METHOD AND DEVICE FOR CONTROLLING A VEHICLE'S VEHICLE APPROACHING A TRAFFIC SIGNAL

Description

technical field

[0001] The present invention relates to methods and devices for controlling a vehicle's speed regulation system, particularly for a motor vehicle. The present invention also relates to a method and device for controlling a vehicle's acceleration and / or speed. 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 corresponds, for example, to the distance between the vehicle equipped with the ACC system and a vehicle traveling in front, the speed (for example relative) of the vehicle traveling in front, the acceleration of the vehicle traveling in front and / or a regulatory speed limit.

[0007] In another example, this environmental information corresponds to information relating to road signage elements, such as traffic signs and / or traffic lights. This information corresponds, for example, to the states of a traffic light (red or green) and is received by the vehicle from the traffic light or a network infrastructure via a wireless connection; these objects (the vehicle and the traffic light) are said to be connected. For this purpose, reference is made to WO 2021 / 121924 A1 and EP 2 902 278 A1.

[0008] Managing traffic signals for speed control systems requires a wireless network infrastructure and communication devices integrated into both the signals and the vehicles. Such components are expensive, leading to increased vehicle manufacturing costs.

[0009] Furthermore, not all life situations encountered by a vehicle are foreseen or managed by existing systems, which can lead to safety problems for the vehicle and its passengers. 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 control of a speed regulation system embedded in a vehicle.

[0012] According to a first aspect, the present invention relates to a method for controlling a speed regulation system of a vehicle, according to claim 1, the vehicle traveling on a section of road approaching a signal element, the method comprising the following steps: detection of the signaling element at a first time instant; determination of a first time interval associated with a first phase of a vehicle speed regulation profile, of a second time interval associated with a second phase of the profile, the second phase temporally following the first phase, and determination of a target vehicle speed as a function of the detected signaling element, the target speed being associated with a third phase of the profile, the third phase temporally following the second phase, the third phase having a determined duration, a start of the first time interval being determined as a function of the result of a comparison between a first target deceleration value associated with the first phase and a current deceleration value determined as a function of a current vehicle speed, the target speed,of a current distance between the vehicle and the signaling element and the determined duration of the third phase, and a start of the second time interval being determined based on the result of a comparison between a second target deceleration value associated with the second phase and the current deceleration value, the second target deceleration value being less than or equal to the first target deceleration value; control of the speed regulation system according to the speed regulation profile, the first target deceleration value, the second target deceleration value and the target speed being provided to the speed regulation system to control the latter during, respectively, the first phase, the second phase and the third phase.

[0013] This method improves the control of the vehicle's speed regulation system by determining a regulation profile that includes one or more deceleration phases followed by a constant-speed phase, the specific speed of which depends on the detected traffic signal. This method requires only means configured to detect the traffic signal (e.g., an on-board camera and / or road mapping data) and the distance between the vehicle and the signal, without needing to receive any data from the signal itself.

[0014] The deceleration phase(s) replicate a classic approach of a driver coming towards a signal element, the target speed associated with the last phase being, for example, designed to give the driver the opportunity to manually take control of the vehicle if needed, which increases the safety of the vehicle and its passengers.

[0015] According to one variant, the start of the first time interval is equal to a second time instant corresponding to, when the vehicle is at a distance less than a determined distance from the signaling element, the time instant at which the current deceleration value reaches the first target deceleration value, and the start of the second time interval is equal to a third time instant corresponding to the time instant at which the current deceleration value reaches the second target deceleration value.

[0016] According to another variant, the current deceleration value, denoted dn, is determined according to the following equation: d n = V cible 2 − V 2 / 2 * D − X * V cible with target V corresponding to said target speed, V corresponding to the current speed of said vehicle, D corresponding to the current distance between the vehicle and the signaling element and X corresponding to the determined duration of the third phase.

[0017] According to a further variant, the signage element belongs to a set of signage elements comprising: a STOP sign; a YIELD sign; a red traffic light; and a green traffic light.

[0018] According to yet another variant, the target speed is 25 km / h when the signal element corresponds to the YIELD sign, the target speed is 30 km / h when the signal element corresponds to the STOP sign or the traffic light in red and the target speed is 50 km / h when the signal element corresponds to the traffic light in green.

[0019] According to an additional variant, the determined duration of the third phase is 5 seconds, the first target deceleration value is -0.3 ms -2< and the second target deceleration value is -0.7 ms -2< or -1.2 ms -2<.

[0020] According to a further variant, the profile further includes a fourth phase between the second and third phases when a vehicle speed reaches a value lower than the target speed before the start of the third phase, an acceleration value being associated with the fourth phase, the acceleration value being determined so that a vehicle speed at the end of the fourth phase is equal to the target speed.

[0021] According to a second aspect, the present invention relates to a control device for a vehicle speed regulation system, 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.

[0022] 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.

[0023] 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.

[0024] 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. Brief description of the figures

[0025] 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 speed regulation profile for controlling a vehicle's speed regulation system] figure 1 , according to a particular and non-limiting example of the present invention; [ Fig. 3 [This schematically illustrates a device configured to control a vehicle's speed regulation system] 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 process for controlling a vehicle's speed regulation system figure 1 , according to a particular and non-limiting example of the present invention. Description of examples of achievements

[0026] A method and a device for controlling a vehicle's speed regulation system 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.

[0027] According to a particular and non-limiting embodiment of the present invention, the control of a vehicle's speed regulation system, for example an ACC system, includes the detection of a traffic signal positioned at the edge of the road on which the vehicle is traveling. Such a traffic signal corresponds to a traffic sign or a traffic light designed to regulate the passage of vehicles at an intersection, for example. The vehicle's speed regulation system is advantageously regulated according to a speed control profile comprising one or more deceleration phases (negative acceleration of the vehicle) followed by an approach phase to the traffic signal (of a predetermined duration) during which the speed is regulated to conform to a target speed that is a function of the detected traffic signal.Each deceleration phase(s) is / are associated with a time interval of a predetermined duration. The duration of each time interval is determined by determining the start of each time interval, which is a function of a result of a comparison between a target deceleration value associated with the considered deceleration phase of the profile and a current deceleration value determined as a function of a current vehicle speed, the target speed, a current distance between the vehicle and the signaling element and the duration of the approach phase.

[0028] There figure 1 schematically illustrates an environment 1 of a vehicle 10, according to a particular and non-limiting embodiment of the present invention.

[0029] There figure 1illustrates a vehicle 10, for example a motor vehicle, carrying, for example, means configured to detect the presence of a signaling element 110 arranged along the traffic lane 101 used by the vehicle 10, in front of the vehicle 10 according to the direction of travel 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.

[0030] 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.

[0031] Following the example of the figure 1, vehicle 10 travels on a section of road comprising a first traffic lane 101 on which vehicle 10 travels. The first traffic lane 101 crosses a second traffic lane, the passage at the intersection between these two traffic lanes being regulated by the signaling element 110.

[0032] The environment of vehicle 10 is not limited to the example of the figure 1 but extends to any road environment including a road on which the vehicle is traveling, the passage or crossing of a portion of which is regulated by a sign. Such a portion corresponds, for example, to a crossroads, a road intersection, a roundabout, a level crossing, etc.

[0033] For example, signal element 110 corresponds to one of the following elements: a STOP sign requiring vehicle 10 to stop; a YIELD sign requiring vehicle 10 to stop if necessary; a three-color traffic light taking a first state corresponding to the green light (passing the light is authorized for vehicle 10) and a second state corresponding to the red light (stop required for vehicle 10).

[0034] Vehicle 10 carries, for example, one or more of the following signaling element detection means: one or more cameras (with or without a depth sensor) for acquiring one or more images of the environment around the vehicle 10 within the field of vision of the camera(s); and / or a navigation system and / or a geolocation system including road mapping information of the road environment in which the vehicle 10 is traveling, the mapping information including information on the presence and position of signage elements.

[0035] According to one alternative embodiment, vehicle 10 also carries one or more of the following devices or systems: 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 a vehicle travelling in front of the vehicle 10 or the signaling element 110), 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 including 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 the vehicle 10 or the signaling element 110) located in the emitted light beam and to measure the distance between the sensor and each detected object;and / or a receiver of a satellite geolocation system configured to determine the current position of the vehicle 10, for example a GPS (Global Positioning System) or Galileo type system; the current position is for example expressed in the form of coordinates, for example as a latitude / longitude pair.

[0036] 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.

[0037] In a first example, vehicle 10 is equipped with an ADAS system corresponding to an automatic speed control system, known as a CC (Cruise Control) system. Such a system is designed to automatically stabilize the vehicle's speed around a set speed determined 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 setpoint acceleration values ​​that change over time based on the vehicle's current speed (for example, obtained from a speed sensor onboard vehicle 10, such as an odometer) and the setpoint speed. Thus, the data obtained from the speed sensor(s) onboard vehicle 10 allows the CC system of vehicle 10 to establish a longitudinal acceleration setpoint Asetpoint(t).

[0038] 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 Aset(t), which varies over time 't' and allows the vehicle to maintain or reach a set speed. The ACC, or a control unit within this system, transmits, for example, the acceleration commands Aset(t) that it has determined to the control unit(s) monitoring the operation of a powertrain in vehicle 10, specifically so that these control units can determine the torque commands to be generated by the powertrain to meet the acceleration commands Aset(t) and regulate the longitudinal speed of vehicle 10.

[0039] According to a third example, vehicle 10 incorporates both a CC system and an ACC system, or a single system embedded in vehicle 10 implements both the CC function and the ACC function.

[0040] A process for controlling a speed regulation system, for example an ACC system, 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 or computers in charge of controlling the ACC system.

[0041] The speed regulation system control according to the invention is based on a predetermined speed regulation profile, such a profile advantageously comprising one or more successive deceleration phases (each with a predetermined negative setpoint acceleration, a negative acceleration corresponding to a deceleration) followed by a constant speed phase. The speed regulation system is thus controlled according to setpoint deceleration values, each associated with a deceleration phase of the profile, and a setpoint speed associated with the final constant speed phase.

[0042] An example of such a speed regulation profile is illustrated in the figure 2 , according to a particular and non-limiting embodiment of the present invention.

[0043] Diagram 2 of the figure 2This illustrates a profile of the velocity, denoted 'V' (on the ordinate of the diagram, expressed in m / s), as a function of time, denoted 't' (expressed in seconds, denoted 's'). According to a variant, diagram 2 equivalently illustrates the velocity V as a function of distance (expressed in m), the relationship between time 't' and distance 'd' being known and a function of the velocity (and acceleration) of vehicle 10.

[0044] According to the specific example of the figure 2 The speed regulation profile comprises 3 phases, namely: a first deceleration phase 21, a first target deceleration value, note d phase1 being associated with this first phase 21 and being for example equal to -0.3 ms -2< (according to other examples d phase1 is -0.2, -0.4 or -0.5 ms -2< ); d phase1 corresponds to the setpoint acceleration value provided to the speed control system to control the latter during the first deceleration phase 21; the first deceleration phase begins at a time t1 (after a time t0 corresponding to the time of detection of the signaling element 210) and ends at a time t2, the first time interval between t1 and t2 being associated with the first deceleration phase 21 and corresponding to the duration of the first deceleration phase 21;a second deceleration phase 22, a second target deceleration value, denoted d phase2, being associated with this second phase 22 and being, for example, equal to -0.7 ms -2< or -1.2 ms -2< (according to other examples, d phase2 takes any value between -0.7 and -1.2 ms -2<); d phase2 corresponds to the setpoint acceleration value provided to the speed control system to control the latter during the second deceleration phase 22; the second deceleration phase 22 begins at time t2 and ends at time t3, the second time interval between t2 and t3 being associated with the second deceleration phase 22 and corresponding to the duration of the second deceleration phase 22; and a third phase 23, a constant speed value called target speed V target being associated with this third phase and being a function of the type of signaling element 210 detected;V target corresponds to the setpoint speed provided to the speed control system to control the latter during the third phase 23; the third phase 23 begins at time t3 and ends at time t4, t4 corresponding to the time at which the vehicle 10 reaches the signaling element 210; the third time interval associated with the third phase and between t3 and t4 has a determined duration, denoted 'X', X being for example equal to 5 s (according to other examples, X is 4, 6, 8 or 10 s); X corresponds for example to a parameter of the speed control system whose value can be modified, for example via an HMI (human-machine interface) accessible by a user of the vehicle 10.

[0045] The operations of the vehicle speed regulation system control process 10 described below are implemented sequentially or simultaneously. For example, some of the operations described below, even if described as different unit operations, are implemented in parallel and may constitute a single operation.

[0046] In a first operation, the signaling element 210 is detected by the vehicle 10 at a first time instant t0.

[0047] Signaling element 210 corresponds, for example, to one of the following 4 elements: a STOP sign; a YIELD sign; a red traffic light; and a green traffic light.

[0048] The signaling element 210 is detected for example by applying one or more image processing methods to image data of the vehicle environment 10 received from a camera mounted in the vehicle.

[0049] An object recognition method is applied, for example, to the received image data to detect the presence of signaling element 210 and identify the type of signaling element. The image processing method implemented corresponds, for example, to a method called machine learning, such as one implemented by a neural network.

[0050] The distance between vehicle 10 and signaling element 210 at time t0 is, for example, determined from the received image data. In another variant, this distance is determined from data received from an object detection sensor (e.g., radar or LiDAR) mounted on vehicle 10.

[0051] According to another example, the signaling element 210 and the distance separating this element 210 from the vehicle 10 at the time of detection are determined from mapping data accessible by the vehicle 10, this data being for example stored in a memory of the vehicle 10. This mapping data corresponds for example to map data from a navigation system of the vehicle 10, the detection of the element 210 and the determination of the distance being obtained by knowing the geographical position of the vehicle 10 (obtained for example via a geolocation system of the GPS type).

[0052] In a second operation, the target speed V target associated with the third phase 23 of the speed regulation profile is determined according to the type of signaling element detected.

[0053] For example, the target speed Vtarget is 25 km / h (approximately 7 ms-1) when the signal element 210 corresponds to the YIELD sign, the target speed is 30 km / h (approximately 8.3 ms-1) when the signal element corresponds to the STOP sign or the traffic light in red, and the target speed is 50 km / h (approximately 14 ms-1) when the signal element corresponds to the traffic light in green.

[0054] Of course, these speed values ​​are given as examples and are not exhaustive. According to other examples, the target speed is 20 or 30 km / h for a YIELD sign, 35 or 40 km / h for a STOP sign or a red traffic light, and 40 or 45 km / h for a green traffic light.

[0055] The target value is, for example, selected from a lookup table, called a LUT (from the English "Look-Up Table"), stored in a memory accessible by the computer implementing the process; such a LUT matches a target V value for each type of signaling element.

[0056] In a third operation, the first time interval associated with the first phase 21 of the vehicle speed regulation profile and the second time interval associated with the second phase 22 of the profile are determined.

[0057] To this end, the time instant t1 corresponding to the beginning of the first phase 21 and the time instant t2 corresponding to the beginning of the second phase 22 are determined. The time instant t3 corresponding to the end of the second time interval is determined from the value X of the duration of the third phase, which corresponds to a specific system parameter, for example, 5 s. This parameter corresponds, for example, to a fixed distance from the location of the detected signaling element 210. This distance corresponds, for example, to the system parameter stored in memory, the value of X being deduced from this distance once the target V has been determined.

[0058] The time instant t1 is for example determined by comparing the first target deceleration value d phase1 associated with the first phase 21 and a current deceleration value, denoted 'dn', determined as a function of a current speed, denoted 'V', of the vehicle, the target speed V target, a current distance, denoted 'D', between the vehicle 10 and the signaling element 210 and the determined duration X of the third phase.

[0059] Thus, once the signaling element 210 is detected, dn is calculated as the vehicle 10 moves, for example at regular intervals (for example every 10, 20, 50 or 100 ms), and compared to d phase1.

[0060] The current value of deceleration dn is obtained, for example, from the following equation: d n = V cible 2 − V 2 2 ∗ D − X ∗ V cible

[0061] A value is said to be current when it is determined at a current time. When dn is determined at regular intervals, the current value of dn corresponds to the value of dn at the time it is calculated, the current speed of the vehicle used to calculate dn corresponding to the value of the vehicle's speed at the time dn is calculated.

[0062] When the signal element 210 is detected at t0, the calculation of dn is triggered. In one variant, the calculation of dn is triggered provided that the distance between the vehicle 10 and the signal element is less than a threshold distance, for example, less than 160 m, or, in other examples, less than 250, 200, or 150 m. In another variant, this threshold distance depends on the speed of the vehicle 10 at the time t0 of detection of the element 210 and the determined target speed V.

[0063] The start t1 of the first time interval is thus determined, for example, when the following two conditions are met: the distance between vehicle 10 and element 210 is less than the threshold distance; d phase1 ≥ dn.

[0064] Put another way, t1 corresponds to the time instant at which dn reaches d phase1, provided that at t1 the distance between vehicle 10 and element 210 is less than the threshold distance.

[0065] According to the equation of dn above, considering that the current speed of vehicle 10 is constant (i.e. with variations around an average speed below a threshold, for example less than 2 or 5% of the average speed) from t0, the value of dn will decrease (considering that V target is less than the current speed of vehicle 10) as vehicle 10 approaches the signaling element 210.

[0066] Expressing the deceleration dn with a negative value means that the deceleration dn decreases as the distance between vehicle 10 and element 210 increases. Expressing the deceleration dn with a positive value (which is equivalent to using a negative acceleration to define deceleration) means that the deceleration dn increases as the distance between vehicle 10 and element 210 increases.

[0067] In the rest of the description, deceleration is expressed with a negative value, this value decreasing as deceleration increases.

[0068] When the first phase 21 begins (at t1), the first target deceleration value d phase1 becomes the target acceleration supplied to the vehicle's speed control system 10, for example the ACC system. The speed of the vehicle 10 then decreases during this first phase according to the first target deceleration value d phase1.

[0069] The start t2 of the second phase 22 (which corresponds to the end of the first phase) is determined by comparing the second target deceleration value d phase2 associated with the second phase 22 to dn which is for example calculated according to the equation above.

[0070] t2 thus corresponds for example to the time instant at which dn reaches d phase2, that is to say when the following condition is met: d phase2 ≥ dn.

[0071] A speed regulation profile based on the example of the figure 2 with a first phase of gentle deceleration followed by a second phase of stronger deceleration (i.e. with a first target deceleration value d phase1, which is for example equal to -0.3 ms -2<, greater than the first target deceleration value d phase2, which is for example equal to -0.7 ms -2<) presents several advantages, namely: The first deceleration phase 21 alerts the driver of vehicle 10 that a signal element 210 has been detected, with a slight or gentle deceleration; the second deceleration phase 22, with a greater or more pronounced deceleration, allows the target speed V of the third phase to be reached more quickly and also allows the driver to feel the difference with the third phase 23 during which the speed of vehicle 10 will be maintained and regulated around V target; and the third phase 23, with a determined duration (or a determined travel distance) and with a target speed adapted to the detected signal element 210, gives the driver the opportunity to regain full control of vehicle 10 if necessary, by deactivating the speed regulation system.For example, if traffic signal element 210 corresponded to a green light at t0 and it turns red during the third phase 23, the driver must take control of the vehicle to stop vehicle 10 and come to a complete stop at the red light. As another example, in the case of a YIELD sign, if a vehicle is approaching on road 102, vehicle 10 must stop at the sign. Similarly, in the case of a STOP sign or a red light, a moderate or low target speed allows the driver time to regain control of vehicle 10 during the third phase 23 to stop vehicle 10 and come to a complete stop at the sign or light; if the red light turns green again during the third phase 23, or during one of the deceleration phases, the driver can then decide to let the cruise control system regulate the speed of vehicle 10 until traffic signal element 210 passes.

[0072] In other particular embodiments which do not strictly correspond to the claimed invention, the number of deceleration phases 21, 22 can vary according to the speed of the vehicle 10 at the time t0 of detection of the signaling element 210.

[0073] For example, when the speed of vehicle 10 is below a threshold at time t0, the profile comprises only one deceleration phase; that is, the first phase 21 and the second phase 22 form a single phase with the same target deceleration value, which corresponds, for example, to the first target deceleration value d phase1 or another value. The deceleration value of this single phase depends on the vehicle's speed at t0 and the target speed V, which is a function of the type of signaling element detected.

[0074] According to another example, which does not strictly correspond to the claimed invention, when the speed of vehicle 10 exceeds a threshold (for example, above 90, 100, or 110 km / h) at time t0, the profile comprises only a single deceleration phase. That is, the first phase 21 and the second phase 22 form a single phase with the same target deceleration value, which corresponds, for example, to the second target deceleration value d phase1 or to another value, for example, lower than this value (i.e., for a greater deceleration). The deceleration value of this single phase depends on the vehicle's speed at t0 and the target speed V, which is a function of the type of signaling element detected.

[0075] According to another particular embodiment which does not strictly correspond to the claimed invention, the profile further comprises a fourth phase between the second phase 22 and the third phase 23 when the speed of the vehicle 10 reaches, before the end of the second phase, a value lower than the target speed V target.

[0076] According to this embodiment, an acceleration value (positive value) is for example associated with the fourth phase, the acceleration value being determined so that a vehicle speed at the end of the fourth phase is equal to the target speed V target.

[0077] According to another embodiment, when the speed of the vehicle 10 reaches at the end of the second phase 22, that is to say at time t3, a speed having a value less than the target speed V target, the value of the speed associated with the third phase 23 becomes this speed of value less than V target.

[0078] In a fourth operation, the vehicle's speed control system 10 is controlled according to the speed control profile determined in the previous operations. The setpoint acceleration values ​​of the control system correspond to the target deceleration values ​​d phase1 and d phase2 associated with each deceleration phase 21, 22, and the setpoint speed of the control system for the third phase 23 at constant speed corresponds to the target speed (or the modified target speed, if applicable).

[0079] There figure 3 This schematically illustrates a device 3 configured to control a vehicle speed regulation system, for example, of 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.

[0080] 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 4 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, 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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).

[0086] 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.

[0087] There figure 4 illustrates a flowchart of the different stages of a control method for a vehicle's control system, for example, an ACC system of 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 .

[0088] In a first step 41, a signaling element is detected at a first time instant.

[0089] In a second step 42, a first time interval associated with a first phase of a vehicle speed regulation profile and a second time interval associated with a second phase of the profile are determined, the second phase temporally following the first phase.

[0090] A target speed of the vehicle is further determined based on the detected signaling element, the target speed being associated with a third phase of the profile, the third phase temporally following the second phase, the third phase having a determined duration.

[0091] The start of the first time interval is determined based on the result of a comparison between a first target deceleration value associated with the first phase and a current deceleration value determined based on a current vehicle speed, the target speed, a current distance between the vehicle and the signaling element and the determined duration of the third phase.

[0092] The start of the second time interval is determined based on the result of a comparison between a second target deceleration value associated with the second phase and the current deceleration value, the second target deceleration value being less than or equal to the first target deceleration value.

[0093] In a third step 43, the speed regulation system is controlled according to the speed regulation profile determined in the second operation.

[0094] 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 .

Claims

1. Method for controlling a speed regulation system of a vehicle (10), said vehicle (10) travelling on a portion of the highway (101) on approach to a signalling item (110), said method comprising the steps of: - detecting (41) said signalling item at a first time instant; - determining (42) a first time interval associated with a first phase (21) of a speed regulation profile of said vehicle (10), a second time interval associated with a second phase (22) of said profile, said second phase (22) following said first phase (21) in time, and determining (42) a target speed of said vehicle (10) as a function of said signalling item (10) detected, said target speed being associated with a third phase (23) of said profile, said third phase (23) temporally following said second phase (22), said third phase (23) having a determined period of time, - a beginning of said first time interval being determined as a function of a result of a comparison between a first target deceleration value associated with said first phase (21) and a current deceleration value determined as a function of a current speed of said item (10), of said target speed, of a current distance between said vehicle (10) and said signalling beginning (110) and of said determined period of the third phase (23), and a result of said second time interval being determined as a function of a profile of a comparison between a second target deceleration value associated with said second phase (22) and said current deceleration value said first target deceleration value; - control (43) of said speed regulation system according to said speed regulation , the first target deceleration value, the second target deceleration value and the target speed being supplied to the speed regulation system to control the latter during, respectively, the first phase (21), the second phase (22) and the third phase (23).

2. Method according to claim 1, wherein the beginning of said first time interval is equal to a second time instant corresponding to, when said vehicle (10) is at a distance less than a determined distance from said signalling item (110), the time instant at which said current deceleration value reaches said first target deceleration value, and the beginning of said second time interval is equal to a third time instant corresponding to the time instant at which said current deceleration value reaches said second target deceleration value.

3. Method according to claim 1 or 2, wherein said current deceleration value, denoted dn, is determined according to the equation: dn = Vtarget 2 − V 2 / 2 * D − X * Vtarget with Vtarget corresponding to said target speed, V corresponding to the current speed of said vehicle (10), D corresponding to the current distance between said vehicle (10) and said signalling item (110) and X corresponding to said determined period of the third phase (23).

4. Method according to one of claims 1 to 3, for which said signaling item belongs to a set of signaling items comprising: - a STOP sign; - a sign GIVE THE WAY; - a red signaling light; and - a green signaling light.

5. The method according to claim 4, wherein said target speed is equal to 25 km / h when said signalling item corresponds to the sign GIVE THE WAY, said target speed is equal to 30 km / h when said signalling item corresponds to the sign STOP or to the red signal light and said target speed is equal to 50 km / h when said signalling item corresponds to the green signal light.

6. Method according to one of claims 1 to 5, for which the determined duration of said third phase is equal to 5 seconds, said first target deceleration value is equal to -0.3 m.s-2 and said second target deceleration value is equal to -0.7 m.s-2 or -1.2 m.s-2.

7. Method according to one of claims 1 to 6, for which said profile further comprises a fourth phase comprised between said second phase (22) and said third phase (23) when a speed of said vehicle (10) reaches a value lower than said target speed before the beginning of said third phase, an acceleration value being associated with said fourth phase, said acceleration value being determined so that a speed of said vehicle (10) at the end of the fourth phase is equal to said target speed.

8. Computer plan comprising instructions for the implementation of the method according to any one of the previous claims, when these instructions are executed by a processor.

9. Device (3) for controlling a 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 (10) comprising the device (3) according to claim 9.