FR2987588B1 - METHOD FOR AVOIDING OR MITIGATING THE CONSEQUENCES OF A COLLISION OF A VEHICLE WITH AN OBSTACLE IN THE SIDE AREA CLOSE TO THE VEHICLE AND DRIVING ASSISTANCE SYSTEM USING THE SAME - Google Patents

Abstract

Method for preventing a collision between a vehicle and an obstacle in the lateral zone close to the vehicle or for mitigating the consequences of a collision of the vehicle with an obstacle in the lateral zone close to the vehicle consisting in: - grasping an obstacle in the lateral zone close to the vehicle, - determine the traffic lane of the vehicle, - determine a risk of collision using the vehicle's taxiway and the position of the obstacle or the position and movement of the obstacle, and - adjust a steering angle of the rear wheels of the vehicle according to a collision risk determined to avoid the obstacle.

Description

Field of the invention

The present invention relates to a method for preventing collisions between a vehicle and an obstacle in the lateral zone close to the vehicle or for mitigating the consequences of a collision of a vehicle with an obstacle in the lateral zone close to the vehicle. The invention also relates to a driving assistance system for preventing the collision of a vehicle with an obstacle in the lateral zone close to the vehicle or for mitigating the consequences of a collision of the vehicle with an obstacle in the near lateral zone. of the vehicle.

State of the art

DE 10 2008 061359 A1 discloses a vehicle environment monitoring system which detects a fixed obstacle at the edge of the taxiway. This installation continuously detects the position of the obstacle seized and an operating installation determines the risk of collision between the vehicle and the obstacle. If a risk of collision between the vehicle and the obstacle is detected, a warning signal is issued to the driver of the vehicle which, if necessary, acts on the brake or on the steering.

EP 1 447 271 A2 describes a device for monitoring the area close to a vehicle to avoid collision with obstacles. A computing unit determines a traffic lane for the vehicle based on the detected steering angle and other body information. To avoid a risk of collision, an actuator automatically changes the steering or brakes the vehicle automatically.

Known devices use rear wheel steering which consists of variably adjusting the transmission ratio between the steering wheel angle and the steering angle. As the front wheels are guided in an angular range of 30 °, the concern from the point of view of safety is that for example a defect in the program can set a deviation steering angle very important that the driver can not, the if necessary, no longer avoid.

Description and advantages of the invention

The present invention relates to a method for preventing collisions between a vehicle and an obstacle in the lateral zone close to the vehicle or for mitigating the consequences of a collision of a vehicle with an obstacle in the near lateral zone of the vehicle comprising the vehicles. following steps: - picking up an obstacle in the lateral area close to the vehicle, - determining the vehicle's taxiway, - determining a collision risk using the vehicle's taxiway and the position of the obstacle or the position and movement of the obstacle, and - adjust a steering angle of the rear wheels of the vehicle according to a collision risk determined so as to avoid the obstacle.

By acting on the rear wheels with a steering torque, the rear of the vehicle is moved away from the obstacle. The steering angle of the rear wheels of the vehicle is preferably adjusted to escape the obstacle. This may, for example, consist of turning the rear wheels as far as possible until after passing the obstacle.

In a particularly preferred manner, the obstacle is evaded by a relatively reduced steering action. According to preferred embodiments of the invention, calculations are made to optimize the steering or steering angle of the rear wheels of the vehicle and which control them. The optimum steering angle of the rear wheels of the vehicle must be as small as possible and the steering torque applied to the rear wheels must avoid the collision between the vehicle and the obstacle or mitigate the consequences of a collision. Preferably, for an optimum steering angle of the rear wheels of the vehicle, the obstacle is passed at a defined distance for example from 5 cm to 50 cm and in particular from 10 cm to 20 cm.

According to a particularly advantageous characteristic, the distance to the obstacle or the distance to the obstacle and the relative speed of the obstacle relative to the vehicle are detected periodically, for example, at intervals of between 1 ms and 1 s in particular between 10 ms and 100 ms for example using ultrasonic sensors and the steering angle of the rear wheels of the vehicle will be adjusted according to the distance to the obstacle or the distance to the obstacle and the relative speed of the obstacle relative to the vehicle. The regulation of the steering angle is particularly advantageous if the obstacle moves itself. In this case, too, it is possible to pass the vehicle at a defined distance for example from 5 cm to 50 cm including 10 cm to 20 cm in front of the obstacle.

The distance to the obstacle or the distance to the obstacle and the relative speed of the obstacle relative to the vehicle are detected periodically, for example at intervals of 1 ms and / 1 s and in particular between 10 ms and 100 ms, by example, using ultrasonic sensors and the steering angle of the rear wheels of the vehicle is adjusted according to the distance to the obstacle or the distance to the obstacle and the relative speed of the obstacle by relative to the vehicle. The regulation of the steering angle is particularly advantageous if the obstacle, itself, moves. In this case, too, it is possible to navigate the vehicle at a defined distance for example from 5 cm to 50 cm and in particular from 10 to 20 cm in front of the obstacle.

If the obstacle can not be bypassed and the collision with the obstacle is unavoidable, according to the invention, the steering angle of the rear wheels of the vehicle is adjusted so that the time until the collision, that is to say the TTC time is maximum, allowing the driver to react again in time. Alternatively or in addition, it is proposed to navigate the vehicle so that the collision of the vehicle with the obstacle occurs in a target meeting area of the vehicle that is to say, so that the collision is made to a vehicle. the side of the vehicle where the bodywork repair will be relatively advantageous and preferably in the door area, that is to say the passenger door or by avoiding components of the body such as for example, the column A, column B, column C or column D. The target meeting area may be, for example, an area at a side door and in addition, from the point of view of safety, it is provided a border, that is to say a distance of a centimeter from the outer contour of the side door.

The method, according to some embodiments, includes the state of determining the speed of the vehicle. It can thus be provided that the control of the rear wheels of the vehicle is done only below a defined speed, for example below 20 km / h and preferably below 10 km / h and particularly preferential below 6 km / h. For higher speeds, it will be possible to perform maneuvers for the safety of people in the vicinity or for the driver, which is to be avoided. In addition, it is provided that the adjustable steering angle of the rear wheels for the exhaust maneuver is limited to a maximum value including a maximum of 3 ° - 10 ° or 3 ° to 5 °.

According to another characteristic, the subject of the invention is a computer program implementing the method as described above when the program is executed by a programmable computer. The computer program is for example a module powered by a driver assistance system or a subsystem on the vehicle or an application for driving assistance functions performed by a telephone. The computer program can be stored on a machine visible memory medium or on a permanent or rewritable memory medium or associated with a computer installation or on a CR-DOM, DVD or USB stick. In addition or alternatively, the computer program is provided to a computer installation by downloading from a server, for example from a data transmission network such as the Internet or a communication link such as a telephone line or a wireless link.

In addition, the subject of the invention is a driving assistance system for preventing collisions of a vehicle with an obstacle in the lateral zone close to the vehicle or for mitigating the consequences of a collision of the vehicle with an obstacle in the vehicle. lateral zone close to the vehicle comprising: - sensors for capturing the environment to enter the lateral zone close to the vehicle, - an obstacle capture module for capturing an obstacle on the basis of the data entered by the data entry sensors. environment, - a model for determining a traffic lane for a vehicle, - a module for determining a risk of collision of the vehicle with the obstacle using the vehicle's taxiway and the position of the obstacle, or using the vehicle traffic lane and the position and movement of the obstacle, - a module for calculating optimum steering angles, - and a module for controlling a d rear wheel irection by determining the risk of collision of the vehicle with the obstacle.

The driver assistance system performs the method described above. In principle, this system is combined with other driver assistance systems such as collision avoidance assistants, parking assistants, lane assist assistants or backup assistants. In particular, integration with existing SDW systems (lateral distance warning system) or FKP systems (sidewall protection system) can be envisaged to warn the driver of obstacles on the side of the vehicle. These systems are easily complemented by program modifications with the functions according to the invention.

The driving assistance system may furthermore apply to an existing technique for the active guidance of the rear wheels. Preferably, the driver assistance system uses the control module fitted to the vehicle and provides active guidance of the rear wheels.

Rear wheel control is preferably via a CAN bus or a Flexray bus.

The steering of the rear wheels as proposed according to the invention makes it possible to escape an obstacle or to fix the location of the collision between the vehicle and the obstacle to minimize the possible costs of repairing the vehicle. A faulty operation of the system causes, on the other hand, that the safety of the driver of the vehicle and other passengers is uncontrollably deteriorated.

drawings

The present invention will be described hereinafter in more detail with the aid of an example of a method for preventing collisions of a vehicle with an obstacle, shown in the accompanying drawings, in which: FIG. case of a vehicle and an obstacle in the lateral zone close to the vehicle, the assembly being represented in plan view, - Figure 2 shows the case of Figure 1 showing the vehicle at two different times, - the figure 3 shows the case of FIG. 1 with the vehicle at two different times and the execution of a driving maneuver according to the invention; FIG. 4 is a diagram of the functional components of a driving assistance system according to the invention equipping a vehicle, - Figure 5 is a flow chart showing parts of the method of the invention.

Description of Embodiments of the Invention

FIG. 1 shows the case of a vehicle 1 and an obstacle 2 in the lateral zone close to the vehicle 1. During the forward movement 3 of the vehicle 1 with respect to the obstacle 2, sensors for detecting the environment 4, for example optical sensors, ultrasonic sensors, radar sensors, lidar sensors or laser sensors, detect the obstacle 2 and an SDW system 5 (lateral deviation warning system 3) determines the distance 18 to the obstacle and, if applicable, the speed thereof for the steering angle set, the front wheels 6 of the vehicle and the relative speed of the vehicle 1 with respect to the obstacle 2 by checking the situation by relation to obstacle 2 with respect to the risk of collision. Some SDW systems define the position of the obstacle 2 while continuing even when the obstacle 2 is no longer in the gripping area 7 of the sensor 4 as shown. For this, the SDW control unit 5 exploits for example, the steering angle set to front wheels 6 and stroke sensors. In the example shown, the front wheels 6 are turned to the right. The vehicle 1 thus circulates in a curve and the system 5 recognizes that there is a risk of collision with the obstacle 2 previously detected.

FIG. 2 shows the case where the vehicle 1 is furthermore represented at the moment of collision with the obstacle 2. A first position 8 of the vehicle 1 corresponds to that described with reference to FIG. 1. The second position 9 of the vehicle 1 corresponds to the moment of collision with obstacle 2. It was calculated by a collision monitoring module using data from a traffic corridor determination module and the position of the vehicle. obstacle or the position and speed of the obstacle as will be detailed next with the aid of Figure 4. The module to determine a traffic corridor calculates with the help of the position 8, speed and α and β steering angles set for the front wheels 6 and the rear wheels 14 of the vehicle 1, a traffic lane 10 for the vehicle 1, namely the swept surface at a time defined by the vehicle 1. It is shown, for this, for example, the trajectories 11a, 11b of the front corners 12a, 12b of the vehicle 1 and the trajectories 13a, 13b of the rear wheels 14a, 14b of the vehicle 1. The moment of the collision is that at which the obstacle 2 is at a moment in the corridor In addition, as far as possible from the received signals, the movement 15 is extrapolated from the detected obstacle 2 and a potential trajectory is determined. The instant of the collision can also be defined if it is predicted on the basis of the potential trajectory of the obstacle 2 that it is, in the future, in the calculated circulation lane 10 of the vehicle 1.

Figure 3 shows the case of Figure 1 for the vehicle 1 having the functional components of the driving assistance system of the invention to apply the method of the invention to avoid collisions or mitigate the consequences of collisions. Figure 3 shows the case of Figure 1, the vehicle 1 being further shown at a later time. A first position 8 of the vehicle 1 corresponds to that which has been described with reference to FIG. 1. The second position 9 'of the vehicle 1 has been represented at the instant corresponding to that of the second position 9 described in connection with FIG. Figure 2. The collision with obstacle 2 did not occur. As described in particular with reference to Figure 4, a collision monitoring module triggers a module to determine the risk of collision and the latter calculates the steering angle β of the rear wheels 14 to avoid the collision.

Vehicle 1 performs a bypass operation as shown. The rear wheels 14 are for that purpose steered so that the rear 22 of the vehicle deviates from the obstacle 2. The rotation point 17 of the vehicle for the steering maneuver with the steering of the rear wheels, and where appropriate with the front wheels, is moved only by the steering of the front wheels relative to the point of rotation 16 of the vehicle. As a result, the vehicle 1 bypasses the obstacle 2 at a distance 23.

The collision (contact) ranges 20, 21 are defined on the lateral flank 19 of the vehicle 1 and comprise, for example, here a first target meeting zone 20 at the front side door and a second target collision zone 21. at the rear side door of the vehicle 1.

If the system finds that a collision with the obstacle 1 is inevitable, it can calculate the steering angle β of the rear wheels 14 to direct the collision between the vehicle 1 at the target collision zones 20, 21. Alternatively or in addition, the system can calculate the time to the collision (time TTC) for different steering angles β of the rear wheels 14 and define the angle or angles β which give a maximum time until the collision. This gives the driver the ability to escape obstacle 2 or stop the vehicle before the collision.

Figure 4 is a diagram of the functional components of the driver assistance system for implementing the method of the invention.

The driving assistance system comprises environmental detection sensors 4, optical sensor systems for example a mono or stereo video camera and / or ultrasonic sensors, radar sensors, laser sensors and / or sensors. Lidar sensors. The signals of the environmental sensors 4 are received by a receiver circuit 40. The receiver circuit 40 is connected to a bus system 41, for example a CAN bus or a Flexray bus for data exchange with an installation 42. The capture sensors of the environment 4 make it possible to capture at least the lateral zone close to a vehicle. The data processing installation 42 comprises an obstacle capture module 43 which receives and processes the signals of the environmental detection sensors 4. The environment capture module 43 makes it possible to determine the position and preferably , also, the speed of the obstacle. From the position and the speed of the obstacle, the trajectory of the obstacle used to determine the risk of collision is determined. The data processing facility further comprises a module 44 for determining a traffic corridor of the vehicle. The module 44 for determining the traffic corridor of the vehicle processes the vehicle data, in particular the settings of the steering angle of the front wheels and the rear wheels, the current speed of the vehicle, the odometer data, the GPS data, the data. the vehicle model such as the width and / or length of the bodywork, the width of the axle, the distance and / or spacing of the wheels, the position and the position of the lateral sides of the vehicle. In general, the data is available on the CAN bus and / or the Flexray bus or in higher level protocols. The module 44 for determining the circulation corridor of the vehicle thus calculates in particular the location and position of the vehicle at future times. The data processing installation 42 furthermore comprises a collision monitoring module 45. The collision monitoring module 45 receives the data from the module 44 to determine the traffic corridor of the vehicle and the data of the obstacle capture module. 43 providing the collision monitoring module 45 information relating to the position of the obstacle including the distance of the obstacle relative to the vehicle at given times. The collision monitoring module 45 includes a TTC module that calculates the TTC time until the future collision with the obstacle. The collision monitoring module 45 may be coupled to other modules not shown and which make it possible to warn the driver and / or modules which produce an automatic braking of the vehicle and / or modules which modify the steering angle of the vehicles. front wheels of the vehicle to avoid collision with the obstacle. The data processing installation 42 further includes a module 46 for determining a risk of collision. The module 46 for determining the risk of collision is triggered by the collision monitoring module 45. As soon as a potential collision is detected by the collision monitoring module 45, the module 46 will become active to determine the risk of collision. It exchanges data with the module 44 to determine the traffic corridor of the vehicle and with the obstacle capture module 43 which provides the module 46 determining the risk of collision, the information relating to the position and the speed of the vehicle. obstacle including the distance of the obstacle relative to the vehicle at specific times. The module 46 for determining the risk of collision has the function of calculating for different steering angles of the rear wheels, if a collision will occur with the obstacle and / or at which location the vehicle will encounter the obstacle. For the calculations, there are particular indications with respect to the steering angle of the rear wheels given to the module 44 to calculate the traffic corridor. An algorithm makes it possible to calculate the optimum steering angle of the rear axle under accessory conditions such as the target collision ranges and the maximum time TTC, as will be described in more detail with reference to the flow chart of the figure. 5. The collision risk determining module 46 may provide output values for further processing for different rear wheel steering angles which further include information as to whether or not a collision will occur and in addition the time TTC and the point of impact on the vehicle. The data processing installation further comprises a module 47 for adjusting the steering angle of the rear wheels of the vehicle. The module 47 for adjusting the steering angle of the rear wheels of the vehicle notably receives the data from the module 46 to determine the risk of collision. With these data, the module 47 for adjusting the steering angle of the rear wheels controls the rear wheels and in response to the risk of collision, it sets the optimum steering angle of the rear wheels. The module 47 for adjusting the steering angle of the rear wheels controls via a data bus of the CAN bus or the Flexray bus.

The modules can in particular be managed so that a regulation of the control of the rear wheels is done according to the current distance to the obstacle and the set distance, which is interesting in the case of mobile obstacle. Direct communication of the obstacle detection module with the collision risk determination module is an advantageous communication.

Figure 5 shows a flow chart showing parts of the method of the invention with the steps performed in particular by the module determining the risk of collision. The process begins with step SO at which the obstacle is detected in the near lateral area of the vehicle.

According to a first step S1, the steering angle of the rear wheels is initialized. The steering angle preferably initialises the maximum possible or maximum steering angle allowed for example 10 °, 5 ° or 3 °. In a second step S2, the predictable circulation corridor is calculated. In a third step S3, the trajectory of the obstacle is checked. In a fourth step S4, it is calculated whether a collision with the obstacle is announced. In the fourth step S4, depending on the result, it is calculated, preferably when and where the vehicle will occur the collision or how far it will pass the obstacle.

If in the fourth step S4, we have not calculated a collision and if the distance to the obstacle is large enough for the passage, we better define the angle at that moment. In a fifth step S5, a failure criterion is verified. The failure criterion can be defined, for example, using the angle if sufficient accuracy is obtained. Alternatively or additionally, one can also consider whether it is worthwhile to treat immediately.

If, however, in the fourth step S4, it is found that for the calculated angle, there is a risk of collision and that the passage distance in front of the obstacle is too low, then the calculated time is fixed until the collision and the point of impact to the vehicle to have the best values at that moment. In the second step S5, the breaking criterion is checked if the TTC time is maximum and if a target impact zone has been determined.

If the breaking criterion in the fifth step S5 is filled, then the output of the method in the sixth step S6 in the event of a collision is the angle by which the rear wheels are steered, for which the time to the collision is maximum and the collision occurs in the target meeting area; in the case where there is no collision, the angle provided is that by which the rear wheels are actuated and which avoids the collision with a minimum steering action.

In another step S7, the adjustment module of the steering angle of the rear wheels of the vehicle adjusts this steering angle to avoid the obstacle.

If the breaking criterion of the fifth step S5 is not fulfilled, then in an eighth step S8 a new angle is applied by which the process is performed again from the second step, i.e. Your procedure is iteration. The method may continue to nest, interval or successive scanning of the angle with equidistant steps.

In the event of a collision, it is preferable to predict the interlocking of the intervals and in the case of a non-collision, it is preferable to scan the possible angles with equidistant steps in the latter case, since in the latter case a minimum must be found for the collision. weather TTC. In the case of nesting the intervals, divide the initial angle by two and calculate with the half angle. If, moreover, no collision is detected and the distance to the obstacle at the passage is sufficiently large, then one takes half of the best angle. If, however, the risk of collision exists, then the other interval is set. Then, the calculation is again carried out with a value of the angle which reduces the interval by half and iterations are carried out until the rupture criterion is fulfilled.

NOMENCLATURE 1 Vehicle 2 Obstacle 3 Passage in front of the obstacle 4 Sensors for environmental detection

5 SDW system 6 Front wheel 7 Sensor input area 4 8 First vehicle position 9 Second vehicle position 10 Traffic lane 11a, 11b Front corner trajectory 12a, 12b Front corners of the vehicle 13a, 13b Rear wheel path 14a , 14b Vehicle rear wheels 16 Vehicle rotation point 17 Vehicle rotation point 18 Distance 19 Side 20/21 Target impact area 22 Vehicle rear 23 Distance 40 Input circuit 41 Bus system 42 Processing plant 43 Obstacle detection module 44 Module for determining a traffic corridor 45 Collision monitoring module 46 Module for determining the risk of collision 47 Module for adjusting the steering angle of the rear wheels

Claims (2)

1) Method for avoiding a collision between a vehicle (1) and an obstacle (2) in the lateral zone close to the vehicle (1) or for mitigating the consequences of a collision of the vehicle (1) with an obstacle (2) ) in the lateral zone close to the vehicle (1) comprising the following steps: grasping (SO) an obstacle (2) in the lateral zone close to the vehicle (IL - determining (S2) the circulation corridor (10) of the vehicle (1), - determining (S4) a risk of collision using the traffic lane (10) of the vehicle (1) and the position of the obstacle (2) or the position and movement of the vehicle. obstacle (2), and - adjusting (S7) a steering angle (β) of the rear wheels (14) of the vehicle (1) according to a determined risk of collision, so as to avoid the obstacle (2), characterized in that an optimum steering angle (β) is determined for the rear wheels (14) of the motor vehicle (1) n that the vehicle navigates passing a defined distance for example from 5 cm to 50 cm and in particular from 10 cm to 20 cm in front of the obstacle. Method according to Claim 1, characterized in that the distance (18) between the vehicle (1) and the obstacle (2) is periodically recorded, for example at intervals of 1 and 1 s, in particular intervals. between 10 ms and 100 ms and adjusting the steering angle (β) of the rear wheels (14) of the vehicle (1), 3 °) Method according to claim 1, characterized in that the steering angle is adjusted (β) the rear wheels (14) of the vehicle (1) so that the time to the collision is maximum if a collision with the obstacle (2) can not be avoided. Method according to Claim 1, characterized in that the steering angle (β) of the rear wheels (14) of the vehicle (1) is set so that the collision of the vehicle (1) with the obstacle ( 2) is made in a set meeting range (20, 21) on the vehicle (1) if the collision with the obstacle (2) is unavoidable. Method according to Claim 1, characterized in that the rear wheels (14) of the vehicle (1) are controlled only below a defined speed, in particular below 20 km / h, preferably below 10 km / h. km / h and particularly preferably below 6 km / h. 6 °) A method according to claim 1, characterized in that the adjustable steering angle (β) of the rear wheels (14) is at most between 3 ° and 10 ° or between 3 ° and 5 °. 7) Method according to claim 1, characterized in that the control of the rear wheels (14) of the vehicle (1) is via a CAN bus or a Flexray bus. 8 °) computer program for implementing a method according to any one of claims 1 to 7, when the computer program is executed by a programmable computer. 9 °) Driving assistance system for preventing collisions of a vehicle (1) with an obstacle (2) in the lateral zone close to the vehicle (1) or for mitigating the consequences of a collision of the vehicle (1) with an obstacle (2) in the lateral zone close to the vehicle (1) comprising: - sensors for capturing the environment (4) to enter the lateral zone close to the vehicle (1), - an obstacle capture module (43) for gripping an obstacle (2) on the basis of the data inputted by the environmental sensors (4), - a model (44) for determining a traffic corridor (10) for a vehicle (1) a module (46) for determining a risk of collision of the vehicle (1) with the obstacle (2) by means of the traffic corridor (10) of the vehicle (1) and the position of the obstacle or using the traffic corridor (10) of the vehicle (1) and the position and movement of the obstacle (2), - a module for calculating angles steering wheel, ~ and a module (47) for controlling a rear wheel direction by determining the risk of collision of the vehicle (1) with the obstacle (2), characterized in that a steering angle is determined ( β) optimum for the rear wheels (14) of the motor vehicle (1) so that the vehicle navigates passing a defined distance, for example from 5 cm to 50 cm and in particular from 10 cm to 20 cm in front of the obstacle.