JP2022149205A - Object detection device, vehicle and object detection method - Google Patents

Abstract

To provide an object detection device, vehicle and object detection method which can improve the estimation accuracy of a position of an object.SOLUTION: An object detection device comprises: a position detection unit which detects a position of an object around a vehicle on the basis of a reflection wave of a sound wave radiated from each of a plurality of ultrasonic sensors provided in the vehicle; a movement direction specification unit which specifies the movement direction of the object on the basis of the detected positions when the position is detected plural times; and a position estimation unit which estimates the position of the object on the basis of a distance from the one ultrasonic sensor to the object and the movement direction when the object is detected by only one ultrasonic sensor of the plurality of ultrasonic sensors after the position is detected plural times.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to object detection devices, vehicles, and object detection methods.

2. Description of the Related Art Conventionally, an object detection device is known that measures the distance to an object existing around a vehicle using a plurality of ultrasonic sensors and calculates the coordinates of the object using the principle of triangulation. In an object detection apparatus using a plurality of ultrasonic sensors, it becomes difficult to continue detecting the object well when the object moves from a position where triangulation is established to a position where triangulation is not established.

Therefore, the prior art of Patent Document 1 discloses a device that calculates the coordinates of an object from information on the orientation of the object acquired at the previous object detection timing and information on the distance measured by one ultrasonic sensor. It is

Japanese Unexamined Patent Application Publication No. 2020-91158

However, the conventional technology disclosed in Patent Document 1 only uses the information about the object acquired at the previous object detection timing. There is a problem that it is difficult to estimate.

Non-limiting embodiments of the present disclosure contribute to providing an object detection device, a vehicle, and an object detection method that can improve the accuracy of estimating the position of an object.

An object detection device according to an embodiment of the present disclosure includes a position detection unit that detects the position of an object around a vehicle based on reflected waves of sound waves emitted from each of a plurality of ultrasonic sensors provided on the vehicle. and a moving direction identifying unit that identifies a moving direction of the object based on the plurality of detected positions when the position is detected a plurality of times, and a plurality of ultrasonic sensors after the position is detected a plurality of times. position estimating unit for estimating the position of the object based on the distance from the one ultrasonic sensor to the object and the direction of movement when the object is detected by only one of the ultrasonic sensors And prepare.

A vehicle according to an embodiment of the present disclosure includes the object detection device described above.

An object detection method according to an embodiment of the present disclosure detects the position of an object around the vehicle based on reflected waves of sound waves emitted from each of a plurality of ultrasonic sensors provided on the vehicle; identifying a moving direction of the object based on the detected positions when the position is detected multiple times; and estimating the position of the object based on the distance from the one ultrasonic sensor to the object and the direction of movement when the object is detected only by an ultrasonic sensor.

According to an embodiment of the present disclosure, it is possible to provide an object detection device, a vehicle, and an object detection method capable of improving the accuracy of estimating the position of an object.

Further advantages and advantages of an embodiment of the present disclosure are apparent from the specification and drawings. Such advantages and/or advantages are provided by the several embodiments and features described in the specification and drawings, respectively, but not necessarily all to obtain one or more of the same features. No need.

1 shows a vehicle 1 equipped with an object detection device 200 according to an embodiment of the present disclosure; FIG. A diagram showing an example of the functional configuration of the object detection device 200. Flowchart for explaining the operation of the object detection device 200 FIG. 4 is a diagram showing sound waves radiated from each of the ultrasonic sensors 2-1 and 2-2 and the position of the object 100; FIG. 4 is a diagram showing sound waves radiated from each of the ultrasonic sensors 2-1 and 2-2 and the position of the object 100; FIG. 4 is a diagram showing sound waves radiated from each of the ultrasonic sensors 2-1 and 2-2 and the position of the object 100; FIG. 4 is a diagram showing sound waves radiated from each of the ultrasonic sensors 2-1 and 2-2 and the position of the object 100; A diagram for explaining the position of an object 100 detected by an object detection device 200A according to a comparative example.

Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functions are denoted by the same reference numerals, thereby omitting redundant description.

(Embodiment)
First, the background leading to the creation of the embodiments according to the present disclosure will be described.

2. Description of the Related Art Conventionally, an object detection device is known that measures the distance to an object existing around a vehicle using a plurality of ultrasonic sensors and calculates the coordinates of the object using the principle of triangulation. In an object detection apparatus using a plurality of ultrasonic sensors, it becomes difficult to continue detecting the object well when the object moves from a position where triangulation is established to a position where triangulation is not established.

Therefore, the prior art of Patent Document 1 discloses a device that calculates the coordinates of an object from information on the orientation of the object acquired at the previous object detection timing and information on the distance measured by one ultrasonic sensor. It is

However, the conventional technology disclosed in Patent Document 1 only uses the information about the object acquired at the previous object detection timing. There is a problem that it is difficult to estimate.

For this reason, it is desirable to improve the accuracy of estimating the position of an object that can be detected by a single ultrasonic sensor. Embodiments according to the present disclosure will be described below.

FIG. 1 is a diagram showing a vehicle 1 equipped with an object detection device 200 according to one embodiment of the present disclosure. The vehicle 1 includes an object detection device 200, an ultrasonic sensor 2-1, an ultrasonic sensor 2-2, an ultrasonic sensor 2-3, and an ultrasonic sensor 2-4.

Hereinafter, the ultrasonic sensor 2-1, the ultrasonic sensor 2-2, the ultrasonic sensor 2-3, and the ultrasonic sensor 2-4 may be simply referred to as the ultrasonic sensor 2 when not distinguished.

(Object detection device 200)
The object detection device 200 is a device that detects an object 100 around the vehicle 1, and is an ECU (Electronic Control Unit), for example. Details of the configuration of the object detection device 200 will be described later. Objects 100 are, for example, automobiles, motorcycles, pedestrians, small animals, walls of buildings, and the like.

(Ultrasonic sensor 2)
The ultrasonic sensor 2 is provided, for example, in the front bumper of the vehicle 1 and used to detect the position of the object 100 with respect to the vehicle 1 .

Specifically, the ultrasonic sensor 2 emits a pulsed sound wave with a constant frequency, and when the sound wave hits the object 100 , it is reflected, and part of the sound wave returns to the ultrasonic sensor 2 . As the distance from the vehicle 1 to the object 100 increases, the round trip time from when the ultrasonic sensor 2 emits a sound wave to when a part of the sound wave returns to the ultrasonic sensor 2 increases.

Using this relationship, the ultrasonic sensor 2 detects the distance to the object 100 by measuring the round trip time. The ultrasonic sensor 2 transmits distance information indicating the distance to the object 100 to the object detection device 200 .

The installation position of the ultrasonic sensor 2 is not limited to the front bumper of the vehicle 1, and may be the rear bumper of the vehicle 1, for example.

Next, an example of the functional configuration of the object detection device 200 will be described with reference to FIG. FIG. 2 is a diagram showing an example of the functional configuration of the object detection device 200. As shown in FIG.

A vehicle 1 includes an ultrasonic sensor 2 , a vehicle control device 3 and an object detection device 200 .

(Vehicle control device 3)
The vehicle control device 3 is an electronic control unit that performs various controls related to driving assistance in the vehicle 1 . For example, when the object 100 is detected by the object detection device 200, the vehicle control device 3 notifies the presence of the detected object 100 to the driver or the like, and performs brake control, steering control, and the like.

(Object detection device 200)
The object detection device 200 includes a position detection section 201 , a moving direction identification section 202 , a position estimation section 203 and a control section 204 .

(Position detector 201)
The position detection unit 201 detects the position of the object 100 existing around the vehicle 1 based on the reflected waves detected by each of the plurality of ultrasonic sensors 2 . Among the plurality of ultrasonic sensors 2, the detected reflected waves include not only the reflected waves of the sound waves transmitted by the first ultrasonic sensor itself, but also the reflected waves transmitted by the second ultrasonic sensor other than the first ultrasonic sensor. It also includes reflected waves of sound waves.

For example, the position detection unit 201 calculates the distance between each ultrasonic sensor 2 and the object 100 from the timing at which each of the plurality of ultrasonic sensors 2 detects the reflected wave at each predetermined cycle, and calculates the distance between each ultrasonic sensor 2 and the object 100. The position of the object 100 is detected from the positions of intersections of a plurality of circles centered on the radial end of 2 and having radii of each distance.

The position detection unit 201 transmits data indicating the position detected at predetermined intervals to the movement direction identification unit 202 .

(Movement direction identification unit 202)
The moving direction identifying unit 202 identifies the moving direction of the object 100 based on the data indicating the position.

For example, the movement direction identification unit 202 determines the coordinates (first coordinates) of the object 100 detected by the position detection unit 201 at a predetermined time t and the coordinates (first coordinates) of the object 100 detected at time t+1 after a predetermined time has passed from time t. A movement direction line passing through the coordinates (second coordinates) is calculated.

Note that the moving direction line may be a line that passes through at least the first coordinate and the second coordinate. For example, in addition to the first coordinate and the second coordinate, A line further passing through the coordinates of the object 100 may be used. Also, the moving direction line is not limited to a straight line, and may be a curved line.

The moving direction identifying unit 202 identifies the extending direction of the calculated moving direction line as the moving direction of the object 100 and transmits data indicating the identified moving direction to the position estimating unit 203 .

(Position estimation unit 203)
A position estimation unit 203 estimates the position of the object 100 detected by only one ultrasonic sensor 2 .

For example, the position estimating unit 203 first determines that the object 100 whose position is specified by a set of two ultrasonic sensors 2 is one It is determined whether or not it has moved to a position detected by only one ultrasonic sensor 2 .

When the object 100 moves to a position detected by only one ultrasonic sensor 2, the position estimating unit 203 draws a moving direction line in the moving direction specified by the moving direction specifying unit 202 based on the data indicating the moving direction. The position of the object 100 is estimated at the intersection of the extended line and a circle centered at the radiation end of the ultrasonic sensor 2 and having a radius equal to the distance from the radiation end to the object 100 . The position estimation unit 203 transmits data indicating the estimated position of the object 100 to the control unit 204 .

(control unit 204)
Based on the data indicating the position of the object 100, the control unit 204 transmits a signal to the vehicle control device 3 to execute notification control or the like.

(Vehicle control device 3)
When the vehicle control device 3 receives a signal for executing notification control or the like, the vehicle control device 3 performs notification control to notify the driver of the vehicle 1 that the object 100 is approaching the vehicle 1, and also controls the vehicle 1. It controls braking, steering, etc.

In the notification control, for example, an image warning that there is an object 100 that the vehicle 1 may collide with is displayed on the center display, head-up display, or the like of the vehicle 1, and a voice warning that the object 100 exists. is reproduced from the speaker mounted on the vehicle 1.

Next, the operation of the object detection device 200 will be described with reference to FIGS. 3, 4, 5, 6, and 7. FIG.

FIG. 3 is a flow chart for explaining the operation of the object detection device 200. FIG. The processing from step S1 to step S5 in FIG. 3 is repeatedly executed at a predetermined cycle (time t, t+1, t+2, . . . ). 4, 5, 6 and 7 are diagrams showing the position of the object 100 and the sound waves radiated from the ultrasonic sensors 2-1 and 2-2, respectively. The X-axis represents the direction of travel of the vehicle, and the Y-axis represents the width direction of the vehicle.

In step S1 shown in FIG. 3, the position detection unit 201 detects the object 100 with at least two ultrasonic sensors 2 based on whether or not reflected waves from the object 100 are detected by each of the at least two ultrasonic sensors 2. is detected.

When the object 100 is detected by at least two ultrasonic sensors 2 (step S1, YES), the process of step S2 is performed.

In step S2, the position detection unit 201 calculates the distance between each ultrasonic sensor 2 and the object 100 from the timing at which each ultrasonic sensor 2 detects the reflected wave, and , and the position of the object 100 is detected from the positions of intersections of a plurality of circles with radii equal to the respective distances (for example, positions P1 and P2 in FIGS. 4 to 6).

In step S3, the movement direction identifying unit 202 calculates a movement direction line RL (see FIG. 6) passing through the position of the object 100 detected this time and the position of the object 100 detected last time, and the calculated movement direction line RL The stretching direction is specified as the moving direction D of the object 100 . Then, the position detection processing of the object 100 at this time is terminated. After that, the process of step S4 is executed. The processing of step S4 will be described later.

Returning to step S1, if the object 100 is not detected by at least two ultrasonic sensors 2 (step S1, NO), the process of step S4 is executed. Here, as shown in FIG. 7, it is assumed that the object 100 has moved to a position where it can be detected only by the ultrasonic sensor 2-1.

In this case, in step S4, the position estimating unit 203 calculates a line obtained by extending the moving direction line RL calculated in the past and a distance from the radiating end of the ultrasonic sensor 2-1 to the object 100. The point of intersection with the radius circle CC is estimated as the position of object 100 (position P3 in FIG. 7).

Next, in step S<b>5 , the position estimation unit 203 transmits data indicating the estimated position of the object 100 to the vehicle control device 3 .

FIG. 8 is a diagram for explaining the position of the object 100 detected by the object detection device 200A according to the comparative example.

FIG. 8 shows the position of the object 100 and the sound waves emitted from the ultrasonic sensors 2-1 and 2-2 connected to the object detection device 200A according to the comparative example. The X-axis represents the direction of travel of the vehicle, and the Y-axis represents the width direction of the vehicle.

When the object 100 moves out of the detection range of the ultrasonic sensor 2-2 after detecting the positions P1 and P2 of the object 100, the object detection apparatus 200A detects the previously detected position P2 of the object 100. and a circle whose center is the radiation end of the ultrasonic sensor 2-1 and whose radius is the distance from the radiation end to the object 100, to detect the position of the object 100. is also conceivable.

An object that has moved from position P1 to position P2 is predicted to move to position P3R thereafter. However, with the above method, the detected position of object 100 is position P3V, so an error may occur.

On the other hand, the object detection apparatus 200 according to the present embodiment specifies the movement direction of the object 100 based on the positions of the object 100 detected by at least two ultrasonic sensors 2, and It is arranged to estimate the position of the object 100 . Therefore, even when the object 100 is detected by one ultrasonic sensor 1, it is possible to accurately estimate the position of the object 100 in the moving direction, and as a result, the automatic brake is activated at a more appropriate timing. can be triggered or an alarm can be issued.

(Another configuration example)
Object detection apparatus 200 according to the present embodiment may be configured as follows.

For example, in the arrangement of the ultrasonic sensor 2-1 and the ultrasonic sensor 2-2 as shown in FIG. , the object 100 is newly detected only by the ultrasonic sensor 2-1, and at time t+1 after a certain period of time has passed since time t, the object 100 is detected by both the ultrasonic sensor 2-1 and the ultrasonic sensor 2-2. may be

Specifically, at time t, only the distance from the emitting end of the ultrasonic sensor 2-1 to the object 100 is detected, and at time t+1, from the emitting ends of the ultrasonic sensors 2-1 and 2-2 In addition to the distance to object 100, the position of object 100 will be detected.

In this case, at time t, the position estimation unit 203 detects the detection area of the ultrasonic sensor 2-1 (the fan-shaped area corresponding to the ultrasonic sensor 2-1 in FIG. 8) on the outer boundary line ( The position corresponding to the distance to the object 100 detected by the ultrasonic sensor 2-1 on the straight line defining the left boundary of the fan-shaped area in FIG. 8 is estimated as the position of the object 100.

By performing such processing, even when the object 100 jumps out in front of the vehicle 1, the position of the object 100 can be estimated early.

As described above, the object detection device according to one embodiment of the present disclosure detects objects around the vehicle based on reflected waves of sound waves emitted from each of a plurality of ultrasonic sensors provided on the vehicle. a position detection unit for detecting a position; a movement direction identification unit for identifying a movement direction of the object based on the plurality of positions detected when the position is detected a plurality of times; Later, when the object is detected by only one ultrasonic sensor out of a plurality of ultrasonic sensors, the object is detected based on the distance from the one ultrasonic sensor to the object and the direction of movement. a position estimator for estimating a position.

With this configuration, the moving direction of the object 100 is identified based on the positions of the object 100 detected by at least two ultrasonic sensors 2, and then the position of the object 100 in the moving direction is estimated. there is Therefore, even when the object 100 is detected by one ultrasonic sensor 1, it is possible to estimate the position of the object 100 in the direction of movement. An alarm can be issued.

For example, it is understood that the following aspects also belong to the technical scope of the present disclosure.

(1) An object detection device according to an embodiment of the present disclosure detects the position of an object around a vehicle based on reflected waves of sound waves emitted from each of a plurality of ultrasonic sensors provided on the vehicle. a position detection unit, a movement direction identification unit that identifies a movement direction of the object based on the plurality of detected positions when the position is detected a plurality of times, and a plurality of When the object is detected by only one of the ultrasonic sensors, the position of the object is estimated based on the distance from the one ultrasonic sensor to the object and the moving direction. and a position estimator.

(2) After the object is newly detected by only one of the plurality of ultrasonic sensors, the position estimating unit is configured to detect the position outside the vehicle in the detection area of the one ultrasonic sensor. and is on the boundary line of and corresponding to the distance to the object detected by the one ultrasonic sensor is estimated as the position of the object.

(3) A vehicle according to an embodiment of the present disclosure includes the object detection device described above.

(4) An object detection method according to an embodiment of the present disclosure detects the position of an object around the vehicle based on reflected waves of sound waves emitted from each of a plurality of ultrasonic sensors provided on the vehicle. identifying a moving direction of the object based on the plurality of detected positions when the position is detected a plurality of times; and estimating the position of the object based on the distance from the one ultrasonic sensor to the object and the direction of movement when the object is detected by only one ultrasonic sensor of .

Various embodiments have been described above with reference to the drawings, but it goes without saying that the present disclosure is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope described in the present disclosure, and it is understood that these also belong to the technical scope of the present disclosure. be. Also, the components in the above embodiments may be combined arbitrarily within the scope of the present disclosure.

Although specific examples of the present disclosure have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims may include various modifications and changes of the specific examples illustrated in the present disclosure.

An embodiment of the present disclosure is suitable for object detection devices, vehicles and object detection methods.

1 vehicle 2 ultrasonic sensor 2-1 ultrasonic sensor 2-2 ultrasonic sensor 2-3 ultrasonic sensor 2-4 ultrasonic sensor 3 vehicle control device 100 object 200 object detection device 200A object detection device 201 position detection unit 202 movement Direction identifying unit 203 Position estimating unit 204 Control unit

Claims (4)

a position detection unit that detects the position of an object around the vehicle based on reflected waves of sound waves emitted from each of a plurality of ultrasonic sensors provided in the vehicle;
a moving direction identifying unit that identifies a moving direction of the object based on the plurality of detected positions when the position is detected a plurality of times;
After the position is detected a plurality of times, when the object is detected by only one ultrasonic sensor out of a plurality of ultrasonic sensors, the distance from the one ultrasonic sensor to the object and the movement a position estimator for estimating the position of the object based on the direction;
An object detection device comprising: After the object is newly detected by only one ultrasonic sensor out of a plurality of ultrasonic sensors, the position estimating unit detects the object on the boundary line outside the vehicle in the detection area of the one ultrasonic sensor. 2. The object detection apparatus according to claim 1, wherein a position corresponding to a distance to said object detected by said one ultrasonic sensor is estimated as the position of said object. A vehicle comprising the object detection device according to claim 1 or 2. detecting the position of an object around the vehicle based on reflected waves of sound waves emitted from each of a plurality of ultrasonic sensors provided in the vehicle;
identifying a moving direction of the object based on the plurality of detected positions when the position is detected multiple times;
After the position is detected a plurality of times, when the object is detected by only one ultrasonic sensor out of a plurality of ultrasonic sensors, the distance from the one ultrasonic sensor to the object and the movement estimating the position of the object based on the direction;
An object detection method, comprising:

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