Method and device for controlling an adaptive speed regulation system embedded in a vehicle via steering wheel dynamics.

Abstract

The present invention relates to a method and device for controlling an adaptive cruise control system installed in a vehicle traveling at a speed lower than a target speed. Specifically, the method comprises receiving (31) data representing a change in the vehicle's steering angle, the vehicle's speed, the vehicle's yaw rate, and the vehicle's longitudinal acceleration. The method also comprises filtering (32) the change in steering angle based on a first threshold value of angular rotation, determining (33) a positive jerk gradient based on the received data and the filtered steering angle change, and controlling (34) the ACC system based, in particular, on the positive jerk gradient, the received data, and the filtered steering angle change. Figure 5

Description

Title of the invention: Method and device for controlling an adaptive speed regulation system embedded in a vehicle via steering wheel dynamics. technical field

[0001] The present invention relates to methods and devices for controlling an adaptive speed control system installed in a vehicle, particularly a motor vehicle. The present invention also relates to a method and device for regulating the speed of a vehicle. Technological background

[0002] Some contemporary vehicles are equipped with functions or system(s) or driving assistance, called AD AS (from the English "Advanced Driver-Assistance System" or in French "Système d'aide à la conduite avancé").

[0003] Among these systems, the adaptive cruise control system, or ACC, has as its primary function the automatic and adaptive regulation of the speed of the vehicles equipped with it, according to their environment. Such an ACC system determines one or more acceleration and / or braking commands based on a speed command and information relating to the vehicle's environment, the acceleration and / or braking command(s) being specific to regulating the vehicle's speed adaptively, that is to say, by taking into account the vehicle's environment.

[0004] The derivative of the acceleration with respect to time is called jerk, this quantity representing for example jolts during sudden changes in acceleration.

[0005] Environmental information corresponds, for example, to the distance between the vehicle equipped with the ACC system and a vehicle traveling in front of it, the speed (e.g., relative speed) of the vehicle in front, the acceleration (or deceleration) 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, for example, determined 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.

[0006] Such an ACC system acts on the vehicle's behavior and thus influences the comfort of the vehicle's occupants. It is therefore important to take this notion of comfort into account when developing such a driver assistance system. Summary of the present invention

[0007] One object of the present invention is to solve at least one of the problems of the technological background described above.

[0008] Another object of the present invention is to improve the comfort of the occupants of a vehicle equipped with an adaptive cruise control system.

[0009] Another object of the invention is to improve the control of an adaptive speed regulation system embedded in a vehicle.

[0010] According to a first aspect, the present invention relates to a method for controlling an adaptive speed regulation system installed in a vehicle, called an ACC system, the vehicle moving at a speed lower than a target speed, the method comprising the following steps: - receipt of representative data: • from a variation in the steering angle of the vehicle, • the vehicle's speed, • of the vehicle's yaw rate, and • of a longitudinal acceleration of the vehicle; • of a radius of curvature of a vehicle's trajectory; - filtering of the flying angle variation as a function of a first threshold value of angular rotation to obtain a filtered flying angle variation, the threshold value of angular rotation being determined from the speed of movement; - Determining the gradient of a positive jerk as a function of: • of the filtered flying angle variation, • a second threshold value for angular rotation, and • of a lateral acceleration of the vehicle determined from the speed of travel and the yaw rate; - ACC system control in operation: • of the filtered flying angle variation, • of longitudinal acceleration, • of lateral acceleration, • the positive jerk gradient, and • the radius of curvature of a vehicle's trajectory.

[0011] Such a method makes it possible to obtain control of the adaptive speed regulation system improving the comfort of the vehicle's passengers by determining a jerk and its variation via the gradient, thus limiting a longitudinal acceleration of the vehicle.

[0012] According to a variant of the method, the filtering is obtained by saturating the absolute value of the flying angle variation with respect to the first threshold value of angular rotation and by a sliding averaging of the saturated flying angle variation when the absolute value of the saturated flying angle variation decreases.

[0013] Such filtering makes it possible to reduce noise when retrieving the value of steering wheel angle variation.

[0014] According to another variant, the lateral acceleration is determined by the following function: ^Lat ~ XV«,>»with: • aLat; the lateral acceleration of the vehicle (10), • V': the yaw rate of the vehicle (10), . Vego • ia vehicle speed (10).

[0015] Calculating the lateral acceleration allows its value to be determined more quickly than by using a sensor.

[0016] According to yet another variant, the positive jerk gradient is determined by the following function: "jr / ii \ i / 1 \ with: — 1^1 / • V JPos; the positive jerk gradient, • aLat; the lateral acceleration of the vehicle; • kay( : a first coefficient depending on an absolute value of the vehicle's lateral acceleration, • 5fa: the filtered flying angle variation, • £5: the second threshold value for angular rotation, and * / / R • a second coefficient depending on a ratio between the variation filtered flying angle and the second angular rotation threshold value.

[0017] According to a variant of the additional method, the positive jerk is defined by the following function when a first condition is met, the first condition being met when a first anterior lateral acceleration determined at a time instant so prior to a current instant is greater than a first threshold acceleration: J Pas ( 0 — .t ( 1 a ref “ a CurvesRaw 1) aV£C ' * Jpo^J): Ie Jerk Posdif at an instant, • aref: the longitudinal acceleration of the vehicle, • ^CiïrvesRaw: the first threshold acceleration, and • / : a function using a lookup table.

[0018] The positive jerk is thus determined when a first condition corresponding to a vehicle located in a curve or a turn is verified.

[0019] According to another embodiment of the method, a corrected positive jerk is defined by the following function when a second condition is met, said second condition being met when the first condition is met and a lateral acceleration an The acceleration between time t and the current time is less than a second threshold acceleration, the second threshold acceleration being less than the first threshold acceleration: Jpjt) = JpJj-At) VJPos if (JpaM -JpoAt-^ï) > JpoM = ^»(^0 + JpoM -JposÀ-^A S1 ( JPos{ t) - JPos( t-At ) ) < (At with : • JPoAA: The positive jerk at an instant • jp ( : the corrected positive jerk at a given instant z, At: a period of time, and • V JPox; the positive jerk gradient.

[0020] The corrected positive jerk is thus determined when a second condition corresponding to a vehicle located at the exit of a curve or a turn is verified.

[0021] According to yet another variant of the method, the control is further a function of a first maximum acceleration when the first condition is met and the second condition is not met, and of a second maximum acceleration when the first and second conditions are met, said first and second maximum accelerations being determined by the following functions: ^MaxCurvea ( 0 5 MaxCurveAjA ) ^MaxCurvesÀ^ ^MaxCurvesÀ + At (pMaxCm-veAA) ~ ^MaxCurvesA~^^ ) > ^MaxCurves(^ — ^MaxCurvesA'^ ') ^MaxCurvesA ') ~ ^MaxCurves^~^^ ( ^MaxCunes( ) ^MaxCurves( x Pos( 0) with : * aMaxC'urveA 0 • a first maximum acceleration at an instant f, * ^MaxCurves^ 0 • a second maximum acceleration at a given instant1 • 8; a function using a lookup table, . VeSo • |a vehicle travel speed (10), * vMaxCunxA^) • a maximum speed of movement as a function of the radius of curvature R, • At: a period of time, * JpiAj): The Positive Jerk at a given moment and • jp j: the corrected positive jerk at a given moment!

[0022] A maximum acceleration is thus defined in each of the situations and applicable during the control of a vehicle's adaptive speed regulation system.

[0023] According to a second aspect, the present invention relates to a control device for an adaptive speed regulation system of a vehicle, 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.

[0024] 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.

[0025] 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.

[0026] Such a computer program may use any programming language, and be in the form of source code, object code, or an intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0027] 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.

[0028] 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 disk drive.

[0029] 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 an Internet-type network.

[0030] 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

[0031] Other features and advantages of the present invention will become apparent from the description of the particular and non-limiting embodiments of the present invention below, with reference to the attached Figures 1 to 5, in which:

[0032] [Fig.1] schematically illustrates an environment of a vehicle, according to a particular and non-limiting embodiment of the present invention;

[0033] [Fig.2] schematically illustrates a passenger compartment of the vehicle of [Fig.1], according to a a particular and non-limiting example of a realization of the present invention;

[0034] [Fig.3] schematically illustrates a first evolution curve of a variation flying angle and a second filtered flying angle variation curve, according to a particular and non-limiting embodiment of the present invention;

[0035] [Fig.4] schematically illustrates a device configured to control a system of adaptive speed regulation on board the vehicle of [Fig.1], according to a particular and non-limiting embodiment of the present invention;

[0036] [Fig. 5] illustrates a flowchart of the different stages of a control process for a adaptive speed control system embedded in the vehicle of [Fig. 1], according to a particular and non-limiting embodiment of the present invention. Description of embodiment examples

[0037] A method and a control device for an adaptive speed regulation system embedded in a vehicle will now be described in what follows with joint reference to Figures 1 to 5. The same elements are identified with the same reference signs throughout the description that follows.

[0038] The terms "first," "second" (or "firsts," "seconds"), etc., are used in this document by arbitrary convention to allow for the identification and distinction of different elements (such as operations, means, etc.) implemented in the embodiments described below. Such elements may be distinct or correspond to a single element, depending on the embodiment.

[0039] According to a particular and non-limiting embodiment, the present invention relates to a method and a device for controlling an adaptive cruise control system installed in a vehicle traveling at a speed lower than a target speed. Specifically, the method comprises receiving data representing a change in the vehicle's steering angle, the vehicle's speed, the vehicle's yaw rate, and the vehicle's longitudinal acceleration. The method also comprises filtering the steering angle change based on a first angular rotation threshold value, determining a positive jerk gradient based on the received data and the filtered steering angle change, and controlling the ACC system based, in particular, on the positive jerk gradient, the received data, and the filtered steering angle change.

[0040] Fig. 1 illustrates a vehicle 10, for example a motor vehicle, travelling on a portion of road 1001 of environment 1. 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.

[0041] Vehicle 10 corresponds for example to a vehicle with a thermal engine, with electric motor(s) or even a hybrid vehicle with a thermal engine and one or more electric motors.

[0042] Vehicle 10 corresponds to a vehicle operating under the full supervision of a driver or operating in a semi-autonomous mode. Vehicle 10 operates according to an autonomy level of 0 or according to an autonomy level ranging from 1 to 2, for example, according to the scale defined by the American federal agency which has established 5 levels of autonomy ranging 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.

[0043] The 5 levels of autonomy in the classification of the federal agency responsible for road safety are: - level 0: no automation, the vehicle driver fully controls the main functions of the vehicle (engine, accelerator, steering, brakes); - level 1: driver assistance, automation is active for certain vehicle functions, the driver retaining overall control over driving the vehicle; cruise control is part of this level, as are other aids such as ABS (anti-lock braking system) or ESP (electronic stability program); - level 2: automation of combined functions, the control of at least two main functions is combined in the automation to replace the driver in certain situations; for example, adaptive cruise control combined with lane centering allows a vehicle to be classified as level 2, as does automatic parking assist; - level 3: limited autonomous driving, the driver can cede complete control of the vehicle to the automated system which will then be in charge of critical safety functions; however, autonomous driving can only take place under certain specific environmental and traffic conditions (only on highways for example); - level 4: fully autonomous driving under certain conditions, the vehicle is designed to independently perform all critical safety functions over a complete journey; the driver provides a destination or navigation instructions but is not required to be available to take back control of the vehicle; - Level 5: Completely autonomous driving without driver assistance in all circumstances.

[0044] According to the example in [Fig. 1], the vehicle 10 is travelling on a section of road 1001 in a curve and makes a turn following a radius of curvature r.

[0045] The vehicle 10 includes, in particular, one or more driver assistance systems, known as ADAS (Advanced Driver-Assistance System), including an automatic speed control system, known as ACC. Such an ADAS system is configured to assist, or even replace, the driver of the vehicle 10 in controlling the vehicle 10 during its journey.

[0046] The first vehicle 10 carries, for example, 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, the second vehicle 11 located in front of the vehicle 10 as shown in [Fig. 1]), in order to detect obstacles and their distances from the vehicle 10; and / or - one or more LIDAR(s) (Light Detection and Ranging), a LIDAR sensor corresponding to an optoelectronic system composed of a laser emitter, a receiver including a light collector (to collect the portion of the light emitted by the emitter and reflected by any object located in the path of the light rays emitted by the emitter) and a photodetector that transforms the collected light into an electrical signal; a LIDAR sensor thus makes it possible to detect the presence of objects (for example, the second vehicle 11) 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 the vehicle 10 located in the field of vision of the camera(s).

[0047] The data obtained from this sensor or these sensors vary depending on the type of sensor. In the case of a radar or a 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 representing the envelope (or part of the envelope) of the detected object as seen by the sensor and ultimately by the vehicle 10 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, the determination of positions. successive paths taken by an object moving in environment 1, for example the second vehicle 11, and from this, one or more dynamic parameters of the moving object such as position, speed and / or acceleration. This data also makes it possible to determine the lines on the ground to, for example, help determine whether the second vehicle 11 and vehicle 10 belong to the same traffic lane.

[0048] The data acquired by the on-board sensor(s) feeds, for example, one or more on-board systems in the vehicle 10, including the ACC system.

[0049] According to the example in [Fig. 1], the vehicle 10 is moving at a current speed lower than a target speed determined for the ACC system. Such a situation arises, for example, when the vehicle 10 loses sight of a target vehicle that it was following and that was moving at a speed lower than the target speed, or when a user requests the vehicle 10 to move at a target speed higher than the current speed, for example by activating the ACC system or by increasing its target speed.

[0050] [Fig.2] schematically illustrates a vehicle interior, for example vehicle 10 of [Fig.1], according to a particular and non-limiting embodiment of the present invention.

[0051] The vehicle 10 may, for example, be equipped with a steering wheel 11 for steering the vehicle 10, for example by determining the angle of rotation of one or more wheels of the vehicle 10 via a mechanical and / or electrical linkage. However, the invention is not limited to a steering wheel 11; other devices such as handlebars or a joystick are also suitable for guiding a vehicle.

[0052] The steering wheel 11 is for example connected to a steering wheel angle sensor 11.

[0053] A movement of the steering wheel 11 then generates a data transmission, for example to destination of a computer, via one or more communication buses of the vehicle's on-board system 10, for example a communication bus of the type CAN data bus (from the English "Controller Area Network" or in French "Réseau de contrôles"), CAN FD (from the English "Controller Area Network Flexible Data-Rate" or in French "Réseau de contrôles à débit de données flexible"), FlexRay (according to the ISO 17458 standard), Ethernet (according to the ISO / IEC 802-3 standard) or LIN (from the English "Local Interconnect Network" or in French "Réseau interconnecté local").

[0054] Other sensors or on-board computers are also connected via communication, for example through the communication bus. These include, for example, a vehicle speed sensor or odometer, a longitudinal acceleration sensor or a wheel angle sensor.

[0055] A control process for an adaptive speed regulation system embedded in the vehicle 10, called the ACC system, is advantageously implemented by the vehicle 10, i.e. by a computer or a combination of computers of the vehicle 10 embedded system, for example by the computer(s) in charge of controlling the vehicle 10 ACC system.

[0056] In a first operation, data is received, for example by the computer responsible for controlling the ACC system. This data is representative: • of a variation in steering angle 11 of the vehicle 10, • the vehicle's speed of movement 10, • with a yaw rate of 10 for the vehicle, • of a longitudinal acceleration of the vehicle 10, and • of a radius of curvature of a vehicle trajectory 10.

[0057] The longitudinal acceleration of the vehicle 10 is obtained for example from an acceleration sensor arranged along an x-axis corresponding to the longitudinal axis of the vehicle 10 or from a multi-axis acceleration sensor, one of these axes being arranged along the x-direction.

[0058] Yaw rate is obtained for example from a rotation speed sensor or determined from a wheel angle sensor of vehicle 10.

[0059] The radius of curvature of a trajectory of the vehicle 10 is obtained for example from a computer determining this radius as a function of the angle of a wheel and the speed of the vehicle, from a measurement made by an optical system or from data from a map of an on-board navigation system.

[0060] In a second operation, the steering angle variation is filtered according to a first threshold value of angular rotation to obtain a filtered steering angle variation. The threshold value of angular rotation is determined in particular from the speed of movement of the vehicle 10, for example from a first lookup table.

[0061] According to a particular embodiment illustrated by [Fig.3], the filtering is obtained by saturating the absolute value of the flying angle variation with respect to the first threshold value of angular rotation and by a moving average over a determined time period of the saturated flying angle variation when the absolute value of the saturated flying angle variation decreases.

[0062] We observe on the curve corresponding to the variation of flying angle 5 an exceeding of the first threshold value of angular rotation 2 x on the time periods t1, t2 and t3, the variation of saturated flying angle therefore follows a plateau on these periods.

[0063] We also observe a separation of the two curves when the absolute value of the flying angle variation decreases after applying the moving average of the saturated flying angle variation.

[0064] Such filtering makes it possible to reduce noise or interference and is also effective when the vehicle 10 makes several consecutive turns.

[0065] In a third step, a gradient of a positive jerk is determined as a function of: • of the filtered flying angle variation, • a second threshold value for angular rotation, and • of a lateral acceleration of vehicle 10 determined from the speed of movement of vehicle 10 and the yaw rate of vehicle 10.

[0066] According to a particular embodiment, the positive jerk gradient is determined by the following function:

[0067] [Math.l] VJPas “(I a Lat 1 ) X | )

[0068] With: • VJPos; the positive jerk gradient, • aLat; the lateral acceleration of the vehicle (10); • kav( : a first coefficient depending on an absolute value of the lateral acceleration of the vehicle (10), • 5fn: the filtered flying angle variation, • ^3: the second threshold value for angular rotation, and • . H 1 V second coefficient depending on a ratio between the variation « \ J y filtered flying angle and the second angular rotation threshold value.

[0069] The first and second coefficients are for example determined empirically and are entered in correspondence tables or in a map.

[0070] According to a particular embodiment, the lateral acceleration is determined by the following function:

[0071] [Math.2] ^Lat ~ V' X Vego

[0072] With: • aLat; the lateral acceleration of the vehicle 10, • ÿ' : the yaw rate of vehicle 10, . Vego • | the vehicle's travel speed 10.

[0073] Lateral acceleration is acceleration along a transverse axis normal to the longitudinal axis x; this axis is represented by the transverse axis y in [Fig. 1]. This transverse axis y is oriented, in particular, towards the instantaneous center of rotation of the vehicle 10.

[0074] The yaw rate of vehicle 10 represents the angular rate of rotation of vehicle 10 around an axis z defined normal to the longitudinal x and transverse y axes.

[0075] According to a particular embodiment, this yaw rate is determined by A computer in vehicle 10 uses, among other things, the angle of one of vehicle 10's wheels. Using wheel angle instead of a sensor allows for faster determination of this yaw rate, thus making the system more responsive. The gain from determining yaw rate based on wheel angle rather than a sensor results in a reduction of approximately 500 ms in obtaining this rate.

[0076] Lateral acceleration is a quantity which has a strong influence on the comfort of the occupants of the vehicle 10, indeed a strong variation of lateral acceleration in a turn creates discomfort for the occupants of the vehicle 10. It is therefore important to limit the variation of this lateral acceleration, in particular by limiting the jerk which, as a reminder, is the derivative of the lateral acceleration with respect to time. 1. In a fourth operation, the ACC system is controlled according to: • of the filtered flying angle variation, • of the longitudinal acceleration of the vehicle 10, • of the lateral acceleration of the vehicle 10, and • of the gradient of said positive jerk, and Method for controlling an adaptive speed regulation system installed in a vehicle (10), referred to as the ACC system, said vehicle (10) moving at a travel speed lower than a target speed, said method comprising the following steps: - receipt (31) of representative data: • of a variation in steering angle (11) of the vehicle (10), • of said vehicle speed (10), • of a yaw rate of the vehicle (10), • of a longitudinal acceleration of the vehicle (10), and • of a radius of curvature of a trajectory of the vehicle (10); - filtering (32) of said flying angle variation as a function of a first threshold value of angular rotation to obtain a filtered flying angle variation, said threshold value of angular rotation being determined from said speed of movement; - determination (33) of a gradient of a positive jerk as a function of: • of said filtered flying angle variation, • a second threshold value for angular rotation, and • of a lateral acceleration of the vehicle (10) determined from said travel speed and said yaw rate; - control (34) of said ACC system in operation: • of said filtered flying angle variation, • of said longitudinal acceleration, • of said lateral acceleration, • said gradient of said positive jerk, and • of the radius of curvature of a vehicle trajectory 10.

[0077] In a fifth operation, the type of situation is determined, the first type of situation corresponding to a vehicle 10 in a curve, the second type of situation corresponding to a vehicle 10 exiting a curve. In both situations, it is necessary to limit the variation in acceleration of the vehicle 10 to improve the comfort of the vehicle 10's occupants.

[0078] The first situation, corresponding to a vehicle 10 in a turn, is characterized by the verification of a first condition. The first condition is verified when a first anterior lateral acceleration determined at a time instant t prior to a current instant is greater than a first threshold acceleration.

[0079] A positive jerk is then determined by the following function:

[0080] [Math.3] (0 — ( 1 ^ref ” ^CurvesRaw I )

[0081] With: • J: The positive jerk at a given instant • aref; the longitudinal acceleration of the vehicle (10), • acUrvesRaw; the first threshold acceleration, and • f: a function using a lookup table.

[0082] The second situation, corresponding to a vehicle 10 exiting a curve, is characterized by the fulfillment of a second condition. The second condition is met when the first condition is met and a previous lateral acceleration between time t and the current time is less than a second threshold acceleration, the second threshold acceleration being less than the first threshold acceleration. This second situation thus occurs after the first situation, that is, the vehicle 10 exits a curve after having been in a curve.

[0083] A corrected positive jerk is then determined by the following function:

[0084] [Math.4] if [Math.4] , And

[0085] = + JpJj)-JpJl-4t) if

[0086] With:

[0087]

[0088]

[0089] • Jpo,f(j): the positive jerk at a given instant f, • ) / : the corrected positive jerk at a given moment • At: a time period, and • V JPos; the positive jerk gradient. The positive jerk and the corrected positive jerk allow, for example, the determination of a maximum acceleration in each of the previous situations. According to a particular embodiment, the control of the ACC system is further a function of a first maximum acceleration when the first condition is met and the second condition is not met, and of a second maximum acceleration when the first and second conditions are met, said first and second maximum accelerations being determined by the following functions: [Math.5]

[0090] ^MaxCurves [Math.6] 'eg^MaxCurves ^MaxCurves(^t) aMaxCurves ) + ^1? X Jpas^) if [Math.6]

[0091] ✓MaxC urves [Math.7] .. urves

[0092] ^MaxC urves \ 1 if [Math.7] ( ^MaxCurves ^McucCur ( ^ ) ^MaxCurvi with : (f-Æ) + ÜMaxCurves (axCurves^'^)

[0093] • ^MaxCurves^): a first maximum acceleration at an instant, * atMaxCurves^): a second maximum acceleration at a given instant T, • 8; a function using a lookup table, . Vego • |the vehicle's travel speed 10, * vMaxCurvek^): a maximum speed of movement as a function of the radius of curvature R, • At: a period of time, • JpOK{t): The positive jerk at a given instant, and • j .( t ) • 'c Jerk Positive corrected at an instantl. The V^faxCurves(R) function is a function that uses a lookup table to determine the maximum speed of the vehicle in a curve. function of the radius of curvature of the vehicle's trajectory 10.

[0094] The function S also uses a lookup table, allowing the maximum acceleration of the vehicle 10 to be determined in a turn as a function of the difference between the maximum speed of the vehicle and its actual speed of movement.

[0095] Thus, a longitudinal acceleration of the vehicle 10 determined by the ACC system is limited by the first maximum acceleration in a curve or turn, and is limited by the second maximum acceleration at the exit of the curve or turn.

[0096] The comfort of the occupants of vehicle 10 is thus improved, the variation of the acceleration being thus limited by, depending on the situation, the jerk, the corrected jerk and the gradient of the jerk.

[0097] Such a process thus makes it possible to improve the vehicle's behavior law during acceleration in a turn or when exiting a turn.

[0098] Figure 4 schematically illustrates a device 2 configured to control an adaptive cruise control system installed in a vehicle, for example, the vehicle 10 of Figure 1, according to a particular and non-limiting embodiment of the present invention. The device 2 corresponds, for example, to a device installed in the first vehicle 10, for example, the ACC system control unit.

[0099] Device 2 is, for example, configured to carry out the operations described opposite Figures 1 to 3 and / or the steps of the process 3 described opposite [Fig. 5]. Examples 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, or a laptop computer. The elements of device 2, individually or in combination, can be integrated into a single integrated circuit, into several integrated circuits, and / or into discrete components. Device 2 can be implemented in the form of electronic circuits or software (or computer) modules, or a combination of electronic circuits and software modules.

[0100] The device 2 comprises one (or more) processor(s) 20 configured to execute instructions for carrying out the steps of the process and / or for executing instructions from the software embedded in the device 2. The processor 20 may include integrated memory, an input / output interface, and various circuits known to those skilled in the art. The device 2 further comprises at least one memory 21, 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.

[0101] The computer code of the embedded software(s) including the instructions to The information loaded and executed by the processor is, for example, stored in memory 21.

[0102] According to various particular and non-limiting embodiments, the device 2 is coupled in communication with other similar devices or systems and / or with communication devices, for example a TCU (Telematic Control Unit), for example via a communication bus or through dedicated input / output ports.

[0103] According to a particular and non-limiting embodiment, the device 2 includes a block 22 of interface elements for communicating with external devices, for example a remote server, or the vehicle 10 when the device 2 corresponds to a smartphone or tablet, for example. The interface elements of the block 22 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 interface (from the English "Universal Serial Bus" or "Universal Serial Bus" in French); - HDMI interface (from the English "High Definition Multimedia Interface", or "High Definition Multimedia Interface" in French).

[0104] According to another particular and non-limiting embodiment, the device 2 includes a communication interface 23 which enables communication with other devices (such as other computers in the embedded system or embedded sensors) via a communication channel 230. The communication interface 23 corresponds, for example, to a transmitter configured to transmit and receive information and / or data via the communication channel 230.Communication interface 23 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), Ethernet (standardized by ISO / IEC 802-3) or LIN (Local Interconnect Network).

[0105] According to a particular and non-limiting embodiment, the device 2 can provide output signals to one or more external devices, such as a screen display, touch or otherwise, and / or other peripherals via respective output interfaces. In one variant, one or the other of the external devices is integrated into device 2.

[0106] Figure 5 illustrates a flowchart of the different steps of a method 3 for controlling an on-board adaptive speed control system of a vehicle, for example vehicle 10, according to a particular and non-limiting embodiment of the present invention. The method 3 is implemented, for example, by a device on-board in the vehicle 10 or by the device 2 of Figure 4.

[0107] In a first step 31, data are received. This data is representative: • of a variation in steering angle 11 of the vehicle 10, • the vehicle's speed of movement 10, • a yaw rate of 10 for the vehicle, and • of a longitudinal acceleration of the vehicle 10.

[0108] In a second step 32, the steering angle variation is filtered according to a first threshold value of angular rotation to obtain a filtered steering angle variation, the threshold value of angular rotation being determined from the speed of movement of the vehicle 10.

[0109] In a third step 33, a gradient of a positive jerk is determined as a function of: • of the filtered flying angle variation, • a second threshold value for angular rotation, and • of a lateral acceleration of vehicle 10 determined from said vehicle 10 travel speed and vehicle 10 yaw rate.

[0110] In a fourth step 34, the adaptive speed control system is controlled according to: • of the filtered flying angle variation, • of the longitudinal acceleration of the vehicle 10, • of the lateral acceleration of the vehicle 10, and • the positive jerk gradient.

[0111] According to one variant, the variants and examples of the operations described in relation to Figures 1 to 3 apply to the steps of process 3 of [Fig.5].

[0112] The present invention also relates to an adaptive speed control system for vehicles comprising device 2 of [Fig.4].

[0113] The present invention also relates to a vehicle, for example a motor vehicle or more generally a land motor vehicle, comprising the device 2 of [Fig.4] or the adaptive speed control system for vehicles above.

Claims

Claims

1. Method for controlling an adaptive cruise control system on board a vehicle (10), called an ACC system, said vehicle (10) moving at a travel speed lower than a target speed, said method comprising the following steps: - receiving (31) data representative of: • a steering wheel angle variation (11) of the vehicle (10), • said travel speed of the vehicle (10), • a yaw rate of the vehicle (10), • a longitudinal acceleration of the vehicle (10), and • a radius of curvature of a trajectory of the vehicle (10); - filtering (32) said steering wheel angle variation as a function of a first angular rotation threshold value to obtain a filtered steering wheel angle variation, said angular rotation threshold value being determined from said travel speed;- determination (33) of a gradient of a positive jerk as a function of: • said filtered steering wheel angle variation, • a second angular rotation threshold value, and • a lateral acceleration of the vehicle (10) determined from said travel speed and said yaw rate; - control (34) of said ACC system as a function of: • said filtered steering wheel angle variation, • said longitudinal acceleration, • said lateral acceleration, • said gradient of said positive jerk, and • said radius of curvature of a trajectory of the vehicle (10).;

2. A method according to claim 1, wherein said filtering is obtained by saturating the absolute value of said steering wheel angle variation with respect to said first threshold angular rotation value and by sliding averaging said saturated steering wheel angle variation when the absolute value of said saturated steering wheel angle variation decreases.

3. Method according to one of claims 1 to 2, for which said lateral acceleration is determined by the following function: ^Lat ~ V'x ^owith: • aLat; the lateral acceleration of the vehicle (10), • V'; the yaw rate of the vehicle (10), . Vego • |the speed of movement of the vehicle (10).

4. Method according to one of claims 1 to 3, for which the positive jerk gradient is determined by the following function: ™ i \ . z H ii 1 \ with: y J Pos - ^y ( ! aLat\ ) X \ | ^ | / •VJ Pos ; the positive jerk gradient, • aLat ; the lateral acceleration of the vehicle (10); • kay{ ): a first coefficient depending on an absolute value of the lateral acceleration of the vehicle (10), • 5fn : the filtered steering wheel angle variation, • : the second angular rotation threshold value, and • , / 1 $fu 1 \ : a second coefficient depending on a ratio between the filtered steering wheel angle variation and the second angular rotation threshold value.

5. Method according to one of claims 1 to 4, for which the positive jerk is defined by the following function when a first condition is verified, said first condition being verified when a first prior lateral acceleration determined at a time instant prior to a current instant is greater than a first threshold acceleration: JpoM = / ( )with: * JPoA^) • The Positive Jerk at an instant • ^ref ; the longitudinal acceleration of the vehicle (10), • acun 'esRaw ; the first threshold acceleration, and • / : a function using a lookup table.

6. The method of claim 5, wherein a corrected positive jerk is defined by the following function when a second condition is satisfied, said second condition being satisfied when the first condition is satisfied and a prior lateral acceleration between said time instant tant and said current instant is less than a second threshold acceleration, the second threshold acceleration being less than the first threshold acceleration: + 4txVJp„ / ' (JPos( 0 " JPos('^))> (dt x V JPos), and Jpo.M = Jpos(^t) +JPos(t) -Jpjj-At) If ( JPos ( r) " JPos ( X JPos) with : * J) • The Positive Jerk at an instant z, • j ( t ) • The corrected Positive Jerk at an instant f, • At ; a time period, and • V JPos ; the positive jerk gradient.

7. The method of claim 6, wherein said control is further a function of a first maximum acceleration when the first condition is satisfied and the second condition is not satisfied and a second maximum acceleration when the first and second conditions are satisfied, said first and second maximum accelerations being determined by the following functions: axCurves ( 0 — 8 ( go ~ MoxCurvest^) ) ^MaxCurves( 0 — ^MaxCurves^ ) "h Pas( 0 ^MaxCurves^) — ^MaxCurvesi f ^MaxCurves ( 0 " ^MaxCurvesi (.^MaxCurves^) ~ ^MaxCurvesU~^) ) ^Pos(j)) with: * aMaxCunei( 0 • a First maximum acceleration at an instant • à™ ( l ): a second maximum acceleration at an instant f, • 8 ; a function using a look-up table, • vego • the vehicle's moving speed (10), * vMa xCune^): a maximum moving speed as a function of the radius of curvature R, • At ; a time period, • JpOT(?): The positive jerk at an instant • j ( t ) • The corrected Positive Jerk at an instant f.

8. Computer program comprising instructions for implementing the method according to any one of the preceding claims, when these instructions are executed by a processor.

9. Device (3) for controlling an adaptive vehicle speed regulation system, 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 7.

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

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