JPH07128455A - Contact detector - Google Patents

Abstract

PURPOSE:To provide a contact detector which can specify a position where collapse deformation occurs and degree of collapse deformation due to contact concerning contact detector. CONSTITUTION:An elastomer tube 10 is formed out of an elastomer. An ultrasonic sensor 11 is arranged at one end of the elastomer tube 10 and transmits ultrasonic waves at a fixed cycle. A measurement circuit measures a period of time from transmission of ultrasonic waves to detection of ultrasonic waves reflected by the collapse deformation of the elastomer tube 10 by an ultrsonic sensor 11, thereby measuring a deformation position of the elastomer tube 10. Further, the measurement circuit measures a degree of collapse deformation of the elastomer tube 10 according to the detected intensity of reflected ultrasonic waves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact detecting device, and more particularly to a contact detecting device for detecting contact of an object.

[0002]

2. Description of the Related Art Conventionally, as a device for detecting the contact of an object, there is a contact detecting device described in, for example, Japanese Patent Application Laid-Open No. 61-253487.

In this contact detecting device, a light emitting element or an ultrasonic wave transmitting element is provided at one end of a rubber tube, and a light receiving element or an ultrasonic wave receiving element is provided at the other end of the rubber tube. When deformed, the inner diameter of the tube is reduced and the light receiving level or the receiving level is lowered. Therefore, when the light receiving level or the receiving level becomes equal to or less than a predetermined value, it is determined that an object has come into contact with the rubber tube.

[0004]

However, the conventional device is
The first problem is that it is impossible to detect the contact position of the rubber tube at which the object contacts. Furthermore, there is a second problem that it is not possible to determine what the contact pressure is when an object contacts.

The present invention has been made in view of the above points,
A first object of the present invention is to provide a contact detection device capable of specifying the occurrence position of crush deformation due to contact of an object by measuring the time from the transmission of ultrasonic waves to the reception of ultrasonic waves reflected by the crush deformation of an elastic tube. A second object of the present invention is to provide a contact detection device capable of detecting the collapse deformation degree of a tube.

[0006]

A contact detection device of the present invention comprises an elastic tube formed of an elastic body and an ultrasonic wave which is disposed at one end of the elastic tube and which transmits ultrasonic waves at a constant cycle. Measuring the crush deformation position of the elastic tube by measuring the time from the sensor and the ultrasonic wave being transmitted until the ultrasonic wave reflected by the crush deformation of the elastic tube is detected by the ultrasonic sensor And a measuring circuit for

Further, the measuring circuit measures the degree of crush deformation of the elastic tube according to the detected intensity of the reflected ultrasonic waves.

The measuring circuit measures the degree of collapse deformation of the elastic tube based on the amount of time change of the detection signal of the ultrasonic sensor.

[0009]

In the present invention, the time from the transmission of ultrasonic waves to the reception of the ultrasonic waves reflected by the crush deformation of the elastic tube is measured, and this measured time is set to the distance from the ultrasonic sensor to the crush deformation. By corresponding, it is possible to know the collapse deformation position, that is, the contact position.

Further, the greater the degree of crush deformation, the greater the amount of reflection of ultrasonic waves. Therefore, the degree of crush deformation can be known from the detected intensity of the reflected ultrasonic waves.

Further, the greater the degree of crush deformation, the greater the amount of reflection of ultrasonic waves, and the greater the slope of the increase or attenuation of the ultrasonic detection signal, that is, the amount of change with time. You can

[0012]

1 is a block diagram of an embodiment of the device of the present invention. In the figure, 10 is a rubber tube as an elastic tube. The rubber tube 10 is elastically deformed by the contact of an object, and its cross-sectional area changes. Rubber tube 10
An ultrasonic sensor 11 is fitted and attached to one end of the closed position. The other end of the rubber tube 10 is open. However, the other end may be closed.

As shown in FIG. 2, the ultrasonic sensor 11 has a structure in which a piezoelectric ceramic plate 14 having a horn-shaped resonator 12 is fixed to a base 15 and covered with an open type case 16, and between terminals 17a and 17b. When a high frequency oscillating signal is applied to the horn 12, ultrasonic waves are transmitted forward from the horn 12, and the horn 12 receives the ultrasonic waves and outputs high frequency signals from the terminals 17a and 17b.

The transmitting / receiving circuit 18 shown in FIG. 1 supplies a high-frequency oscillation signal to the ultrasonic sensor 11 and a high-frequency signal output from the ultrasonic sensor 11, and analyzes the signal.

FIG. 3 is a block diagram of a first embodiment of the signal analysis section in the transmission / reception circuit 18, and FIG. 4 is a signal waveform diagram of each section of the transmission / reception circuit 18. The transmitter / receiver circuit 18 is shown in FIG.
When the rectangular wave shown in FIG. 5 (A) is at the H level, a high-frequency transmission signal of a constant frequency is supplied to the ultrasonic sensor 11 for several to several tens of cycles, and the ultrasonic wave is emitted. The high frequency signal output from 11 is received. The above rectangular wave is a signal with a constant period.

In FIG. 3, the terminal 21 receives a high frequency signal received by the ultrasonic sensor 11 as shown in FIGS. 4 (B) and 5 (B). This high frequency signal is transmitted to the preamplifier 2
After being amplified by 2, it is full-wave rectified by the rectifier circuit 23 and
(C) and a signal as shown in FIG. 5 (C). The full-wave rectified signal output from the rectifying circuit 23 is integrated by the integrating circuit 24 and then compared with the reference level by the comparing circuit 25. The comparison circuit 25 outputs a comparison result signal as shown in FIGS. 4 (D) and 5 (D), which is H level when the level of the full-wave rectified signal is below the reference level and L level when the level exceeds the reference level. .

The comparison result signal is supplied to the measuring circuit 26. The measuring circuit 26 is composed of, for example, a microcomputer or a clock generator and a counter, and has a terminal 2
The rectangular wave shown in FIG. 4 (A) and FIG. 5 (A) is supplied from 7. The measurement circuit 26 measures the time ΔT ₁ from the rising time of the rectangular wave to the falling time of the second negative polarity pulse of the comparison result signal, and at the same time, measures the pulse width ΔT of the second negative polarity pulse of the comparison result signal. Measure ₂ .

Immediately after the falling of the rectangular wave shown in FIGS. 4A and 5A, the level increase of the full-wave rectified signal shown in FIGS. 4C and 5C is in the transmission state. Is a noise that accompanies the transition from the receiving state to the receiving state, and is always generated even if the rubber tube 10 is not in contact with an object. When the rubber tube 10 is not in contact with the object, the second level increase from immediately after the falling of the rectangular wave of the full-wave rectified signal does not occur, and thus, FIG. 4 (D) and FIG. 5 (D)
The second negative pulse from the trailing edge of the rectangular wave of the comparison result signal shown in FIG.

However, when an object comes into contact with the rubber tube 10 and the rubber tube 10 is crushed and deformed, the ultrasonic wave transmitted from the ultrasonic sensor 11 and reflected by the deformed portion is received by the ultrasonic sensor 11, 4 (C) and 5
The second level increase occurs immediately after the falling of the rectangular wave of the full-wave rectified signal shown in (C), and the second negative electrode immediately after the falling of the rectangular wave of the comparison result signal shown in FIGS. 4 (D) and 5 (D). A sex pulse is generated.

Time ΔT ₁ from the rising time of the rectangular wave to the falling time of the second negative polarity pulse of the comparison result signal
Is the relationship between the length L of the rubber tube 10 from the position where the ultrasonic sensor 11 is attached to the collapse deformation position and the following expression.

L = ΔT ₁ × V / 2 where V is the speed of sound.

That is, by measuring the time ΔT ₁ , it is possible to know the collapse deformation position generated in the rubber tube 10.

Further, the second level increase immediately after the rising of the rectangular wave of the full-wave rectified signal becomes larger because the amount of reflected ultrasonic waves becomes larger as the size of the crush deformation becomes larger. Therefore, as the level of the full-wave rectified signal increases, the integrated signal of the full-wave rectified signal has a longer period of exceeding the reference level.
This prolongs the time ΔT ₂ . That is, time ΔT
By measuring ₂ , it is possible to know that the crush deformation of the rubber tube 10 is larger as the time ΔT ₂ is longer, that is, the degree of tube deformation.

FIG. 6 shows a block diagram of a second embodiment of the signal analysis section in the transmission / reception circuit 18. In the figure, those parts which are the same as those corresponding parts in FIG. 3 are designated by the same reference numerals, and a description thereof will be omitted. In FIG. 6, the integrated signal output from the integration circuit 24, which is obtained by rectifying and integrating the output signals of the ultrasonic sensors 11 shown in FIGS. 7B and 7C, is supplied to the peak detection circuit 35 and the measurement circuit 36. . FIG. 7B shows that when the deformation is large,
(C) is a waveform when the crush deformation is small.

The peak detection circuit 35 detects the peak of the integrated signal and supplies a peak detection pulse which rises at the peak position and falls after a predetermined time Δt from the peak position to the measurement circuit 36 as shown in FIG. 7D. .

The measuring circuit 36 is supplied with the rectangular wave shown in FIG. 7A from the terminal 27. The measuring circuit 36 samples and holds the integrated signal levels V ₁ and V ₂ or V ₃ and V ₄ at the rising and falling edges of the second peak detection pulse from the rising edge of the rectangular wave, and the difference between the two sample values. ΔV (= V ₁ −V ₂ or V ₃ −V ₄ ) is measured.

Here, the greater the size of the crush deformation, the greater the amount of reflection of the ultrasonic waves, and the larger the slope of increase or attenuation of the second integral signal immediately after the rising of the rectangular wave, that is, the amount of time change ΔV / Δt, becomes larger. The magnitude of the crush deformation, that is, the crush deformation degree of the tube can be known from the time change amount ΔV / Δt.

By the way, in this contact detecting device, for example, the rubber tube 10 can be attached to the bumper of the vehicle to be used for detecting the contact of foreign matters, and the rubber tube can be attached to the underfloor of the vehicle to dig into under the vehicle, for example. The rubber tube 10 can be attached to the slide door or the sunroof portion to detect the trapping when the slide door or the sunroof is closed.

In addition, the contact position or contact pressure with the rubber tube 10 can also be determined.

As another application of this contact detection device, a signal output device for outputting a signal having a different value depending on the crushing deformation position of the rubber tube 10 is installed, and the signal from the signal output device is sent to a computer or the like. When connected, it becomes possible to input data to a computer or the like through the rubber tube.

Furthermore, it is possible to apply the output signal from the signal output device to a sounding signal output device of an electronic musical instrument.
In this case, a scale information converter that converts the output signal into scale information and a sound source that emits sound according to the scale information may be provided, and an unprecedented electronic musical instrument can be configured.

When applied to an electronic musical instrument, the size of crushing is converted into a modulation signal, and the sound output from the sound source is subtly changed according to the modulation signal.
It is also possible to improve performance expression.

For example, the volume of sound emitted may be increased in proportion to the size of the collapse, or the pitch (pitch) may be changed in proportion to the size of the collapse.

As described above, the contact detection device of the present invention can be applied to various fields such as contact detection of an object and various data input.

[0035]

As described above, according to the contact detecting apparatus of the present invention, the contact of the object is measured by measuring the time from the transmission of the ultrasonic wave to the reception of the ultrasonic wave reflected by the elastic deformation of the elastic tube. It is possible to identify the position of the crush deformation due to, and further, to know the crush deformation degree of the tube from the detection intensity of the reflected ultrasonic wave or the time change amount of the detection signal of the ultrasonic sensor, which is extremely useful in practice. .

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus of the present invention.

FIG. 2 is a structural diagram of an ultrasonic sensor.

FIG. 3 is a block diagram of a signal analysis unit.

FIG. 4 is a signal waveform diagram of each part of the transmission / reception circuit.

FIG. 5 is a signal waveform diagram of each part of the transmission / reception circuit.

FIG. 6 is a block diagram of a signal analysis unit.

FIG. 7 is a signal waveform diagram of each part of the transmission / reception circuit.

[Explanation of symbols]

 10 Rubber Tube 11 Ultrasonic Sensor 18 Transmitter / Receiver Circuit 23 Rectifier Circuit 24 Integrator Circuit 25 Comparison Circuit 26, 36 Measurement Circuit 35 Peak Detection Circuit

Claims (3)

[Claims] 1. An elastic tube formed of an elastic body, an ultrasonic sensor which is disposed at one end of the elastic tube and which emits ultrasonic waves at a constant cycle, and after transmitting the ultrasonic waves, A contact having a measuring circuit for measuring the time until the ultrasonic wave reflected by the elastic deformation of the elastic tube is detected by the ultrasonic sensor to measure the elastic deformation position of the elastic tube. Detection device. 2. The contact detection device according to claim 1, wherein the measurement circuit measures a crush deformation degree of the elastic tube according to a detection intensity of reflected ultrasonic waves. 3. The contact detection device according to claim 1, wherein the measurement circuit measures a crush deformation degree of the elastic tube based on a time change amount of a detection signal of the ultrasonic sensor.