JPH0366631B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to scanning sonar, and more particularly, to an ultrasonic sensor for bulk detection that detects all target areas at once, and a directional sensor with a limited detection area. The present invention relates to a scanning sonar comprising an ultrasonic sensor.

Conventional technology Conventional scanning sonar uses a directional ultrasonic sensor with a limited detection area, scans the target area by sequentially changing the direction of the sensor using a motor, detects the presence or absence of an object, and detects the presence or absence of an object. The direction of the object is detected from the direction of the directional ultrasonic sensor when the object is moving.

Problems with the conventional technology In the conventional scanning sonar described above, the direction of the directional ultrasonic sensor is sequentially changed and detection is performed multiple times to cover the entire target area. In order to detect an object, it is necessary to wait until the directional ultrasonic sensor is pointed in that direction, and there is a problem in that it lacks a quick response to detect the presence or absence of an object.

Additionally, a motor-driven scanning mechanism is typically used to change the orientation of the directional ultrasonic sensor, but the scanning mechanism is overworked and has a short lifespan.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a scanning sonar that has improved responsiveness for detecting the presence or absence of an object and has a longer service life.

Structure of the Invention The scanning sonar of the present invention performs detection by sequentially changing the direction of a directional ultrasonic sensor with a limited detection area, and detects the presence of an object by determining the direction of the directional ultrasonic sensor when an object is detected. In scanning sonar that determines a position, an ultrasonic sensor for simultaneous detection is provided, which uses a hollow cylindrical transducer to be virtually omnidirectional and can detect all target areas at once. The directional ultrasonic sensor does not detect an object while the sonic sensor detects it all at once, and the directional ultrasonic sensor does not detect the object when the object is detected. The structure is characterized by the provision of a detection control means for detecting the location of an object.

Operation In the scanning sonar of the present invention, the presence or absence of an object is detected in all target areas at once using a collective detection ultrasonic sensor. This batch detection can be repeated at intervals of 100 ms or less, for example.

Therefore, the responsiveness of detecting the presence or absence of an object is significantly improved compared to the conventional technology.

Note that conventional scanning sonar requires, for example, about 1 second to detect the entire target area.

Further, the detection control means according to the present invention suspends detection by the directional ultrasonic sensor while no object is detected in the batch detection, and activates the detection only when an object is detected.

Therefore, the scanning mechanism is not overworked and its lifespan can be extended.

Furthermore, since the quick response of detecting the presence or absence of an object is ensured by the collective detection ultrasonic sensor, there is a restriction that the detection area of the directional ultrasonic sensor cannot be narrowed too much due to the need for quick response of detecting the presence or absence of an object. Since the detection area of the directional ultrasonic sensor can be arbitrarily narrowed, the resolution for detecting the direction in which an object exists can be improved.

EXAMPLES The present invention will be described in more detail below based on examples shown in the drawings. Here, FIG. 1 is a perspective view of the rear of an automobile equipped with a scanning sonar according to an embodiment of the present invention, FIG. 2 is a block diagram of the structure of an embodiment of the scanning sonar according to the present invention, and FIG. 3 is an all-in-one diagram. FIG. 4 is a plan view showing the detection areas of the detection ultrasonic sensor and the directional ultrasonic sensor, and is a flowchart of the operation of the scanning sonar shown in FIG. 2. Note that the present invention is not limited to the embodiments shown in the figures.

In Figure 1, the rear end panel A of a car
A collective detection unit 20 is installed inside the collective detection unit 20, and a hollow cylindrical electrostrictive vibrator 2 as shown in FIG. 2 is installed inside the collective detection unit 20.

Further, the rear bumper B is provided with a swivel base 40 and a directional detection unit 30, and inside the directional detection unit 30, a plate-shaped piezoelectric bimorph vibrator 3 as shown in FIG. 2 is installed. There is. The swivel base 40 has a stepping motor 4 shown in FIG.
It is driven to rotate by.

FIG. 2 shows the overall configuration of the scanning sonar 1, in which the microprocessor 5 opens the AND gate 7 or 8 at a predetermined timing, and converts the signal of a predetermined frequency output from the fundamental wave generation circuit 6 into a cylindrical shape. It is added to the electrostrictive vibrator driver 12 or the piezoelectric bimorph vibrator driver 13. Then, the cylindrical electrostrictive vibrator driver 12 drives the cylindrical electrostrictive vibrator 2 to emit ultrasonic waves, and the piezoelectric bimorph vibrator driver 13 drives the piezoelectric bimorph vibrator 3 to emit ultrasonic waves.

The signal that opens AND gate 7 or 8 is applied via OR gate 9 to set input S of R-S flip-flop 10. Therefore, the R-S flip-flop 10 is set at the timing when the AND gate 7 or 8 is opened.

The microprocessor 5 has a cylindrical electrostrictive vibrator 2
When receiving reflected ultrasonic waves using the piezoelectric bimorph transducer 3, connect the selector 15 as shown in the solid line in FIG. 2, and connect the selector 15 as shown in the solid line in FIG. Connect as shown in the dashed line.

The output signal of selector 15 is applied to reset input R of R-S flip-flop 10 through amplifier 16 and filter 17.

Therefore, the R-S flip-flop 10 is reset at the timing when the reflected ultrasonic wave is received.

The microprocessor 5 measures the time from when the R-S flip-flop 10 is set until it is reset, and determines the presence or absence of an object and the distance to the object based on that time.

Further, the microprocessor 5 drives the stepping motor 4 via the stepping motor driver 14 to rotate the swivel table 40 and change the direction of detection by the piezoelectric bimorph vibrator 3. Then, the direction in which the object exists is determined based on the angular position of the stepping motor 4 when the object is detected.

α shown in FIG. 3 is the cylindrical electrostrictive vibrator 2
This figure shows the detection area behind the car. Since the cylindrical electrostrictive vibrator 2 transmits and receives ultrasonic waves in its radial direction, it is substantially non-directional and can detect the rear area of the automobile all at once.

On the other hand, β shown in FIG. 3 indicates a detection area of the piezoelectric bimorph vibrator 3, and has a directivity of, for example, a half width of 30°. Therefore, in order to cover the entire detection area behind the vehicle, it is necessary to perform detection in each direction from l=0 to l=8 shown in FIG. Note that β shown in FIG. 3 depicts the detection area when the piezoelectric bimol oscillator 3 is oriented in the direction of l=4.

Next, referring to Figure 4, scanning sonar 1
Explain how it works.

When Scanning Sonar 1 starts operating,
The microprocessor 5 first initializes S1, and then opens the AND gate 7 for a predetermined period of time to emit an ultrasonic pulse from the cylindrical electrostrictive vibrator 2.
2.

Then, in step S3, the cylindrical electrostrictive vibrator 2 receives the reflected wave and analyzes the presence or absence and distance of the object based on the time required from transmission to reception.

If the existence of the object is not confirmed, the process returns to step S4 and the process returns to step S2, and the batch detection using the cylindrical electrostrictive vibrator 2 is repeated. The batch detection is repeated every 100ms, for example.

During this batch detection, the piezoelectric bimorph vibrator 3 is not operated, and the rotation scanning by the stepping motor 4 is also stopped.

When the presence of an object is detected by batch detection, step S4 drives the stepping motor 4 and sets the direction of detection by the piezoelectric bimorph vibrator 3 to l=0 in step S5.

Then, open the AND gate 8 for a predetermined period of time,
Ultrasonic waves are emitted from the piezoelectric bimorph vibrator 3 and S
6. S7 which receives the reflected wave and analyzes the presence or absence and distance of the object from the time required from transmission to reception.

If an object is detected in the direction of l=0, the direction and position are stored in step S9, and if no object is detected, nothing is done and the process moves to step S10.

In step S10, the detection direction l is turned to the next direction.

Then, the above detection is repeated until l=1, 2, 3, .

Thus, according to the scanning sonar 1, it is possible to quickly detect whether or not there is an object behind the vehicle, and also to detect the position of the object with high resolution. Furthermore, since the driving of the stepping motor 4 is stopped when the presence of an object is not detected,
There is no wear and tear, resulting in a longer service life.

Effects of the Invention According to the present invention, detection is performed by sequentially changing the direction of a directional ultrasonic sensor with a limited detection area, and the location of an object is determined based on the direction of the directional ultrasonic sensor when the object is detected. In scanning sonar, we provide an ultrasonic sensor for simultaneous detection that uses a hollow cylindrical transducer to be virtually omnidirectional and can detect all target areas at once. The directional ultrasonic sensor does not detect the object while the object is not detected by the directional ultrasonic sensor, and when the object is detected by the directional ultrasonic sensor, the directional ultrasonic sensor detects the object. A scanning sonar is provided that is characterized by being equipped with a detection control means for detecting the location of an object, which makes it possible to quickly detect the presence or absence of an object and to detect the location of the object with high resolution. . Furthermore, since detection by the directional ultrasonic sensor is suspended when an object is not present, wear and tear is reduced and the lifespan can be extended.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the rear of an automobile equipped with a scanning sonar according to an embodiment of the present invention, Fig. 2 is a block diagram of a configuration of an embodiment of the scanning sonar according to the present invention, and Fig. 3 is a block diagram for collective detection. FIG. 4 is a plan view showing the detection areas of the ultrasonic sensor and the directional ultrasonic sensor, and is a flowchart of the operation of the scanning sonar shown in FIG. 2. (Explanation of symbols), 1...Scanning sonar,
2... Cylindrical electrostrictive vibrator, 3... Piezoelectric bimorph vibrator, 4... Stepping motor, 5... Microprocessor, 15... Selector, 20...
Bulk detection unit, 30... Directionality detection unit, 40... Swivel base.

Claims (1)

[Claims] 1. Scanning, in which detection is performed by sequentially changing the direction of a directional ultrasonic sensor with a limited detection area, and the location of an object is determined based on the direction of the directional ultrasonic sensor when the object is detected.・In sonar, an ultrasonic sensor for simultaneous detection is installed, which uses a hollow cylindrical transducer to make it virtually omnidirectional and can detect all target areas at once. While the object is not detected, the directional ultrasonic sensor does not perform detection, and when the object is detected by the batch detection ultrasonic sensor, the directional ultrasonic sensor detects the object and detects the presence of the object. A scanning sonar characterized by having a detection control means for detecting the position.