Braking management method, on-board driving assistance system and motor vehicle comprising this system and implementing this method

Abstract

Method for managing braking, on-board driving assistance system and motor vehicle comprising this system and implementing this method The invention relates to a method for managing the braking of a motor vehicle (EGO) comprising an emergency braking system (AEB) and an adaptive cruise control system (ACC), mutually independent, the effective triggering of emergency braking being subject to the verification of determined criteria and to the application of one or more reliability strategies. This method is characterized in that it consists, in the event of the occurrence of a dangerous situation detected by the emergency braking system (AEB), in exploiting information produced by the adaptive cruise control system (ACC) in order, where appropriate, to modify or ignore certain limiting criteria and / or to inhibit at least partially certain reliability strategies, controlling the effective triggering of emergency braking.Figure to be published with the abstract: Fig. 1.

Description

Title of the invention: Braking management method, on-board driving assistance system and motor vehicle comprising this system and implementing this method

[0001] The present invention relates to the field of assistance with driving a motor vehicle, and more specifically assistance with braking, and relates to a braking management method, an on-board driving assistance system and a motor vehicle comprising such a system and implementing such a method.

[0002] Currently, almost all motor vehicles include, in particular for regulatory reasons, driving assistance systems, including in particular an emergency braking system / application.

[0003] The invention finds its application more particularly in the context of a motor vehicle implementing a method for managing the braking of a motor vehicle comprising an emergency braking system (AEB) and a comfort system of the adaptive cruise control system (ACC) type, mutually independent, as well as means for detecting and evaluating the environment of the vehicle and the current situation of the latter, on the one hand, and means for determining the trajectory and controlling the movement of the vehicle, on the other hand, these means collaborating with the two aforementioned systems for the selective performance of their respective functions, the effective triggering of emergency braking being subject to the verification of determined criteria and to the application of one or more reliability strategies.In this context, the two AEB and ACC systems may be developed by different entities, and if so, may not be able to communicate with each other at all and therefore be designed to operate separately and be able to integrate into a modular software architecture.

[0004] Emergency braking systems called "Autonomous Emergency Braking" (AEB), in their main action, brake the EGO vehicle concerned to maximum braking when a potential collision is detected. The maximum braking of the vehicle depends on the road conditions / slope / mass, but the order of magnitude is -10m / s2.

[0005] Emergency braking therefore corresponds to a very strong, even brutal action (for example, a vehicle at 90 km / h takes 2.5 seconds to come to a complete stop): it is therefore fundamental not to do it inappropriately, which is called a false positive. This is justified for at least three reasons: 1) this braking can cause a rear-end accident; 2) the driver's confidence will be greatly reduced if such strong braking is triggered without a valid reason; 3) the impact on the occupants can be traumatic, even damaging (flying objects).

[0006] For this reason, different reliability strategies are generally implemented, such as:

[0007] Strategy 1: A set of physical quantities is analyzed to trigger emergency braking, namely for example: 1. Time before collision. 2. The distance to the target. 3. The lateral position of the EGO vehicle relative to the target at the current time (corridor at the current time). 4. The lateral position of the EGO vehicle relative to the predicted impact target (impact corridor).

[0008] Strategy 2: Implementation of different levels of parameterization depending on the situation. Thus, emergency braking can be delayed if it is estimated that the driver is active during the dangerous situation, or even the function can be put on hold if the driver is controlling the vehicle.

[0009] Strategy 3: A required braking haptic signal can be generated and emitted to indicate to the driver that the situation is at risk.

[0010] The purpose of these strategies is in particular to ensure that it is a real target detection on which the EGO vehicle must brake. However, these reliability strategies in certain situations lead to a mitigation of the accident rather than an avoidance.

[0011] Generally speaking, the invention seeks to improve the overall performance of an emergency braking application (AEB type system). When a comfort braking application is also embedded in the vehicle (ACC type system - adaptive cruise control system), better performance / robustness must be able to be achieved. These improvements must be obtained without there being two-way communication between the two applications / systems: the modularity of the general architecture of the driving assistance system will then be respected.

[0012] However, today, a "grey area" exists between these two functions: in fact, in certain situations, if the comfort or regulation system engaged (which is limited in braking intensity by design - ISO 22179 standard) is not able to brake the vehicle sufficiently, the AEB only provides mitigation, which is not acceptable.

[0013] Solutions already exist to improve the robustness of AEB, but they are either complex, and require for example the use of 1TA, or require communication between vehicles (for example information of the type "imminent braking" or "danger detected" coming from the vehicle in front).

[0014] The aim of the invention therefore consists, more precisely, in seeking to improve the continuity of intervention between these two systems when they are both present and more generally to improve the robustness of the emergency braking system, in a simple manner and without the need for communication between them, nor between the vehicles.

[0015] To this end, the invention has as its first and main object a method for managing the braking of a motor vehicle comprising an emergency braking system and an adaptive speed regulation system, mutually independent, as well as means for detecting and evaluating the environment of the vehicle and the current situation of the latter, on the one hand, and means for determining the trajectory and controlling the movement of the vehicle, on the other hand, these means collaborating with the two aforementioned systems for the selective realization of their respective functions, the effective triggering of emergency braking being subject to the verification of determined criteria and to the application of one or more reliability strategies,

[0016] method characterized in that it consists, in the event of occurrence of a dangerous situation detected by the emergency braking system,to exploit information produced by the adaptive cruise control system in order, where appropriate, to modify or ignore certain limiting criteria and / or at least partially inhibit certain reliability strategies, controlling the effective triggering of emergency braking.

[0017] It also relates to an on-board driving assistance system for a vehicle for implementing this method and a vehicle comprising this system.

[0018] The invention will be better understood from the following description, which relates to a preferred embodiment, given as a non-limiting example, and explained with reference to the appended schematic drawings, in which:

[0019] [Fig.l] schematically and simplifiedly represents an architecture of a driving assistance system for a motor vehicle, and,

[0020] [Fig.2] represents a flowchart corresponding to an example of a process decision-making that can be followed by the method according to the invention.

[0021] According to a first aspect, the invention relates to a method for managing the braking of a motor vehicle (EGO) comprising an emergency braking system (AEB) and an adaptive cruise control system (ACC), mutually independent, as well as means (A, WM, SU) for detecting and evaluating the environment of the vehicle and the current situation of the latter, on the one hand, and means (PP, TMC, A) for determining the trajectory and controlling the movement of the vehicle, on the other hand, these means collaborating with the two aforementioned systems (AEB and ACC) for the selective performance of their respective functions, the effective triggering of emergency braking being subject to the verification of determined criteria and to the application of one or more reliability strategies.

[0022] According to the invention, this method consists in the event of occurrence of a situation of danger detected by the emergency braking system (AEB), to use information produced by the adaptive cruise control system (ACC) to, where appropriate, modify or ignore certain limiting criteria and / or at least partially inhibit certain reliability strategies, controlling the effective triggering of emergency braking.

[0023] Thus, thanks to the aforementioned provisions of the invention, it is possible to take advantage of information provided by the system (ACC) to adapt or alter the operation of the system (AEB), so as to avoid false positives in terms of emergency braking (improving reliability and robustness), but also constrained mitigation situations (it is necessary to prevent emergency braking from intervening too late in the event of an actual danger situation). The invention also improves the continuity of intervention between these two systems, without the need for communication between them. The set goal is therefore achieved in a simple manner, without implementing specific sophisticated software means (AI type) and without the need for additional resources compared to those usually forming part of a driving assistance system.

[0024] In accordance with an advantageous characteristic of the invention, the information used corresponds to information relating to a target (ID) continuously detected by the adaptive cruise control system (ACC) for at least a predetermined minimum duration and at the origin of a situation of imminent potential collision, or similar danger, with the vehicle (EGO).

[0025] Preferably, the target (ID) corresponds to a vehicle preceding the vehicle (EGO) for at least a predetermined minimum duration and currently followed by the latter. The aforementioned minimum duration is several seconds, for example 5.

[0026] According to a first variant embodiment, the method consists of inhibiting a function for delaying or waiting for the triggering of emergency braking normally active when the driver is considered to be active or in control of the vehicle (EGO).

[0027] According to a second variant embodiment, the method consists of ignoring the criterion of distance to the target (ID) of the vehicle (EGO).

[0028] According to a third variant embodiment, the method consists of modifying at least one of the criterion of lateral position of the vehicle (EGO) relative to the target (ID) at the current time and the criterion of lateral position of the vehicle (EGO) relative to the target (ID) at the predicted impact, by widening the respectively corresponding corridor.

[0029] The invention may also provide for cumulatively implementing two of the three aforementioned variants, or even all three.

[0030] According to a preferred embodiment of the invention, in relation to the architecture shown in [Fig.l], it is provided that the exploitation of the information produced by the adaptive cruise control system (ACC) to act on the emergency braking system (AEB) if necessary, with a view to modifying or ignoring certain criteria and / or inhibiting at least partially certain reliability strategies controlling the effective triggering of emergency braking, is carried out by trajectory planner software (PP), to which the two systems (ACC and AEB) transmit their respective requests and which is part of the means (PP, TMC, A) for determining the trajectory and controlling the movement of the vehicle (EGO). This software is advantageously adapted to also arbitrate and apply the modifications and inhibitions to the system (AEB).

[0031] In the context of the arbitration of the possible application or not of an alteration or adaptation of the application of emergency braking, the method according to the invention can consist of implementing, in relation to constant monitoring by the emergency braking system (AEB) and in the event of a positive determination of a situation requiring emergency braking (dangerous situation), a decision-making process comprising the following steps:

[0032] - a) verification of the existence of a target tracking (ID) by the adaptive re cruise control (ACC) for at least a predetermined minimum duration, for example 5 seconds,

[0033] - if not for a): then operation and action of the braking system not altered emergency (AEB)

[0034] - if yes for a): then b) check if the target (ID) followed corresponds to the target causing the situation requiring emergency braking

[0035] - if not for b): then operation and action of the braking system not altered emergency (AEB)

[0036] - if yes for b): then adapted operation and action of the braking system emergency braking (AEB), with modification or not taking into account certain limiting criteria and / or at least partial inhibition of certain reliability strategies controlling the effective triggering of emergency braking.

[0037] [Fig.2] illustrates in the form of a flowchart a possible implementation of this decision-making process.

[0038] In relation to this figure, and as an example of implementation, it is understood that the trajectory planner (PP) software has arbitrated a target tracking constraint following a request from the application of the adaptive cruise control (ACC) system taking into account the vehicle situation information transmitted to this application. This target is identified through a precise identifier (ID) and different information concerning it is transmitted to the planner (PP) software: distance and relative speed, as well as the acceleration of the target.

[0039] The trajectory planner (PP) software generates a speed trajectory compatible with this situation. Comfort maneuvers are limited in dynamics to approximately ± 3.5 m / s2. If the target (ID) stops very abruptly (either very hard braking or an accident), the adaptive cruise control system (ACC) will potentially not be able to avoid a collision with its own deceleration constraints.

[0040] When this strong deceleration of the target (ID) is detected, the emergency braking application (AEB) is activated to request a braking order at -10 m / s2.

[0041] Given the mechanisms explained above and in the absence of the invention, emergency braking would potentially begin late, because it would first be necessary to confirm that it is a real target.

[0042] The invention proposes to use the information coming back from the trajectory planner (PP) software (therefore the information provided by the ACC system), which amounts to coupling the two systems (AEB and ACC). In other words: if we follow a target with a precise ID for a certain period of time (for example 5 seconds), we are sure that it is a real detection and we do not need confirmation.

[0043] Furthermore, by further applying at least one of the three variants mentioned above, and preferably all three simultaneously, the triggering of the emergency braking is even faster and makes it possible to maximize the possibilities of avoiding the impact.

[0044] The invention also relates, as illustrated schematically in [Fig.l], to an on-board driving assistance system for a vehicle comprising in particular an emergency braking system (AEB) and an adaptive cruise control system (ACC), mutually independent, as well as means (C, WM, SU) for detecting and evaluating the environment of the vehicle and the current situation of the latter, on the one hand, and means (PP, TMC, A) for determining the trajectory and controlling the movement of the vehicle, on the other hand, these means collaborating with the two aforementioned systems (AEB and ACC) for the selective performance of their respective functions, the effective triggering of emergency braking being subject to the verification of determined criteria and to the application of one or more reliability strategies.

[0045] A possible architecture of a driving assistance system that can be implemented within the framework of the invention is represented in a simplified manner in [Fig.l].

[0046] It comprises three layers represented in a superimposed manner, namely: 1. the lower layer of hardware equipping the vehicle and comprising internal and external sensors and detectors (C) providing status and situation data and actuators (A) executing vehicle movement control command instructions (EGO) 2. the intermediate layer of vehicle-specific middleware, including a software (WM) for modeling the vehicle (EGO) and its environment, software (SU) for understanding the environment and the situation and state of the vehicle (EGO), software (PP) for planning the vehicle's path (EGO) and software (TMC) for controlling / commanding the trajectory and movement of the vehicle (EGO) 3. the upper layer of applications (APP 1, APP 2, ..., APPN), including in particular an application corresponding to the emergency braking system (AEB) and an application corresponding to the adaptive cruise control system (ACC).

[0047] In this architecture, the input data comes from sensors (C), such as camera, LIDAR, sonar, tracker or similar, internal vehicle detectors (EGO). This data is processed (eg merged) by the software component (WM), then sent to the software component (SU) so that the latter can analyze situations (eg a collision) by predicting the position of objects in the future. This set of hardware and software elements composes the information feed to the applications.

[0048] The applications (APP 1, APP 2, ..., APPN) then subscribe to situations of the software component (SU) to analyze a risk (for example the AEB application) or request to follow a vehicle (for example the ACC application). The applications send constraints (of the maneuver request type) to the software component (PP) for planning the vehicle's path (EGO) whose purpose is to generate a trajectory to satisfy the constraints it has received, in particular by arbitrating between the different requests / constraints issued by the applications. The software (TMC) for controlling / commanding the trajectory and movement makes it possible to generate the data / instructions making it possible to control the vehicle's actuators such as the brakes, the steering (via the chassis interfaces) or even the propulsion means. This set of hardware and software elements makes up the descending part of the information.

[0049] According to the invention, this driving assistance system is characterized in that it comprises hardware and software means configured and programmed to, in the event of the occurrence of a dangerous situation detected by the emergency braking system (AEB), use information produced by the adaptive cruise control system (ACC) and, where appropriate, modify or ignore certain limiting criteria and / or at least partially inhibit certain reliability strategies, controlling the effective triggering of emergency braking.

[0050] Preferably, the emergency braking system (AEB) and the adaptive cruise control system (ACC) consist of mutually independent software applications that do not communicate directly with each other, both supplied with data and information by the detection and evaluation means (C, WM, SU). of the vehicle environment (EGO) and the current situation of the latter, on the one hand, and both transmitting their requests to a trajectory planner software (PP), forming part of the means (PP, TMC, A) for determining the trajectory and controlling the movement of the vehicle (EGO), on the other hand.

[0051] Advantageously, the aforementioned driving assistance system, shown as an example in [Fig. 1], is suitable for implementing the braking management method described above.

[0052] The invention also relates to a motor vehicle (EGO) comprising an on-board driving assistance system as described previously, and preferably implementing a method for managing its braking as mentioned above.

[0053] Of course, the invention is not limited to the embodiment described and shown in the attached drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Claims

1. Method for managing the braking of a motor vehicle (EGO) comprising an emergency braking system (AEB) and an adaptive cruise control system (ACC), mutually independent, as well as means (A, WM, SU) for detecting and evaluating the environment of the vehicle and the current situation of the latter, on the one hand, and means (PP, TMC, A) for determining the trajectory and controlling the movement of the vehicle, on the other hand, these means collaborating with the two aforementioned systems (AEB and ACC) for the selective performance of their respective functions, the effective triggering of emergency braking being subject to the verification of determined criteria and the application of one or more reliability strategies, method characterized in that it consists, in the event of occurrence of a dangerous situation detected by the emergency braking system (AEB),to exploit information produced by the adaptive cruise control system (ACC) in order, where appropriate, to modify or ignore certain limiting criteria and / or at least partially inhibit certain reliability strategies, controlling the effective triggering of emergency braking.,

2. Method according to claim 1, characterized in that the information used corresponds to information relating to a target (ID) continuously detected by the adaptive cruise control system (ACC) for at least a predetermined minimum duration and at the origin of a situation of imminent potential collision, or similar danger, with the vehicle (EGO).

3. Method according to claim 2, characterized in that the target (ID) corresponds to a vehicle preceding the vehicle (EGO) for at least a predetermined minimum duration and currently followed by the latter.

4. Method according to any one of claims 1 to 3, characterized in that it consists of inhibiting a function of delaying or waiting for the triggering of emergency braking normally active when the driver is considered to be active or in control of the vehicle (EGO).

5. Method according to any one of claims 1 to 4, characterized in that it consists of ignoring the criterion of distance to the target (ID) of the vehicle (EGO).

6. Method according to any one of claims 1 to 5, characterized in that it consists of modifying at least one of the criterion of lateral position of the vehicle (EGO) relative to the target (ID) at the current time and the criterion of lateral position of the vehicle (EGO) relative to the target (ID) at the predicted impact, by widening the respectively corresponding corridor.

7. Method according to any one of claims 1 to 6, characterized in that the exploitation of the information produced by the adaptive cruise control system (ACC), to act where appropriate on the emergency braking system (AEB), with a view to modifying or ignoring certain criteria and / or at least partially inhibiting certain reliability strategies controlling the effective triggering of emergency braking, is carried out by trajectory planner software (PP), to which the two systems (ACC and AEB) transmit their respective requests and which is part of the means (PP, TMC, A) for determining the trajectory and controlling the movement of the vehicle (EGO).

8. Method according to any one of claims 1 to 7, characterized in that it consists of implementing, in relation to constant monitoring by the emergency braking system (AEB) and in the event of a positive determination of a situation requiring emergency braking (dangerous situation), a decision-making process comprising the following steps: - a) verification of the existence of target tracking (ID) by the adaptive cruise control system (ACC) for at least a predetermined minimum duration, for example 5 seconds,- if no for a): then unaltered operation and action of the emergency braking system (AEB) - if yes for a): then b) verification whether the target (ID) followed corresponds to the target causing the situation requiring emergency braking - if no for b): then unaltered operation and action of the emergency braking system (AEB) - if yes for b): then adapted operation and action of the emergency braking system (AEB), with modification or not taking into account certain limiting criteria and / or at least partial inhibition of certain reliability strategies controlling the effective triggering of emergency braking.,

9. On-board driving assistance system for a vehicle comprising in particular an emergency braking system (AEB) and a system adaptive cruise control (ACC), mutually independent, as well as means (C, WM, SU) for detecting and evaluating the environment of the vehicle and the current situation of the latter, on the one hand, and means (PP, TMC, A) for determining the trajectory and controlling the movement of the vehicle, on the other hand, these means collaborating with the two aforementioned systems (AEB and ACC) for the selective performance of their respective functions, the effective triggering of emergency braking being subject to the verification of determined criteria and the application of one or more reliability strategies, system characterized in that it comprises hardware and software means configured and programmed to, in the event of the occurrence of a dangerous situation detected by the emergency braking system (AEB), use information produced by the adaptive cruise control system (ACC) and to, where appropriate,modify or ignore certain limiting criteria and / or at least partially inhibit certain reliability strategies, controlling the effective triggering of emergency braking.,

10. System according to claim 9, characterized in that the emergency braking system (AEB) and the adaptive cruise control system (ACC) consist of mutually independent software applications which do not communicate directly with each other, both supplied with data and information by the means (C, WM, SU) for detecting and evaluating the environment of the vehicle (EGO) and the current situation of the latter, on the one hand, and both transmitting their requests to trajectory planner software (PP), forming part of the means (PP, TMC, A) for determining the trajectory and controlling the movement of the vehicle (EGO), on the other hand.

11. System according to claim 9 or 10, characterized in that it is suitable for implementing the method according to any one of claims 1 to 8.

12. Motor vehicle (EGO) comprising an on-board driving assistance system according to any one of claims 9 to 11, preferably implementing a method for managing its braking according to any one of claims 1 to 8.

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