METHOD AND DEVICE FOR CONTROLLING THE ACCELERATION OF A VEHICLE WITH AN ON-BOARD SPEED CONTROL SYSTEM

Description

technical field

[0001] The present invention relates to methods and devices for controlling the acceleration of a vehicle, particularly a motor vehicle. The present invention also relates to a method and device for controlling a vehicle's speed regulation system. The present invention further relates to a method and device for controlling a vehicle, particularly an autonomous vehicle. Technological background

[0002] Some contemporary vehicles are equipped with functions or systems or driver assistance systems, known as ADAS (from the English "Advanced Driver-Assistance System" or in French "Système d'aide à la conduite avancé").

[0003] Among these systems, the speed regulation system or adaptive speed regulation system, known as ACC (from the English "Adaptive Cruise Control"), has as its primary function the automatic regulation (adaptively for the ACC system) of the speed of the vehicles which are equipped with it according to their environment.

[0004] The speed control system determines one or more acceleration commands to reach a set speed, for example set by the vehicle driver.

[0005] The ACC system determines one or more acceleration commands based on a speed command and information relating to the vehicle's environment, the acceleration command(s) being specific to regulate the vehicle's speed adaptively, that is to say, taking into account the vehicle's environment.

[0006] This environmental information includes, for example, the distance between the vehicle equipped with the ACC system and a vehicle traveling ahead, the speed (e.g., relative speed) of the vehicle in front, the acceleration of the vehicle in front, and / or a regulatory speed limit. Such a vehicle is called the target vehicle or target object of the ACC system. The acceleration command(s) are determined, for example, from a control law based on estimates of the torque supplied by a powertrain (e.g., an internal combustion or electric motor) to one or more wheels of the vehicle and the vehicle's current acceleration.

[0007] A vehicle's environmental information is obtained, for example, from sensors onboard the vehicle, such as radar. This information is particularly important for a vehicle, for example, to improve vehicle safety by taking into account the surrounding environment, including other vehicles.

[0008] Passenger comfort is another important factor, particularly for the acceptance of driver assistance systems. For example, excessive acceleration can cause discomfort for passengers, especially when acceleration is controlled by a cruise control system. Significant acceleration can occur, for instance, when the driver increases the set speed. Finding the right balance between passenger comfort and the speed at which the vehicle reaches the set speed can sometimes be challenging.

[0009] Furthermore, the prior art is known from document US2018126987A1. Summary of the present invention

[0010] One object of the present invention is to solve at least one of the problems of the technological background described above.

[0011] Another object of the present invention is to improve the regulation of the acceleration of a vehicle.

[0012] According to a first aspect, the present invention relates to a method for controlling the acceleration of a vehicle equipped with a speed regulation system, the method comprising the following steps: receiving information representing a set speed for the speed control system; determining the difference between the set speed and the vehicle's current speed; determining a parameter representing a maximum acceleration value for the speed control system based on the sign of the difference, the absolute value of the difference, a determined shock value, and a determined constant coefficient; controlling the vehicle's acceleration based on the parameter, the parameter, denoted A max (DV), being equal to: A max DV = sign DV ∗ k ∗ j 0 ∗ DV , with DV corresponding to the difference with DV = V cons -V cour , where V cons corresponds to the set speed and V cour to the current speed of said vehicle, j0 corresponding to the determined shock value and k corresponding to the determined constant coefficient.

[0013] This method improves vehicle acceleration control by determining a parameter in the control system that sets the maximum acceleration based on the difference between the target speed and the vehicle's current speed. This allows acceleration to be regulated according to the difference between the target speed and the vehicle's speed, for example, maximizing acceleration when the difference between the target speed and the vehicle's speed is large and reducing acceleration as the difference decreases.

[0014] This makes it possible to find a compromise between the speed of stabilization (for example to reach the set speed) and the dynamic comfort of the passengers by regulating the acceleration of the vehicle via the speed control system according to the value of the difference between the set speed and the speed of the vehicle.

[0015] According to one variant, the value of the j0 shock is equal to 0.55 ms -3< and the coefficient k is equal to 8 / 27.

[0016] According to an additional variant, the parameter is between a determined lower limit, denoted A inf, and a determined upper limit, denoted A sup.

[0017] According to yet another variant, the lower limit A int is equal to -1.5 ms -2< and the upper limit A sup is equal to 1.5 ms -2< .

[0018] According to an additional variant, the speed control system corresponds to an adaptive speed control system.

[0019] According to a second aspect, the present invention relates to a vehicle acceleration control device, the device comprising a memory associated with a processor configured for the implementation of the steps of the process according to the first aspect of the present invention.

[0020] According to a third aspect, the present invention relates to a vehicle, for example of the automobile type, comprising a device as described above according to the second aspect of the present invention.

[0021] According to a fourth aspect, the present invention relates to a computer program which includes instructions adapted for carrying out the steps of the process according to the first aspect of the present invention, in particular when the computer program is executed by at least one processor.

[0022] Such a computer program can use any programming language, and be in the form of source code, object code, or an intermediate form between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0023] According to a fifth aspect, the present invention relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the process according to the first aspect of the present invention.

[0024] On the one hand, the recording medium can be any entity or device capable of storing the program. For example, the medium can include a storage means, such as a ROM, a CD-ROM or a microelectronic circuit-type ROM, or a magnetic recording means or a hard drive.

[0025] On the other hand, this recording medium can also be a transmissible medium such as an electrical or optical signal, such a signal being able to be transmitted via an electrical or optical cable, by conventional or radio frequency, by self-directing laser beam, or by other means. The computer program according to the present invention can, in particular, be downloaded from a network such as the Internet.

[0026] Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to execute or to be used in the execution of the process in question. Brief description of the figures

[0027] Other features and advantages of the present invention will become apparent from the description of the specific and non-limiting embodiments of the present invention below, with reference to figures 1 to 4 attached, on which: [ Fig. 1] schematically illustrates a vehicle environment, according to a particular and non-limiting embodiment of the present invention; [ Fig. 2 ] illustrates a diagram representing a curve of a parameter representative of the maximum acceleration of the vehicle of the figure 1 based on a difference between a set speed and the vehicle's speed figure 1 , according to a particular and non-limiting example of the present invention; [ Fig. 3 [This schematically illustrates a device configured to control the acceleration of the vehicle] figure 1 , according to a particular and non-limiting example of the present invention; [ Fig. 4 ] illustrates a flowchart of the different stages of a vehicle acceleration control process figure 1 , according to a particular and non-limiting example of the present invention. Description of examples of achievements

[0028] A method and device for controlling the acceleration of a vehicle will now be described in what follows, with joint reference to figures 1 to 4 The same elements are identified with the same reference symbols throughout the description that follows.

[0029] According to a particular and non-limiting embodiment of the present invention, controlling the acceleration of a vehicle, for example by a vehicle-mounted speed control system, includes receiving information representing a setpoint speed for the speed control system. This setpoint speed is, for example, configured by the vehicle driver via a human-machine interface (HMI). The difference between the setpoint speed and the vehicle's speed is determined or calculated, and for example, stored in memory.A parameter of the speed control system, representing a maximum acceleration speed (corresponding, for example, to a parameter called gross potential acceleration), is determined or calculated based on the sign of the difference between the set speed and the vehicle's speed, the absolute value of this difference, a specific vibration value, and a specific constant coefficient. Finally, the vehicle's acceleration is determined based on this parameter, in order to regulate the vehicle's acceleration by the speed control system, based on the difference between the set speed and the vehicle's actual speed, for example.

[0030] A raw potential acceleration corresponds, for example, to an acceleration command determined or calculated by the speed control system, before any filtering to improve, for example, the comfort or safety of the vehicle's passengers.

[0031] The parameter representing maximum acceleration represents, for example, the maximum acceleration that the control system can apply to control the acceleration of the vehicle.

[0032] The coefficient k is chosen for example in such a way that the value of the parameter representing the maximum acceleration increases with the difference in speed, the maximum acceleration being for example all the higher as the difference between the target speed and the speed of the vehicle is high.

[0033] A shock value advantageously corresponds to a quantity representing a variation of the acceleration over time, expressed in ms -3< .

[0034] There figure 1 schematically illustrates an environment 1 of a vehicle 10, according to a particular and non-limiting embodiment of the present invention.

[0035] There figure 1illustrates a vehicle 10, for example a motor vehicle, carrying one or more sensors configured to detect the presence of objects in the environment 1 of the vehicle 10. According to other examples, the vehicle 10 corresponds to a coach, a bus, a truck, a utility vehicle or a motorcycle, that is to say a motorized land vehicle type vehicle.

[0036] Vehicle 10 corresponds to a vehicle operating under the full supervision of a driver or operating in an autonomous or semi-autonomous mode. The vehicle operates according to an autonomy level of 0 or according to an autonomy level ranging from 1 to 5, for example, according to the scale defined by the American federal agency which has established 5 levels of autonomy from 1 to 5, level 0 corresponding to a vehicle with no autonomy, whose driving is under the full supervision of the driver, level 1 corresponding to a vehicle with a minimal level of autonomy, whose driving is under the supervision of the driver with minimal assistance from an ADAS system, and level 5 corresponding to a fully autonomous vehicle.

[0037] Following the example of the figure 1, vehicle 10 is travelling on a section of road 100 with two traffic lanes 101, 102. Vehicle 10 is travelling for example on the right traffic lane 101, the two traffic lanes 101 and 102 being in the same direction or in opposite directions.

[0038] Vehicle 10, for example, carries one or more of the following sensors: one or more millimeter wave radars arranged on the vehicle 10, for example at the front, at the rear, on each front / rear corner of the vehicle; each radar is adapted to emit electromagnetic waves and to receive the echoes of these waves reflected by one or more objects (for example a vehicle traveling in front of the vehicle 10), in order to detect obstacles and their distances from the vehicle 10; and / or one or more LIDAR(s) (from the English "Light Detection And Ranging", or "Detection and estimation of distance by light" in French), a LIDAR sensor corresponding to an optoelectronic system composed of a laser emitting device, a receiving device comprising a light collector (to collect the part of the light radiation emitted by the emitter and reflected by any object located in the path of the light rays emitted by the emitter) and a photodetector which transforms the collected light into an electrical signal;A LIDAR sensor thus makes it possible to detect the presence of objects (for example a vehicle traveling in front of vehicle 10) located in the emitted light beam and to measure the distance between the sensor and each detected object; and / or one or more cameras (associated or not with a depth sensor) for the acquisition of one or more images of the environment around vehicle 10 located in the field of vision of the camera(s).

[0039] The data obtained from this sensor or these sensors varies depending on the type of sensor. In the case of radar or LiDAR, the data corresponds, for example, to distance data between points on the detected object and the sensor. Each detected object is thus represented by a point cloud (each point corresponding to a point on the object receiving the radiation emitted by the sensor and reflecting at least part of this radiation). The point cloud represents the envelope (or part of the envelope) of the detected object as seen by the sensor and ultimately by the vehicle carrying the sensor. In the case of a video camera, the data corresponds to data associated with each pixel of the acquired image(s), for example, grayscale values ​​coded on, for example, 8, 10, 12 or more bits for each color channel, for example RGB (Red, Green, Blue).This data allows, for example, to determine the successive positions taken by an object moving in the environment 1, for example a vehicle moving in front of the vehicle 10, and to deduce one or more dynamic parameters of the moving object such as lateral velocity, longitudinal velocity and / or lateral and longitudinal accelerations.

[0040] The data acquired by the on-board sensor(s) feeds, for example, one or more driver assistance systems, known as ADAS (Advanced Driver-Assistance System), on-board in vehicle 10. Such an ADAS system is configured to assist, or even replace, the driver of vehicle 10 in controlling vehicle 10 on its journey.

[0041] In a first example, vehicle 10 is equipped with an ADAS system corresponding to an automatic speed regulation system, known as a CC (Cruise Control) system. Such a system is designed to automatically stabilize the vehicle's speed around a target speed set by the driver of vehicle 10, for example, via a control lever located near the steering wheel, without the driver having to press the accelerator pedal. The CC system manages the speed by determining or calculating target acceleration values ​​that change over time based on the vehicle's current speed (for example, obtained from a speed sensor on board vehicle 10, such as an odometer) and the target speed set by the driver.Thus, the data obtained from the speed sensor(s) onboard vehicle 10 allows the vehicle 10's CC system to establish a target acceleration value Atarget(t) (corresponding, for example, to the raw potential acceleration determined as described below) over time 't'. The target acceleration Atarget(t) becomes a longitudinal acceleration setpoint Asetpoint(t), optionally with one or more filters applied to Atarget(t) to obtain Asetpoint(t).

[0042] In a second example, vehicle 10 is equipped with an ADAS system corresponding to an adaptive speed control system, known as ACC. When the ACC is activated, its objective is to achieve a target acceleration, called Atarget(t), which varies over time 't' and allows the vehicle to maintain or reach a set speed and / or maintain a predetermined safety distance from the second vehicle 11 ahead of vehicle 10, i.e., a target vehicle traveling in front of vehicle 10 in the same direction of travel in the same lane. The data obtained from the sensor(s) onboard vehicle 10 allows the ACC system of vehicle 10 to establish a target acceleration value Atarget(t) (a maximum of which corresponds, for example, to the raw potential acceleration determined as described below) over time 't'.The target acceleration Atarget(t) becomes a longitudinal acceleration setpoint Asetpoint(t), optionally with one or more filters applied to Atarget(t) to obtain Asetpoint(t). The ACC system or a computer within this system transmits, for example, the acceleration setpoints Asetpoint(t) that it has determined to the computer(s) supervising the operation of a powertrain of the vehicle 10, in particular so that the latter (they) can determine the torque setpoints to be generated by the powertrain to comply with the acceleration setpoints Asetpoint(t) and regulate the longitudinal speed of the vehicle 10.

[0043] A target acceleration value is determined, for example, at a current instant t0 from a set of data obtained from one or more object detection sensors on board the vehicle 10 and / or from setpoint parameters entered, for example, by the driver or determined from data on the environment of the vehicle 10. The target acceleration value (expressed in ms⁻²) is, for example, calculated from: data representative of the dynamic behavior of a vehicle traveling in front of vehicle 10 (for example speed and / or acceleration) and corresponding to the target object of the ACC system, this data being obtained for example from a set of positions taken by this vehicle traveling in front over a time interval preceding the current instant t 0 for which the target acceleration is determined; data representative of the dynamic behavior of vehicle 10 (for example speed, acceleration, distance vis-à-vis the second vehicle 11), this data being obtained from sensors on board vehicle 10, the distance being obtained for example from the data received from the object detection sensor(s);and / or setpoint parameters provided to the ACC system, such as, for example, a target speed, distance, or inter-vehicle time (IVT or IVT), these parameters being stored in memory, determined by environmental analysis (for example, the target speed is determined by reading speed limit signs or from data received from a navigation system) or entered by a user via a Human-Machine Interface, known as an HMI.

[0044] According to a third example, vehicle 10 carries both a CC system and an ACC system, or a single system within vehicle 10 implements both the CC and ACC functions. If no target vehicle is detected in front of vehicle 10, only the CC system or the CC function is activated.

[0045] A process for controlling the acceleration of vehicle 10 is advantageously implemented by the vehicle 10, i.e. by a computer or a combination of computers of the vehicle 10's on-board system, for example by the computer(s) in charge of controlling the CC system and / or the ACC system.

[0046] In the first operation, information representing a set speed for the speed control system is received. This information corresponds, for example, to a speed value in ms-1 set, parameterized or entered by the driver of vehicle 10 via an HMI, for example a control lever for the speed control system, a graphic HMI displayed on a screen, for example touch screen, mounted in the vehicle or by voice command.

[0047] In a second operation, the speed (for example the longitudinal speed Vx of vehicle 10 along the longitudinal axis X of a frame X,Y associated with vehicle 10, the longitudinal axis corresponding to the axis in the direction of movement of vehicle 10) of vehicle 10 is determined or received, for example from a speed sensor of the odometer type.

[0048] In a third operation, the difference, denoted DV, between the target speed obtained in the first operation and the speed of vehicle 10 obtained in the second operation is determined or calculated. At a current instant 't', the difference DV is thus determined as a function of the target speed and the speed measured or obtained at that instant 't'.

[0049] The velocity difference DV is obtained from the following equation: DV = V cons − V cour , With V cons corresponding to the setpoint speed and V cour to the current speed of the vehicle measured or obtained at a current instant 't'.

[0050] The difference DV is for example stored in a memory associated with the computer implementing the process, for example in a transient manner.

[0051] In a fourth operation, a parameter of the speed control system representative of a maximum acceleration value, denoted A max (DV), is determined or calculated as a function of a sign of the difference DV, the absolute value of the difference DV, a determined shock value, denoted j0, and a determined constant coefficient, denoted k.

[0052] According to a particular embodiment, the parameter A max (DV) increases with the speed difference DV, with, for example, a lower limit, denoted A inf, and an upper limit, denoted A sup. The parameter A max (DV) is a monotonically increasing function of the difference DV between the setpoint speed and the vehicle speed 10.

[0053] There figure 2represents an example of function 21 between the parameter A max (DV) (noted A max on the ordinate of diagram 2, in ms -2< ) and the difference between the set speed and the speed of vehicle 10 (noted DV on the abscissa of diagram 2, in ms -1< ).

[0054] According to the specific example of the figure 2 The parameter is only represented for positive acceleration values. According to this example, Amax = 0 for a difference DV = 0, then Amax increases according to a strictly increasing function determined with DV for DV between 0 and a first threshold equal, for example, to 13.8 m / s (i.e., 50 km / h), Amax reaching an upper limit Asup which is, for example, equal to 1.5 m / s. For any value of DV greater than the first threshold, Amax is constant and remains equal to the value of Asup, for example, 1.5 m / s.

[0055] The value of the parameter A max (DV) is obtained, for example, from a lookup table, known as a LUT (Look-Up Table), stored in a memory location of the vehicle 10 associated with the control unit implementing the process. A lookup table relates or matches a value of A max to a value of speed difference, for each value of DV in a set of speed difference values. If the calculated difference DV falls between two values ​​of difference DV stored in the table, the value of A max for this difference DV is obtained, for example, by interpolating the two values ​​of A max associated with the DV values ​​in the table surrounding the calculated DV value.

[0056] According to the invention, the value of the parameter A max (DV) is obtained as a function of the difference in speeds DV according to the following function: A max DV = sign DV ∗ k ∗ j 0 ∗ DV , with DV corresponding to the difference (DV = V cons - V cour ), j0 corresponding to the determined shock value and k corresponding to a determined coefficient, k corresponding for example to a constant.

[0057] According to a particular embodiment, the value of the j0 shake is equal to 0.55 ms -3< and the coefficient k is equal to 8 / 27. These two parameters of the speed control system are, for example, predefined by the manufacturer of the vehicle 10 or by the designer of the speed control system, these two parameters being stored in a memory accessible by the computer in charge of the process.

[0058] The coefficient k is advantageously chosen to obtain a monotonically increasing function of A max as a function of DV. The coefficient k is, for example, defined empirically or by simulation using a speed control system simulation tool.

[0059] According to one embodiment, these two parameters, or at least one of them, can be modified by a user, for example by the driver of the car via an HMI and / or by a person in charge of the maintenance of the vehicle 10, for example via a diagnostic tool.

[0060] According to other examples, j0 is for example equal to 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8 ms -3< and / or k is for example equal to 1 / 5, 6 / 25, 6 / 27, 7 / 27, 1 / 3, 10 / 27, 2 / 5 or any other value allowing A max to vary according to a monotonically increasing function of DV.

[0061] According to a particular embodiment, the function A max (DV) is saturated between two values, namely a minimum or lower value A inf and a maximum or upper value A sup. This means that A max is bounded or limited between a lower limit A inf and an upper limit A sup, with A max taking any value between these two limits according to a monotonically increasing function of DV.

[0062] As a non-limiting example, the lower limit A min is equal to -1.5 ms⁻², for example, for DV = 0, and the upper limit A max is equal to 1.5 ms⁻², for example, for all DV values ​​greater than or equal to a given threshold, for example, for DV ≥ 13.8 ms⁻¹. In other examples, the DV threshold for which A max = A sup is equal to 10, 11, 12, 14, 15, 16, 20 ms⁻¹ or more.

[0063] The values ​​of Ainf and Asup correspond, for example, to predetermined or defined parameters of the speed control system and stored in memory. In one variant, these parameters are adjustable, for example, by the car driver via an HMI and / or by a person responsible for vehicle maintenance 10, for example via a diagnostic tool.

[0064] The values ​​taken by A inf and A sup are not limited to the example above. For example, A inf is equal to -2, -1.8, -1.6 ms -2< and A sup is equal to 1.6, 1.8, 2, 2.5 or 3 ms -2< .

[0065] In a fifth operation, the acceleration of vehicle 10 is controlled as a function of the representative parameter of maximum acceleration obtained in the fourth operation as a function of the current speed difference DV.

[0066] For example, in the case of a CC system, the setpoint acceleration corresponds to the maximum acceleration Amax obtained in the fourth operation, this setpoint acceleration evolving over time as a function of the vehicle speed and the difference DV, until it reaches the setpoint speed, i.e. until DV = 0.

[0067] Thus, according to the invention, when DV is large, the target acceleration is large (for example) and the more DV decreases, that is, the closer the speed of vehicle 10 gets to the target speed, the more the target acceleration decreases.

[0068] According to another example, for example in the case of an ACC system, the acceleration is determined according to the dynamic parameters of vehicle 10 and a target vehicle traveling in front of vehicle 10, with the constraint of not exceeding (i.e. not being greater than) the maximum acceleration A max obtained in the fourth operation as a function of DV.

[0069] There figure 3Figure 3 schematically illustrates a device configured to control the acceleration of a vehicle, for example vehicle 10, according to a particular and non-limiting embodiment of the present invention. Device 3 corresponds, for example, to a device embedded in vehicle 10, such as a computer.

[0070] Device 3, for example, is configured to implement the operations described alongside the figures 1 and 2 and / or steps of the process described in relation to the figure 4Examples of such a device 3 include, but are not limited to, embedded electronic equipment such as a vehicle's on-board computer, an electronic control unit such as an ECU (Electronic Control Unit), a smartphone, a tablet, and a laptop computer. The elements of the device 3, individually or in combination, may be integrated into a single integrated circuit, into several integrated circuits, and / or into discrete components. The device 3 may be implemented as electronic circuits, software (or computer) modules, or a combination of electronic circuits and software modules.

[0071] Device 3 includes one or more processors 30 configured to execute instructions for carrying out the steps of the process and / or for executing instructions from the software embedded in Device 3. The processor 30 may include integrated memory, an input / output interface, and various circuits known to those skilled in the art. Device 3 further includes at least one memory 31, for example, volatile and / or non-volatile memory, and / or includes a memory storage device that may include volatile and / or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, magnetic disk, or optical disk.

[0072] The computer code of the embedded software(s) including the instructions to be loaded and executed by the processor is, for example, stored on memory 31.

[0073] According to various specific and non-limiting embodiment examples, device 3 is coupled in communication with other similar devices or systems (e.g. other computers) and / or with communication devices, e.g. a TCU (Telematic Control Unit), e.g. via a communication bus or through dedicated input / output ports.

[0074] According to a specific and non-limiting embodiment, device 3 includes a block 32 of interface elements for communicating with external devices. The interface elements of block 32 include one or more of the following interfaces: radio frequency (RF) interface, for example of the Wi-Fi® type (according to IEEE 802.11), for example in the 2.4 or 5 GHz frequency bands, or of the Bluetooth® type (according to IEEE 802.15.1), in the 2.4 GHz frequency band, or of the Sigfox type using UBN (Ultra Narrow Band) radio technology, or LoRa in the 868 MHz frequency band, LTE (Long-Term Evolution), LTE-Advanced; USB (Universal Serial Bus) interface; HDMI (High Definition Multimedia Interface); LIN (Local Interconnect Network) interface.

[0075] According to another particular and non-limiting embodiment, the device 3 includes a communication interface 33 which enables communication with other devices (such as other computers in the embedded system) via a communication channel 330. The communication interface 33 corresponds, for example, to a transmitter configured to transmit and receive information and / or data via the communication channel 330. The communication interface 33 corresponds, for example, to a wired network of the type CAN (Controller Area Network), CAN FD (Controller Area Network Flexible Data-Rate), FlexRay (standardized by ISO 17458) or Ethernet (standardized by ISO / IEC 802-3).

[0076] In a particular, non-limiting embodiment, device 3 can provide output signals to one or more external devices, such as a display screen (touchscreen or not), one or more speakers, and / or other peripherals (projection system), via respective output interfaces. In one variant, one or more of the external devices is integrated into device 3.

[0077] There figure 4 illustrates a flowchart of the different stages of a method for controlling the acceleration of a vehicle, for example vehicle 10, according to a particular and non-limiting embodiment of the present invention. The method is implemented, for example, by a device embedded in vehicle 10 or by device 3 of the figure 3 .

[0078] In a first step 41, information representing a setpoint speed for the speed control system is received.

[0079] In a second step 42, a difference between the set speed and a current speed of the vehicle is determined.

[0080] In a third step 43, a parameter representing a maximum acceleration value for the speed control system is determined as a function of a sign of the difference, the absolute value of the difference, a determined shock value and a determined constant coefficient.

[0081] In a fourth step 44, the acceleration of the vehicle is controlled according to the parameter obtained in the third operation 43.

[0082] According to one variant, the variants and examples of the operations described in relation to the figure 1 and / or 2 apply to the steps of the process of the figure 4 .

[0083] Of course, the present invention is not limited to the embodiments described above but extends to a method for controlling a vehicle's speed regulation system, for example, an autonomous vehicle, which would include secondary steps without falling outside the scope of the present invention. The same would apply to a device configured for implementing such a method.

[0084] The present invention also relates to a vehicle speed control system comprising device 3 of the figure 3 .

[0085] The present invention also relates to a vehicle, for example a motor vehicle or more generally an autonomous land-powered vehicle, comprising device 3 of the figure 3 or the above vehicle speed control system.

Claims

1. A method of controlling the acceleration of a vehicle (10) carrying a speed control system, said method comprising the steps of: - receipt (41) of information representative of a set speed for said speed control system; - determination (42) of a difference between said set speed and a current speed of said vehicle; - determination (43) of a parameter representative of a maximum acceleration value for said speed control system as a function of a sign of said difference, of the absolute value of said difference, of a determined shake value and of a determined constant ; - control (44) of the acceleration of said vehicle (10) as a function of said parameter, said parameter, denoted Amax (DV), being equal to: A max DV = sign DV ∗ k ∗ j 0 ∗ DV , with DV corresponding to said difference with DV= Vcons-Vcour, where Vcons corresponds to the set speed and Vcour to the current speed of said vehicle, j0 corresponding to said determined shake value and k corresponding to said determined constant coefficient.

2. Method according to claim 1, for which the jolt value j0 is equal to 0.55 m.s-3 and the coefficient k is equal to 8 / 27.

3. Method according to claim 1 or 2, for which the said parameter lies between a determined lower limit, denoted Ainf, and a determined upper limit, denoted Asup.

4. The method according to claim 3, wherein said lower limit Ainf is equal to -1.5 m.s-2 and said upper limit Asup is equal to 1.5 m.s-2.

5. Method according to one of claims 1 to 4, for which the said speed regulation system corresponds to an adaptive speed regulation system.

6. A computer plan including instructions for implementing the method according to any one of the previous claims, when these instructions are executed by a processor.

7. Computer-readable recording medium on which a computer plan is recorded, comprising instructions for executing the steps of the method according to one of claims 1 to 5.

8. Device (3) for controlling the acceleration of a vehicle, said device (3) comprising a memory (31) associated with at least one processor (30) configured for implementing the steps of the method according to any one of claims 1 to 5.

9. Vehicle (10) comprising the device (3) according to claim 8.