JPH04163250A - Obstacle detecting device for vehicle - Google Patents

Abstract

PURPOSE:To detect the position of an obstacle in a narrow range with high precision through the detecting operation of sensors by detecting the presence of the obstacle in a wide range by means of stationary sensors and rotating a moving sensor by a motor by means of that detecting signal therefrom. CONSTITUTION:During running of a vehicle, ultrasonic waves S1 having low directional properties are transmitted from stationary sensors 15 and 16 under control of a control unit 19 and it is decided whether or not an obstacle F is detected by the stationary sensors 15 and 16. When it is decided that the obstacle is detected, a transmission signal is outputted to a moving sensor 13 to transmit ultrasonic waves having high directional properties S. It is decided whether or not the moving sensor 13 detects the obstacle F, and when it is decided that the sensor does not detect the obstacle, for example, when the stationary sensors 15 and 16 detect the obstacle F, a signal for rotation in a direction L is outputted to a ultrasonic motor 11, and the moving sensor 13 is rotated in the direction of an arrow mark L until the moving sensor 13 detects the obstacle F. When the moving sensor 13 detects the obstacle F, a distance and a direction to the obstacle F are computed, and a computing result is displayed on a display unit 20.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is provided in a vehicle such as an automobile, and is suitable for use in detecting obstacles such as pedestrians in the blind spot of the automobile. The present invention relates to an obstacle detection device.

[Prior Art] FIG. 4 shows an example in which a vehicle obstacle detection device according to the prior art is used as a rear safety confirmation device.

In the figure, 1 is a car as a vehicle, 2 is the car 1
2 shows an ultrasonic sensor installed at the rear of the ultrasonic sensor 2. The ultrasonic sensor 2 is composed of a vibrator, a horn (none of which are shown), and the like. The ultrasonic sensor 2 is connected to a control unit (none of which is shown) via a lead wire, and directs highly directional ultrasonic waves S toward the rear of the automobile 1 based on a signal transmitted from the control unit. At the same time, the ultrasonic wave reflected by an obstacle F such as a pedestrian is received, converted into an electrical signal, and outputted to the control unit as an obstacle detection signal. Further, the ultrasonic sensor 2 is rotated in the direction of arrow A in the figure by an electric motor (not shown).

The rear safety confirmation device according to the prior art has the above-described configuration, and the control unit outputs a multiplication signal to cause the ultrasonic sensor 2 to emit highly directional ultrasonic waves S, and also controls the electric motor using a rotation signal. The rotational force of the electric motor is transmitted to the ultrasonic sensor 2 via a reducer (not shown), etc., thereby rotating the ultrasonic sensor 2 in the direction of arrow A. The highly directional ultrasonic waves S emitted from the ultrasonic sensor 2 are transmitted to obstacles F such as pedestrians.
When the wave is reflected by the ultrasonic sensor 2, the vibrator receives the reflected wave, converts it into an electrical signal, and outputs it to the control unit. Thus, the control unit determines the position of the obstacle F based on the detection signal from the ultrasonic sensor 2 and the detection signal from a motor rotation position detection sensor (not shown) such as a rotary encoder provided on the electric motor. can be specified and notified to the driver via a display in the driver's cabin, a buzzer (none of which are shown), etc.

[Problems to be Solved by the Invention] By the way, in the above-mentioned conventional technology, the ultrasonic sensor 2 is rotated in the direction of arrow A by an electric motor while transmitting highly directional ultrasonic waves S from the ultrasonic sensor 2. By doing so, it is possible to scan the rear of the vehicle 1 with highly directional ultrasonic waves S, and detect obstacles F such as pedestrians with high precision. However, since the electric motor is constantly driven, not only do its parts wear out and its lifespan is significantly shortened, but also mechanical play occurs, reducing detection accuracy and significantly reducing reliability. There is.

On the other hand, in order to solve the above problem, for example, it is possible to install a large number of ultrasonic sensors at the rear of the car 1 and use these ultrasonic sensors by electrically switching them sequentially. There are problems in that the entire structure becomes complicated and large, and the cost increases significantly.

The present invention has been made in view of the problems of the prior art described above, and the present invention can detect obstacles such as pedestrians with high accuracy.
An object of the present invention is to provide an obstacle detection device for a vehicle that can improve longevity and reliability.

[Means for Solving the Problems] The configuration adopted by the present invention in order to solve the above-mentioned problems includes a motor that is provided in a vehicle and rotates in response to a control signal, and a motor that is rotationally driven by the motor and that prevents obstacles within a narrow range. a first detection means that detects an object and outputs a detection signal; a second detection means that is fixedly provided on the vehicle and detects an obstacle within a wide range and outputs a detection signal; and detection operation control means for outputting the control signal to the motor based on the detection signal from the second detection means and causing the first detection means to perform a detection operation.

[Function] With the above configuration, the second detection means can detect the presence or absence of an obstacle within a wide range, and the detection operation control means outputs a control signal to the motor based on this detection signal, and the second detection means outputs a control signal to the motor via the motor. The obstacle can be detected within a narrow range by rotationally driving the first detection means and causing the first detection means to perform a detection operation.

[Example] Hereinafter, examples of the present invention will be described based on FIGS. 1 to 3.
This will be explained using an example where it is used as a rear safety confirmation device. In the embodiment, the same components as those in the prior art described above are given the same reference numerals, and their explanations will be omitted.

In the figure, reference numeral 11 indicates an ultrasonic motor as a motor that is installed at the rear of the automobile 1 and is composed of a rotor, an elastic body, a piezoelectric body (not shown), etc. It is connected to a control unit 19, which will be described later. Further, the ultrasonic motor 11 is provided with a motor rotational position detection sensor (not shown) such as a low rotation encoder. The ultrasonic motor 11 rotates in the R direction about the axis 0-0 in response to a rotation signal as a control signal output from the control unit 19, and is movable via the rotation axis 11A as described below. sensor 1
3 to rotate.

That is, reference numeral 13 denotes an ultrasonic sensor (
The movable sensor 13 is connected to a control unit 19 via a lead wire 14. Further, the movable sensor 13 is always positioned on the axis O-0 when not in operation by the ultrasonic motor 11. The movable sensor 13 is rotated by one ultrasonic motor in the R direction indicated by the arrow, and the control unit 19
A highly directional ultrasonic wave S is emitted by a transmission signal as a control signal from the controller, and the ultrasonic wave S hits an obstacle F such as a pedestrian and receives the reflected wave, which is converted into an electrical signal. It is configured to output to the control unit 19.

Reference numerals 15 and 16 indicate a left side fixed sensor and a right side fixed sensor as second detection means located on both the left and right sides of the movable sensor 13 and fixed to the rear of the automobile 1, and each of the fixed sensors 1
5 and 16 are composed of ultrasonic sensors (not shown), etc.;
Lead wire 17. ．． Control unit 1 via 18
9 is connected. And each fixed sensor 15,1
6 emits a low-directional ultrasonic wave S1 in response to a transmission signal from the control unit 19, and when this ultrasonic wave 8 hits an obstacle F and is reflected, it receives this reflected wave and converts it into an electrical signal, which is then sent to the obstacle F. It is arranged to be outputted to the control unit 19 as an object detection signal.

19 indicates control units 1 to 19 consisting of arithmetic processing circuits such as a CPU, storage circuits such as ROM and RAM, etc.;
A storage area 19A is provided in the storage circuit of the controller/roll unit 19, and a second
Programs shown in the figure and the like are stored. The control unit 19 outputs a rotation signal and a transmission signal as control signals to the ultrasonic motor 11 and each ultrasonic sensor 13, 15, 16,
6. The position of the obstacle P behind the vehicle 1 is specified based on each detection signal from the motor rotation position detection sensor, and this is notified to the driver outside via the display 20. .

The rear safety confirmation device according to this embodiment has the above-mentioned configuration, and the detection operation control process will be explained next with reference to FIG. 2.

First, in step 1, the control unit 19 outputs a transmission signal to each fixed sensor 15, 16 to cause each fixed sensor 15, 16 to emit ultrasonic waves S with low directivity, and in step 2, each fixed sensor Sensors 15 and 16 are obstacles F
is detected. In this step 2, “NO”
”, the process returns to step 1 and continues to emit ultrasonic waves S1 with low directivity from each of the fixed sensors 15 and 16. Furthermore, when it is determined that rYESJ is determined in step 2, this means that there is an obstacle F within the wide detection range formed by the ultrasonic waves S from each of the fixed sensors 15 and 16, so the process moves to the next step 3. Now, it is necessary to accurately identify the position of this obstacle F (and output a transmission signal to the movable sensor 13 to transmit highly directional ultrasonic waves S.

Next, in step 4, it is determined whether the movable sensor 13 has detected the obstacle F whose presence or absence was detected in step 2. When the determination in step 4 is "NO", as shown in FIG.
Proceeding to step 5, it is determined whether the left or right fixed sensor 15, 16 detected the obstacle F in step 2. If it is determined to be "left" in step 5, this means that there is an obstacle F within the detection range of the left fixed sensor 15 as shown in FIG. The movable sensor 13 outputs step 4 as shown by the dashed line in FIG.
While rotating the movable sensor 13 in the direction of the arrow until the obstacle F is detected, highly directional ultrasonic waves S are emitted.

Furthermore, when it is determined in step 5 that the object is on the right, this means that there is an obstacle F within the detection range of the fixed right sensor 16, so the process moves to step 7. The movable sensor 13 is rotated in the direction of arrow R until the obstacle F is detected, and highly directional ultrasonic waves S are emitted.

Then, when the movable sensor 13 detects the obstacle F, the step 4 determines that it is rYEsJ and moves to the next step 8. In this step 8, the distance and direction to the obstacle F are calculated based on the obstacle detection signal from the movable sensor 13 and the rotational position detection signal from the motor rotational position detection sensor, and thereby the position of the obstacle F is calculated. Identify. In the next step 9, the position information of the obstacle F obtained in the step 8 is outputted and displayed on the display 20, and at the same time, in step 1
0, a return signal is output to the ultrasonic motor 11 to drive it, and the movable sensor 13 is placed on standby on the axis 0-0, which is the initial position.

(Thus, according to this embodiment, as shown in FIG. 3, if there is an obstacle F such as a pedestrian behind the vehicle I, first,
The presence or absence of this obstacle F can be reliably detected by the low-directivity ultrasonic waves S1 from the fixed sensors 15 and 16, and the control unit 19 moves the movable sensor 13 in the direction of the arrow using the ultrasonic motor 11 based on this detection signal. , by transmitting highly directional ultrasonic waves S while rotating in the R direction, the position of the obstacle F can be identified with high precision, and this position can be displayed on the display 20 to notify the driver, and the vehicle 1 can be moved backwards. Driving safety can be greatly improved. Further, since the ultrasonic motor 11 can be driven only when the fixed sensors 15 and 16 detect the presence or absence of the obstacle F, the ultrasonic motor 11 can be operated efficiently and wear of various parts can be effectively prevented. Not only can the durability and lifespan be greatly improved, but since the movable sensor 13 is on standby on the axis 0-O during non-detection operation, the distance traveled in the direction of arrow R during detection operation can be shortened. (It is possible to significantly shorten the detection time for the obstacle F.

In the above embodiment, the program shown in FIG. 2 is a specific example of the detection operation control means which is a component of the present invention.

Further, in the above embodiment, the first. As a second detection means,
A movable sensor 13 consisting of an ultrasonic sensor, etc., and a fixed sensor 1
5 and 16, the obstacle F is detected by ultrasonic waves, but the present invention is not limited to this. For example, the movable sensor and the fixed sensor may be composed of a photodiode, a lens, etc., and the obstacle F is detected by an ultrasonic wave. It may be detected by.

Furthermore, in the embodiments described above, a rotating body is used as the motor.

Although it has been described that the ultrasonic motor 11 made of an elastic body or the like is used, for example, an electric motor may be used instead.

Furthermore, in the embodiment described above, the fixed sensors 15 and 16 as the second detection means are positioned on both the left and right sides of the movable sensor 13 and are fixed to the rear of the automobile 1. For example, three or four fixed sensors may be provided at the rear of the automobile 1.

Further, in the above embodiment, the vehicle obstacle detection device is used as a rear safety confirmation device, but the present invention is not limited to this. It may also be used as a forward safety confirmation device.

[Effects of the Invention] As detailed above, according to the present invention, provided in a vehicle,
a motor that rotates in response to a control signal; a first detection means that is rotationally driven by the motor and that detects an obstacle within a narrow range and outputs a detection signal; a second detection means that detects an obstacle and outputs a detection signal; and outputs the control signal to the motor based on the detection signal from the second detection means, and causes the first detection means to perform a detection operation. Since the second detection means can detect the presence or absence of an obstacle within a wide range, the detection operation control means outputs a control signal to the motor based on this detection signal. The first detection means is rotationally driven via a motor, and the first detection means is caused to perform a detection operation, thereby making it possible to accurately detect the position of an obstacle within a narrow range. It is possible to effectively prevent various parts of the motor from being worn out due to driving, and it is possible to improve the durability and life of the vehicle obstacle detection device.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, FIG. 1 is an overall configuration diagram of a vehicle obstacle detection device according to this embodiment, FIG. 2 is a flow chart showing detection operation control processing, and FIG. 3 is a flowchart showing a detection operation control process. is an explanatory diagram showing the obstacle detection status of the movable sensor and the fixed sensor;
The figure is a configuration diagram of a vehicle obstacle detection device according to the prior art. 11... Ultrasonic motor (motor), 13... Movable sensor (first detection means), 15.16... Fixed sensor (second detection means). Patent applicant Japan Electronics Co., Ltd.

Claims (1)

[Claims] a motor provided on a vehicle and rotated by a control signal; a first detection means rotationally driven by the motor to detect an obstacle within a narrow range and output a detection signal; and a first detection means fixedly provided on the vehicle. , a second detection means for detecting obstacles within a wide range and outputting a detection signal; and outputting the control signal to the motor based on the detection signal from the second detection means; An obstacle detection device for a vehicle comprising detection operation control means for causing the detection means to perform a detection operation.