JP2000009457A - Two-dimensional position detector for vehicles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-dimensional position detector for vehicles, capable of detecting the two-dimensional position of a vehicle from an obstacle. SOLUTION: A control unit 5 actuates two piezoelectric elements 11, 12 of each ultrasonic wave sensor 1-4 one after the other for only a fixed time to radiate an ultrasonic wave and receive its reflected ultrasonic wave, thereby obtaining the calculated position of an obstacle, based on the time difference between them. The piezoelectric elements 11, 12 are mounted and oriented in directions different 90 deg. and hence only the distances can be detected from input/output signals of the piezoelectric elements but the position can be obtd. as an intersection point of concentric circles with the radii of the distances.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensional position detecting apparatus for a vehicle suitable for a sonar system for detecting obstacles, a human body, etc. around a vehicle using an ultrasonic sensor comprising a piezoelectric element.

[0002]

2. Description of the Related Art Conventionally, as a vehicle-mounted sonar system for detecting the presence or absence of an obstacle or a human body around a vehicle using an ultrasonic sensor comprising a piezoelectric element or the like, or a distance to the vehicle, the detection result is "distance". Only one-dimensional data was obtained. Therefore, for example, it cannot be used as an auxiliary means in combination with a blind spot visual recognition device using a CCD camera or the like, and its use is limited. In addition, since the mounting method is such that the piezoelectric element housing is embedded in a bumper or the like of a vehicle, many man-hours are required for mounting.

[0003]

According to the present invention, two-dimensional position data of an obstacle or the like around a vehicle can be easily obtained.
Moreover, an object of the present invention is to provide a two-dimensional position detecting device for a vehicle, which can further improve its function by being combined as auxiliary means such as the blind spot visual recognition device.

[0004]

According to a first aspect of the present invention, there is provided a vehicle two-dimensional position detecting apparatus comprising: a first piezoelectric element mounted on a desired portion of a vehicle; and a first piezoelectric element. A second piezoelectric element attached to another part of the vehicle which is different from the first piezoelectric element by 90 °, and the first and second piezoelectric elements are energized to emit ultrasonic waves, and the first ultrasonic waves are reflected by the reflected ultrasonic waves.
Ultrasonic input / output means for inputting the electromotive force generated by the second and the second piezoelectric elements, the ultrasonic emission timing by the first and the second piezoelectric elements, the input timing of the reflected ultrasonic waves, and the attachment of the respective piezoelectric elements And calculating means for calculating the position of the reflection object from the position.

Further, a two-dimensional position detecting device for a vehicle according to a second aspect of the present invention includes a first part and a second part attached to a right part near the right front end of the vehicle and a front part different from the right part by 90 °. And third and fourth piezoelectric elements attached to a left portion near the front left end of the vehicle, a front portion different from the left portion by 90 °, and a rear right end of the vehicle. Fifth and sixth piezoelectric elements attached to a right side portion in the vicinity, a rear side portion different from the right side portion by 90 °, a left side portion near the rear left end portion of the vehicle, and a rear portion different from the left side portion by 90 °. The seventh and eighth piezoelectric elements attached to the side part and at least one or all of the first to eighth piezoelectric elements are energized to emit ultrasonic waves, and the first to eighth elements are reflected by the reflected ultrasonic waves. Electromotive force generated by at least one or all of the eighth piezoelectric elements An ultrasonic input / output means for inputting an ultrasonic wave, at least one or all of the first to eighth piezoelectric elements emit ultrasonic waves, input reflected ultrasonic waves, and determine the position of the reflected object from the mounting position of each piezoelectric element. And calculating means for obtaining the position.

Further, in the apparatus according to the first or second aspect of the present invention, the apparatus further comprises an image pickup device installed near the mounting position of the piezoelectric element, and display means for displaying an image by the image pickup device. May be configured to display the position of the image by the calculation means.

Further, in each of the above-described devices of the present invention, a selection means for selecting a desired piezoelectric element and requesting display of the position of a reflecting object and / or the position of an image may be provided.

Alternatively, the selection means may respond to a steering operation of the vehicle.

Further, a sound notifying means may be provided so that a corresponding piezoelectric element is selected in response to a steering operation of the vehicle and the position of the reflector is notified by sound.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a two-dimensional position detecting device for a vehicle according to the present invention will be described below. FIG. 1 shows an embodiment of a two-dimensional position detecting device for a vehicle according to the present invention. In the figure, 1 is an ultrasonic sensor mounted near the front right end of the vehicle, 2 is an ultrasonic sensor mounted near the front left end, and 3 is mounted near the right rear end of the vehicle. Reference numeral 4 denotes an ultrasonic sensor mounted near the left end of the rear portion, 5 denotes a control unit including a microcomputer, and 6 denotes a display including an LCD panel or the like. The ultrasonic sensor 1 includes piezoelectric elements 11 and 12,
Amplifiers 13 and 14 for radiation wave and amplifiers 15 and 1 for reflected wave
The amplifiers 13, 14, 15, 16 are connected to the control unit 5, and the other ultrasonic sensors have the same configuration.

FIG. 2 shows the mounting structure of the ultrasonic sensor. For example, the ultrasonic sensor 3 is housed in the mounting case 7,
The mounting case 7 is attached to a bumper 9 at the rear right end of the vehicle by an adhesive means such as a double-sided tape 8 or a screwing means.
And so on. The mounting case 7 is curved so that the mounting positions of the piezoelectric element housings 31 and 32 are different from each other by 90 degrees as shown in the figure, and the amplifier parts 34 and 35 are also mounted inside the same as shown in the figure, and the lead wire 33 therefrom is It is connected to a control unit 5 in the vehicle. Therefore, if the mounting case 7 is mounted on the right rear end of the vehicle as described above, 2
Each of the two piezoelectric elements is located on the right side of
This means that they are attached to the rear part different by 0 °.

FIG. 3 shows a case body 7a of the mounting case 7, wherein (a) is a front view, (b) is a right side view, (c) is a plan view, and (d) is an arrow A in FIG. It is an end view in the -A 'line direction. The case main body 7a is a substantially L-shaped box body having a semi-cylindrical shape at both ends, and has an engaging portion 7d which is engaged with a projection 7c described later inside the opening on the front side and the side surface. . 7
“e” is a through hole through which the lead wire 33 is inserted and drawn out of the case body 7a, and is formed in the inner wall of the case body 7a.

FIG. 4 shows a cover 7b of the mounting case 7,
(A) is a front view, (b) is a right side view, and (c) is a plan view. The cover 7b is a substantially L-shaped plate member having semicircular cutouts 7f formed at both ends, and has projections 7c formed on the upper and lower sides of the front side and the side surfaces, respectively. The cover 7b is mounted by engaging the projection 7c with the engaging portion 7d of the case body 7a, thereby closing the opening of the case body 7a. By attaching the cover 7b to the case body 7a, the inner walls at both ends of the case body 7a
A circular hole is formed with the notch 7f of b. The piezoelectric element housings 31, 32 are arranged in the case main body 7a so as to match the holes.

In FIG. 1, a control unit 5 outputs a sine wave signal of a predetermined frequency at regular intervals to each of the ultrasonic sensors 1.
4 are sequentially output for a fixed time. The output sine wave signal is amplified through, for example, radiation wave amplifiers 13 and 14 in the ultrasonic sensor 1 and input to the piezoelectric elements 11 and 12. The piezoelectric elements 11 and 12 are excited by the input signal to generate micro-vibration and emit ultrasonic waves for a fixed time.

The radiated ultrasonic wave is reflected by an obstacle, a human body, and the like around the vehicle, and the reflected ultrasonic wave is incident, which in turn causes the piezoelectric elements 11 and 12 to vibrate. An electromotive force is generated by this vibration. This electromotive force is applied to the reflected wave amplifier 15,
It is amplified via 16 and input to the control unit 5. Similarly, the above-described operation is performed in the other ultrasonic sensors 2 to 4 at regular intervals.

As shown in FIG. 5, the control unit 5 measures the time difference t from the emission of the ultrasonic wave by each of the piezoelectric elements 11 and 12 in each of the ultrasonic sensors 1 to 4 to the incidence of the reflected ultrasonic wave. Calculate the distance to etc. In each of the ultrasonic sensors 1 to 4, as described above, the two piezoelectric elements 11 and 12 are mounted in directions different from each other by 90 °, and the distance is calculated for each. Is one-dimensional. However, each piezoelectric element 11, 1
Since the position from 2 to the obstacle is on a concentric circle whose radius is the above distance, if two intersections of each of the peripheral circles are obtained by using the two piezoelectric elements 11 and 12, any one of the intersections is determined. This is the position of the obstacle with respect to the vehicle (center), which can be determined from the mounting position of the ultrasonic sensor. Thus, the position of the obstacle can be easily detected. The detected position is displayed on the screen of the display 6.

FIG. 6 shows a blind spot visual recognition device in which the above-described vehicle two-dimensional position detection device is combined as an auxiliary means. Reference numeral 20 denotes the above-described two-dimensional position detection device. Reference numeral 21 denotes a known blind spot visual recognition device. C installed near the mounting position
It has CD cameras 22 to 25. Reference numeral 26 denotes a display device which displays an image of the obstacle taken by each of the CCD cameras 22 to 25 and displays the position of the obstacle obtained by the two-dimensional position detecting device 20 as described above together with the image. Is done. Reference numeral 27 denotes a selection switch. By operating the selection switch 27, only a desired image by the CCD camera and the ultrasonic sensor and its position may be displayed. In this case, the selection switch 27 may be made to respond to the steering operation of the vehicle.

Further, in the apparatus shown in FIG. 1 or FIG. 5, an appropriate sound annunciator 28 is provided together with or instead of the display 6 and the display 26 so as to notify the position to the obstacle by audio. It may be.

[0019]

As described above, according to the present invention, it is possible to detect a two-dimensional position of an obstacle or the like, and thereby to construct a system for preventing the vehicle from traveling in the direction of the obstacle or the like. Alternatively, it can be combined as an auxiliary means of the blind spot visual recognition device when changing lanes, and the number of steps for mounting the ultrasonic sensor can be simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method of mounting an ultrasonic sensor.

FIG. 3 is a view showing a mounting case body of the ultrasonic sensor;
(A) is a front view, (b) is a right side view, (c) is a plan view,
(D) is an end view in the direction of arrows AA 'in FIG. (B).

4 (a) is a front view, FIG. 4 (b) is a right side view, and FIG. 4 (c) is a plan view.

FIG. 5 is a waveform chart for explaining the operation of the ultrasonic sensor.

FIG. 6 is a block diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1-4 Ultrasonic sensor 5 Control unit 6 Indicator 11, 12 Piezoelectric element 13, 14 Radiation wave amplifier 15, 16 Reflection wave amplifier

Claims (6)

[Claims] A first piezoelectric element attached to a desired part of the vehicle; a second piezoelectric element attached to another part of the vehicle different from the first piezoelectric element by 90 °; Ultrasonic input / output means for urging the second piezoelectric element to emit ultrasonic waves and for inputting the electromotive force generated by the first and second piezoelectric elements by reflected ultrasonic waves, and the first and second ultrasonic elements A two-dimensional position detecting device for a vehicle, comprising: calculating means for obtaining a position of a reflection object from a timing of emitting ultrasonic waves by the piezoelectric elements, an input timing of reflected ultrasonic waves, and a mounting position of each piezoelectric element. . 2. A right part near a right front end of a vehicle,
A first and a second piezoelectric element attached to a front part different by 90 °, a left part near the front left end of the vehicle, and nine parts.
Third and fourth attached to the front part different by 0 °
And a right part near the rear right end of the vehicle.
Fifth and sixth attached to the rear part different by 0 °
And a left part near the rear left end of the vehicle.
Seventh and eighth attached to the rear part different by 0 °
And the at least one or all of the first to eighth piezoelectric elements are energized to emit ultrasonic waves, and at least one or all of the first to eighth piezoelectric elements are reflected by the reflected ultrasonic waves. Ultrasonic input / output means for inputting the generated electromotive force; timing of emitting ultrasonic waves by at least one or all of the first to eighth piezoelectric elements; input timing of reflected ultrasonic waves; and mounting position of each piezoelectric element 2. A two-dimensional position detecting device for a vehicle, comprising: calculating means for further calculating the position of a reflecting object. 3. An image pickup device installed near a mounting position of the piezoelectric element, and display means for displaying an image by the image pickup device, wherein the display means displays the position of the image by the arithmetic means. The two-dimensional position detecting device for a vehicle according to claim 1, wherein the two-dimensional position detecting device is configured to perform the control. 4. The vehicle vehicle according to claim 1, further comprising a selection unit for selecting a desired piezoelectric element and requesting display of a position of a reflection object and / or a position of an image. Dimensional position detector. 5. The two-dimensional position detecting device for a vehicle according to claim 4, wherein said selecting means responds to a steering operation of the vehicle. 6. The apparatus according to claim 2, further comprising a voice notifying unit, wherein a corresponding piezoelectric element is selected in response to a steering operation of the vehicle to notify the position of the reflector by voice. 4. The two-dimensional position detecting device for vehicles according to 3.