Method of controlling a motor vehicle

Abstract

The invention relates to a method for automatically controlling an actuator (15) of a control system of an automotive device (10), comprising the following steps: - determining a reference trajectory (T0), - determining the position of the device relative to the reference trajectory, - obtaining parameters (Cc) related to the force applied by the driver to a manual control device of the control system, and - calculating a control setpoint (Cr) of the actuator by means of a computer. According to the invention, the control setpoint is calculated as a function of the parameters and the position of the device relative to the reference trajectory.

Description

Technical Field

[0001] The present invention generally relates to the automation of automotive equipment trajectory tracking.

[0002] The invention is particularly advantageous in the context of driving assistance in motor vehicles, but it may also be applied in the fields of aeronautics or robotics.

[0003] More specifically, the present invention relates to a method for autonomously controlling an actuator of a control system of an automotive device, the method comprising the following steps:

[0004] - determine the reference trajectory,

[0005] - determining the position of the device relative to this reference trajectory,

[0006] - obtaining parameters related to the force applied by the driver to the manual controls of said control system, and

[0007] - Calculating the control set points of said actuators by means of a computer.

[0008] The invention also relates to a device provided with a computer suitable for implementing the method. Background Art

[0009] For safety purposes, motor vehicles are increasingly equipped with driver assistance systems or autonomous driving systems.

[0010] Among these systems, automatic emergency braking (AEB) systems are well known and are designed to avoid any collision with obstacles located in the lane in which the vehicle is travelling by simply acting on the conventional braking system of the motor vehicle.

[0011] However, in some situations, these emergency braking systems cannot avoid a collision or cannot be used at all (for example, if a vehicle is following closely behind the motor vehicle).

[0012] For these situations, automatic avoidance systems (better known by the abbreviation AES, which stands for "automatic evasive steering" or "automatic emergency steering") have been developed, which make it possible to avoid obstacles by acting on the vehicle's steering or on its differential braking system to deviate from its trajectory.

[0013] It is possible that the AES system may conflict with the driver in order to avoid an obstacle, forcing the vehicle to follow a different avoidance trajectory than the one the driver intended. This situation results in a hindrance to the driver at best (who then risks disabling the AES system and compromising his or her safety), and a lack of driver understanding at worst, which may result in an inadequate understanding of the situation.

[0014] Therefore, management of the interaction between the driver and the AES system proves to be difficult in practice. Summary of the Invention

[0015] The present invention therefore proposes to enhance existing AES systems by adding to them additional functionality that ensures a better arbitration between the driver's wishes and the decisions taken by the AES system.

[0016] More specifically, according to the invention, a method as defined in the introduction is proposed, wherein a control setpoint is calculated as a function of said parameters and as a function of the position of said device relative to a reference trajectory.

[0017] Thus, by virtue of the invention, the trajectory adopted by the vehicle's equipment depends not only on the setpoints generated by the AES system, but also on the wishes expressed by the driver.

[0018] The invention then makes it possible to arbitrate and support the wishes expressed by the AES system or the driver, depending on the situation encountered and, in particular, on the position of the vehicle equipment relative to obstacles.

[0019] The invention thus makes it possible to avoid putting the driver in situations where he or she might lack understanding, while at the same time guaranteeing him or her the best possible driving comfort.

[0020] The following are further advantageous and non-limiting features of the control method according to the invention, which are considered individually or in all technically possible combinations:

[0021] - the device is a motor vehicle suitable for traveling on roads and comprising at least one driving wheel,

[0022] - the manual control device is a steering wheel,

[0023] - said control system allows steering each driving wheel,

[0024] - this parameter is related to the torque applied to the steering wheel by the driver of the motor vehicle;

[0025] - the reference trajectory is determined so that the device avoids obstacles,

[0026] - taking into account at least two areas of the environment of the device, the limits of which depend on the position of obstacles and / or the position of reference trajectories relative to the obstacles, performing the calculation of the control setpoints by determining the area in which the device is located and then using an algorithm for calculating the control setpoints selected according to the area in which the device is located;

[0027] - provision is made for determining an indicator whose value depends on the zone in which the device is located and on the parameter, for generating a preliminary control setpoint for the actuator which makes it possible to bring the device to a reference trajectory, and for correcting the preliminary setpoint as a function of the value of the indicator;

[0028] - the indicator is suitable for taking only one or the other of two values, provision is made for determining a correction indicator varying continuously between the two values ​​according to the indicator, and for correcting the preliminary set point by multiplying the value of the preliminary set point by the value of the correction indicator;

[0029] - when the correction index changes, determining the rate of change of the correction index as a function of the speed of the motor vehicle and the radius of curvature of the road, so that the lateral acceleration of the motor vehicle does not exceed a determined threshold value;

[0030] - the preliminary setpoint is inferred from the steering angle setpoint of the wheel, itself calculated from the position of the device relative to a reference trajectory and filtered by a controller satisfying a setpoint amplitude limitation model and a setpoint variation limitation model;

[0031] - The computer considers four areas associated with four different calculation algorithms, namely:

[0032] * the area upstream of the obstacle, between the reference trajectory and the protection line, beyond which any collision with the obstacle will be avoided,

[0033] * an area flush with and downstream of the obstacle, between the reference trajectory and the protection line,

[0034] * the area upstream of the obstacle, on the opposite side of the reference trajectory from the protection line, and

[0035] * an area where a portion is located upstream of the obstacle and on the side of the protection line opposite to the reference trajectory, and another portion is flush with the obstacle and located downstream of the obstacle and on the side of the reference trajectory opposite to the protection line;

[0036] - when the device moves from the first area to the second area, the computer continues to use the algorithm associated with the first area as long as the device has not yet exceeded the hysteresis trajectory determined based on the reference trajectory;

[0037] - determining a reference trajectory to avoid an obstacle by circumventing at least one protection boundary located around a portion of the obstacle;

[0038] The form and position of the first protection limit depend on the form of the obstacle and / or the measurement errors of the sensors with which the motor vehicle is equipped and / or the speed of the obstacle;

[0039] - The form and position of the second protection limit depends on the predetermined safety margin.

[0040] The invention also proposes an automotive device, such as a car, comprising at least one actuator suitable for influencing the trajectory of said device and a computer for controlling said actuator, the computer being programmed to implement the above method.

[0041] Of course, as long as the various features of the present invention are not mutually incompatible or mutually exclusive, they can be associated with each other in various combinations. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The following description, given as a non-limiting example with the aid of the accompanying drawings, will give a good understanding of what the invention consists of and how it can be produced.

[0043] In the attached figure:

[0044] Figure 1 is a schematic top view of a motor vehicle traveling on a road, showing the avoidance trajectory that the vehicle must take;

[0045] Figure 2 is a block diagram showing the architecture of a control system suitable for implementing the control method according to the present invention;

[0046] Figure 3 It's an obstacle, Figure 1 A schematic diagram of a motor vehicle, an obstacle avoidance trajectory of the motor vehicle and different areas used in the context of the control method according to the invention;

[0047] Figure 4 is a schematic diagram of an obstacle, an obstacle avoidance trajectory and two trajectories that can be envisaged in the context of a first example of using the control method according to the invention;

[0048] Figure 5 is Figure 4 A graph showing trends of different control torques of a motor vehicle drawn on the basis of a graph of

[0049] Figure 6 is a schematic diagram of an obstacle, an obstacle avoidance trajectory and two trajectories that can be envisaged in the context of a first example of using the control method according to the invention;

[0050] Figure 7 is Figure 6 A graph showing trends of different control torques of a motor vehicle drawn on the basis of a graph of

[0051] Figure 8 is a schematic diagram of an obstacle, an obstacle avoidance trajectory and two trajectories that can be envisaged in the context of a first example of using the control method according to the invention;

[0052] Figure 9 is Figure 8 A graph showing trends of different control torques of a motor vehicle drawn on the basis of a graph of

[0053] Figure 10 is a schematic diagram of an obstacle, an obstacle avoidance trajectory and two trajectories that can be envisaged in the context of a first example of using the control method according to the invention;

[0054] Figure 11 is Figure 10 A graph showing trends of different control torques of a motor vehicle drawn on the basis of a graph of

[0055] Figure 12 is a schematic diagram of an obstacle, an obstacle avoidance trajectory and two trajectories that can be envisaged in the context of a first example of using the control method according to the invention;

[0056] Figure 13 is Figure 12 A graph showing trends of different control torques of a motor vehicle drawn on the basis of a graph of

[0057] Figure 14 is a schematic diagram of an obstacle, an obstacle avoidance trajectory and two trajectories that can be envisaged in the context of a first example of using the control method according to the invention;

[0058] Figure 15 is Figure 14 A graph showing trends of different control torques of a motor vehicle drawn on the basis of a graph of

[0059] Figure 16 is a graph showing an example of a steering angle set point changing over time;

[0060] Figure 17 is Figure 16 The graph is drawn on the basis of the graph showing that in the context of the control method according to the present invention Figure 1 A graph showing the timing of activation and deactivation of a control system of a vehicle; and

[0061] Figure 18 is Figure 16 The parameters K1 and K1 used in the context of the method according to the invention are shown on the basis of a graph of rt Graph of the changes. DETAILED DESCRIPTION

[0062] Figure 1 A motor vehicle 10 is shown travelling on a road. In the following examples, consideration will be given to a situation where the law requires the vehicle to travel in the right lane, but the invention will be equally applicable symmetrically to situations where the vehicle travels on the left (as is the case in the UK, for example).

[0063] like Figure 1 As shown, the motor vehicle 10 generally comprises a chassis defining the interior of the vehicle, two front driven wheels 11 and two rear non-driven wheels 12. As a variant, the two rear wheels may also be driven wheels.

[0064] The motor vehicle 10 comprises a conventional steering system 18 which makes it possible to act on the orientation of the front wheels 11 in order to steer the vehicle. In the example considered, the steering system 18 is controlled by an auxiliary steering actuator 15 which makes it possible to act on the orientation of the front wheels 11 as a function of the orientation of the steering wheel 16 and / or, in certain cases, as a function of a setpoint issued by the computer 13.

[0065] Furthermore, the motor vehicle may include a differential braking system making it possible to act differently on the rotational speeds of the front wheels 11 (and even on the rotational speeds of the rear wheels 12) in order to decelerate the motor vehicle by turning it. This differential braking system would comprise, for example, controlled differentials or electric motors placed at the vehicle wheels.

[0066] In the explanation hereinafter, the steering system considered will be formed solely of a conventional steering system. As a variant, it may be formed of a combination of a conventional steering system and a differential braking system.

[0067] A computer 13 is provided for controlling the actuator 15. To this end, the computer comprises at least one processor, at least one memory and different input and output interfaces.

[0068] The computer 13 is adapted to receive input signals originating from various sensors via its input interfaces.

[0069] Among these sensors, the following are provided, for example:

[0070] - a device making it possible to mark the position of the vehicle relative to its lane, such as a front camera,

[0071] - makes it possible to detect obstacles 100 located on the trajectory of the motor vehicle 10 ( Figure 3 ) devices, such as RADAR or LIDAR remote sensors,

[0072] at least one side device making it possible to observe the environment to the side of the vehicle, such as a RADAR or LIDAR remote sensor,

[0073] - a device making it possible to determine the yaw rate of rotation (about a vertical axis) of the motor vehicle 10 , such as a gyroscope, and

[0074] - a sensor for the forces applied to the steering wheel and / or a sensor for the angular position of the steering wheel.

[0075] The computer 13 is adapted to transmit setpoints to the auxiliary steering actuator 15 by means of its output interface.

[0076] This therefore makes it possible to ensure that the vehicle follows the reference trajectory as best as conditions permit, which is Figure 3 In the example shown, the avoidance trajectory T0 is formed by obstacle 100 .

[0077] The computer 13 stores, by means of its memory, data used in the context of the method described below.

[0078] The computer notably stores a computer application consisting of a computer program comprising instructions which, when executed by a processor, enable the computer to implement the method described below.

[0079] This computer stores in particular two computer applications: a first application, hereinafter referred to as “AES system 20 ”, which makes it possible to determine the avoidance trajectory T0 to be followed and the steering angle setpoint δ enabling the motor vehicle 10 to follow the avoidance trajectory T0 . c and hereinafter referred to as the "EPS system 21" second application, which makes it possible to take into account the above-mentioned steering angle set point δ c The set point to be sent to the auxiliary steering actuator 15 is determined in accordance with the driver's expressed wishes.

[0080] The driver's expressed desire is inferred here from the torque applied by the driver to the steering wheel 16, which will be referred to below as "steering wheel torque Cc". As a variant, the desire can be inferred as a combination of this steering wheel torque and other factors, such as, for example, the steering wheel angular position.

[0081] Before describing in detail the two systems AES and EPS, it is possible to introduce the different variables that will be used in the context of the control method described below, Figure 1 Show some of these variables.

[0082] The steering angle formed by the front drive wheels with the longitudinal axis A1 of the motor vehicle 10 will be denoted as “δ” and expressed in radians.

[0083] At a sight distance "ls" in front of the vehicle, the lateral deviation between the longitudinal axis A1 of the motor vehicle 10 (passing through the center of gravity CG) and the avoidance trajectory T0 will be denoted as "y L ” and is expressed in meters.

[0084] The above sight distance "ls" will be measured from the center of gravity CG and expressed in meters.

[0085] The speed of the motor vehicle along the longitudinal axis A1 will be denoted as “V” and will be expressed in m / s.

[0086] Figure 2 There are shown the two systems mentioned above, AES 20 and EPS 21. The way in which these systems operate in practice can then be explained.

[0087] When motor vehicle 10 is traveling on a road along an initial trajectory (not shown and substantially parallel to the road) and detects a potentially dangerous obstacle 100 , the AES system is activated.

[0088] Potentially dangerous obstacles are fixed obstacles located on or near the initial trajectory, or mobile obstacles whose trajectories risk intersecting the initial trajectory.

[0089] The system AES 20 then receives as input parameters P1 which make it possible to characterize the attitude of the motor vehicle 10 in its environment. For example, these parameters are the lateral deviation y of the motor vehicle at the sight distance ls L , the heading of the motor vehicle relative to the road, the yaw speed of the motor vehicle, etc.

[0090] The motor vehicle is also suitable for determining or receiving from another computer an avoidance trajectory T0 for the obstacle 100. This avoidance trajectory T0 is generated, for example, based on the above-mentioned parameters P1 and the characteristics of the obstacle 100 (size, speed, etc.).

[0091] exist Figure 3 As in all the examples that will be considered below, it can be seen that this avoidance trajectory T0 is planned to avoid the obstacle 100 from the left by bypassing the protection limits 101 and 102 , which makes it possible to avoid any collision with the obstacle.

[0092] The rectangular form of the first protection demarcation 101 is determined by the form of the obstacle 100 and any measurement errors of the sensors with which the motor vehicle is equipped. The position of the first protection demarcation takes into account the possible speed of the obstacle 100 .

[0093] The size of the second protection margin 102 is selected according to the safety margin that is desired to be provided. Here, the second protection margin takes the form of a circle, the center of which is located at the corner of the first protection margin 101 that is closest to the avoidance trajectory T0.

[0094] The method of generating the avoidance trajectory T0 is not the specific purpose of the present invention and will not be described in detail.

[0095] Given the parameter P1 and the avoidance trajectory T0, the AES system 20 can determine the preliminary steering angle set point δ of the vehicle front wheels 11 c , which will allow the vehicle to best follow the avoidance trajectory T0.

[0096] Receive the preliminary steering angle set point δ c The EPS system 21 uses the controller 22 as input to determine a filtered steering angle setpoint δ that is saturated in magnitude and rate of change. s .

[0097] In other words, if the initial steering angle set point δ c If (the absolute value of) exceeds a predetermined threshold, it is overridden and it is adjusted to not change faster than another predetermined limit.

[0098] These thresholds are selected so that the motor vehicle 10 remains controllable by the driver at all times, in situations where it is possible to assume sole control of the vehicle.

[0099] The filtered steering angle setpoint δ s The deviation from the instantaneous steering angle δ of the driving wheels 11 (measured by the angle sensor) is then used to determine a preliminary torque setpoint Ca which, if sent directly to the auxiliary steering actuator 15, would make it possible to determine the torque setpoint Ca according to the filtered steering angle setpoint δ. s To control the steering of the wheels.

[0100] This preliminary torque set point Ca is then multiplied by parameter K1 rt , the calculation of which will be explained below, which makes it possible to obtain the intermediate torque setpoint Ci.

[0101] The deviation (in a multiplicative term) between this intermediate torque setpoint Ci and the steering wheel torque Cc makes it possible to obtain a final torque setpoint Cr, which is sent to the auxiliary steering actuator 15 .

[0102] The present invention here more specifically relates to the above-mentioned parameter K1 rt Calculation.

[0103] This parameter (hereinafter referred to as "correction gain K1 rt ”) is used to deactivate the AES system 20 when conditions permit and the driver appears to want to take back control of the driving of the motor vehicle 10.

[0104] In order to check whether the conditions permit this operation, provision is made here to determine the surrounding area of ​​obstacle 100 in which motor vehicle 10 is located.

[0105] How to calculate the correction gain K1 is described in detail. rt Before, the environmental areas that will be considered in order to carry out these calculations can be detailed.

[0106] like Figure 3 As shown, four environmental zones are preferably distinguished. As variants, a lower number (at least two) or a higher number can be considered, and these zones can be defined differently.

[0107] Here, the four areas are defined relative to the avoidance trajectory T0 , relative to the obstacle 100 , and relative to the protection line L1 (outside of which any collision with the obstacle 100 is to be avoided).

[0108] More specifically, the protection line L1 corresponds to an imaginary line parallel to the road and passing through the point P1 of the second protection boundary 102 that is farthest from the obstacle 100 (the imaginary line is a straight line here, but may be a curve if the road is curved).

[0109] The passage of the motor vehicle 10 (and more particularly of its centre of gravity CG) through this line makes it possible to ensure good avoidance of the obstacle 100 .

[0110] The four regions are defined as follows.

[0111] The first zone Z1 is located upstream of the obstacle (more specifically, upstream of the first protection limit 101 ) and between the avoidance trajectory T0 and the protection line L1 .

[0112] In this first zone Z1 , the driver's intention should be close to the set point calculated by the AES system 20 , so that for safety purposes it is not desirable that the operation of the AES system be suspended.

[0113] The second zone Z2 is flush with the obstacle and located downstream of the obstacle (more specifically, flush with the first protection limit 101 and located downstream of the first protection limit), between the avoidance trajectory T0 and the protection line L1.

[0114] Since this area is behind the obstacle 100 and therefore no longer presents any danger, it would be desirable to allow the driver to fully regain control of the vehicle as long as he or she has both hands on the steering wheel.

[0115] The third zone Z3 is located upstream of the obstacle 100 (more specifically, upstream of the first protection limit 101 ) and on the other side of the reference trajectory T0 relative to the first zone Z1 .

[0116] In this region, it is desirable to allow the driver to take back control of the vehicle's driving if he or she firmly objects to the AES system 20 .

[0117] The fourth zone Z4 covers the rest of the environment.

[0118] In this fourth region, it is desirable to allow the driver to take back control of the vehicle's driving if he or she objects to the AES system 20. Thus, in the fourth region, once the driver objects to an AES system-commanded maneuver, no matter how gently, the AES request is interrupted.

[0119] To calculate the correction gain K1 rt , the computer 13 determines in which of these four areas the motor vehicle 1 is located, and the computer then uses a calculation algorithm that differs between the areas.

[0120] When the motor vehicle 10 changes zones, the computer does not immediately change the calculation algorithm to avoid instability. It then changes the algorithm only when the vehicle exceeds the so-called hysteresis trajectory (calculated according to the avoidance trajectory T0).

[0121] exist Figure 3 In FIG, two hysteresis trajectories T01 , T02 are shown, which follow the avoidance trajectory T0 at a predetermined constant distance (for example one meter) to the right or left of the avoidance trajectory T0 .

[0122] When the motor vehicle 10 travels from zone Z1 to zone Z3 (or vice versa), or from zone Z2 to zone Z4 (or vice versa), the computer changes the calculation algorithm only after the vehicle has not only passed through the avoidance trajectory T0, but also through the two lag trajectories T01 and T02, which in particular makes it possible to avoid oscillations between zones.

[0123] The correction gain K1 can now be described in detail rt Calculation method.

[0124] The correction gain K1 rt The value of is inferred from the value of gain K1, which is a Boolean value whose value is determined as shown below.

[0125] If the motor vehicle is located in the first zone Z1 , the gain K1 is set equal to one, which means that no interruption of the AES system 20 is desired.

[0126] If the motor vehicle is located in the second zone Z2 , the driver has both hands on the steering wheel and the absolute value of the steering wheel torque Cc is above a first threshold Cc2 , the gain K1 is set equal to zero, which means that interruption of the AES system 20 is desired.

[0127] In any other case in the third zone Z2 , the gain K1 is set equal to one.

[0128] If the motor vehicle is located in the third zone Z3 and the driver intends to avoid the obstacle from the right (contrary to the AES system 20 ) while remaining in zone Z3 (i.e. by shifting as little as possible relative to the obstacle 100 ), the gain K1 is set equal to zero, which means that the AES system 20 is desired to be interrupted.

[0129] In order for the computer 13 to believe that the driver intends to avoid the obstacle on the right by shifting as little as possible, the computer checks whether the steering wheel torque Cc is negative and whether this steering wheel torque is below a negative threshold Cc 3min (e.g. -2Nm).

[0130] Similarly, if the motor vehicle is in the third zone Z3 and the driver intends to 3max If a steering wheel torque CC of (eg 2 Nm) is applied to avoid an obstacle from the left (opposite to the AES system 20 ), and the AES system generates a negative torque, the gain K1 is likewise set equal to zero, which means that it is desired to interrupt the AES system 20 .

[0131] In any other case in the third zone Z3 , the gain K1 is set equal to one, which means that it is desired to maintain the AES system 20 .

[0132] If the motor vehicle is in the fourth zone Z4 and the driver wants to return to his or her initial lane or at least to the lane by applying a negative threshold Cc which is lower than the threshold Cc which is negative itself 4min If a steering wheel torque Cc of (eg -3 Nm) is applied to cancel the lateral velocity of the motor vehicle 10 and the AES system produces positive torque, the gain K1 is set equal to zero.

[0133] If the motor vehicle is in the fourth zone Z4 and the driver wants to 4max If a positive steering wheel torque Cc (eg, 3 Nm) is applied to continue maximally away from the obstacle 100 to change lanes, and the AES system generates a negative torque, the gain K1 is set equal to zero.

[0134] In any other case in the fourth zone Z4 , the gain K1 is set equal to one.

[0135] It should be noted that in case the gain K1 is equal to zero and at least one of the above conditions is no longer satisfied, the gain is immediately set to unity again.

[0136] The computer 13 can then calculate the correction gain K1 rt , where the correction gain is a real number between zero and one and varies continuously.

[0137] Determine the correction gain K1 rt To avoid any sudden modification of the control of the motor vehicle 10 .

[0138] In other words, the correction gain K1 rt The rate of change of is zero (when the value of the correction gain is equal to zero or one), or it is constant and equal to a predetermined speed. Figure 18 As shown, if the gain K1 shows a change in the form of a rectangular pulse, the gain K1 is corrected rt It shows a change in the form of a trapezoidal pulse, where the rising and falling edges are not vertical but inclined, in the form of a ramp.

[0139] It will be possible to specify that the rate of change of the rising edge is greater than the rate of change exhibited by the falling edge.Each rising edge is initiated when the gain K1 changes from zero to one, and each falling edge is triggered when the gain K1 changes from one to zero.

[0140] The rate of change on each rising or falling edge is determined according to the vehicle's speed V and the curvature radius of the road so that the vehicle's lateral acceleration does not exceed a threshold value (e.g., 1 m.s -2 ).

[0141] Thus, when the speed V is higher, the gradient used will be correspondingly lower, and when the radius of curvature of the road is larger, the gradient used will be correspondingly higher. It would be possible to use a mapping that could determine the gradient to be used.

[0142] Once the correction gain K1 is obtained rt , the correction gain is multiplied by the preliminary torque set point Ca.

[0143] When the correction gain K1 rt When equal to one (which means that the AES system 20 is operational), the preliminary torque setpoint Ca is not modified and the auxiliary steering actuator 15 is controlled solely by the AES system 20 .

[0144] When the correction gain K1 rt When equal to zero (which means that the operation of the AES system 20 must be suspended), the preliminary torque setpoint Ca is cancelled and the auxiliary steering actuator 15 is controlled solely by the steering wheel 16 .

[0145] Correction gain K1 rt The change between zero and one allows for a gradual and gentle transition from one operating mode to another, avoiding threshold effects.

[0146] exist Figure 2 In FIG, two signals SA and SB corresponding to reset signals are shown.

[0147] The two reset signals SA, SB can be used in particular to correct the gain K1 rt The calculation of the preliminary torque setpoint Ca is reset to zero when it changes from zero to a non-zero value, and the measured steering angle value δ is assigned to the filtered steering angle setpoint δ s .

[0148] refer to Figures 16 to 18 , the benefits of these two signals will become apparent later in this explanation.

[0149] Several specific situations that demonstrate the benefits of the present invention may now be described.

[0150] like Figure 4 and Figure 5 The first specific situation illustrated corresponds to a situation in which, after the first obstacle 100 avoidance phase, the motor vehicle 10 enters the second zone Z2 and the driver wants to return very quickly to his or her original driving lane.

[0151] In this case, the driver turns the steering wheel to the right by applying a negative steering wheel torque Cc. Figure 4 This is shown by curve C3.

[0152] In this case, the AES system 20 calculates a positive torque that would bring the motor vehicle 10 to the avoidance trajectory T0 (ie, pull the vehicle to the left). Figure 5 It is shown by curve C1. Figure 4 The curve T1 shown in FIG. 1 shows the trajectory followed by the motor vehicle 10 when the motor vehicle 10 is controlled without interrupting the operation of the AES system 20 .

[0153] It will therefore be appreciated that without the present invention (ie, it would be impossible to interrupt the AES system 20), the steering wheel torque and the torque generated by the AES system would be opposite, which would give the driver a negative feeling.

[0154] Now, since the situation envisioned here is not dangerous, the driver's wishes will not be violated.

[0155] Then, by virtue of the present invention, the gain K1 is chosen equal to zero, so that the correction gain K1 rt The intermediate torque setpoint Ci will then gradually decrease until it is canceled (see Figure 5 This will allow the vehicle to return to the initial lane at the driver's will (see Figure 4 The trajectory T2 is shown in FIG.

[0156] Figure 6 and Figure 7The second specific situation illustrated corresponds to a situation in which the driver wants to perform a larger avoidance than planned by the AES system 20 , for example, in order to change lanes.

[0157] In this case, after passing the obstacle 100, the driver continues to turn the steering wheel to the left by applying a positive steering wheel torque Cc. Figure 6 This is shown by curve C6.

[0158] For its part, the AES system 20 calculates a negative torque that would bring the motor vehicle 10 to the avoidance trajectory T0 (ie, pull the vehicle to the right). Figure 7 It is shown by curve C4. Figure 6 Curve T4 shown in FIG. 4 shows the trajectory followed by the motor vehicle 10 when the motor vehicle 10 is controlled without interrupting the operation of the AES system 20 .

[0159] It should therefore be understood that without the present invention, the steering wheel torque and the torque generated by the AES system would be opposite, and since this situation is not dangerous, it would not go against the driver's will.

[0160] Then, by virtue of the present invention, the gain K1 is chosen equal to zero, so that the correction gain K1 rt The intermediate torque setpoint Ci will then gradually increase until it is canceled (see Figure 7 This will allow the vehicle to move in another lane at the driver's will (see Figure 6 The trajectory T3 is shown in FIG.

[0161] Figure 8 and Figure 9 The third specific situation illustrated corresponds to a situation where the driver wants to perform a larger avoidance than planned by the AES system 20 and then wants to quickly return to his or her original lane of travel.

[0162] At the beginning of the avoidance, the driver turns the steering wheel hard to the left, and then when the vehicle enters the fourth zone Z4, he or she applies a negative torque to the steering wheel in turn. Figure 8 This is shown by curve C9.

[0163] From the start of the avoidance, in order to bring the motor vehicle 10 to the avoidance trajectory T0, the AES system 20 then calculates a negative torque (ie, to pull the vehicle to the right). Figure 9 This is shown by curve C7. Figure 8 Curve T6 shown in shows the trajectory followed by the motor vehicle 10 when the motor vehicle 10 is controlled without interrupting the operation of the AES system 20 .

[0164] As long as the vehicle is in zone Z4 and it is considered undesirable to interrupt the operation of the AES system 20 , the gain K1 remains equal to one.

[0165] On the other hand, when the vehicle enters the second zone Z2 and the driver maintains his or her intention to quickly return to the original lane, there will be a moment when the steering wheel torque Cc and the torque generated by the AES system have opposite signs. Since this situation is not considered dangerous, the driver's intention will not be violated.

[0166] Then, by virtue of the present invention, the gain K1 is chosen equal to zero, so that the correction gain K1 rt The intermediate torque setpoint Ci applied by the actuator 15 will then gradually decrease until it is canceled (see Figure 9 This will allow the vehicle to quickly return to its original lane at the driver's will (see Figure 8 The trajectory T5 is shown in FIG.

[0167] Figure 10 and Figure 11 The fourth specific situation illustrated corresponds to a situation where the driver wants to avoid the obstacle 100 from the left, but the torque he or she applies to the steering wheel is not sufficient to effectively avoid the obstacle 100 .

[0168] In this case, the driver therefore applies a positive and sufficiently high steering wheel torque Cc only when he or she detects an obstacle and then he or she relaxes the force too quickly. Figure 11 This is shown by curve C11. Figure 10 The curve T8 shown in FIG. 8 shows the trajectory followed by the motor vehicle 10 if the motor vehicle 10 is controlled solely by the driver.

[0169] In this case, as long as the motor vehicle 10 is upstream of the obstacle 100, in the zone Z3, the AES system 20 calculates a positive torque that makes it possible to bring the motor vehicle 10 to the avoidance trajectory T0 (ie, to veer the vehicle to the left). Figure 11 This is shown by curve C10.

[0170] Therefore, this situation is potentially dangerous and therefore will not interrupt the operation of the AES system 20 against the driver's will.

[0171] Then, by virtue of the present invention, the gain K1 is kept equal to one, so that the influence of the steering wheel torque Cc on the vehicle's running trajectory is reduced.

[0172] Figure 10 Curve T7 shown in FIG. 1 shows the trajectory that the motor vehicle 10 will then follow.

[0173] Figure 12and 13 The fifth specific situation illustrated corresponds to a situation where the driver has satisfactorily avoided obstacle 100 , but then does not want to stray too far from the initial lane in which he or she was traveling in order to pass obstacle 100 at a reduced distance.

[0174] In this case, the driver initially turns the steering wheel to the left by applying a positive steering wheel torque Cc, and then even before the motor vehicle 10 is flush with the obstacle 100, he or she turns the steering wheel to the right by applying a negative torque. Figure 13 This is shown by curve C13.

[0175] In this case, the AES system 20 calculates a positive torque (ie, swerving the vehicle to the left) as long as the vehicle is upstream of the obstacle 100. Figure 13 This is shown by curve C12.

[0176] Figure 12 Curve T10 shown in FIG. 1 shows the trajectory followed by the motor vehicle 10 when the motor vehicle 10 is controlled without interrupting the operation of the AES system 20 .

[0177] It will therefore be appreciated that without the present invention (ie, without the possibility of interrupting the operation of the AES system 20), the steering wheel torque and the torque generated by the AES system would initially have the same sign, then be opposite, which would give the driver a bad feeling.

[0178] Since the situation considered here is not dangerous, the driver's wishes will not be violated.

[0179] Then, by virtue of the present invention, the gain K1 is initially kept equal to unity and then becomes negative and falls below the threshold Cc. 3min (-2Nm), the gain will become zero. Therefore, the correction gain K1 rt The intermediate torque setpoint Ci will then gradually decrease until it is canceled (see Figure 13 This will allow the vehicle to pass the obstacle 100 at a reduced distance as desired by the driver (see Figure 12 The trajectory T9 shown in FIG.

[0180] Figure 14 and 15 The sixth specific case shown corresponds to a case where the driver wants to avoid the obstacle 100 to the right, and the avoidance trajectory T0 passes the obstacle 100 from the left.

[0181] In this case, for the driver himself, he or she turns the steering wheel to the right by applying a steering wheel torque Cc which is always negative and high. Figure 15This is shown by curve C17.

[0182] In this case, the AES system 20 calculates a positive torque (ie, to pull the vehicle to the left). Figure 15 This is shown by curve C15.

[0183] Figure 14 The curve T12 shown in FIG. 1 shows the trajectory that the motor vehicle 10 follows when the motor vehicle 10 is controlled without interrupting the operation of the AES system 20. As can be seen, the torque applied by the driver is high enough to offset the torque applied by the AES system. However, this feeling is still very unpleasant for the driver.

[0184] In such cases, it is therefore desirable to allow the driver to select which side he or she wants to avoid obstacle 100 from.

[0185] Then, by virtue of the present invention, the gain K1 is set equal to zero, so that the correction gain K1 rt The final torque setpoint Cr applied by the actuator 15 will then gradually decrease until it is canceled (see Figure 15 curve C16 in the figure), which will allow the vehicle to avoid obstacles on the right side as desired by the driver (see Figure 14 The trajectory T11 is shown in FIG.

[0186] exist Figures 16 to 18 In FIG. 1 , an example of a trend of a parameter over time is shown, thereby clearly illustrating the present invention.

[0187] exist Figure 17 , it can be seen that, by means of signal S1, the AES system is activated at time t0, which corresponds to the time when an obstacle 100 is detected close to the motor vehicle 10 on its initial trajectory. It can also be seen that, by means of signal S2, it is desired to suspend the operation of the AES system between times t2 and t4.

[0188] Figure 16 The following trends are shown:

[0189] - Preliminary steering angle set point δ c The trend,

[0190] - saturation steering angle setpoint δ s trends, and

[0191] -Measure the trend of the steering angle δ.

[0192] It can be seen that at the moment t0 when the obstacle is detected, the steering angle must be directly higher than the actually measured steering angle.

[0193] By making the initial steering angle set point δc Saturated controller, saturated steering angle set point δ s The rate of change of remains limited between times t0 and t1 so that no instability occurs.

[0194] Between the times t1 and t2, it is no longer necessary to change the preliminary steering angle setpoint δ in terms of magnitude or rate of change. c saturation, and therefore the saturation steering angle setpoint δ s will be equal to the preliminary steering angle set point.

[0195] At time t2, if Figure 18 As shown, the gain K1 is set to zero to disable operation of the AES system 20 .

[0196] Correction gain K1 rt It then decreases linearly to reach the value zero at time t3.

[0197] By means of the reset signals SA and SB, the initial steering angle setting point δ c While continuing to increase, the saturation steering angle set point δ s will remain constant between times t2 and t3.

[0198] At time t3 and until time t4, the saturated steering angle setpoint δ s Then it will remain equal to the measured steering angle δ. In this way, the intermediate torque setpoint Ci remains equal to zero, which will leave the driver alone with the steering control.

[0199] At time t4, if Figure 18 As shown, the gain K1 is set to unity to suspend the operation of the AES system 20 .

[0200] Correction gain K1 rt It then increases linearly to also reach the value one.

[0201] At time t4, the initial steering angle setting point δ is set by means of the reset signals SA and SB. c Then δ will become equal to the measured steering angle δ. The preliminary steering angle set point is then rapidly increased.

[0202] By making the initial steering angle set point δ c Saturated controller, saturated steering angle set point δ s The rate of change of remains limited in this case so that no instability occurs.

[0203] exist Figure 16 As can be seen in FIG, due to the torque still applied by the driver on the steering wheel 16, the measured steering angle δ does not correctly follow the saturation steering angle setpoint δ sIn fact, the trajectory followed is the result of the driver's torque and the AES request. If the driver actively expresses his or her own will on the steering wheel, he or she will then take back control.

[0204] The invention is in no way limited to the described and shown embodiments, but a person skilled in the art will be able to add thereto any variant according to the invention.

[0205] Therefore, the method will be applicable to other types of fields where specific trajectories must be followed, such as aeronautics or robotics.

Claims

1. A control method for an actuator (15) of a control system (18) for autonomously controlling an automobile device (10), the control method comprising the following steps: - determine the reference trajectory (T0), - determining the position of said device (10) relative to this reference trajectory (T0), - obtaining a parameter (Cc) related to the force applied by the driver to the manual control device (16) of the control system (18), - calculating, by means of a computer (13), a control set point (Cr) of said actuator (15), characterised in that said control set point (Cr) is calculated as a function of said parameter (Cc) and the position of said device (10) relative to said reference trajectory (T0), wherein the reference trajectory (T0) is determined so that the device (10) avoids an obstacle (100), and wherein, taking into account at least two areas of the environment of the device (10), the limits of the at least two areas being dependent on the position of the obstacle (100) and / or the position of the reference trajectory (T0) relative to the obstacle (100), the calculation of the control setpoint (Cr) is performed in the following manner: - by determining the area in which said device (10) is located, - by using an algorithm for calculating the control set point (Cr), the algorithm being selected according to the zone in which the device (10) is located, and Among other things, the computer considers four areas associated with four different calculation algorithms, namely: - a zone Z1 located upstream of the obstacle (100), between the reference trajectory (T0) and a protection line (L1), outside which any collision with the obstacle (100) will be avoided, - a zone Z2 flush with the obstacle (100) and situated downstream of the obstacle, between the reference trajectory (T0) and the protection line (L1), - a zone Z3 situated upstream of the obstacle (100) on the opposite side of the reference trajectory (T0) from the protection line (L1), and - a zone Z4, a portion of which is located upstream of the obstacle (100) and on the side of the protection line (L1) opposite to the reference trajectory (T0), and another portion of which is flush with the obstacle (100) and located downstream of the obstacle and on the side of the reference trajectory (T0) opposite to the protection line (L1).

2. The control method according to claim 1, wherein: The device (10) is a motor vehicle suitable for traveling on a road and comprising at least one drive wheel (11), wherein the manual control device (16) is a steering wheel, wherein the control system (18) allows each drive wheel (11) to be steered, and wherein the parameter (Cc) is related to the torque (Cc) applied to the steering wheel by the driver of the motor vehicle.

3. The control method according to claim 1, wherein: Provision is made to determine an indicator (K1) whose value depends on the zone in which the device (10) is located and on the parameter (Cc), wherein provision is made to generate a preliminary control set point (Ca) for the actuator (15) which makes it possible to bring the device (10) to the reference trajectory (T0), and wherein provision is made to correct the preliminary control set point (Ca) as a function of the value of the indicator (K1).

4. The control method according to claim 3, wherein: The indicator (K1) is adapted to take only one or the other of two values, wherein provision is made for determining a correction indicator (K1) that varies continuously between the two values ​​based on the indicator (K1). rt ), and wherein, by multiplying the value of the preliminary control set point (Ca) by the correction index (K1 rt ) value to correct the preliminary control set point.

5. The control method according to claim 4, wherein: The device (10) is suitable for a motor vehicle traveling on a road, when the correction index (K1 rt ) changes, determining the correction index (K1) according to the speed of the motor vehicle and the curvature radius of the road rt ) at a rate of change such that the lateral acceleration of the motor vehicle does not exceed a determined threshold value.

6. The control method according to claim 5, wherein: The preliminary control set point (Ca) is obtained from the steering angle set point (δ c ), the steering angle set point itself being calculated based on the position of the device (10) relative to the reference trajectory (T0) and filtered through a controller that satisfies a set point amplitude limitation model and a set point variation limitation model.

7. The control method according to any one of claims 1 to 6, wherein: When the device (10) moves from the first area to the second area, the computer (13) continues to use the algorithm associated with the first area as long as the device has not yet exceeded the hysteresis trajectory (T01, T02) determined based on the reference trajectory (T0).

8. An automotive device (10) comprising at least one actuator adapted to influence the trajectory of the device (10) and a computer (13) for controlling the actuator, characterized in that The computer (13) is programmed to implement the method according to one of the preceding claims.

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