Method and device for controlling an adaptive cruise control system on board a vehicle via the steering wheel dynamics

Abstract

The present invention relates to a method and device for controlling an adaptive cruise control system on board a vehicle travelling at a speed of travel below a target speed. Indeed, the method comprises receiving (31) data representative of a variation in the steering wheel angle of the vehicle, the speed of travel of the vehicle, a yaw rate of the vehicle, and a longitudinal acceleration of the vehicle. The method further comprises filtering (32) the steering wheel angle variation according to a first threshold angular rotation value, determining (33) a gradient of a positive jerk according to the received data and the filtered steering wheel angle variation, and controlling (34) the ACC system in particular according to the positive jerk gradient, the received data and the filtered steering wheel angle variation.

Description

DESCRIPTION Title: Method and device for controlling an adaptive cruise control system on board a vehicle via the dynamics of the steering wheel. The present invention claims priority over French application 2309460 filed on 08.09.2023, the content of which (text, drawings and claims) is incorporated herein by reference. Technical field

[0001] ^ The present invention relates to methods and devices for controlling an adaptive cruise control system on board a vehicle, in particular 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 systems or driving assistance systems, known as ADAS (from the English "Advanced Driver Assistance System" or in French "Advanced Driving Assistance System").

[0003] ^ Among these systems, the adaptive cruise control system, known as ACC (from the English "Adaptive Cruise Control"), has as its primary function the automatic, adaptive regulation of the speed of vehicles equipped with it, based on their environment. Such an ACC system determines one or more acceleration and / or braking instructions based on a speed instruction and information relating to the vehicle's environment, the acceleration and / or braking instruction(s) being capable of regulating the speed of the vehicle in an appropriate manner. adaptive, that is to say, taking into account the vehicle's environment.

[0004] ^ We call jerk the derivative of acceleration with respect to time, this quantity representing, for example, jolts during sudden variations in acceleration.

[0005] ^ The^environmental^information^corresponds^for^example^to^the^distance^between^the^vehicle^equipped^with^the^ACC^system^and^a^vehicle^traveling^in^front^of^it,^to^the^speed^(for^example^relative)^of^the^vehicle^traveling^in^front,^to^the^acceleration^(or^deceleration)^of^the^vehicle^traveling^in^front^and / or^to^a^regulatory^speed^limit.^Such^a^vehicle^is^called^target^vehicle^or^target^object^of^the^ACC^system.^The^acceleration^setpoint(s)^are^for^example^determined^from^a^control^law^based^on^estimates^of^the^torque^provided^by^a^powertrain^(for^example^ a thermal or electric engine) to one or more wheels of the vehicle and the current acceleration of the vehicle.

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

[0007] ^ An^object^of^the^present^invention^is^to^solve^at^least^one^of^the^problems^ of^the^technological^background^described^previously.

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

[0009] ^ Another object of the invention is to improve the control of an adaptive cruise control system on board a vehicle.

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

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

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

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

[0014] ^ According to^another^variant,^the^lateral^acceleration^is^determined^by^the^following^function^: with: •^ ^ ^ ^ ^ :^the^lateral^acceleration^of^the^vehicle^(10), :^the^yaw^speed^of^the^vehicle^(10), •^ ^ ^ ^ ^ :^the^speed^of^movement^of^the^vehicle^(10).

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

[0016] ^ According to^yet^a^variant,^the^positive^jerk^gradient^is^determined^by^the^following^function: with: •^ ^ ^ ^ ^ ^ :^the^gradient^of^positive^jerk, •^ ^ ^ ^ ^ :^the^lateral^acceleration^of^the^vehicle; •^ side of the vehicle, •^ ^ ^ ^ ^ ^ :^the^variation^of^the^steering^angle^filtered, •^ ^ ^ ^ :^the^second^threshold^value^of^angular^rotation,^and^ ^ •^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^: a second coefficient dependent on a ratio between the filtered steering wheel angle variation 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 verified, the first condition being verified when a first prior lateral acceleration is determined at a time instant t ant prior to a current instant is greater than a first threshold acceleration: with: •^ ^ ^ ^ ^ ^ ^ ^ :^the^positive^jerk^at^a^moment^ ^, •^ ^ ^ ^ ^ :^the^longitudinal^acceleration^of^the^vehicle, •^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^:^the^first^threshold^acceleration,^and •^ ^ :^a^function^using^a^correspondence^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 variant of the method, a corrected positive jerk is defined by the following function when a second condition is verified, said second condition being verified when the first condition is verified and a previous lateral acceleration between the current time instant and the current time instant is less than a second threshold acceleration, the second threshold acceleration being less than the first threshold acceleration: with: •^ ^ ^ ^ ^ ^ ^ ^ :^the^positive^jerk^at^a^moment^ ^, •^ ^ ^ ^ ^ ^ ^ ^ ^ :^the^corrected^positive^jerk^at^a^time^ ^, •^ ^ ^ :^a^time^period,^and •^ ^ ^ ^ ^ ^ :^the^gradient^of^positive^jerk.

[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 bend is verified.

[0021] ^ According to^yet^another^variant^of^the^method,^the^control^is^a^function,^in^addition,^of^a^first^maximum^acceleration^when^the^first^condition^is^verified^and^the^second^condition^is^not^verified^and^of^a^second^maximum^acceleration^when^the^first^and^second^conditions^are^verified,^said^first^and^second^maximum^accelerations^being^determined^by^the^following^functions: with: •^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^^ ^ :^a^first^maximal^acceleration^at^a^instant^ ^, •^ ^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ :^a^second^maximum^acceleration^at^a^time^ ^ •^ ^ : a^function^using^a^correspondence^table, •^ ^ ^ ^ ^ :^the^vehicle^movement^speed^(10), •^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^^ ^ :^a^maximum^movement^speed^as^a^function^of^the^radius^of^curvature^ ^, • ^ ^ :^a^temporal^period, •^ ^ ^ ^ ^ ^ ^ ^ :^the^positive^jerk^at^a^moment^ ^,^and •^ ^ ^ ^ ^ ^^ ^ ^ :^the^positive^jerk^corrected^at^a^moment^ ^.

[0022] ^ A^maximum^acceleration^is^thus^defined^in^each^of^the^situations^and^applicable^when^controlling^the^adaptive^cruise^regulation^system^of^a^vehicle.

[0023] ^ According to a second aspect, the present invention relates to a device for controlling an adaptive speed regulation system of a vehicle, the device comprising a memory associated with a processor configured to implement the steps of the method 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 comprises instructions adapted for executing the steps of the method 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 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 a program is recorded. computer system comprising instructions for carrying out the steps of the method according to the first aspect of the present invention.

[0028] ^ On the one hand, the recording medium may be any entity or device capable of storing the program. For example, the medium may 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.

[0029] ^ On the other hand, this recording medium may also be a transmissible medium such as an electrical or optical signal, such a signal being able to be conveyed via an electrical or optical cable, by conventional or terrestrial radio or by self-directed laser beam or by other means. The computer program according to the present invention may 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 perform or to be used in performing the method in question. Brief description of the figures

[0031] ^ Other^characteristics^and^advantages^of^the^present^invention^will^emerge^from^the^description^of^the^particular^and^non^limiting^exemplary^embodiments^of^the^present^invention^below,^with^reference^to^the^appended^figures^1^to^5,^in^which:

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

[0033] ^ [Fig.^2]^illustrates^schematically^a^passenger compartment^of^the^vehicle^of^figure^1,^according^to^a^particular^and^non^limiting^exemplary^embodiment^of^the^present^invention;

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

[0035] ^ [Fig.^4]^illustrates^schematically^a^device^configured^to^control^an^adaptive^cruise^regulation^system^onboard^the^vehicle^of^figure^1,^according^to^a^particular^and^non^limiting^exemplary^embodiment^of^the^present^invention;

[0036] ^ [Fig.^5]^illustrates^a^flowchart^of^the^different^steps^of^a^method^for^controlling^an^adaptive^speed^regulation^system^embedded^in^the^vehicle^of^Figure^1,^according^to^a^particular^and^non^limiting^exemplary^embodiment^of^the^present^invention. Description^of^the^exemplary^embodiments

[0037] ^ A^method^and^a^device^for^controlling^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^which^follows.

[0038] ^ The terms "first(s)", "second(s)" (or "first(s)", "second(s)"), etc. are used in this document by arbitrary convention to enable 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 example of embodiment, the present invention relates to a method and a device for controlling an adaptive speed regulation system on board a vehicle traveling at a travel speed lower than a target speed. Indeed, the method comprises receiving data representative of a variation in the steering wheel angle of the vehicle, the travel speed of the vehicle, a yaw speed of the vehicle, and a longitudinal acceleration of the vehicle. vehicle.^The^method^also^includes^filtering^the^steering^wheel^angle^variation^as^a^function^of^a^first^threshold^value^of^angular^rotation,^determining^a^gradient^of^a^positive^jerk^as^a^function^of^the^received^data^and^the^filtered^steering^wheel^angle^variation^and^controlling^the^ACC^system^as^a^function^in^particular^of^the^positive^jerk^gradient,^the^received^data^and^the^filtered^steering^wheel^angle^variation.

[0040] ^ Figure 1 illustrates a vehicle 10, for example a motor vehicle, traveling on a portion of a road 1001 in the environment 1. According to other examples, the vehicle 10 corresponds to a car, a bus, a truck, a utility vehicle or a motorcycle, that is to say, a vehicle of the motorized land vehicle type.

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

[0042] ^ The vehicle^10^corresponds^to^a^vehicle^circulating^under^the^total^supervision^of^a^driver^or^circulating^in^a^semi-autonomous^mode.^The^vehicle^10^circulates^according^to^a^level^of^autonomy^equal^to^0^or^according^to^a^level^of^autonomy^ranging^from^1^to^2^for^example,^according^to^the^scale^defined^by^the^American^federal^agency^which^established^5^levels^of^autonomy^ranging^from^1^to^5,^the^level^0^corresponding^to^a^vehicle^having^no^autonomy,^the^driving^of^which^is^under^the^total^supervision^of^the^driver,^the^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 completely autonomous vehicle.

[0043] ^ The^5^levels^of^autonomy^of^the^federal^agency^responsible^for^road^safety^classification^are: - level^0:^no^automation,^the^vehicle^driver^has^full^control^of^the^main^vehicle^functions^(engine,^accelerator,^steering,^brakes); - level^1:^driver^assistance,^automation^is^active^for^certain^vehicle^functions,^the^driver^maintaining^overall^control^over^the^driving^of^the^vehicle;^cruise^regulator^is^part^of^this^level,^as^other^aids^such^as^ABS^(anti-lock^brake^system)^or^ESP^(programmed^electric^stabilizer); - 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^regulator^combined^with^lane^centering^allows^a^vehicle^to^be^classified^level^2,^as^does^automatic^park^assist^(from^the^English^"Park^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;^autonomous^driving^can^however^only^take^place^in^certain^determined^environmental^and^traffic^conditions^(only^on^motorways^for^example); - level 4: fully autonomous driving under certain conditions, the vehicle is designed to ensure all critical safety functions on its own over a complete journey; the driver provides a destination or navigation instructions but is not required to make himself available to take back control of the vehicle; - level 5: fully autonomous driving without driver assistance in all circumstances.

[0044] ^ According to the example of figure 1, the vehicle 10 travels on a portion of road 1001 in a curve and makes a turn following a radius of curvature r.

[0045] ^ The^vehicle^10^includes^one^or^more^driving^assistance^systems,^called^ADAS^(from^the^English^"Advanced^Driver-Assistance^System"^or^in^French^"Advanced^Driver^Assistance^System"),^including^an^automatic^speed^regulation^system,^called^ACC^system.^Such^ADAS^system^is^configured^to^assist,^or^replace,^the^driver^of^the^vehicle^10^to^control^the^vehicle^10^on^its^route.

[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^returned^by^one^or^more^objects^(for^example^the^second^vehicle^11^located^in^front^of^the^vehicle^10^according^to^the^example^of^figure^1),^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^the^distance^by^light"^in^French),^a^LIDAR^sensor^corresponding^to^an^optoelectronic^system^composed^of^a^laser^transmitting^device,^a^receiving^device^comprising^a^light^collector^(to^collect^the^part^of^the^ light radiation emitted by the transmitter and reflected by any object located on the path of the light rays emitted by the transmitter) 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 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 located in the field of vision of the camera(s).

[0047] ^ The data obtained from this or these sensors vary depending on the type of sensor. When it is a radar or a LIDAR, the data corresponds, for example, to distance data between points of the detected object and the sensor. Each detected object is thus represented by a point cloud (each point corresponding to a point of 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 it) of the envelope) of the detected object as seen by the sensor and ultimately by the vehicle carrying the sensor. When it is a video camera, the data corresponds to data associated with each pixel of the acquired image(s), for example, grayscale values ​​coded on 8, 10, 12 or more bits for each color channel, for example RGB (from the English "Red, Green, Blue" or in French "Rouge, vert, bleu").^These^data^allow^for^example^to^determine^the^successive^positions^taken^by^an^object^moving^in^the^environment^1,^for^example^the^second^vehicle^11,^and^to^deduce^one^or^more^dynamic^parameters^of^the^moving^object^such^as^the^position,^the^speed^and / or^the^acceleration.^These^data^also^allow^to^determine^the^lines^on^the^ground^to^for^example^participate^in^the^determination^of^the^membership^of^the^second^vehicle^11^and^the^vehicle^10^to^the^same^traffic^lane^for^example.^ .

[0048] ^ The data acquired by the on-board sensor(s) feed, for example, one or more on-board systems in the vehicle10, including the ACC system.

[0049] ^ According to the example in Figure 1, the vehicle 10 is moving at a current speed lower than a target speed determined for the ACC system. Such a situation occurs, for example, when the vehicle 10 loses a target vehicle that it was following and which 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 increasing its target speed.

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

[0051] ^ The^vehicle^10^carries^for^example^a^steering^wheel^11^allowing^the^vehicle^10^to^be^steered,^for^example^by^determining^an^angle^of^rotation^of^one^or^more^wheels^of^the^vehicle^10^via^a^mechanical^and / or^electrical^connection.^The^invention^is^not^limited^however^to^a^steering^wheel^11,^other^devices^such^as^a^handlebar^or^a^joystick^are^also^suitable^for^guiding^a^vehicle.

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

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

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

[0055] ^ A process for controlling an adaptive cruise control system on board the vehicle 10, called an ACC system, is advantageously implemented by the vehicle 10, that is to say by a computer or a combination of computers of the on-board system of the vehicle 10, for example by the computer or computers in charge of controlling the ACC system of the vehicle 10.

[0056] ^ In a first operation, data are received, for example by the computer in charge of controlling the ACC system. These data are representative of: • a variation in the steering wheel angle of the vehicle 10, • the speed of movement of the vehicle 10, • a yaw speed of the vehicle 10, • a longitudinal acceleration of the vehicle 10, and • a radius of curvature of a trajectory of the vehicle 10.

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

[0058] ^ The yaw rate is, for example, obtained from a rotational speed sensor or determined from a wheel angle sensor of the vehicle10.

[0059] ^ The^radius^of^curvature^of^a^trajectory^of^the^vehicle^10^is^for^example^obtained^from^a^computer^determining^this^radius^as^a^function^of^the^angle^of^a^wheel^and^the^speed^of^the^vehicle,^from^a^measurement^carried^out^by^an^optical^system^or^from^data^from^a^mapping^of^an^onboard^navigation^system.

[0060] ^ In a second operation, the steering wheel angle variation is filtered according to a first angular rotation threshold value to obtain a filtered steering wheel angle variation. The angular rotation threshold value is determined in particular from the vehicle's travel speed, for example from a first correspondence table.

[0061] ^ According to a particular example of implementation and illustrated by figure 3, the filtering is obtained by a saturation of the absolute value of the variation of the steering wheel angle by relative to the first threshold value of angular rotation and by a sliding average over a determined time period of the saturated steering wheel angle variation when the absolute value of the saturated steering wheel angle variation decreases.

[0062] ^ We observe on the curve corresponding to the variation of the steering wheel angle ^ ^ an^exceeding^of^the^first^threshold^value^of^angular^rotation^^ temporal^t1,^t2^and^t3,^the^variation^of^saturated^steering^angle^^ ^ ^ ^ ^ therefore follows a plateau over these periods.

[0063] ^ We also observe a separation of the two curves when the absolute value of the steering wheel angle variation decreases after applying the sliding averaging of the saturated steering wheel angle variation.

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

[0065] ^ In a third step, a gradient of a positive jerk is determined as a function of: • the filtered steering wheel angle variation, • a second angular rotation threshold value, and • a lateral acceleration of the vehicle determined from the vehicle's travel speed and the vehicle's yaw rate.

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

[0067] ^ [Math^1]

[0069] ^ With: •^ ^ ^ ^ ^ ^ :^the^gradient^of^positive^jerk, •^ ^ ^ ^ ^ :^the^lateral^acceleration^of^the^vehicle^(10); •^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ :^a^first^coefficient^dependent^on^an^absolute^value^of^the^lateral^acceleration^of^the^vehicle^(10), •^ ^ ^ ^ ^ ^ :^the^variation^of^the^steering^angle^filtered, •^ ^ ^ ^ :^the^second^threshold^value^of^angular^rotation,^and^ ^ •^ ^ ^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ :^a^second^coefficient^dependent^on^a^ratio^between^the^filtered^steering^angle^variation^and^the^second^threshold^value^of^angular^rotation.

[0070] ^ The^first^and^second^coefficients^are^for^example^determined^empirically^and^are^informed^in^correspondence^tables^or^in^a^map.

[0071] ^ According to a particular example of implementation, the lateral acceleration is determined by the following function:

[0072] ^ [Math^2]

[0073] ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^

[0074] ^ With: •^ ^ ^ ^ ^ :^the^lateral^acceleration^of^the^vehicle^10, :^the^yaw^speed^of^the^vehicle^10, •^ ^ ^ ^ ^ :^the^movement^speed^of^the^vehicle^10.

[0075] ^ Lateral acceleration is the acceleration along a transverse axis normal to the longitudinal x axis, this axis is represented by the transverse y axis in figure 1. This transverse y axis is notably oriented towards the instantaneous center of rotation of the vehicle 10.

[0076] ^ The^yaw^speed^of^the^vehicle^10^represents^the^angular^speed^of^rotation^of^the^vehicle^10^around^a^z^axis^defined^normal^to^the^longitudinal^x^and^transverse^y^axes.

[0077] ^ According to a particular example of implementation, this yaw rate is determined by a vehicle computer10, in particular as a function of the angle of a wheel of the vehicle10. The fact of using the angle of a wheel rather than a sensor also makes it possible to determine this yaw rate more quickly and thus to make the system more responsive. The gain in determining the yaw rate relative to an angle of a wheel rather than by a sensor allows a gain of around 500 ms to obtain this speed.

[0078] ^ Lateral acceleration is a quantity that has a strong influence on the comfort of the occupants of the vehicle10, in fact a strong variation in lateral acceleration in a bend creates discomfort for the occupants of the vehicle10. It is therefore important to limit the variation in 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 as a function of: • the filtered steering wheel angle variation, • the longitudinal acceleration of the vehicle 10, • the lateral acceleration of the vehicle 10, and • the gradient of said positive jerk, and Method of controlling an adaptive cruise control system on board a vehicle (10), said ACC system, said vehicle (10) moving at a travel speed lower than a target speed,^said^method^comprising^the^following^steps^: - reception^(31)^of^representative^data: •^of^a^variation^in^steering^angle^(11)^of^the^vehicle^(10), •^of^said^movement^speed^of^the^vehicle^(10), •^of^a^yaw^speed^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^steering^angle^variation^as^a^function^of^a^first^threshold^value^of^angular^rotation^to^obtain^a^filtered^steering^angle^variation^,^said^threshold^value^of^angular^rotation^being^determined^from^said^movement^speed; - determination^(33)^of^a^gradient^of^a^positive^jerk^as^a^function: •^of^said^filtered^steering^angle^variation^, •^of^a^second^threshold^value^of^angular^rotation,^and •^a^lateral^acceleration^of^the^vehicle^(10)^determined^from^said^movement^speed^and^said^yaw^speed; - control^(34)^of^said^ACC^system^as^a^function^of: •^said^filtered^steering^wheel^angle^variation, •^of^said^longitudinal^acceleration, •^of^said^lateral^acceleration, •^of^said^gradient^of^said^positive^jerk,^and •^of^the^radius^of^curvature^of^a^trajectory^of^the^vehicle^10.

[0079] ^ In a fifth operation, the type of situation is determined, a first type of situation corresponding to a vehicle in a bend, a second type of situation corresponding to a vehicle coming out of a bend. In these two situations, it is appropriate to limit the variation in acceleration of the vehicle to improve the comfort of the occupants of the vehicle.

[0080] ^ The^first^situation,^corresponding^to^a^vehicle^10^in^a^bend,^is^characterized^by^the^verification^of^a^first^condition.^The^first^condition^is^verified^when^a^first^lateral^acceleration^prior^determined^at^a^temporal^instant^being^prior^to^a^current^instant^is^greater^than^a^first^threshold^acceleration.

[0081] ^ A^positive^jerk^is^then^determined^by^the^following^function:

[0082] ^ [Math^3]

[0084] ^ With: •^ ^ ^ ^ ^ ^ ^ ^ :^the^positive^jerk^at^a^moment^ ^, •^ ^ ^ ^ ^ :^the^longitudinal^acceleration^of^the^vehicle^(10), •^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^:^the^first^threshold^acceleration,^and •^ ^ :^a^function^using^a^correspondence^table.

[0085] ^ The^second^situation,^corresponding^to^a^vehicle^10^exiting^a^turn,^is^characterized^by^the^verification^of^a^second^condition.^The^second^condition^is^verified^when^the^first^condition^is^verified^and^a^previous^lateral^acceleration^between^the^temporal^instant^t ant and the current instant 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 to say that the vehicle 10 comes out of a bend after having been in a bend.

[0086] ^ A^corrected^positive^jerk^is^then^determined^by^the^following^function:

[0087] ^ [Math^4]

[0088] ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ yes^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^,^and

[0089] ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ yes^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^

[0090] ^ With: •^ ^ ^ ^ ^ ^ ^ ^ :^the^positive^jerk^at^a^moment^ ^, •^ ^ ^ ^ ^ ^ ^ ^ ^ :^the^corrected^positive^jerk^at^a^time^ ^, •^ ^ ^ :^a^time^period,^and •^ ^ ^ ^ ^ ^ :^the^gradient^of^positive^jerk.

[0091] ^ The^positive^jerk^and^the^corrected^positive^jerk^allow^for^example^to^determine^a^maximum^acceleration^in^each^of^the^previous^situations.

[0092] ^ According to a particular exemplary embodiment, the control of the ACC system is a function, in addition, of a first maximum acceleration when the first condition is satisfied and the second condition is not satisfied and of a second maximum acceleration when the first and second conditions are satisfied, said first and second maximum accelerations being determined by the following functions:

[0093] ^ [Math^5]

[0099] ^ with: •^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ :^a^first^maximal^acceleration^at^a^instant^ ^, •^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ :^a^second^maximum^acceleration^at^a^time^ ^, •^ ^ :^a^function^using^a^correspondence^table, •^ ^ ^ ^ ^ :^the^vehicle^movement^speed^10, •^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ :^a^maximum^movement^speed^as^a^function^of^the^radius^of^curvature^ ^, • ^ ^ :^a^temporal^period, •^ ^^ ^ ^ ^ ^ ^ :^the^positive^jerk^at^a^time^ ^,^and:^the^corrected^positive^jerk^at^a^time^ ^.

[0100] ^ The^function^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^^ ^ is^a^function^using^a^correspondence^table,^allowing^the^maximum^speed^of^the^vehicle^in^a^ bend^to^be^determined^as^a^function^of^the^radius^of^curvature^of^the^vehicle's^trajectory^10.

[0101] ^ The^function^ also^uses^a^correspondence^table,^allowing^the^determination^of^a^maximum^acceleration^of^the^vehicle^10^in^a^bend^as^a^function^of^the^difference^between^the^maximum^speed^of^the^vehicle^and^its^actual^movement^speed.

[0102] ^ Thus,^a^longitudinal^acceleration^of^the^vehicle^10^determined^by^the^ACC^system^is^limited^by^the^first^maximum^acceleration^in^a^curve^or^a^turn,^and^is^limited^by^the^second^maximum^acceleration^on^exit^of^the^curve^or^turn.

[0103] ^ The^comfort^of^the^occupants^of^the^vehicle^10^is^thus^improved,^the^variation^of^the^acceleration^being^thus^bridled^by,^depending^on^the^situations,^the^jerk,^the^corrected^jerk^and^the^gradient^of^the^jerk.

[0104] ^ Such a process thus makes it possible to improve the behavior law of the vehicle in an acceleration phase when cornering or exiting a corner.

[0105] ^ Figure 4 schematically illustrates a device 2 configured to control an adaptive cruise control system embedded in a vehicle, for example the vehicle 10 of Figure 1, according to a particular and non-limiting exemplary embodiment of the present invention. The device 2 corresponds, for example, to a device embedded in the first vehicle 10, for example the ACC system computer.

[0106] ^ The^device 2 is^for^example^configured^for^the^implementation^of^the^operations^described^with^regard^to^figures^1^to^3^and / or^the^steps^of^the^method^3^described^with^regard^to^figure^5.^Examples^of^such^a^device^3^include,^but^not^are^limited^to^an^onboard^electronic^equipment^such^as^an^onboard^computer^of^a^vehicle,^an^electronic^computer^such^as^an^ECU^("Electronic^Control^Unit"),^a^smartphone^(from^the^English^"smartphone"),^a^tablet,^a^laptop.^ The^elements^of^the^device^2,^individually^or^in^combination,^may^be^integrated^ in a single integrated circuit, in several integrated circuits, and / or in discrete components. The device 2 may be implemented in the form of electronic circuits or software (or computer) modules, or even a combination of electronic circuits and software modules.

[0107] ^ The^device^2^ comprises^one^(or^more^)^processor(s)^20^configured^to^execute^instructions^for^performing^the^steps^of^the^method^and / or^for^executing^the^instructions^of^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^corresponding^for^example^to^a^volatile^and / or^non^memory^ volatile^and / or^includes^a^memory^storage^device^which^may^include^volatile^and / or^non^volatile^memory,^such^as^EEPROM,^ROM,^PROM,^RAM,^DRAM,^SRAM,^flash,^magnetic^or^optical^disk.^

[0108] ^ The computer code of the embedded software(s) including the instructions to be loaded and executed by the processor is, for example, stored in memory 21.

[0109] ^ According to^different^particular^and^non^limiting^exemplary^embodiments,^the^device^ 2^is^coupled^in^communication^with^other^similar^devices^or^systems^and / or^with^communication^devices,^for^example^a^TCU^(from^the^English^"Telematic^ Control Unit or in French "Telematic Control Unit"), for example via a communication bus or through dedicated input / output ports.

[0110] ^ According to a particular and non-limiting exemplary embodiment, the device 2 comprises a block 22 of interface elements for communicating with external devices, for example a remote server, or the vehicle when the device 2 corresponds to a smart phone or a tablet, for example. The interface elements of the block 22 comprise one or more of the following interfaces: - RF radio frequency interface, for example of the Wi-Fi® type (according to IEEE 802.11), for example example^in^the^frequency^bands^at^2.4^or^5^GHz,^or^of^Bluetooth®^type^(according^ to^ IEEE^802.15.1), in the 2.4 GHz frequency band, or of the Sigfox type using a UBN radio technology (from the English Ultra Narrow Band, in French ultra narrow band), or LoRa in the 868 MHz frequency band, LTE (from the English Long-Term Evolution or in French Long-Term Evolution), LTE-Advanced (or in French 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).

[0111] ^ According to another particular and non-limiting example of embodiment, the device 2 comprises a communication interface 23 which makes it possible to establish communication with other devices (such as other computers of the on-board system or on-board 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. The communication interface 23 corresponds, for example, to a wired network of the CAN type (from the English "Controller Area Network"). »^or^in^French^« Controller^Area^Network^Flexible^Data-Rate»^or^in^French^« Flexible^Data-Rate^Controller^Area^Network»),^FlexRay^(standardized^by^the^ISO^standard^ 17458), Ethernet (standardized by ISO / IEC 802-3) or LIN (from the English "Local Interconnect Network" or "Réseau interconnexion local").

[0112] ^ According to a particular and non-limiting exemplary embodiment, the device 2 may provide output signals to one or more external devices, such as a display screen, whether touch-sensitive or not, and / or other peripherals via respective output interfaces. According to a variant, one or the other of the external devices is integrated into the device 2.

[0113] ^ 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 of the vehicle 10, according to a particular and non-limiting example of the present invention. The method 3 is, for example, implemented by a device on board the vehicle 10 or by the device 2 of Figure 4.

[0114] ^ In a first step 31, data are received. These data are representative of: • a variation in the steering wheel angle 11 of the vehicle 10, • the speed of movement of the vehicle 10, • a yaw speed of the vehicle 10, and • a longitudinal acceleration of the vehicle 10.

[0115] ^ In a second step 32, the steering wheel angle variation is filtered as a function of a first angular rotation threshold value to obtain a filtered steering wheel angle variation, the angular rotation threshold value being determined from the vehicle's travel speed 10.

[0116] ^ In a third step 33, a gradient of a positive jerk is determined as a function of: • the filtered steering wheel angle variation, • a second angular rotation threshold value, and • a lateral acceleration of the vehicle 10 determined from said vehicle displacement speed and the yaw rate of the vehicle 10.

[0117] ^ In a fourth step 34, the adaptive cruise control system is controlled as a function of: • the filtered steering wheel angle variation, • the longitudinal acceleration of the vehicle 10, • the lateral acceleration of the vehicle 10, and • the positive jerk gradient.

[0118] ^ According to a variant, the variants and examples of the operations described in relation to figures 1 to 3 apply to the steps of the method 3 of figure 5.

[0119] ^ The^present^invention^also^relates^to^an^adaptive^cruise^regulation^system^for^a^vehicle^comprising^the^device^2^of^figure^4.

[0120] ^ The^present^invention^also^relates^to^a^vehicle,^for^example^an^automobile^or^more^generally^a^land^motor^vehicle,^comprising^the^device^2^of^figure^4^or^the^adaptive^vehicle^cruise^regulation^system^above.

Claims

CLAIMS 1. Method for controlling an adaptive cruise control system on board a vehicle (10), said 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 variation in the steering wheel angle (11) of the vehicle (10), • said travel speed of the vehicle (10), • a yaw speed of the vehicle (10), • a longitudinal acceleration of the vehicle (10), and •^of a^radius^of^curvature^of^a^trajectory^of^the^vehicle^(10); - filtering (32)^of^said^variation^of^steering^angle^as^a^function^of^a^first^threshold^value^of^angular^rotation^to^obtain^a^filtered^variation^of^steering^angle^,^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^said^filtered^steering^wheel^angle^variation, •^of^a^second^threshold^value^of^angular^rotation, and •^of^a^lateral^acceleration^of^the^vehicle^(10)^determined^from^said^movement^speed^and^of^said^yaw^speed; - control^(34)^of^said^ACC^system^as^a^function^of^said^filtered^steering^wheel^angle^variation, •^of^said^longitudinal^acceleration, •^of^said^lateral^acceleration, •^of^said^gradient^of^said^positive^jerk,^and •^of^said^radius^of^curvature^of^a^trajectory^of^the^vehicle^(10).

2. Method according to claim 1, for which said filtering is obtained by saturating the absolute value of said steering wheel angle variation with respect to said first threshold value of angular rotation and by sliding averaging of 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: with: • ^ ^ ^ ^ ^ :^the^lateral^acceleration^of^the^vehicle^(10), •^ ^ :^the^yaw^speed^of^the^vehicle^(10), •^ ^ ^ ^ ^ :^the^movement^speed^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: with: •^ ^ ^ ^ ^ ^ :^the^gradient^of^positive^jerk, •^ ^ ^ ^ ^ :^the^lateral^acceleration^of^the^vehicle^(10); • ^first^coefficient^dependent^on^an^absolute^value^of^the^lateral^acceleration^of^the^vehicle^(10), •^ ^ ^ ^ ^ ^ :^the^variation^of^the^steering^angle^filtered, •^ ^ ^ ^ :^the second^threshold^value^of^angular^rotation,^and:^a^second^coefficient^dependent^on^a^ratio^between^the^angle^variation^ 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 being prior to a current instant is greater than a first threshold acceleration: with: • ^ ^ ^ ^ ^ ^ ^ ^ :^the^positive^jerk^at^a^moment^ ^, •^ ^ ^ ^ ^ :^the^longitudinal^acceleration^of^the^vehicle^(10), •^ ^^ ^ ^ ^ ^ ^ ^ ^ ^:^the^first^threshold^acceleration,^and •^ ^ :^a^function^using^a^correspondence^table.

6. Method^according^to^claim^5,^for^which^a^corrected^positive^jerk^is^defined^by^the^following^function^when^a^second^condition^is^verified,^said^second^condition^being^verified^when^the^first^condition^is^verified^and^a^previous^lateral^acceleration^between^said^time^instant^and^said^current^instant^is^less^than^a^second^threshold^acceleration,^the^second^threshold^acceleration^being^less^than^the^first^threshold^acceleration: with: •^ ^ ^ ^ ^ ^ ^ ^ :^the^positive^jerk^at^a^moment^ ^, •^ ^ ^ ^ ^ ^ ^ ^ ^ :^the^corrected^positive^jerk^at^a^time^ ^, •^ ^ ^ :^a^time^period,^and •^ ^ ^ ^ ^ ^:^the^positive^jerk^gradient.

7. Method^according^to^claim^6,^for^which^said^control^is^a^further^function^of^a^first^maximum^acceleration^when^the^first^condition^is^verified^and^the^second^condition^is^not^verified^and^of^a^second^maximum^acceleration^when^the^first^and^second^conditions^are^verified,^said^first^and^second^maximum^accelerations^being^determined^by^the^following^functions: with: •^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ :^a^first^maximum^acceleration^at^a^time^ ^, •^ ^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ :^a^second^maximum^acceleration^at^a^time^ ^, •^ ^ : a^function using^a^correspondence^table, •^ ^ ^ ^ ^ :^the^speed^of^movement^of^the^vehicle^(10), •^ ^^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ :^a^maximum^speed^of^displacement^as^a^function^of^the^radius^of^curvature^ ^, • ^ ^ :^a^temporal^period, •^ ^ ^ ^ ^ ^ ^ ^:^the^positive^jerk^at^a^time^^, and:^the^corrected^positive^jerk^at^a^time^^.

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^a^vehicle^adaptive^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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