阅读说明：本技术 驾驶辅助车辆的目标车速生成方法及目标车速生成装置 (Target vehicle speed generation method and target vehicle speed generation device for driving assistance vehicle ) 是由 后藤明之 福重孝志 田家智 于 2017-07-03 设计创作，主要内容包括：本发明在通过驾驶辅助进行行驶时,除了抑制不必要的加速以外,还降低从加速过渡到减速时的冲击。本发明的驾驶辅助车辆(自动驾驶车辆)的目标车速生成装置搭载了具有多个车速指令生成单元(21),生成车辆行驶/停止时的目标车速的自动驾驶控制单元(2)(控制器),其中,自动驾驶控制单元(2)具备预读车速指令计算单元(22)和最小车速指令调停单元(23)。预读车速指令计算单元(22)对于由多个车速指令生成单元(21)生成的各车速指令值,算出从当前时刻起经过了规定时间后的预读车速指令值。最小车速指令调停单元(23)从预读车速指令计算单元(22)算出的多个预读车速指令值中选择最小值作为目标车速。(The present invention reduces a shock at the time of transition from acceleration to deceleration in addition to suppressing unnecessary acceleration when traveling by driving assistance. A target vehicle speed generation device for a driving assistance vehicle (an autonomous vehicle) is equipped with an autonomous control unit (2) (controller) having a plurality of vehicle speed command generation means (21) and generating a target vehicle speed when the vehicle is running or stopped, wherein the autonomous control unit (2) is provided with a pre-read vehicle speed command calculation means (22) and a minimum vehicle speed command mediation means (23). A read-ahead vehicle speed command calculation unit (22) calculates, for each vehicle speed command value generated by a plurality of vehicle speed command generation units (21), a read-ahead vehicle speed command value after a predetermined time has elapsed from the current time. A minimum vehicle speed command mediation unit (23) selects a minimum value as a target vehicle speed from a plurality of pre-read vehicle speed command values calculated by a pre-read vehicle speed command calculation unit (22).)

1. A target vehicle speed generation method for a driving assistance vehicle, which generates a target vehicle speed at the time of driving/stopping the vehicle based on a plurality of vehicle speed command values,

calculating a pre-read vehicle speed command value after a predetermined time has elapsed from a current time for each of the plurality of vehicle speed command values,

and selecting the minimum value from the plurality of calculated pre-reading vehicle speed command values as the target vehicle speed.

2. The target vehicle speed generation method of the drive assist vehicle according to claim 1,

when the pre-reading vehicle speed instruction value is calculated, the pre-reading vehicle speed instruction value after the pre-reading time is calculated based on the vehicle speed instruction value, the target acceleration and the pre-reading time at the current moment,

calculating the necessary acceleration required from the previous vehicle speed command value to the current pre-reading vehicle speed command value,

and calculating the pre-reading vehicle speed instruction value at the current moment according to the necessary acceleration, the calculation period and the previous vehicle speed instruction value.

3. The target vehicle speed generation method of the drive assist vehicle according to claim 2,

when the read-ahead time is changed by the target acceleration/deceleration characteristic when the read-ahead vehicle speed command value is calculated, the read-ahead time is set to a longer time when the control is desired to be slow than when the control is desired to be quick.

4. The target vehicle speed generation method of the drive assist vehicle according to claim 2 or 3,

when the read-ahead vehicle speed command value is calculated, the read-ahead time is set longer than the other vehicle speed command values when the read-ahead vehicle speed command value is a vehicle speed command value for limiting the vehicle speed.

5. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 2 to 4,

when the read-ahead time is changed by the target acceleration/deceleration characteristic when the read-ahead vehicle speed command value is calculated, the read-ahead time is set to a shorter time when prompt control is desired than when slow control is desired.

6. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 2 to 5,

when the read-ahead vehicle speed command value is calculated, the read-ahead time is set shorter than the other vehicle speed command values when the read-ahead vehicle speed command value is a vehicle speed command value for a following preceding vehicle.

7. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 2 to 6,

when the required acceleration exceeds a preset upper limit acceleration when calculating the pre-read vehicle speed command value, the current pre-read vehicle speed command value is not selected and the previous pre-read vehicle speed command value is selected.

8. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 2 to 7,

and when the pre-reading vehicle speed instruction value at the current moment is calculated and the pre-reading vehicle speed instruction value at the current moment exceeds the vehicle speed area where the target vehicle speed can be obtained, limiting the pre-reading vehicle speed instruction value at the current moment through the vehicle speed area where the target vehicle speed can be obtained.

9. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 1 to 8,

when the minimum value is selected from the plurality of pre-read vehicle speed command values to generate the target vehicle speed, the acceleration and deceleration limiting amount corresponding to the type of the selected pre-read vehicle speed command value is selected at the same time.

10. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 1 to 9,

when the vehicle speed command value is generated, the inter-vehicle distance and the relative vehicle speed with the preceding vehicle are acquired, and the vehicle speed command value necessary for the own vehicle to follow the preceding vehicle is calculated from the acquired inter-vehicle distance and the relative vehicle speed.

11. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 1 to 10,

when the vehicle speed command value is generated, vehicle speed limit information of a road is acquired, and a vehicle speed command value necessary for following the acquired vehicle speed limit is calculated.

12. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 1 to 11,

when the vehicle speed command value is generated, the distance from the vehicle to the stop line is acquired, and the vehicle speed command value necessary for deceleration and stopping with respect to the acquired stop line relative distance is calculated.

13. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 1 to 12,

when the vehicle speed command value is generated, the curvature of the traveling road is acquired, and the vehicle speed command value not exceeding a preset limit lateral acceleration is calculated according to the acquired road curvature information.

14. A target vehicle speed generation device for a driving assistance vehicle, which is equipped with a controller having a plurality of vehicle speed command generation means and generating a target vehicle speed when the vehicle is running or stopped,

the controller is provided with:

a read-ahead vehicle speed command calculation unit that calculates a read-ahead vehicle speed command value after a predetermined time has elapsed from a current time for each of the vehicle speed command values generated by the plurality of vehicle speed command generation units; and

and a minimum vehicle speed command mediation unit that selects a minimum value as the target vehicle speed from the plurality of pre-read vehicle speed command values calculated by the pre-read vehicle speed command calculation unit.

Technical Field

The present disclosure relates to a target vehicle speed generation method and a target vehicle speed generation device for a driving assistance vehicle that generate a target vehicle speed based on a plurality of vehicle speed command values.

Background

Conventionally, there is known a driving assistance control device for a vehicle that calculates a speed that is within a braking distance recognizable forward as a vehicle speed limit and sets a target vehicle speed limit to at least the vehicle speed limit or less (see, for example, patent document 1).

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional apparatus, the lower one of the target vehicle speeds based on the limit vehicle speed and the inter-vehicle distance set by the driver is selected to be set as the target vehicle speed. Therefore, even if the vehicle is known to decelerate, if the target vehicle speed is set to an acceleration-side vehicle speed that is higher than the vehicle speed at the present time, unnecessary acceleration occurs, and there is a problem that the shock (change in acceleration) increases when the vehicle transitions from acceleration to deceleration.

The present disclosure has been made in view of the above problems, and an object of the present disclosure is to reduce a shock at the time of transition from acceleration to deceleration in addition to suppressing unnecessary acceleration when traveling by driving assistance.

Means for solving the problems

In order to achieve the above object, the present disclosure provides a target vehicle speed generation method of a driving assistance vehicle that generates a target vehicle speed at the time of vehicle running/stopping based on a plurality of vehicle speed command values.

A pre-read vehicle speed command value is calculated for each of a plurality of vehicle speed command values after a predetermined time has elapsed from the current time.

The minimum value of the calculated plurality of pre-read vehicle speed command values is selected as a target vehicle speed.

Effects of the invention

As described above, by predicting the future value (the read-ahead vehicle speed command value) and selecting the generation target vehicle speed based on the minimum value from the plurality of future values, it is possible to suppress unnecessary acceleration and reduce a shock at the time of transition from acceleration to deceleration when traveling with driving assistance.

Drawings

Fig. 1 is an overall system diagram showing an automatic driving control system to which a target vehicle speed generation method and a target vehicle speed generation device of embodiment 1 are applied.

Fig. 2 is a block diagram showing a first vehicle speed command generation means (ACC) of the target vehicle speed generation method and the target vehicle speed generation device of embodiment 1.

Fig. 3 is a block diagram showing second vehicle speed command generating means (stop line) of the target vehicle speed generating method and the target vehicle speed generating device of embodiment 1.

Fig. 4 is a vehicle speed curve characteristic diagram showing an example of a vehicle speed curve (profile) generated by the second vehicle speed command generating means (stop line).

Fig. 5 is a block diagram showing third vehicle speed command generating means (vehicle speed limit) of the target vehicle speed generating method and target vehicle speed generating device of embodiment 1.

Fig. 6 is a block diagram showing a fourth vehicle speed command generating means (corner deceleration) of the target vehicle speed generating method and the target vehicle speed generating device according to embodiment 1.

Fig. 7 is a block diagram showing the detailed configuration of the read-ahead vehicle speed command calculation means of the target vehicle speed generation method and the target vehicle speed generation device of embodiment 1.

Fig. 8 is a flowchart showing the flow of the target vehicle speed generation process executed by the automatic driving control unit of embodiment 1.

Fig. 9 is a time chart showing characteristics of a target vehicle speed (minimum value) in a traveling scene in which a vehicle ahead disappears after the vehicle starts decelerating to a speed limit due to the generation of fog in a comparative example.

Fig. 10 is a time chart showing characteristics of a target vehicle speed (minimum value of the read-ahead vehicle speed) in a deceleration stop scene in which a preceding vehicle disappears after the deceleration is started toward the stop line ahead in embodiment 1.

Fig. 11 is a target vehicle speed characteristic diagram showing a characteristic of a relationship between a distance from a host vehicle to a parked vehicle and a target vehicle speed in a decelerated parking scene in which the vehicle is parked at a position directly in front of the parked vehicle from traveling at a vehicle speed lower than a limit vehicle speed in the case where the parked vehicle exists in front in embodiment 1.

Fig. 12 is a time chart showing characteristics of a target vehicle speed in a decelerating and turning scene in which a preceding vehicle is accelerating but a corner to be decelerated is present in front in example 1.

Detailed Description

Hereinafter, a preferred embodiment of a target vehicle speed generation method and a target vehicle speed generation device for realizing the driving assistance vehicle according to the present disclosure will be described based on embodiment 1 shown in the drawings.