal. system 100 of the activated state E6 not to the second waiting state E5 but to a fourth operating state E7 (arrow F1 1) in which the speed regulation function is interrupted but the system 100 nevertheless retains the speed of set in a dedicated memory. Thus a subsequent request for a push-button "recovery" is sufficient to control the return of the system 100 from the state E7 to the activated state E6 (arrow F12) with a conservation of the regulation of the speed of movement of the vehicle to the set speed previously memorized. On the other hand, the inactivation of the central switch to the "off" position when the system 100 occupies the state E7 commands a return of the system to the inactivated state E4 (arrow F13).

A fourth embodiment of a control according to the invention (not shown) may consist in providing only the "recovery" function but without incorporating the "waiting" function.

The invention described above can advantageously be associated with a device for immobilizing the accelerator pedal as described for example in the document FR-A1 -2756066. On the other hand, it can be used in combination with a mechanical transmission to the wheels 15 type automatic gearbox. Such a solution advantageously avoids the need to inactivate the system 100 at each gear shift of the transmission and therefore allows its operation even at very low speed (for example in the context of known devices "Stop and Go"). When the invention is coupled to a motorization device 13 using at least one electric motor, the deceleration function obtained by the command in decrement of the reference value V can be accompanied by a recovery of a part of the electrical energy (the electric motor then operating temporarily as an electricity generator).

One embodiment may consist in coupling the invention to a GPS-type mapping system that can provide the system 100 in real time with information concerning the speed limit in the area in which the vehicle is traveling. In case of acceleration with a control according to the invention, a noticeable feedback at the control means (vibrations, hardening, etc.) can be triggered in case of exceeding the prescribed speed. This arrangement makes it possible to limit the necessary frequency of a visual check of the tachometer of the vehicle.

The invention may in particular be associated with motorization and braking devices 13, 14 providing a great progressivity in the acceleration and deceleration parameters they deliver.

Another embodiment may consist in using the invention in combination with a distance control system with respect to the preceding vehicle, so that if the vehicle equipped with the invention approaches the preceding vehicle at an inter-vehicular time below a threshold parameterizable by the driver himself, the servo system is then programmable so as to decelerate the vehicle by an appropriate modulation of the regulation signals S to establish an inter-vehicular time greater than said threshold. The command allowing the specification of a reference value V representative of an acceleration is then inhibited. Conversely, when used in combination with a "stop and go" type system, it may be conceivable that the speed regulation may lead to a stopping of the vehicle if the preceding vehicle itself comes to a standstill. In either case (high set speed or use in the frame "Stop and Go", the system 10 may be designed so that the release of the field in front of the vehicle equipped with the invention can cause automatically or by a manual control of the driver, by an appropriate modulation of the regulation signals S, an acceleration of the vehicle to establish an inter-vehicular time equal to the threshold.

The onboard system 100 detailed above can also possibly be exploited in combination with a speed limiter of moving the vehicle. In this case the system 100 may include a speed limitation mode and a speed control mode.

Finally, the system 100 may be put out of service, or at least the speed control it provides, in the event that the accelerator pedal is exceeded beyond a predetermined position along its course. normal depression.

Moreover, although the exemplary embodiments indicate that the acceleration and deceleration values are controlled via a set speed value in the particular case where the onboard system providing the speed control is a speed control system, the control can act directly in acceleration / deceleration, like the accelerator pedal. The acceleration / deceleration setpoints specified by the driver are then directly interpreted as an acceleration and deceleration (electrically) map. The control signals S are no longer necessarily a target speed for the vehicle, but for example signals representative directly of the desired acceleration / deceleration, the control module knowing how to interpret such signals. When the control means (or one of the control buttons) is released, that is to say in the neutral position, it is possible to return to regulation by servocontrol around the current speed.

Claims

A method of operating an on-board system (100) for controlling the speed of a vehicle, comprising transmitting control signals (S) to a control module (12) of the operator device (13) and / or of the braking device (14) of the vehicle, said signals (S) being modulated according to a set value (V) specified to the system by the driver during a step in which the driver applies an action on a human interface -machine (1 1), characterized in that said setpoint is representative of a desired increase or decrease in speed for the vehicle when the action by the driver on the human-machine interface (1 1) is less than a duration T, said setpoint being representative of the acceleration or deceleration desired for the vehicle when the action by the driver on the human-machine interface (1 1) is greater than or equal to the duration T.

Method according to Claim 1, in which the acquisition of the setpoint value (V) during the action by the driver on the human-machine interface (11) comprises a step in which an intensity value is determined. of this action.

The method of claim 2, wherein the magnitude value of the action comprises an amplitude of displacement of a movable control element of the man-machine interface.

4. Method according to one of claims 2 and 3, characterized in that the intensity value of the action comprises a force exerted on a control element of the man-machine interface.

5. Method according to one of claims 2 to 4, characterized in that the intensity value of the action controls the increment or decrement of the set value (V) in a discrete manner.

Method according to one of Claims 2 to 4, characterized in that the intensity value of the action controls the increment or decrement of the target value (V) in a progressively continuous manner.

Method according to one of Claims 1 to 6, characterized in that the absolute value of the set point (V) is limited to a predetermined value.

Method according to any one of claims 1 to 7, characterized in that the on-board system provides servocontrol of the vehicle speed, the control signals comprising a vehicle speed reference value.

An on-board system for controlling the speed of a vehicle, comprising an interface (1 1) with the driver, characterized in that the interface (1 1) comprises means enabling the driver to specify a set value to the system ( V) representative of a desired increase or decrease of speed for the vehicle when the action by the driver on the interface (1 1) is less than a duration T, said reference value (V) being representative of the acceleration or the desired deceleration for the vehicle when the action by the driver on the human-machine interface (1 1) is greater than or equal to the duration T.

10. System according to claim 9, characterized in that the interface (1 1) comprises a control element arranged near the steering wheel of the vehicle, the intensity of the action exerted on the element carrying out the acquisition of the setpoint (V). System according to claim 10, characterized in that it comprises a position sensor of the control element, the setpoint value (V) being a function of the displacement amplitude of the control element.

System according to claim 10, characterized in that it comprises a force sensor exerted on the control element, the setpoint value (V) being a function of the force exerted on the control element.

System according to any one of claims 9 to 12, characterized in that it comprises a control module (12) of a motorisation device (13) and / or a braking device (14) of the vehicle, the system being configured to control the speed of the vehicle by transmitting control signals (S) to the control module, including a vehicle speed reference value, modulated according to the setpoint value (V).

Motor vehicle comprising an on-board system according to one of Claims 9 to 13.