CN113573963A

CN113573963A - Speed regulation method for a motor vehicle implementing an adaptive speed regulation function

Info

Publication number: CN113573963A
Application number: CN202080022081.9A
Authority: CN
Inventors: C·科昂; T·赫克斯韦勒; N·罗滕布格尔; J·佩里耶
Original assignee: PSA Automobiles SA
Current assignee: PSA Automobiles SA
Priority date: 2019-03-20
Filing date: 2020-02-28
Publication date: 2021-10-29
Also published as: EP3941792A1; FR3093975A1; WO2020188174A1

Abstract

The invention relates to a method for regulating the speed of a motor vehicle, called host vehicle, which implements an adaptive speed regulation function (ACC function), comprising the steps of: -maintaining (30) the speed of the host vehicle equal to a set speed and the vehicle at a distance from a vehicle (or target vehicle) travelling in front of the vehicle, said distance being greater than or equal to a set distance; -reducing (32) the speed of the host vehicle until the host vehicle is parked when the deceleration of the target vehicle forces the host vehicle to park; -maintaining (34) the vehicle in a parked state; -when a re-departure requires driver action and when the distance between the host vehicle and the target vehicle is greater than a threshold, refraining (36) from sending a warning message informing that the ACC function is suspended for a predetermined length of time; -increasing (38) the speed of the host vehicle up to the set speed.

Description

Speed regulation method for a motor vehicle implementing an adaptive speed regulation function

Technical Field

The present invention claims priority from french application 1902849 filed on 3/20/2019, the disclosure (text, drawings and claims) of which is incorporated herein by reference.

The present invention relates to the field of driving assistance systems fitted on motor vehicles. The aim of the driving assistance system, often referred to in english acronym as ADAS (i.e. "Advanced driver-assistance systems"), is to reduce the burden on the driver, in particular by freeing the driver from some tasks, by improving the driver's attention and/or the driver's perception of the environment, by detecting some risks, by automatically performing operations in response to the detection of these risks, etc.

Background

In order to perform the desired function, the driver assistance system is operated by means of sensors fitted on the vehicle, which are able to sense the environment of the vehicle (in particular a vehicle located nearby). This perception of the environment of the driving assistance system enables to prevent accident risks while ensuring compliance with predefined regulations (e.g. regulations specifying that a vehicle maintains a minimum distance from a vehicle travelling in front of the vehicle).

Among the different driving assistance functions, an Adaptive longitudinal adjustment function is known, which is generally denoted by the english initial cruise control. The purpose of this function is to maintain the vehicle with a set speed defined by the driver, while adjusting the speed of the vehicle as necessary to manage the tracking of a slower vehicle. Thus, when a vehicle travelling at a speed less than the set speed defined by the driver is travelling in front of the vehicle in question, the driving assistance system will manage the braking of the vehicle. However, the driver remains responsible for the driving of the vehicle and needs to be able to intervene at any time when the situation requires it.

An improved ACC function is known which is able to manage the deceleration of a vehicle until it is completely parked, and the acceleration of the vehicle when conditions are such that the vehicle can be restarted forward (this stage is called re-departure). This function, called ACC Stop and Go, is applicable to slow traffic conditions and traffic jam conditions. In the following of the present description, the ACC function means an adaptive speed regulation function of the ACC Stop and Go type (that is, capable of managing the parking and re-departure of the vehicle).

In situations that result in a vehicle coming to a complete stop, a subsequent vehicle re-departure may, in some cases, require driver action on the accelerator pedal. Generally, this action is required when a departure is only possible after a time period greater than a predefined value: for example, when the restart is possible within three seconds after the vehicle is stopped, no action is required.

When the vehicle remains parked during the time (requiring the driver's action on the accelerator pedal), the driver may actuate the pedal beyond a position (corresponding to the acceleration setting requested by the ACC function). In this case, it is expected that the driving assist system will send a warning message to the driver to notify the speed adjustment function to halt. The message may take different forms, such as a "regulator pause" type text message, or a cancellation of the display of a set speed tracked by the ACC function. The warning message may be temporary and maintained only during the phase (driver actuation of the accelerator pedal beyond the position corresponding to the acceleration setting requested by the ACC function). In congested traffic situations, where frequent parking and re-departure is required, the warning messages may be displayed very frequently, which may be considered intrusive and unpleasant by the driver.

Disclosure of Invention

The object of the present invention is to overcome the drawbacks of the prior art (and more particularly the drawbacks mentioned above) by providing a speed regulation method of a motor vehicle implementing an adaptive speed regulation function in which the action of the accelerator pedal by the driver does not cause the sending of warning messages considered useless when the vehicle is re-started.

To this end, the invention relates to a motor vehicle (called host vehicle)

) A vehicle implementing an adaptive speed regulation function (hereinafter referred to as ACC function), said method comprising a plurality of steps aimed at:

-maintaining the speed of the host vehicle equal to a set speed and the host vehicle at a distance from a vehicle travelling ahead of the host vehicle on the same traffic lane (hereinafter referred to as target vehicle), the distance being greater than or equal to a set distance;

-in the event of deceleration of the target vehicle, reducing the speed of the host vehicle so as to follow the set distance, until the host vehicle is parked when the deceleration of the target vehicle forces the host vehicle to park;

-maintaining the host vehicle in a parked state when the host vehicle is in a parked state and when the distance to the target vehicle does not allow a further departure;

-refraining from sending a warning message informing that the ACC function is suspended for a predetermined period of time when a re-launch of the host vehicle is possible and driver action on an accelerator pedal is required, and when the distance between the host vehicle and the target vehicle is greater than a threshold;

-increasing the speed of the host vehicle until said speed is equal to said set speed, or to a speed forced to have by following said set distance and less than said set speed.

Thus, the method according to the present invention can greatly limit the number of occurrences of transmission of the warning message notifying the driver that the ACC function is temporarily suspended during the phase of re-departure at the ACC. In fact, by inhibiting the transmission of such messages during a predetermined period of time when the re-launch of the vehicle requires the action of the accelerator pedal by the driver, and when said target vehicle is sufficiently far away, it is avoided to transmit useless warning messages in the event of excessive actuation of the accelerator pedal by the driver. Thereby, it is avoided that the driver considers the sending of the warning message as untimely, without reducing the safety level. By anticipating that the sending of the warning message is not prohibited when the target vehicle is in proximity to the host vehicle, it is ensured that the message is delivered well in useful situations: in fact, when the target vehicle is in the vicinity of the host vehicle, the driver must be warned that braking will not be ensured by the ACC function if required.

In an embodiment, the threshold value is expressed in the form of a time duration or inter-vehicle interval time separating the host vehicle and the target vehicle, the time duration being between 500 milliseconds and 5 seconds, or between 1 second and 3 seconds, for example equal to 2 seconds.

In an embodiment, the action of the accelerator pedal by the driver is required for the reissue of the host vehicle when the parking phase exceeds a period greater than or equal to a limit value greater than 500 milliseconds, preferably between 500 milliseconds and 10 seconds, for example equal to 3 seconds.

In an embodiment, the predetermined duration for disabling the warning message is greater than one second, preferably between 1 and 10 seconds, for example equal to 3 seconds.

In an embodiment, the set speed is adjustable by the driver.

In an embodiment, the set distance is adjustable by the driver.

In an embodiment, the set distance is expressed in the form of a time period or inter-vehicle interval time separating the host vehicle and the target vehicle, the time period being between 500 milliseconds and 10 seconds, preferably between 1.5 seconds and 3 seconds.

The invention also relates to a computer program product comprising instructions which, when the program is executed by a computer, direct said computer to carry out the steps of the method as defined above.

The invention also relates to a driving assistance system (sys me de conduite) comprising a computer configured for implementing the method as defined above, at least one sensor and an actuator.

The invention also relates to a motor vehicle equipped with a driving assistance system as defined above and/or implementing a method as defined more above.

Drawings

The invention will be better understood from a reading of the following detailed description and the accompanying drawings, in which:

fig. 1 shows a motor vehicle equipped with a driving assistance system capable of implementing the method according to the invention;

figure 2 shows the implementation steps of the method according to the invention.

Detailed Description

Fig. 1 shows a motor vehicle which can carry out one or more driving assistance functions and is equipped for this purpose with a driving assistance system 2. Hereinafter, the vehicle is referred to as a host vehicle 1. The driving assistance system 2 comprises, inter alia, a computer 10, an actuator 12 and a plurality of detectors (in this example, a plurality of

sensors

14a, 14b, 16a, 16b, 18 distributed on the front, rear and side of the host vehicle 1). These sensors may include one or more of the following sensor types: ultrasonic sensors, radar sensors, lidar sensors, day view cameras, night vision cameras, and the like. In the example, the driving assistance system 2 comprises four cameras 18 (i.e. one front camera, one rear camera and two side cameras) and a plurality of

sensors

14a, 14b, 16a, 16b of the ultrasonic sensor and/or radar sensor and/or lidar sensor type. The computer 10 receives data provided by all of the

sensors

14a, 14b, 16a, 16b and by all of the cameras 18.

Thanks to all these sensors, the computer 10 is able to detect whether an obstacle is present in the environment of the vehicle (more specifically, whether a vehicle is present in the environment, whether it is in the current lane or in an adjacent lane of the host vehicle 1).

Furthermore, the computer 10 is coupled to a plurality of actuators 12 comprising devices able to act in particular on the accelerator and on the braking system of the host vehicle in order to control the speed (all) of said host vehicle. Advantageously, the actuator 12 also comprises means able to act in the direction of the vehicle in order to control the trajectory of said vehicle.

The driving assistance system is configured to implement one or more assistance functions in the driving assistance mode, including in particular an adaptive cruise control function (hereinafter ACC function) with a "stop and go" function. As mentioned more above, such a function enables the speed of the vehicle to be adjusted without intervention by the driver (who, however, needs to maintain control over the vehicle, in particular over the direction, since it relates to an assistance function), while following a set value of the safety distance with respect to the vehicle travelling before the host vehicle (that is to say a minimum deviation between the two vehicles). The set value may be expressed, for example, as an inter-vehicle separation distance (that is To say, the distance separating two consecutive vehicles on the same traffic lane, this parameter being generally denoted by the acronym DIV), or as an inter-vehicle separation Time (that is To say, the length of Time of passage separating two consecutive vehicles on the same traffic lane, measured at a fixed point of the traffic lane, this parameter being often denoted by the acronym TIV), or as a Time before Collision (that is To say, the estimated Time before a Collision occurs between the target vehicle and the host vehicle, this parameter being often denoted by the english acronym TTC ("Time To Collision"). the ACC function is also able To manage the deceleration of the vehicle, including the deceleration until the vehicle comes To a complete stop, when the deceleration of the vehicle travelling in front of this vehicle forces the vehicle To a complete stop, the driving assistance system 2 comprises at least one camera and a sensor of radar type to implement the ACC function described above.

An embodiment of the method according to the invention is described in the following in connection with fig. 2.

During the starting step of the method according to the invention, the host vehicle is in assisted driving mode while one or more assistance functions are activated, including at least an adaptive speed regulation function with a "stop and go" function (hereinafter referred to as ACC function).

The ACC function enables the speed of the host vehicle 1 to be maintained equal to a set speed value (which is pre-selected by the driver, for example by means of a control button located on or near the steering wheel), while maintaining the host vehicle 1 at a distance greater than or equal to the set distance from a target vehicle travelling in front of the host vehicle, if necessary (step 30). Advantageously, the set distance is adjustable by a user.

When the target vehicle is caused to decelerate, for example due to congested traffic conditions, the speed of the host vehicle 1 is reduced so as to follow the set distance, when necessary until the host vehicle stops (step 32).

When the host vehicle 1 is in a parked state, and when the distance between the target vehicle and the host vehicle does not allow a reissue of the host vehicle 1, the host vehicle is maintained in a parked state (step 34).

When a vehicle re-departure of the host vehicle 1 becomes possible, the vehicle re-departure may be fully automatic, or may require driver action on an accelerator pedal to confirm the vehicle re-departure command. For example, when a certain delay has elapsed between the time when the host vehicle stops and when a vehicle re-issue becomes possible, action by the driver is required. For example, it is conceivable that at least two seconds (in particular at least three seconds) have elapsed between the parking and the restart possibility of the vehicle, requiring an action by the driver. When the vehicle is in a parked state, and when the re-departure is possible and driver action on an accelerator pedal is required, transmission of an alert message notifying that the ACC function is suspended is prohibited for a predetermined period of time on the condition that the distance between the host vehicle and the target vehicle is less than a threshold value (step 36). In the opposite case, that is to say when the distance between the host vehicle and the target vehicle is greater than a threshold value, the transmission of the warning message will not be suspended: the message is immediately sent to the driver. In fact, in case the target vehicle is too close to the host vehicle at restart, the driver has to be warned that the ACC function is suspended, since this means that the braking will not be ensured by the ACC function when it is needed. Advantageously, the threshold value is expressed in the form of a time duration or inter-vehicle interval time separating the host vehicle and the target vehicle, the time duration being between 500 milliseconds and 5 seconds, or between 1 second and 3 seconds, for example equal to 2 seconds.

When the driver exerts an action on the accelerator pedal, a re-launch of the host vehicle is thus triggered, which results in increasing the speed of the host vehicle until it is equal to the set speed, or to a speed forced to have by following the set distance and lower than the set speed (step 38).

Advantageously, the disabling duration for disabling said alarm message is between 1 and 10 seconds, for example equal to 3 seconds.

The method to which the invention relates is thus able to avoid sending warning messages when the driver presses on the accelerator pedal to confirm a re-departure command, unless the vehicle travelling in front of the host vehicle is too close. Thus, the driver is no longer subjected to the potentially untimely and annoying systematic transmission of the warning message, but the message remains transmitted in the important case.

Claims

1. A speed regulation method of a motor vehicle, hereinafter referred to as host vehicle (1), implementing an adaptive speed regulation function, hereinafter referred to as ACC function, comprising a plurality of steps aimed at:

-maintaining (30) the speed of the host vehicle equal to a set speed and the host vehicle at a distance from a vehicle travelling ahead of the host vehicle on the same traffic lane and hereinafter referred to as target vehicle, said distance being greater than or equal to a set distance;

-reducing (32) the speed of the host vehicle so as to follow the set distance when the target vehicle decelerates, until the host vehicle stops when the deceleration of the target vehicle forces the host vehicle to stop;

-maintaining (34) the host vehicle in a parked state when the host vehicle is in a parked state and when the distance to the target vehicle does not allow a further departure;

-inhibiting (36) the sending of an alert message informing that the ACC function is suspended during a predetermined period of time when a re-launch of the host vehicle is possible and driver action on an accelerator pedal is required, and when the distance between the host vehicle and the target vehicle is greater than a threshold;

-increasing (38) the speed of the host vehicle until the speed of the host vehicle is equal to the set speed, or to a speed forced to have by following the set distance and less than the set speed.

2. The speed adjustment method according to claim 1, wherein the threshold value is expressed in the form of a time period or inter-vehicle interval time separating the host vehicle and the target vehicle, the time period being between 500 milliseconds and 5 seconds, or between 1 second and 3 seconds, for example equal to 2 seconds.

3. A speed regulation method according to any one of the preceding claims, in which the action of the accelerator pedal by the driver is required for the reissue of the host vehicle when the parking phase exceeds a period greater than or equal to a limit value greater than 500 milliseconds, preferably between 500 and 10 seconds, for example equal to 3 seconds.

4. A method of regulating speed according to any of the preceding claims, wherein the predetermined duration for disabling the warning message is greater than one second, preferably between 1 and 10 seconds, for example equal to 3 seconds.

5. A speed adjustment method according to any of the preceding claims, wherein the set speed is adjustable by a driver.

6. A speed adjustment method according to any of the preceding claims, wherein the set distance is adjustable by a driver.

7. A speed adjustment method according to any of the preceding claims, wherein the set distance is expressed in the form of a time period separating the host vehicle (1) and the target vehicle or an inter-vehicle interval time, the time period being between 500 milliseconds and 10 seconds, preferably between 1.5 seconds and 3 seconds.

8. A computer program product comprising instructions which, when the program is executed by a computer, direct the computer to carry out the steps of the speed adjustment method according to any one of claims 1 to 7.

9. A driving assistance system (2) comprising a computer (10), at least one sensor (14a, 14b, 16a, 16b, 18) and an actuator (12) configured for implementing a speed adjustment method according to any one of claims 1 to 7.

10. A motor vehicle (1) equipped with a driving assistance system (2) according to claim 9 and/or implementing a speed adjustment method according to any one of claims 1 to 7.