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：在通过驾驶辅助进行行驶时,与限制速度不同的各种各样的公路相对应,不扰乱交通流而防止对乘客产生不协调感。自动驾驶车辆(驾驶辅助车辆)的目标车速生成装置,装载了根据本车行驶路径的限制速度生成本车的目标车速的自动驾驶控制单元(2)(控制器),自动驾驶控制单元(2)包括限制速度信息获取单元(22)和目标车速生成单元(23)。在行驶中,限制速度信息获取单元(22)获取本车行驶路径的限制速度。目标车速生成单元(23)的车速指令计算单元(231)根据限制速度生成目标车速,同时生成目标加速度。而且,具有第1加速度限度计算单元(231b),在生成目标加速度时,限制速度越高,将加速度限制在放宽加速限制的方向上设定得越大(图6)。(When driving by driving assistance, the driver can prevent passengers from having a sense of incongruity without disturbing the traffic flow in accordance with various roads having different speed restrictions. A target vehicle speed generation device for an automated driving vehicle (driving assistance vehicle) is equipped with an automated driving control unit (2) (controller) for generating a target vehicle speed of the vehicle according to a speed limit of a vehicle travel path, and the automated driving control unit (2) includes a speed limit information acquisition unit (22) and a target vehicle speed generation unit (23). During traveling, a speed limit information acquisition unit (22) acquires the speed limit of the traveling path of the vehicle. A vehicle speed command calculation unit (231) of the target vehicle speed generation unit (23) generates a target vehicle speed from the limit speed and also generates a target acceleration. Further, the acceleration limit calculating means (231b) 1 is provided, and the acceleration limit is set to be larger in the direction of relaxing the acceleration limit as the limit speed is higher when the target acceleration is generated (fig. 6).)

1. A target vehicle speed generation method for a driving-assist vehicle, which generates a target vehicle speed of a host vehicle from a speed limit of a travel path of the host vehicle, the method comprising:

acquiring the speed limit of the running path of the vehicle during running,

generating a target acceleration while generating a target vehicle speed on the basis of the limit speed,

in generating the target acceleration, the acceleration limit value is set to be larger in a direction of relaxing the acceleration limit, the higher the limit speed is.

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

when the target acceleration is generated, a target acceleration with a steep gradient of a vehicle speed increase is generated when the acceleration limit value is large, and a target acceleration with a gentle gradient of a vehicle speed increase is generated when the acceleration limit value is small.

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

in generating the target acceleration, the higher the limit speed, the larger the acceleration shock limit value is set in a direction in which the limit of the acceleration shock is relaxed.

4. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 1 to 3,

in setting the acceleration limit value, the 1 st acceleration limit value is set to be larger as the speed limit is higher, the 2 nd acceleration limit value is set to be larger as the speed difference between the speed limit and the vehicle speed is larger, and the smaller one of the 1 st acceleration limit value and the 2 nd acceleration limit value is selected as the acceleration limit value.

5. A method for generating a target vehicle speed of a driving assistance vehicle, the target vehicle speed of the vehicle being generated based on a speed limit of a travel path of the vehicle, the method comprising:

acquiring the speed limit of the running path of the vehicle during running,

generating a target deceleration while generating a target vehicle speed on the basis of the limit speed,

in generating the target deceleration, the deceleration limit value is set to be larger in a direction of relaxing the deceleration limit, the lower the limit speed is.

6. The target vehicle speed generation method of the drive assist vehicle according to claim 5,

when the target deceleration is generated, a target deceleration with a steep gradient in which the vehicle speed decreases is generated when the deceleration limit value is large, and a target deceleration with a gentle gradient in which the vehicle speed decreases is generated when the deceleration limit value is small.

7. The target vehicle speed generation method of the drive assist vehicle according to claim 5 or 6,

in generating the target deceleration, the deceleration impact limit value is set to be larger in a direction of relaxing the limit of the deceleration impact, the lower the limit speed is.

8. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 1 to 7,

and when the speed limit information is obtained, obtaining legal speed based on the identification road sign as the speed limit.

9. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 1 to 7,

in acquiring the speed limit information, a legal speed based on advance information from map data is acquired as the speed limit.

10. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 1 to 7,

when the speed limit information is acquired, when the speed limit cannot be acquired from the road sign or the map data, a speed determined based on a speed that is a speed that can travel without largely deviating from the traffic flow is acquired as the speed limit based on the traffic flow information estimated based on the plurality of pieces of surrounding vehicle position information obtained from the vehicle-mounted sensors.

11. The target vehicle speed generation method of the drive assist vehicle according to any one of claims 8 to 10,

when the speed limit information is acquired, when a plurality of speed limits are acquired, the minimum value of the plurality of speed limits is selected as the speed limit.

12. A target vehicle speed generation device for a driving assistance vehicle, comprising a controller for generating a target vehicle speed of the vehicle based on a speed limit of a vehicle travel path,

the controller includes:

a speed limit information acquiring unit that acquires a speed limit of a vehicle traveling route during traveling; and

a target vehicle speed generation unit that generates a target acceleration while generating a target vehicle speed on the basis of the limit speed,

the target vehicle speed generation unit sets the acceleration limit value to be larger in a direction of relaxing the acceleration limit, as the limit speed is higher, when generating the target acceleration.

Technical Field

The present invention relates to a target vehicle speed generation method and a target vehicle speed generation device for a driving assistance vehicle that generate a target acceleration/deceleration of a vehicle based on a speed limit of a vehicle travel path.

Background

Conventionally, a vehicle speed limiting device is known which sets a limit acceleration in accordance with a deviation between a limit speed and a vehicle speed of the vehicle (for example, see patent document 1).

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional apparatus, only the deviation between the speed limit and the vehicle speed itself is considered, and the speed limit itself is not considered, so that it is difficult to achieve both of an appropriate sense of acceleration in the high-speed highway running with the speed limit and the low-speed urban running with the speed limit. That is, when the deviation between the limit speed and the own vehicle speed is the same, the same acceleration (vehicle speed increase gradient) is set. Therefore, if the acceleration is set to be suitable for restricting the acceleration during running on a highway with a high speed, the acceleration during running in the urban area is too fast, which disturbs the traffic flow and gives passengers a sense of incongruity. On the other hand, if the acceleration is set to be suitable for restricting the acceleration during urban driving at a low speed, the acceleration is insufficient during highway driving, traffic flow is disturbed, and passengers feel uncomfortable.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique for preventing passengers from being uncomfortable without disturbing a traffic flow, in accordance with various roads having different speed restrictions when driving with driving assistance.

Means for solving the problems

In order to achieve the above object, the present invention is a target vehicle speed generation method for driving an auxiliary vehicle in accordance with a target vehicle speed of a host vehicle generated from a speed limit of a travel path of the host vehicle.

During traveling, the speed limit of the traveling path of the vehicle is acquired.

And generating a target vehicle speed according to the limit speed, and simultaneously generating a target acceleration.

In generating the target acceleration, the acceleration limit value is set to be larger in a direction of relaxing the acceleration limit as the limit speed is higher.

Effects of the invention

As described above, by making a vehicle speed plan having an acceleration characteristic according to the speed limit of the vehicle traveling path, it is possible to cope with various roads having different speed limits when traveling by driving assistance, and prevent passengers from being inconvenienced without disturbing the traffic flow.

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 according to embodiment 1 are applied.

Fig. 2 is a block diagram showing the detailed configuration of the target vehicle speed generation means of the target vehicle speed generation method and the target vehicle speed generation device of embodiment 1.

Fig. 3 is a flowchart showing the flow of the acceleration characteristic control process executed by the automatic driving control unit of embodiment 1.

Fig. 4 is a flowchart showing the flow of the speed limit setting process in step S2 of the flowchart of fig. 3.

Fig. 5 is a flowchart showing the flow of the acceleration limit setting process in step S3 of the flowchart of fig. 3.

Fig. 6 is a map showing an example of the 1 st acceleration limit map used in the acceleration limit setting process.

Fig. 7 is a speed difference explanatory diagram showing a speed difference between the limit speed and the actual vehicle speed.

Fig. 8 is a map showing an example of the 2 nd acceleration limit diagram used in the acceleration limit setting process.

Fig. 9 is a flowchart showing the flow of the deceleration characteristic control process executed by the automated driving control unit of embodiment 1.

Fig. 10 is a flowchart showing the flow of the deceleration limit setting process in step S5 of the flowchart of fig. 9.

Fig. 11 is a map showing an example of a deceleration limit map used in the deceleration limit setting process.

Fig. 12 is an explanatory view showing the merging action in a merging road from a general road to an expressway.

Fig. 13 is a time chart showing vehicle speed characteristics based on acceleration when merging from a suburban road to an expressway and vehicle speed characteristics based on acceleration when starting from a stop on an urban road in a comparative example.

Fig. 14 is a time chart showing vehicle speed characteristics based on acceleration when merging from a suburban road to an expressway and vehicle speed characteristics based on acceleration when taking off from a stop on an urban road in embodiment 1.

Fig. 15 is a time chart showing vehicle speed characteristics based on deceleration when branching from an expressway to a suburban highway and vehicle speed characteristics based on deceleration when stopping from low-speed travel on an urban highway in embodiment 1.

Detailed Description

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