FR3089473A1 - Motor vehicle speed control method using an adaptive speed control function - Google Patents

Abstract

The invention relates to a speed control method of a motor vehicle, or host vehicle, implementing an adaptive speed control function (ACC function), the method comprising the steps consisting in: - maintaining (30) the speed from the host vehicle equal to a set speed and maintain the host vehicle at a distance from the vehicle preceding it, or target vehicle, greater than a set distance; - decrease (32) the speed of the vehicle, until the host vehicle stops if the slowdown of the target vehicle so requires; - keep (34) the host vehicle stationary as long as the conditions do not allow a take-off; - when a take-off requires an action by the driver on the accelerator pedal, inhibit (36) the emission of a message informing that the ACC function is suspended for a predetermined period; - increase (38) the speed of the host vehicle to the set speed. Figure for the abstract: Fig. 2

Description

Description

Title of the invention: Method for speed regulation of a motor vehicle implementing an adaptive speed regulation function

The invention relates to the field of driving assistance systems fitted to motor vehicles. Driver assistance systems, often referred to by the acronym ADAS (for "Advanced driver-assistance systems"), are intended to lighten the load on the driver, in particular by freeing him from certain tasks, by improving his attention and / or perception of the environment, by detecting certain risks, by automatically carrying out actions in response to the detection of these risks, etc.

To fulfill the desired functions, the driving assistance systems operate using sensors fitted to the vehicle and making it possible to perceive the environment of the vehicle, and in particular the vehicles located nearby. This perception of the environment by the driving assistance system makes it possible to prevent the risk of accidents by ensuring compliance with predefined rules, such as that of requiring that the vehicle be kept at a minimum distance from the vehicle which precedes it.

Among the various driving assistance functions, there is known an adaptive longitudinal regulation function, commonly designated by the acronym ACC (for "adaptive cruise control"). The purpose of this function is to maintain the vehicle at a set speed defined by the driver, while regulating the vehicle speed to manage the tracking of a slower vehicle if necessary. Thus, if a vehicle traveling at a speed lower than the set speed defined by the driver precedes the vehicle concerned, the driving assistance system will manage the braking of the latter. However, the driver remains responsible for driving the vehicle and must be able to intervene at any time if the situation requires it.

An improved ACC function is known, which makes it possible to manage the slowing down of the vehicle until the vehicle comes to a complete stop, as well as the acceleration of the vehicle when the conditions allow it to start again, phase which is called re-launch. This function called ACC Stop and Go is suitable for slow traffic conditions and traffic jams. In the remainder of this description, the ACC function will denote an adaptive cruise control function of the ACC Stop and Go type, that is to say capable of managing the stopping and relaunching of the vehicle.

In a situation leading to the complete stopping of a vehicle, the next take-off may, in certain cases, require action by the driver on the accelerator pedal.

Generally, this action is required if the takeoff is only possible after a period of time greater than a predefined value: for example, if the restart is possible less than three seconds after the vehicle has stopped, no action is taken. will be required.

When the vehicle has been stationary for a time requiring action by the driver on the accelerator pedal, the latter is capable of actuating the pedal beyond the position corresponding to the acceleration instruction. requested by the ACC function. In such a case, the driver assistance system is expected to issue an alert message to the driver to inform him that the cruise control function has been suspended. This message can take different forms, such as a text message such as "cruise control suspended" or the suppression of the display of the set speed followed by the ACC function. This alert message can be temporary, and can only be maintained during the phase during which the driver actuates the accelerator pedal beyond the position corresponding to the acceleration setpoint requested by the ACC function. In dense traffic situations involving very frequent stops and take-offs, the warning message is likely to be displayed very often, which may be perceived by the driver as intrusive and unpleasant.

The present invention aims to remedy the drawbacks of the state of the art, and more particularly those described above, by proposing a speed regulation method for a motor vehicle implementing a regulation function of adaptive speed in which, when the vehicle takes off again, the action of the driver on the accelerator pedal does not generate the emission of warning messages perceived as useless.

To this end, the invention relates to a speed regulation method of a motor vehicle, hereinafter host vehicle, the vehicle implementing an adaptive speed regulation function, hereinafter ACC function, the method comprising the steps of:

- maintain the speed of the host vehicle equal to a set speed and keep the host vehicle at a distance from a vehicle preceding the host vehicle on the same traffic lane, hereinafter target vehicle, greater than or equal to a set distance ;

- decrease the speed of the host vehicle in the event of the target vehicle slowing down in order to respect the set distance, until the host vehicle stops if the target vehicle slows down so requires;

- when the host vehicle is stationary, keep the host vehicle stationary as long as the distance from the target vehicle does not allow a take-off;

- when a take-off of the host vehicle is possible and requires action from the

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Driver on the accelerator pedal, inhibiting the emission of an alert message informing that the ACC function is suspended for a predetermined period;

- increase the speed of the host vehicle until it is equal to the set speed, or equal to a speed lower than the set speed and imposed by respecting the set distance.

Thus, the method according to the invention makes it possible to greatly limit the number of occurrences of emission of a warning message informing the driver of the temporary suspension of the ACC function during a phase of relaunching in ACC. In fact, by inhibiting the transmission of such a message for a predetermined period of time when the relaunch of the vehicle requires the driver to act on the accelerator pedal, it avoids sending an unnecessary warning message in the event that the driver operates the accelerator pedal too far. This prevents the driver from perceiving the emission of warning messages as untimely, without however reducing the level of safety.

In one embodiment, an action of the driver on the accelerator pedal is required for relaunching of the host vehicle if the stopping phase exceeds a duration greater than or equal to a threshold value, the threshold value being greater than 500 milliseconds, preferably between 500 milliseconds and 10 seconds, and for example equal to 3 seconds.

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

In one embodiment, the set speed can be adjusted by the driver.

In one embodiment, the set distance can be adjusted by the driver.

In one embodiment, the set distance is expressed in the form of a period of time separating the host vehicle from the target vehicle, or inter-vehicle time.

In one embodiment, the set distance is between 500 ms and 10 seconds, preferably between 1.5 and 3 seconds.

The invention also relates to a computer program product comprising instructions which, when the program is executed by a computer, lead the latter to implement the steps of the method as defined above.

The invention also relates to an assisted driving system comprising a computer, at least one sensor and actuators arranged to implement the method as defined above.

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

The present invention will be better understood on reading the detailed description which follows, given with reference to the appended drawings, in which:

[Fig. 1] represents a motor vehicle equipped with an assisted driving system allowing the implementation of a method according to the invention;

[Fig.2] shows the steps for implementing a method according to the invention.

Figure 1 shows a motor vehicle capable of implementing one or more driving assistance functions, and which is for this purpose equipped with an assisted driving system 2. In the following of this description this vehicle will be called host vehicle 1. The assisted driving system 2 comprises in particular a computer 10, actuators 12, as well as a plurality of detectors, in the example a plurality of sensors 14a, 14b, 16a, 16b, 18 distributed over the front, rear and sides of the host vehicle 1. These sensors may include one or more of the following types of sensors: ultrasonic sensors, radars, lidars, day vision cameras, night vision cameras, etc. The assisted driving system 2 comprises in the example four cameras 18 (either a front camera, a rear camera and two side cameras) and a plurality of sensors 14a, 14b, 16a, 16b of the ultrasonic and / or radar sensor type and / or lidar. The computer 10 receives the data supplied by all of the sensors 14a, 14b, 16a, 16b and by all of the cameras 18.

Thanks to all of these sensors, the computer 10 is able to detect the presence of obstacles in the environment of the vehicle, and in particular the presence of vehicles in this environment, whether on the current track of the host vehicle 1 or on adjacent lanes.

The computer 10 is also connected to a plurality of actuators 12, which include devices capable of acting in particular on the accelerator and the braking system of the host vehicle, in order to control its speed. Advantageously, the actuators 12 also include devices capable of acting on the direction of the vehicle in order to control the trajectory.

The assisted driving system is configured to implement, in an assisted driving mode, one or more assistance functions, including in particular an adaptive cruise control function with “stop and go” function, below. ACC function. As mentioned above, such a function makes it possible to regulate the speed of the vehicle without driver intervention (the latter, however, having to retain control of the vehicle, and in particular control of the direction, since this is a assistance function), respecting a safety distance setpoint vis-à-vis the vehicle preceding the host vehicle, i.e. a minimum distance between these two vehicles. This instruction can be expressed for example in distance between vehicles (that is to say the distance separating two successive vehicles on the same traffic lane, this parameter being commonly designated by the acronym

DIV), or in inter-vehicle time (i.e. the duration of time, measured at a fixed point on the taxiway, separating the passage of two successive vehicles on the same taxiway, this parameter is often designated by the acronym TIV) or in time before collision (that is to say the estimated time before collision between the target vehicle and the host vehicle, this parameter is often designated by the acronym TTC, for “Time To Collision ”). The ACC function is also capable of managing the deceleration of the vehicle, including until it comes to a complete stop, if the deceleration of the vehicle preceding it so requires. Preferably, the assisted driving system 2 comprises at least one camera and one radar-type sensor for implementing the ACC function described above.

An example of implementation of the method according to the invention is described below, in relation to FIG. 2.

During the initial step of the method according to the invention, the host vehicle is in an assisted driving mode, one or more assistance functions being activated, including at least the adaptive cruise control function with function "Stop and go", hereinafter ACC function.

The ACC function makes it possible to maintain the speed of the host vehicle 1 equal to a set speed (previously entered by the driver, for example by means of a control button located on or near the steering wheel), while now, if necessary, the host vehicle 1 at a distance from a target vehicle preceding the host vehicle greater than or equal to a set distance (step 30). Advantageously, the set distance can be adjusted by the user.

If the target vehicle is slowed down, for example due to heavy traffic conditions, the speed of the host vehicle 1 is reduced so as to respect the set distance, until the host vehicle stops if required (step 32).

Once the host vehicle 1 has stopped, it is kept stationary as long as the distance between the target vehicle and the host vehicle does not allow the host vehicle 1 to take off again (step 34).

When a take-off of the host vehicle 1 becomes possible, this take-off may be entirely automatic or require the driver's action on the accelerator pedal to confirm the re-take-off order. For example, a driver action is required if a certain period of time elapses between the stopping of the host vehicle and the time when take-off becomes possible. For example, it can be foreseen that a driver action is required if at least two seconds, and in particular three seconds, elapse between the stopping of the vehicle and the possibility of restarting. When the vehicle is stationary and take-off is possible and requires the driver to act on the accelerator pedal, then the issue of an alert message informing that the ACC function is suspended is inhibited during a predetermined duration (step 36).

If the driver performs an action on the accelerator pedal, then the take-off of the host vehicle is initiated, which leads to increasing the speed of the host vehicle until it is equal to the set speed, or equal to a speed lower than the set speed and imposed by compliance with the set distance (step 38).

Advantageously, the duration of inhibition of the alert message is between 1 and 10 seconds, and for example equal to 3 seconds.

The method of the invention therefore avoids an alert message being issued when the driver presses the accelerator pedal to confirm the order to take off. Thus, the driver no longer undergoes a systematic emission of warning messages which could be seen as untimely and annoying.

Claims (1)

Claims [Claim 1] Method for regulating the speed of a motor vehicle, hereinafter host vehicle (1), the vehicle implementing an adaptive speed regulation function, hereinafter ACC function, the method comprising the steps consisting in: - maintain (30) the speed of the host vehicle equal to a set speed and maintain the host vehicle at a distance from a vehicle preceding the host vehicle on the same traffic lane, hereinafter target vehicle, greater than or equal to a set distance; - decrease (32) the speed of the host vehicle in the event of the target vehicle slowing down in order to respect the set distance, until the host vehicle stops if the slowdown of the target vehicle so requires; - when the host vehicle is stationary, keep (34) the host vehicle stationary as long as the distance from the target vehicle does not allow a take-off; - when it is possible to take off from the host vehicle and requires action by the driver on the accelerator pedal, inhibit (36) the issue of an alert message informing that the ACC function is suspended for a predetermined period; - increase (38) the speed of the host vehicle until it is equal to the set speed, or equal to a speed lower than the set speed and imposed by compliance with the set distance. [Claim 2] Method according to the preceding claim, in which an action of the driver on the accelerator pedal is required for relaunching of the host vehicle if the stopping phase exceeds a duration greater than or equal to a threshold value, the threshold value being greater than 500. milliseconds, preferably between 500 milliseconds and 10 seconds, and for example equal to 3 seconds. [Claim 3] Method according to one of the preceding claims, in which the predetermined duration of inhibition of the alert message is greater than one second, preferably between 1 and 10 seconds, and for example equal to 3 seconds. [Claim 4] Method according to one of the preceding claims, in which the set speed can be adjusted by the driver. [Claim 5] Method according to one of the preceding claims, in which the set distance can be adjusted by the driver. [Claim 6] Method according to one of the preceding claims, in which the target distance is expressed in the form of a period of time separating the host vehicle (1) from the target vehicle, or inter-vehicle time. [Claim 7] Method according to the preceding claim, in which the set distance is between 500 ms and 10 seconds, preferably between 1.5 and 3 seconds. [Claim 8] Computer program product comprising instructions which, when the program is executed by a computer, lead the latter to implement the steps of the method according to one of claims 1 Q Ί [Claim 9] d /. Power steering system (2) comprising a computer (10), at least one sensor (14a, 14b, 16a, 16b, 18) and actuators (12) arranged to implement the method according to one of claims 1 to 7. [Claim 10] Motor vehicle (1) equipped with an assisted driving system (2) according to the preceding claim. 1/1