JP2020175700A - Stopping assistance device - Google Patents

Abstract

To provide a stopping assistance device that sets an appropriate stopping point in accordance with an actual road environment.SOLUTION: A stopping assistance device 1 comprises: an information acquisition unit 171 that acquires information about an own vehicle and external environment information during travel from a camera 11, a navigation device 12 and various sensors installed in the vehicle 2; a stop candidate point detection unit 172 that, using as an observation point a position of the own vehicle at a point in time that the information is acquired, detects a stop candidate point lowest in possibility of being collided; an information storage unit 174 that stores the acquired information, the observation point and the stop candidate point in association with one another; and a target stop point setting unit 173 that, in a case where there is a stop request, specifies a stoppable range from the information about the own vehicle and the external environment information at a point of time that the stop request arises, and selects and sets, as a target stop point, the stop candidate point lowest in the possibility of being collided, which is within the stoppable range.SELECTED DRAWING: Figure 1

Description

The present invention relates to a stop support device for stopping a moving vehicle at an appropriate stop point.

If the driver becomes unable to drive normally due to a sudden change in physical condition while driving, or if it becomes necessary to automatically stop the vehicle due to an incoming call on a mobile phone while driving, etc., the driver will take the place of the driver. A device for stopping a vehicle is known.

For example, in Patent Document 1, when a driver's abnormality is detected, the vehicle stops at a stop point with a long line-of-sight distance such as a straight road in cooperation with a vehicle navigation device so that the vehicle does not collide with a following vehicle while the vehicle is stopped. It is disclosed to do.

Japanese Unexamined Patent Publication No. 2017-190048

However, in the setting of the stop point based on the line-of-sight distance using the information from the navigation device shown in Patent Document 1, the line-of-sight distance of the actual road environment such as obstacles and weather without information in the navigation device is obtained. The impact is not considered.

Therefore, an object of the present invention is to provide a stop support device that stops at an appropriate stop point according to an actual road environment.

In order to solve the above problems, the stop support device of the present invention has an information acquisition unit that acquires information on the own vehicle and external environment information while the vehicle is running, and at the time when the information is acquired based on the acquired information. Information storage that stores the stop candidate point detection unit that detects the stop candidate point with the least possibility of collision using the own vehicle position as the observation point, the acquired information, the observation point, and the stop candidate point. When there is a stop request, the stop range is specified by referring to the information of the own vehicle and the external environment information at the time when the stop request is made, and a plurality of stop candidate points stored in the information storage unit. It is characterized by including a target stop point setting unit that selects and sets a stop candidate point having the smallest possibility of being hit by the vehicle within the stoptable range as a target stop point.

According to this configuration, considering the external environmental information that is not reflected in the map information of the navigation device, etc., the possibility of a rear-end collision is the highest at each point in the section where the own vehicle has traveled in the past or in the time zone. By setting the stop candidate point with the smallest possibility of a rear-end collision from the small stop candidate points as the target stop point, the vehicle can be stopped according to the actual road environment.

Here, the possibility of being hit by a vehicle is the possibility of being hit by a following vehicle. The longer the line-of-sight distance of the own vehicle from the following vehicle at the stop point, the smaller the possibility of a rear-end collision.
Further, the line-of-sight distance means the maximum value of the distance from the following vehicle to the vehicle in a state where the stopped vehicle can be visually recognized from the following vehicle.

In the present invention, the stop candidate point detection unit uses the distance from the observation point at the time of acquiring the information to the farthest point where the traveling lane can be visually recognized as the line-of-sight distance, and the traveling lane near the frontmost point from the farthest point. Alternatively, the point on the shoulder of the road is detected as a candidate stop point. According to this configuration, the point having the longest line-of-sight distance at the time of acquiring the information, that is, the point having the smallest possibility of a rear-end collision can be detected as a stop candidate point.

In the present invention, the target stop point setting unit has a stop model formula that specifies a range in which the own vehicle can stop based on the information acquired by the information acquisition unit, and at least the own vehicle is the own vehicle in the stop model formula. Includes an equation to calculate the distance from the current speed to a complete stop with the maximum deceleration of. According to this configuration, it is possible to calculate the range in which the vehicle can be stopped in consideration of the performance of the own vehicle, and it is possible to avoid setting a stop candidate point that cannot be stopped beyond the performance of the own vehicle as a target stop point. ..

In the present invention, the stop model formula includes at least one of deceleration considering the relative relationship with the following vehicle or deceleration considering the comfort of the occupant, and the calculated maximum deceleration of the own vehicle. Specify the range in which the vehicle can be stopped with the one with the lower deceleration as the deceleration of the own vehicle. According to this configuration, it is possible to specify the stop range in consideration of the relative relationship with the following vehicle without causing the occupant to feel uncomfortable.

According to the present invention, it is possible to provide a stop support device capable of selecting and setting an appropriate stop point according to a moving vehicle.

It is a block diagram which shows the stop support device which concerns on embodiment of this invention. It is a figure which shows the relationship between the length of the line-of-sight distance and the possibility of a rear-end collision. It is a flowchart which shows the stop support control. It is a figure which shows the relationship of each point in the process performed by the stop support device during general traveling which concerns on embodiment of this invention. It is a figure which shows the relationship between a traveling lane and a shoulder. It is a schematic diagram which shows each point in the process performed by the stop support device when the automatic stop request which concerns on embodiment of this invention occurs. It is a figure which shows the line-of-sight distance and the stop position.

Hereinafter, embodiments will be described with reference to the accompanying drawings. For the sake of simplicity, the same components are designated by the same reference numerals in each drawing, and duplicate description will be omitted.

First, the configuration of the vehicle stop support device (hereinafter referred to as “device 1”) according to the embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the functions of the device 1. The device 1 is mounted on the vehicle and assists in stopping the running vehicle when an automatic stop is required. In the present specification, the vehicle on which the device 1 is mounted is referred to as "vehicle 2".

The device 1 includes a camera 11, a navigation device 12, a vehicle speed sensor 13, a wheel speed sensor 14, a following vehicle speed sensor 15, a following vehicle distance sensor 16, an ECU 17 (Electronic Control Unit), and the like. It has.

The camera 11 photographs the outside of the vehicle 2, particularly the front of the vehicle, and acquires an image. The camera 11 is installed near, for example, a rearview mirror. The camera 11 can communicate with the ECU 17 and provides a signal corresponding to the image data acquired by the ECU 17 at the request of the ECU 17 or actively.

The navigation device 12 provides information to the occupants of the vehicle 2. The navigation device 12 provides, for example, map information stored inside the navigation device 12 or map information acquired by communicating with a server outside the vehicle. The map information includes the road shape and the maximum speed stipulated by law for each road. In addition, the map information may include information on points where ambulances such as fire stations and hospitals are deployed, and traffic conditions on each road such as traffic congestion and traffic flow speed. Further, the navigation device 12 has a function of detecting the vehicle position by GPS (Global Positioning System), a sensor and an algorithm of self-contained navigation, and the like. Further, the navigation device can communicate with the ECU 17, and at the request of the ECU 17 or actively provides the ECU 17 with the map information and the position information of the own vehicle.

The vehicle speed sensor 13 is a sensor that detects the speed of the vehicle. The vehicle speed sensor 13 can communicate with the ECU 17, and transmits a signal corresponding to the vehicle speed detected by the ECU 17 to the ECU 17 at the request of the ECU 17 or actively.

The wheel speed sensor 14 is a sensor that detects the speed of one wheel or all wheels of the vehicle. The wheel speed sensor 14 can communicate with the ECU 17, and transmits a signal corresponding to the wheel speed detected to the ECU 17 at the request of the ECU 17 or actively.

The following vehicle speed sensor 15 is a sensor that detects the speed of the following vehicle or the relative speed between the own vehicle and the following vehicle. The following vehicle speed sensor 15 can communicate with the ECU 17 and transmits a signal corresponding to the detected speed of the following vehicle detected by the ECU 17 at the request of the ECU 17 or actively. The following vehicle speed sensor 15 may transmit a signal corresponding to the relative speed between the own vehicle and the following vehicle, not limited to the speed of the following vehicle.

The following vehicle distance sensor 16 is a sensor that detects the relative distance between the own vehicle and the following vehicle. The following vehicle distance sensor 16 can communicate with the ECU 17, and transmits a signal corresponding to the relative distance between the own vehicle and the following vehicle detected by the ECU 17 at the request of the ECU 17 or actively.

The information acquired by the vehicle speed sensor 13, the wheel speed sensor 14, the following vehicle speed sensor 15, and the following vehicle distance sensor 16 is used to specify the range in which the own vehicle can stop when an automatic stop request occurs. Information. The sensor that acquires the information that identifies the range in which the own vehicle can stop is not limited to the sensor shown in FIG. 1, and can be appropriately set by those skilled in the art.

The ECU 17 is a control device that controls a device by transmitting and receiving signals. Part or all of the ECU 17 is composed of an analog circuit or a digital processor. The ECU 17 has an information acquisition unit 171, a stop candidate point detection unit 172, a storage unit 173, and a target stop point setting unit 174.

Further, FIG. 1 shows each functional block of the ECU 17. However, the software module incorporated in the analog circuit of the ECU 17 or the digital processor does not necessarily have to be divided as shown in FIG. That is, each functional block shown in FIG. 1 may be further divided, or a plurality of functional blocks may be integrated into a single functional block. Further, it is not necessary to integrate each functional block into one ECU as shown in FIG. 1, and the function may be performed by a plurality of ECUs. Those skilled in the art can appropriately change the configuration as long as the configuration can execute the processing described later.

The information acquisition unit 171 communicates with the camera 11, the navigation device 12, the vehicle speed sensor 13, the wheel speed sensor 14, the following vehicle speed sensor 15, and the following vehicle distance sensor 16 installed in the vehicle to acquire various information. To do.

The stop candidate point detection unit 172 detects the point where the possibility of a rear-end collision at the position of the own vehicle is the smallest, that is, the point where the line-of-sight distance is the longest at predetermined time intervals, and one vehicle slightly before the point can stop. A point within the range is set as a stop candidate point at that time. The line-of-sight distance may be calculated from, for example, an image acquired by the camera 11, or a sensor that directly measures a physical quantity mounted on the vehicle 2, such as an infrared sensor or an ultrasonic sensor, or information outside the vehicle, for example, periodically. Map information from the updated navigation device 12 may be used.

Figure 2 shows the relationship between the line-of-sight distance and the possibility of a rear-end collision. The longer the line-of-sight distance, the longer the operation time of the avoidance movement after the following vehicle visually recognizes the stopped vehicle, and the smaller the possibility of a rear-end collision. On the other hand, the shorter the line-of-sight distance, the shorter the operation time of the avoidance movement after the following vehicle visually recognizes the stopped vehicle, and the greater the possibility of a rear-end collision.
For example, if the vehicle is stopped on a curved or undulating road, or if there are obstacles such as walls or roadside trees near the road, the line-of-sight distance at the point where the vehicle is stopped is compared. It is short and has a high possibility of being hit. On the other hand, if the vehicle is stopped on a straight road or a flat road, or if there are few obstacles near the road, the line-of-sight distance at the point where the vehicle is stopped is relatively long and the possibility of a rear-end collision is small. .. The road condition, obstacles in the vicinity, and the like are determined from the image acquired by the camera 11 by the ECU 17. Further, information included in the map information such as road changes such as curves may be acquired from the navigation device 12.

The target stop point setting unit 173 sets a plurality of stop candidate points stored in the information storage unit 174, information such as the line-of-sight distance associated with the information, and one stop candidate point satisfying a predetermined condition described later as a stop point. select.

The information storage unit 174 temporarily stores the acquired information, the detected stop candidate point, and the line-of-sight distance information at the stop candidate point. The information storage unit 174 is composed of, for example, a non-volatile memory, and information can be written and read by the information acquisition unit 171, the stop candidate point detection unit 172, and the target stop point setting unit 173, and various calculation results can be obtained. Used.

Next, the process of the stop support device 1 will be described with reference to FIGS. 3, 4, 5, and 6. FIG. 3 is a flowchart of a process that the ECU 17 constantly executes while the vehicle is driving, and the process is repeatedly executed at predetermined intervals while the vehicle is running. FIG. 4 is a diagram showing the relationship between each point in the processing performed by the stop support device 1 during general driving. FIG. 5 is a diagram showing the relationship between the traveling lane and the shoulder. FIG. 6 is a diagram showing the relationship between each point in the processing performed by the stop support device 1 when an automatic stop request occurs.

First, in step S1 of FIG. 3, the ECU 17 obtains information from the navigation device 12, the camera 11, the vehicle speed sensor 13, the wheel speed sensor 14, the following vehicle speed sensor 15, and the following vehicle distance sensor 16. Acquire at predetermined intervals. Specifically, for example, when passing the point A in FIG. 4 at a predetermined time, the ECU 17 acquires image data taken by the camera 11, own vehicle position information from the navigation device 12, map information, and the like. The predetermined interval for acquiring information is a condition appropriately set by those skilled in the art according to the processing capacity of the ECU 17 and the actual traveling condition, and is, for example, a time interval such as 0.01 seconds or a traveling distance interval such as 1 meter. ..

In step S2 of FIG. 3, the ECU 17 calculates the distance to the most visible end point of the road at the current position as the line-of-sight distance. For example, the ECU 17 sets the current position of the own vehicle in FIG. 4, that is, the "endmost point" at which the white line outside the traveling lane 41 can be identified from the point A as the most visible end point EPA of the road 4, and calculates the above from the current position A point. The distance from the farthest point EPA is calculated as the line-of-sight distance a. The method of identifying the "endmost" of the white line is, for example, whether the ECU 17 has a number of pixels corresponding to a size that allows a person with a visual acuity of 1.0 to distinguish the white line (width 15 cm) from the image acquired by the camera 11. Whether or not it is detected, and immediately before the number of pixels is insufficient is regarded as the "end". The line-of-sight distance a may be calculated from the image acquired by the camera 11 as described above, or a sensor that directly measures a physical quantity mounted on the vehicle 2, such as an infrared sensor or an ultrasonic sensor, or information outside the vehicle, such as navigation. The map information from the device 12 may be used. Further, the reference for making the road visible is not limited to the white line on the outside, and may be the entire road or a part thereof.

Here, the definitions of the traveling lane 41 and the road shoulder 43 will be described. As shown in FIG. 5, the road 4 includes a traveling lane 41 in which the own vehicle travels, an outer line 42 of the traveling lane 41, and a road shoulder 43 which is a space outside the outer line 42. In addition, in FIG. 4, FIG. 6, and FIG. 7, the road shoulder 43 is not displayed in order to simplify the display.

In step S3 of FIG. 3, the ECU 17 detects a range slightly before the calculated end point EPA as a stop candidate point SPA. The stop candidate point SPA is, for example, a range in which one vehicle can stop at the farthest point EPA in the traveling direction of the road, and the range is at least the traveling lane 41 or the shoulder 43 (not shown) in the width direction of the road. Including some.

In step S4 of FIG. 3, the ECU 17 stores information such as the current position of the own vehicle, the line-of-sight distance at the current position of the own vehicle, and a candidate stop point. For example, the ECU 17 stores the stop candidate point SPA detected when passing through the current position A in FIG. 4 and the line-of-sight distance a in association with each other in the storage unit. At that time, for example, information such as the legal maximum speed at point A and the frictional force between the wheel and the road surface may be associated and stored.

When the ECU 17 receives the request to stop the own vehicle in step S5 of FIG. 3, the process proceeds to step S6 of FIG. The vehicle 2 has, for example, when it detects that the driver is in poor physical condition and cannot continue normal driving, or when the driver voluntarily presses the automatic stop button. Judging that it is necessary to stop automatically, the ECU 17 is requested to stop automatically. On the other hand, the ECU 17 acquires information from the step S1 at predetermined time intervals when there is no request to stop the own vehicle.

In step S6 of FIG. 3, the ECU 17 specifies a range in which the vehicle can stop from the current location of the own vehicle based on the acquired information and a preset stop model formula. Specifically, a predetermined condition and a mathematical formula are set in the stop model formula, and the acquired information is input to the stop model formula to calculate with the predetermined condition and the mathematical formula to specify the range in which the vehicle can stop. For example, in the vehicle stop model formula, the distance required for the vehicle to completely stop from the current position is calculated from the road surface friction coefficient calculated using the wheel speed and vehicle speed information acquired from the sensor and the maximum deceleration of the vehicle. Then, the range beyond the point corresponding to the calculated distance required for stopping is specified as the stopping range.

Therefore, as shown in FIG. 6, if the stop distance required for the own vehicle to decelerate at the maximum deceleration and stop when a stop request is made to the own vehicle at the X point is DX, the distance required for the stop is set. The range beyond the point corresponding to DX is the range DPX where the vehicle can stop.

The above has described an example of a stop model formula that considers only the maximum deceleration of the own vehicle, but the stop model formula may be set in consideration of further conditions, for example, the relative speed and distance to the following vehicle, etc. When using the stop model formula that is calculated by adding the relative relationship with the following vehicle, of the deceleration calculated so that the relative distance to the following vehicle is above a certain level and the calculated maximum deceleration of the own vehicle , The lower one may be used as the deceleration of the own vehicle to calculate the stopping distance, and the range in which the vehicle can be stopped may be specified.

In addition to the deceleration conditions that take into consideration the relative relationship with the following vehicle, for example, the deceleration conditions that do not make the occupants feel uncomfortable (for example, 0.3G or less) and the following vehicle are legally the highest. Legal conditions such as assuming that the vehicle travels at a speed may be incorporated as one condition, or a plurality of these conditions may be combined.

Information corresponding to each of the above conditions may be acquired from each sensor and navigation device 12 installed in the vehicle 2 shown in FIG. 1, or may be set or acquired in advance and stored in the information storage unit 173 of FIG. You may use the information provided. Those skilled in the art can appropriately set the conditions used for calculating the stop model formula and the method of acquiring information corresponding to the conditions.

In step S7 of FIG. 3, the ECU 17 selects and sets a stop candidate point having the smallest possibility of a rear-end collision as a target stop point within the range in which the own vehicle specified from step S6 of FIG. 3 can stop. For example, when an automatic stop request is made to the own vehicle at the X point in FIG. 6, the ECU 17 has a stop candidate point SPB (the own vehicle has passed to the B point) existing outside the range of the stoptable range DPX specified in step S6. Eliminate the stop candidate points detected at the time of the operation, and stop candidate points SPC (stop candidate points detected when the own vehicle passes to point C) and SPD (own vehicle to point D) that exist within the range of DPX. The stop candidate point SPC with the least possibility of being hit is selected and set as the target stop point from the stop candidate points detected when the passage has passed. Before selecting and setting the target stop point, the occupant may be confirmed.

According to the above embodiment, the place with the smallest possibility of a rear-end collision can be selected and set as the target stop point in consideration of the actual road condition.

Next, the relationship between the line-of-sight distance and the stop position will be described with reference to FIG. 7. When the own vehicle passes the E point, the stop candidate point SPE at the E point is detected. When the own vehicle passes the F point, the stop candidate point SPF at the F point is detected. Since the shape of the road and obstacles in the vicinity affect the line-of-sight distance, the line-of-sight distance e at the stop candidate point SPE at the entrance of the previously detected curve is the line-of-sight at the stop candidate point SPF within the curve detected later. It is longer than the distance f. A stop point can be set from a plurality of stop candidate points stored in the information storage unit 173 during past travel, and when a stop request is generated, the vehicle can stop at the point where the possibility of a rear-end collision is the smallest.

Next, the operation of the stop support device of the present embodiment will be described.
The stop support device 2 collides with the information acquisition unit 171 that acquires information on the own vehicle and external environment information while traveling, and the position of the own vehicle at the time when the information is acquired based on the acquired information as an observation point. There is a stop request, a stop candidate point detection unit 172 that detects the least probable stop candidate point, an information storage unit 174 that stores the acquired information, the observation point, and the stop candidate point in association with each other. In that case, the range in which the vehicle can be stopped is specified by referring to the information of the own vehicle and the external environment information at the time when the stop request is generated, and the stop is selected from the plurality of stop candidate points stored in the information storage unit 174. It is provided with a target stop point setting unit 173 that selects and sets a stop candidate point within a possible range with the smallest possibility of collision as a target stop point.

According to this configuration, considering the external environmental information that is not reflected in the map information of the navigation device, etc., the possibility of a rear-end collision is the highest at each point in the section where the own vehicle has traveled in the past or in the time zone. By setting a stop candidate point with the smallest possibility of a rear-end collision from a small stop candidate point as a target stop point, it is possible to stop according to the actual road environment.

The stop candidate point detection unit 172 sets the distance from the observation point at the time of acquiring the information to the farthest point where the traveling lane can be visually recognized as the line-of-sight distance, and sets the distance from the farthest point to the traveling lane or the shoulder of the road in the vicinity thereof. The point is detected as a stop candidate point. According to this configuration, the point having the longest line-of-sight distance at the time of acquiring the information, that is, the point having the smallest possibility of a rear-end collision can be detected as a stop candidate point.

The target stop point setting unit 174 has a stop model formula that specifies a range in which the own vehicle can stop based on the information acquired by the information acquisition unit 171. In the stop model formula, at least the own vehicle is the maximum of the own vehicle. Includes a formula to calculate the distance from the current speed to a complete stop with deceleration. According to this configuration, it is possible to calculate the range in which the vehicle can be stopped in consideration of the performance of the own vehicle, and it is possible to avoid setting a stop candidate point that cannot be stopped beyond the performance of the own vehicle as a target stop point. ..

In the stop model formula, at least one of the deceleration considering the relative relationship with the following vehicle or the deceleration considering the comfort of the occupant, and the maximum deceleration of the own vehicle, whichever is lower is the own vehicle. Specify the range where the vehicle can be stopped as the deceleration of. According to this configuration, it is possible to specify the stop range in consideration of the relative relationship with the following vehicle without causing the occupant to feel uncomfortable.

1 Stop support device 2 Vehicle 4 Road 11 Camera 12 Navigation device 17 ECU (Electronic Control Unit)
171 Information acquisition unit 172 Stop candidate point detection unit 173 Information storage unit 174 Target stop point setting unit SPA Stop candidate point at A point EPA The farthest point at A point DX The distance required to stop at DX X point The range that can be stopped at DPX X point

Claims (4)

Based on the information acquisition unit that acquires information on the own vehicle and external environment information while driving, and the position of the own vehicle at the time of acquiring the information as the observation point, the stop candidate with the least possibility of being hit A stop candidate point detection unit that detects points, and
An information storage unit that stores the acquired information in association with the observation point and the stop candidate point.
When there is a stop request, the range in which the vehicle can be stopped is specified by referring to the information of the own vehicle and the external environment information at the time when the stop request is made, and the stop candidate points stored in the information storage unit are selected. , A stop support device including a target stop point setting unit that selects and sets a stop candidate point within the stoptable range and having the smallest possibility of collision as a target stop point. The stop candidate point detection unit uses the distance from the observation point at the time of acquiring the information to the farthest point where the traveling lane can be visually recognized as the line-of-sight distance, and the traveling lane or the shoulder of the road near the farthest point. The stop support device according to claim 1, wherein is detected as a stop candidate point. The target stop point setting unit has a stop model formula that specifies a range in which the own vehicle can stop based on the information acquired by the information acquisition unit, and the stop model formula has at least the maximum reduction of the own vehicle by the own vehicle. The stop support device according to claim 1 or 2, wherein the vehicle includes a formula for calculating the distance from the current speed to a complete stop by speed. In the stop model formula, at least one of the deceleration considering the relative relationship with the following vehicle or the deceleration considering the comfort of the occupant, and the maximum deceleration of the own vehicle, whichever is lower is the own vehicle. The stop support device according to claim 3, which specifies the range in which the vehicle can be stopped as the deceleration of the vehicle.