JPS6085379A - Moving direction discriminator - Google Patents

Abstract

PURPOSE:To enable the discrimination of the moving direction when a reflecting member is displaced with respect to an ultrasonic vibrator by converting an electrical signal into an ultrasonic wave to be beamed through a propagation medium while an ultrasonic vibrator is used and provided with a terminal to enable the transmitting and receiving of the electrical signal. CONSTITUTION:A continuous sine wave signal which was generated from an oscillator 12 for oscillating sine waves at the resonance frequency of an ultrasonic vibrator 3 is inputted into an ultrasonic wave position sensor 14 through a buffer circuit 13. When the continuous sine wave signal is applied to the vibrator 3 in the position sensor 14, the vibrator 3 beams ultrasonic waves continuously through an ultrasonic propagation medium 2. The ultrasonic wave travels through the medium, reaches an ultrasonic wave reflecting member 4 and then reflected to return to the vibrator 3 again. The position of the reflecting member 4 is movable longitudinally. At this point, if the frequency of the ultrasonic signal is higher by several MHzs, the ultrasonic wave travels straight as light does and is reflected. When an ultrasonic wave propagation path is relatively short, the condition of the wave front (within several tens cm) is satisfactory and the ultrasonic wave signal with the phase arrayed properly reciprocates through the medium.

Description

Detailed Description of the Invention (Technical Field) This invention detects relative position changes between two points in all displacement directions using an ultrasonic position sensor that utilizes the body axis, reflection, and interference of ultrasonic signals. Direction of movement: 1゛] A separate device is required.

(Prior Art) Many examples have been reported in which the entire distance between two points is measured by fixing the propagation time of ultrasonic waves.

In most cases, ultrasonic length measurement, such as an ultrasonic transducer, uses a material to which the object to be measured is self-piercing or conjugated with the object to be measured as the propagation medium for ultrasonic waves. All measurements are performed using ultrasonic waves propagating through the medium.Therefore, it is necessary to compensate for the different sound velocities depending on the propagation medium.
There are many points that need to be considered, such as removal of external noise and percentage reduction in S/N ratio deterioration due to transmission loss. However, from the outside, the development of cutting-edge ultrasonic transducers such as piezoelectric ceramics progressed,
Nowadays, it is easy to generate ultrasonic waves with known wavelengths, where the wave length is several to several tens of MHz and the wavelength in the propagation medium is several tens of micrometers. The industrial practical value is considered to be very high. Wave dynamics of ultrasonic waves with short wavelength and well-aligned phase? (In order to fully utilize the.

It is necessary to keep the -B wave propagation medium in a negative state so as not to disturb the regular wave nature of the ultrasonic signal.

For this purpose, ultrasonic wave #t at using a method of emitting all ultrasonic waves into a medium filled in a closed container and detecting the same.
seems to be suitable.

(Summary of the present invention) The invention is based on the phase of the ultrasonic wave. A device in which a standing wave is generated between the two and the amplitude value information and phase information of this standing wave are used to determine the direction of movement when the reflecting part phase is displaced with respect to the ultrasonic sensor. It is.

(1st layer configuration) FIG.
It is 2. A fluid ultrasonic propagation medium 2 is enclosed in a container 1 having a closed structure. ijA An ultrasonic sensor 6 with a smooth blush and vibrating in the thickness direction is located on the inner wall of the container.
Also, the vibration of this vibrator! An ultrasonic reflecting member 4 for reflecting ultrasonic waves in parallel with and facing the IQ+ surface is installed. This reflective part is attached to the sensing frame 5, and by not moving the sensing frame from the outside of the container,
Only the distance crystal can be changed while maintaining the parallel distance with the vibrator. Inside the container, there are air bubbles for absorbing non-invasive ultrasonic waves and for absorbing pressure changes inside the container caused by the movement of the button frame. A sound-absorbing member 6 containing the sound-absorbing member 6 is installed.The installation field D1 of this sound-absorbing member is such that it does not impede the ultrasonic waves propagating back and forth between the transducer and the reflecting member, and is located between the reflecting member and the sensing frame. Choose a place where there is no support for moving; 1.

A wire for transmitting and receiving electrical signals from the ultrasonic transducer is connected to the detection terminal 7. The detection terminal 7 is connected to the ultrasonic electric signal y;;1 function fi:1.

Next, the sensing frame of this super position sensor 10 is in the front j4:
The 11th device that determines the direction of movement when the object moves to the other direction will be described. To simplify the explanation, first detect ψ;1”
, : All sine wave signals having the resonant frequencies of the ultrasonic transducer 6 and the transducer 7 are input, and ultrasonic waves are continuously emitted from the ultrasonic transducer 6 into the ultrasonic propagation medium 2. The ultrasonic wave propagates through the metal, reaches the reflection phase 4, is reflected, and is again determined to be the oscillator. At this time, j: lJ is the transducer surface. The amplitude and phase of the standing wave generated between
/2) is the period for the tolerance X between these two planes [number of months]. In other words, if the reflection coefficient @yiR on the two reflecting member surfaces, the wavelength constant in the ultra f'4 wave transmission (intermediate) is lc, and the angular frequency is ω, then the sound pressure P of the standing wave is.

P=p'T"j"R%-)-2Rcos 21cx c
It is given by os(ωt-44). However, p is a constant determined by the intensity of the incident wave and the properties of the ultrasonic propagation medium. here.

Using the relationship k=2π/λ, the amplitude A of the above equation P is.

A-pi71-7; τL”+2i is also cos(4πX/λ
)-, and the maximum value 'fi: is obtained every time the distance #I#x moves by a half wavelength (λ/2). At the same time, the phase φ of the above formula P is 1/2 the same as the amplitude A for the movement of the distance X, the length C,
2/2), and the magnitude is 41 times with respect to the amplitude A.
is delayed by V2. (Look at the cross point.) The sound pressure P of the current wave is the distance l from the transducer surface to the reflecting member surface! For l1FX, the amplitude A is changed at a period of half a wavelength (λ/2), and the phase φ, which is 1, has a period of the same half wavelength with a phase delay of π/2 with respect to the change in amplitude A. Sharpen with.

Now, based on my knowledge, the principle of determining the direction of movement of the reflective part with respect to the vibrator will be explained in detail with reference to FIG. FIG. 2(a) shows a change 8 in the phase φ and a change 9 in the amplitude A depending on the distance X of the reflective part from the vibrator. These values are Jjj: large value and no 1
The history values are normalized to all 1 and -1. Divide one period (λ/2) of these two periodic functions into at least two parts, create a total of multiple combinations of two types of signals divided into two or more, and calculate the variation of these multiple sets <Ii! The purpose is to determine the direction of movement based on the f'i order. In the embodiment shown in FIG. 2, the two-phase signal 111 8 and the amplitude signal 9 are converted into a binary signal 10.11 in which plus and minus correspond to 1 and 0 by means of zero-crossing detection or the like. Here, since there is a phase difference of π/2 between the phase signal and the amplitude signal, four combinations (1,0), (1,1),
(0,1), , (0,0) can be created.

These combinations are (1,0) → (1,1) → (0,1)
→(0,0) or (0,0)→(U,1)'
- Distance 1 depending on whether it changes from (1, 1) → (1, 0)
'ii? The moving direction of X can be determined.

Next, an embodiment of the device i' for the moving direction i4 using this principle will be described using a block diagram. tHS 3 Figure 3 shows the configuration of one embodiment of the present invention and is one block M.

A continuous sine wave signal generated by an oscillator 12 that generates a full sine wave at the resonance y1 wave number of the ultrasonic transducer B is input to the ultrasonic position sensor 14 through the buffer circuit 13.

When the continuous sinusoidal signal is applied to the transducer 3 in the position sensor 14, the perturber 3 continuously emits ultrasonic waves into the ultrablind wave propagation medium 2, and this ultrasonic wave It travels through the medium, reaches the ultrasonic reflecting member 4, is reflected, and returns to the vibrator 6 again. The position of the reflecting member 4 can be moved back and forth as indicated by the arrow. At this time, if the frequency of the ultrasonic signal is as high as several N2, the ultrasonic wave travels in a straight line like a field of light.

and reflective. Furthermore, if the ultrasonic propagation path is relatively short (within several tens of meters), the wavefront is in good condition and the ultrasonic signals with well-aligned nine phases reciprocate in the medium. In the ultrasonic position sensor 14, the transducer surface and the reflecting member surface are kept parallel, and the wavefront of the sound wave reflected by the reflecting member 7 and returned is parallel to the transducer surface. Therefore, the vibrator causes a piezoelectric phenomenon due to the sound pressure of this ultrasonic wave, and generates a voltage. -However, since the continuous sine wave signal from the first emitter 12 is applied to the vibrator, the voltage generated by the two reflected ultrasonic signals changes the internal resistance of the vibrator and changes the current flowing into the vibrator. It appears as. In other words, when a reflected ultrasonic signal that is in phase with the sine wave signal applied to the vibrator is applied to the vibrator, the AC voltage generated by the pressure 1- phenomenon becomes in phase with the current voltage applied to the vibrator,
#i As a result, it becomes difficult for alternating current to flow. On the other hand, if two reflected ultrasound signals are applied to the perturber with opposite phases, the alternating current will flow more easily. All this alternating current is generated by the oscillator 12
The voltage is supplied from the buffer circuit 16 and flows through the swing shaft and the foot in common. Therefore, if the current value changes due to the piezoelectric phenomenon of the vibrator due to the voltage of the standing wave generated between the vibrator surface and the reflective material surface, the output terminal voltage of the +641 buffer circuit also changes. The output terminal voltage signal of this buffer circuit and the oscillator 12
The phase difference with the output signal of
Converts to 0. At the same time, the output terminal voltage signal of this buffer circuit is envelope-detected by a wave detector 16, extracted as a divided value signal 9, and further converted into, for example, a binary amplitude signal 11. Next, phase comparator 15 and detector 1
A phase signal 10 and an amplitude signal 1 outputted from 6 and 6, respectively.
1 and the direction detection device 17 in the four types of combinations (1, 0) + (1, 1), (0
, 1) , (Ot[]) All changes in these combinations 1) Determine the direction of movement of the reversing member 4 or the sensing rod 5. Figure 4 shows the direction and simple implementation of the detection device.1
yli'fr: Not shown. First, the one-shot time 11'61B which outputs a rectangular wave pulse at the rising edge of the signal 11 all input rectangular wave signals shown in FIG. 2(a), and the falling point 9 of the same input rectangular wave 1i is input to the one-shot time 1·ψ+19 which outputs a rectangular wave pulse. 'i fc 2
f42 (a) shows [/taat;+l] (?t No. 1o All hrpD is input to gate circuits 20 and 21. Therefore, in the graph of FIG. 2(a), as the distance)li+X increases, 1itj of When exceeding X+, the amplitude signal 11
rises, a rectangular wave pulse is output from the one-shicott circuit 18 and enters the gate 20. At this time, the phase signal 10 has a value of 1 and 9 gates 20, so the output from the one-shot circuit 18 passes through the gate 20 and is input to the input terminal 26 of the Allan down counter 220, and the V2 wavelength The minutes are counted. A similar thing occurs when distance X passes through X3 increasing from left to right.

Furthermore, a cup wavelength is added. Conversely, the distance 1fifj x
is X.

When moving from the right to the left in the direction of decreasing numbers and passing through these two points X1 y xA,
The falling amplitude signal 11 is outputted as a rectangular wave pulse by the one-shot circuit 19 and inputted to the gate 21 . At this time, since the phase signal 10 also takes the value 1, the gate 2
1 is open and one shot times j'? The output from +19 passes through gate 21 and enters up/down counter 2.
2 is input to the countdown input terminal 24 and r'i
'Two wavelengths are subtracted. Further, the counted values in units of all the dedicated wavelengths are outputted to the display 25 and displayed. Also,
When the distance X passes the point X2 to the right or left, the two one-shot circuits 18 and 19 output rectangular wave pulses depending on the case, but at this time the phase signal 10
The value becomes a broom, and the two games) 20 and 21 are closed, so they are not counted by the up-down counter.

(Effects) As explained above, the present invention converts electrical signals into ultrasonic waves and emits ultrasonic waves into a propagation medium.

Ultrasonic waves arriving from a propagation medium All-electric I/I A position sensor is configured to obtain information about the reflection ml facing parallel to the test vibration surface and the distance or position in the perpendicular direction to the vibration surface. If the reflection im is made movable by a completely external drive mechanism, actuator, etc., its position information can be accurately transmitted online. can be expressed. Furthermore, in the present invention, by using sound waves as the sensor, not only the amplitude value information but also the phase information can be directly determined independently, all directions of movement can be easily determined, and It has also become possible to improve the accuracy of the amount of movement at the same time.Also, by incorporating all the ultrasonic waves into the container of the position sensor, it is possible to prevent S from being inferior due to external noise and propagation attenuation. The fact that we have now been able to do this is promising in the future as it provides a simple means of detecting the displacement direction in precise displacement measurements.In particular, it is possible to obtain a wide dynamic range at the same time as a high Jli'i pillow. Worth the hoe.

[Brief explanation of drawings]

Figure 1 is a tjf3 diagram of the ultrahair wave position sensor. FIG. 2 is a detailed explanatory diagram of the present invention. FIG. 3 is a block diagram of an embodiment of the present invention. FIG. 4 is a circuit diagram of an embodiment of the direction detection device. 1 in the figure is a container. 2 is a super, fs wave propagation medium. 6 is an ultrasonic vibrator. 4 is an ultrasonic reflection system. 5 is a sensing stick. 6 is the Hanon component. 7 is Moko. 8 is the sound pressure phase signal. 9 is a sound pressure amplitude value signal. 10 is phase binarization. 11 is an amplitude binary signal. 12 is an oscillator. 13 is a buffer circuit. 14 is a hair wave position sensor. 15 is a phase comparator. 16 is a detector. 17 is a direction detection device. 18 is a one-shot circuit at the rising edge. 19 is a one-shot circuit at the falling edge. 20 and 21 are ANi) gates. 22 is an up/down counter. 26 is the input terminal for counting. 24 is an input terminal for counting down. 25 is a display device. Takekui Applicant: Anritsu Electric Co., Ltd. Agent: Patent Attorney Koike ff1J Abe Figure 1 Figure 2 (b) (1,0') (1, 1') (0,1) (0,0)
(1,0) (1,1) (0,1) (0,0)Figure 3Figure 4//

Claims (1)

[Claims] Electricity (R) is converted into ultrasonic waves and all the ultrasonic waves are emitted into the propagation medium, and the ultrasonic waves arriving from the propagation medium are 'Tj+
an ultrasonic transducer (6) having a vibration surface that converts into air signals;
414 is formed with the terminal (7) connected to the vibrator, and a transducer for detecting the relative movement in the perpendicular direction of one vibration of the reflecting surface facing parallel to the vibrating surface. a sonic position sensor (14); an excavator (12) for inputting an alternating current signal for exciting the vibrator to the terminal; and an excavator (12) for passing the output of the oscillator substantially in one direction to the terminal of the sensor a buffer circuit M (15) for inputting and outputting a signal indicating the relative position of the reflecting surface with respect to the vibrator from the terminal and adding the signal to the output of the oscillator; a phase comparator (15) which outputs a full phase difference signal by specifically collecting the phase between the output and the output of the oscillator; and detecting the envelope of the added output from the buffer circuit to obtain a υ amplitude value. A signal full-output faithful detector (16): detects the reflection surface of the sensor based on the change in the phase difference signal and the change in the amplitude value signal obtained in response to the change in the relative position of the reflection surface. A moving direction determining device 1g-0 comprising a direction detecting device (17) that detects the moving direction of the relative position with respect to the vibrator.