JPH0359478B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention provides an echo method for a moving body such as a rotating body or a reciprocating body by using an energy storage type vibrating element, for example, a piezoelectric sensor such as a crystal oscillator, as a sensor. Regarding the measurement method of an echo telemeter that performs remote measurement in This invention relates to an echo-type mobile telemeter system that can measure both at the same time.

[Prior art]

Regarding a mobile station, when measuring physical events at the measured point and measuring the number of movements and/or movement speed (hereinafter referred to as movement speed, etc.) of the mobile object itself, conventionally, for each measurement, It is common to use separate means for measuring physical phenomena, such as a mobile telemeter that can measure without contacting the moving object to be measured, and a contact meter such as a tachometer or speedometer for measuring movement speed, etc. Shape means are used.

The above-mentioned mobile telemeter generally consists of a mobile station and a fixed station, where the mobile station is fixed to the moving object to be measured and has a sensor and a transmitter that wirelessly transmits data measured by the sensor, and the fixed station is It has a receiving device that receives the above data and an analysis device that analyzes the data received by the receiving device and displays and/or records the data as numerical values, and is installed near the moving object to be measured.

In a mobile telemeter, in order to receive measured data at a fixed station without any loss, the antennas or coupling coils (hereinafter referred to as coupling coils) of the mobile station and fixed station are always effectively coupled to each other (signal The coupling coils of the fixed station and/or mobile station are stretched over the entire range of motion of the mobile station so that both coupling coils are close enough to each other to allow transmission and reception, or If the coupling coil cannot be installed over the entire range of motion of the mobile station, the effective coupling time between the coupling coils of both stations should be limited to a part of the range of motion of the mobile station, and mechanical means such as a micro switch may be used. A method is adopted in which the movement of the mobile station and the measurement time are synchronized.

In addition, as a method of mobile telemeter, the echo telemeter method (the sensor uses a piezoelectric vibrating element, such as a crystal resonator sensor, and the sensor is externally connected A method is adopted in which the residual vibration (echo signal) of the sensor is received after the excitation is stopped.

[Problem that the invention seeks to solve]

According to the above-mentioned conventional technology, (A) the measurement system becomes complicated because it is necessary to measure the physical phenomenon and the measurement of the movement speed, etc. using separate measurement means, and the measurement data needs to be recorded separately, which makes it difficult to measure both. (B) Since the measuring means for measuring movement speed, etc. is of the contact type, the measuring means may become a load on the moving object to be measured and adversely affect the movement of the moving object. (C) In mobile telemeters, in a telemeter that uses a coupling coil that extends over the entire range of motion of the mobile station, installing the coupling coil is not only troublesome, but also may be difficult depending on the structure of the moving body to be measured. (D) In mobile telemeters, where the movement of the mobile station and the measurement time are synchronized by mechanical means, the synchronization means (micro switch) The operating force of the microswitch acts as a load on the moving object to be measured and has a negative effect on the movement of the moving object, and the residual sound generated when the contacts of the microswitch open and close may have a negative effect on the measured data. There are problems such as the fact that it is not suitable for measuring moving objects that move at high speed due to the opening and closing times of the contacts.

The present invention is proposed to solve the above-mentioned problems, and it is possible to simultaneously measure physical events and motion speed, etc.
It is an object of the present invention to provide an echo type mobile object telemeter device which is easy to operate and which can obtain accurate data without missing data even when the moving speed of a moving object to be measured is high.

[Disclosure of the invention]

For the above purposes, the present invention provides a mobile station with a first piezoelectric sensor (energy storage type vibration characteristic sensor) whose vibration frequency is constant, and a second piezoelectric sensor whose vibration frequency changes with changes in the measured event. At the same time, the connection section between the mobile station and the fixed station is set so that it does not cover the entire period of motion of the moving object to be measured, and the fixed station always transmits a signal with a frequency equal to the vibration frequency of the first piezoelectric sensor. An excitation signal is sent out intermittently, and each time the coupling section arrives, an echo signal emitted from the first piezoelectric sensor is received, and the motion speed of the moving object to be measured is measured based on the number of times the echo signal is received. In addition, upon reception of the echo signal, the fixed station starts transmitting an excitation signal whose frequency changes within the variation range of the vibration frequency of the second piezoelectric sensor, and transmits the excitation signal to the coupling section. In this way, the echo signal emitted from the second piezoelectric sensor is received and the measured event is measured from its frequency, and the movement speed etc. This allows non-contact measurement of measurement events, etc. at the same time.

[Configuration of Example]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a circuit diagram showing an example of the configuration of a mobile station, and FIG.
The figure is a diagram showing an example of a system configuration when the embodiment system of the present invention is used to measure a rotating body.
Note that the following embodiments will be described assuming that the moving object to be measured is a rotating shaft.

In FIGS. 1 to 3, 1 is a mobile station, 2 is a fixed station, and 3 is a rotating shaft that is a moving object to be measured.

First, the configuration of mobile station 1 will be explained.

Reference numeral 101 denotes a first piezoelectric sensor (hereinafter referred to as a sensor), which is composed of an energy storage type vibration characteristic element, specifically, for example, a crystal resonator, and its vibration frequency is constant. This first sensor 101 is used to measure the rotational speed and/or rotational speed (hereinafter referred to as rotational speed) of the rotating shaft 3 and to detect the start of measurement of a measured event.

102 is a second sensor, which is composed of the same elements as the first sensor, and whose vibration frequency varies depending on the temperature,
It is set to change with changes in the measured phenomena such as pressure and strain. This second sensor 102 is used to measure a measured event.

Reference numeral 103 denotes an antenna or a coupling coil (hereinafter, a coupling coil will be taken as an example), which receives an excitation signal of the first sensor 101 (hereinafter referred to as a reference excitation signal) sent from the fixed station 2 and an excitation signal of the second sensor 102. Receive an excitation signal (hereinafter referred to as measurement excitation signal),
The first sensor 101 emits an echo signal (hereinafter referred to as a reference echo signal) and the second sensor 102 emits an echo signal (hereinafter referred to as a measurement echo signal).

The mobile station 1 has a case formed in the shape of a bolt, for example, so that a small hole is provided in the rotating shaft 3 so that it can be embedded, and the first and second sensors 10 are installed inside the case.
1, 102, etc., are exposed at the head of the case, and a coupling coil 103 is provided.

If high-Q crystal oscillators are used for the first and second sensors 101 and 102, and the vibration frequency of the first sensor is set outside the change range of the vibration frequency of the second sensor but near the change range, , the first sensor 101 and the second sensor 102 are connected in parallel to a coupling coil 103 as shown in FIG.
and the second sensor 101, 102. In other words, because the Q of the first and second sensors 101 and 102 is high, the frequency of the excitation signal to one sensor does not resonate with the other sensor, and one sensor does not actuate the other sensor. There is no load that would disable it or cause vibration frequency to fluctuate.

Next, the configuration of the fixed station 2 will be explained.

201 is a reference signal oscillator that generates a signal with a constant frequency. This signal is used to create an excitation signal for the first sensor 101, and its frequency is set to a value such that the frequency after being processed by the transmitter 204 is equal to the vibration frequency of the first sensor 101. Ru.

A measurement signal oscillator 202 generates a signal whose frequency is sequentially switched in response to a signal switching pulse from the controller 211. This signal is used to create an excitation signal for the second sensor 102, and its frequency changes in steps, and the range of change is within the transmitter 204.
The frequency change range after processing is the second
The range is set to cover the range of change in the vibration frequency of the second sensor 102 (the range in which the vibration frequency of the second sensor 102 is expected to change due to a change in the measured event). Further, the amount of change in frequency at the time of switching is set to the same amount in any step, and unless a signal switching pulse is input from the controller 211, the oscillation frequency at that time is maintained.

Reference numeral 203 denotes a signal changeover switch that alternately switches between a signal from the reference signal oscillator 201 (hereinafter referred to as a reference signal) and a signal from the measurement signal oscillator 202 (hereinafter referred to as a measurement signal) using a signal changeover pulse from the controller 211. input to transmitter 204;

A transmitter 204 processes (modulates) the reference signal and measurement signal supplied from the signal changeover switch 203 to create a reference excitation signal and a measurement excitation signal. The frequency of the reference excitation signal is the same as that of the first sensor 10.
The frequency of the measurement excitation signal is equal to the vibration frequency of the second sensor 102, and changes in steps within a range that covers the range of change in the vibration frequency of the second sensor 102.

Reference numeral 205 denotes a transmission/reception switching switch, which switches the antenna or coupling coil 2 using the transmission/reception switching pulse from the controller 211.
06 is alternately connected to the transmitter 204 and the receiver 207.

206 is an antenna or a coupling coil (hereinafter, the coupling coil will be taken as an example), which receives the reference echo signal and measurement echo signal sent from the mobile station 1;
The reference excitation signal and measurement excitation signal sent from the transmitter 204 are radiated via the transmission/reception switch 205.

207 is a receiver that processes (demodulates) the frequencies of the reference echo signal and measurement echo signal inputted from the coupling coil 206 via the transmission/reception switch 205 to a frequency range for subsequent processing, and converts the reference echo signal into a frequency range for subsequent processing. When the measurement echo signal is input within the set level range, it is sent to the activation signal generator 208, and when the measurement echo signal is input within the set level range, it is sent to the second data processor 210, respectively. (referred to as demodulated signal).

Reference numeral 208 denotes a starting signal generator, which sends a starting signal to the controller 211 based on the reference echo demodulated signal from the receiver 207.

A first data processor 209 counts the number of times the activation signal is sent out from the activation signal generator 208, calculates the rotational speed of the rotating shaft 3, etc., and sends speed measurement data to the display 212.

210 is a second data processor, which is a receiver 207;
By receiving the measurement echo demodulated signal from the 212, the measured value of the event to be measured is calculated from the frequency, and the event measurement data is sent to the display 212.

Reference numeral 211 denotes a controller that constantly sends a transmission/reception switching pulse with a constant pulse width at a constant cycle to the transmission/reception switching switch 205, and controls the measurement signal oscillator 202 and signal switching while the activation signal from the activation signal generator 208 is input. A control pulse whose period and pulse width are twice those of the transmission/reception switching pulse, ie, a signal switching pulse generated by dividing the transmission/reception switching pulse by two, is sent to the switch 203.

As shown in FIG. 3, the fixed station 2 is installed with a coupling coil 206 facing a part of the periphery of the rotational shaft 3 to be measured where the mobile station 1 is attached in a non-contact manner.
The effective coupling section between the fixed station 2 and the mobile station 1 is a section B in which the mobile station 1 (at least its coupling coil 103) passes through the section where the coupling coil 206 faces each other.

[Effect of the embodiment]

FIG. 4 is a time chart for explaining the operation of the embodiment, which is shown by signal waveforms at points A to L shown in FIG. In addition, in this Figure 4,
The sections indicated by (b) and (c) indicate the operation in the sections with the same symbols shown in FIG. 3, and the signal output as an alternating current signal (high frequency signal) is indicated by its envelope.

The controller 211 always outputs a transmission/reception switching pulse with a constant pulse width at a constant cycle to point A, and the reference signal oscillator 201 always outputs a reference signal with a constant frequency R to point B.

When the rotary shaft 3 is rotating and the mobile station 1 is not in the section B, which is the connection section with the fixed station 2, the measurement signal oscillator 202 measures the frequency at the final switching step in the previous section B at point C. It is outputting a signal.
It is now assumed that when the mobile station 1 is in the H or A interval during a certain period of the rotating shaft 3, the oscillation frequency of the measurement signal oscillator 202 is the frequency n of the final switching step.

When mobile station 1 is in section A, controller 211 does not send signal switching pulses, and signal switching switch 2
03 connects the reference signal oscillator 201 to the transmitter 204, and the transmitter 204 modulates the reference signal (frequency R) output to point B to make the frequency equal to the vibration frequency of the first sensor 101. Output the reference excitation signal with frequency R to point D.

The transmission/reception switching switch 205 constantly performs switching operation (operation of switching and connecting the coupling coil 206 to the transmitter 204 or the receiver 207) by the transmission/reception switching pulse.
At point E, a reference excitation signal (frequency R) is sent from the transmitter 204 every time the transmission/reception switching pulse is at a high level (hereinafter referred to as "H"). In this way, the reference excitation signal is intermittently radiated from the coupling coil 206.

When the mobile station 1 approaches the B interval, coupling by electromagnetic induction begins to occur between the B 103 of the mobile station 1 and the coupling coil 206 of the fixed station 2, and the first sensor 101 of the mobile station 1 receives the reference excitation. Signal is coupled to coil 1
03, it resonates at frequency R as shown in FIG. 4F. This first sensor 10
The resonance intensity of 1 becomes maximum when the mobile station 1 enters the B interval.

The resonance of the first sensor 101 continues attenuating for a while even after the coupling coil 206 is switched to the receiver 207 side by the switching operation of the transmission/reception switch 205 in the fixed station 2 and the reference excitation signal is cut off. do. This damped vibration is a so-called echo signal.

The reference echo signal (frequency R) emitted from the first sensor 101 as described above is immediately emitted from the coupling coil 103, and at this time, the fixed station 2
Now, connect the coupling coil 206 with the transmission/reception switch 205.
is connected to the receiver 207 side, so the reference echo signal received by the coupling coil 206 is output to point G.

When the mobile station 1 enters the B interval and the reference echo signal output to the above G point exceeds the set level, the receiver 20
7, the receiver 207 demodulates it and outputs a reference echo demodulated signal (frequency R) at point H. The reference echo demodulated signal output to the H point is input to the activation signal generator 208, and the activation signal generator 208 thereby sends the activation signal to the controller 211 to the I point. As a result, controller 2
11 sends a signal switching pulse corresponding to a signal obtained by dividing the transmission/reception switching pulse by 2 to point J, and at the leading edge (rising edge) of this signal switching pulse, the measurement signal oscillator 202 changes the frequency of the measurement signal from n to ₁ . switching,
Further, the signal changeover switch 203 switches the input of the transmitter 204 from the reference signal oscillator 201 side to the measurement signal oscillator 202 side. Therefore, transmitter 2 is at point D.
A measurement excitation signal of frequency ₁ is output from 04.
At this time, as is clear from the phase relationship between the transmission/reception switching pulse at point A and the signal switching pulse at point J, the coupling coil 206 is connected to the output of the transmitter 204. The measurement excitation signal output to is emitted from the coupling coil 206 via point E. Like the reference excitation signal, the time during which the measurement excitation signal is emitted from the coupling coil 206 is a time corresponding to the pulse width of the transmission/reception switching pulse (the time during which the transmission/reception switching pulse is at the "H"level); When the transmit/receive switch 20 passes, the trailing edge (falling edge) of the transmit/receive switch pulse
5, the connection of the coupling coil 206 from the transmitter 204 to the receiver 207 is changed, and the fixed station 2 enters a waiting state for receiving the echo signal from the mobile station 1, and the emission of the measurement excitation signal from the coupling coil 206 is stopped.

At the leading edge of the next period of the transmission/reception switching pulse outputted to point A, the signal switching pulse outputted to point J falls, thereby causing the signal switching switch 203 to switch back to the reference signal oscillator 201 side. Switch. However, the frequency switching operation of the measurement signal oscillator 202 is performed at the rising edge (leading edge) of the signal switching pulse, and the frequency of the measurement signal output to point C remains at ₁ . Also, at this time, since the transmission/reception switch 205 is switched to the receiver 207 side, the coupling coil 205 is switched to the receiver 207 side in the same manner as above.
6 emits a reference excitation signal of frequency R,
As a result, the mobile station 1 emits the reference echo signal again, and the fixed station 2 receives it and transmits it to the receiver 2.
From 07 onwards, the reference echo demodulated signal is sent to point H again. The activation signal generator 208 is configured to continue sending the activation signal to the I point while the reference echo demodulation signal is input at a time period corresponding to two periods of the transmission/reception switching pulse, and the activation signal generator 208 continues to send the activation signal to the I point. While is in the B interval, the reference echo demodulated signal is repeatedly input to the start signal generator 208 at the above period, so the start signal continues to be sent to the I point, and the controller 21
1 continuously sends the signal switching pulse to the J point.

When the signal switching pulse is outputted again to point J, the measurement signal oscillator 202 performs a frequency switching operation at its leading edge, switching the frequency of the measurement signal outputted to point C from ₁ to ₂ , and at this time the signal The changeover switch 203 connects the transmitter 204 to the measurement signal oscillator 2.
02, and the transmission/reception changeover switch 205 connects the coupled coil 206 to the transmitter 204, so that the coupled coil 206 emits a measurement excitation signal of frequency ₂ in the same manner as described above. onwards,
By repeating the same operation, while the mobile station 1 is in the B interval, the reference excitation signal and the measurement excitation signal are alternately switched, and the frequency of the measurement excitation signal is switched in a stepwise manner, intermittently. Coupling coil 206
It is radiated from.

In the above operation, the activation signal is sent from the activation signal generator 208 once every time the mobile station 1 enters the B interval, that is, once every time the rotary shaft 3 rotates once. Therefore, by counting the number of times the activation signal is sent, the rotational speed, etc. can be calculated. That is, the first data processor 209 counts the starting signal at the leading edge (rising edge) of the starting signal, calculates the speed measurement data, and displays the result on the display 2.
The speed measurement data is sent to 12.

In addition, in the above operation, the measurement excitation signal is transmitted while the mobile station 1 is in the section B, that is, when the coupling coil 1
3 is transmitted from the fixed station 2 in an area where the coupling coil 206 is effectively coupled. Therefore, the measurement excitation signals of all frequencies are applied to the first sensor 101 of the mobile station 1 in the order in which they are transmitted without any loss.

Now, assuming that the vibration frequency x of the first sensor 101 in the event to be measured at that time is closest to the frequency of the measurement excitation signal of frequency ₄ , the first sensor 101 performs the measurement as shown in FIG. 4K. It resonates with the strongest intensity when an excitation signal (frequency ₄ ) is applied. Therefore, after the measurement excitation signal is cut off until the next reference excitation signal is applied, the first sensor 101 sends out a measurement echo signal with a frequency of Fx, and this measurement echo signal is transmitted to the coupling coil 103.
is radiated from the mobile station 1.

The measurement echo signal emitted from the mobile station 1 as described above is received by the fixed station 2 in the same manner as the reference echo signal, and the receiver 207 sends a measurement echo demodulation signal with a frequency of x to point L. .

The second data processor 210 calculates event measurement data from the frequency x of the measurement echo demodulation signal,
This is sent to the display 212.

Display 212 displays and/or records velocity measurement data sent from first data processor 209 and event measurement data sent from second data processor 210 .

When the mobile station 1 passes through the section B and enters the section C, the coupling between the coupling coils 103 and 104 is severed, so that the excitation signal and echo signal exchange operation between the mobile station 1 and the fixed station 2 is interrupted. stops. Therefore, the activation signal sent from the activation signal generator 208 in the fixed station 2 is cut off (the activation signal disappears after a time corresponding to two periods of the transmission/reception switching pulse from the input of the final reference echo demodulation signal). ), the signal switching pulse sent from the controller 211 is cut off, so that only the reference excitation signal is intermittently emitted from the fixed station 2 while the mobile station 1 is from section C to section A. Further, the frequency of the counting signal oscillator 202 is set to the frequency k ( ₆ in the example shown in FIG. 3) at the time of sending out the final signal switching pulse in the interval B.
In the second cycle of the next period, the frequency switching operation of the count signal starts from frequency k+1. Therefore, event measurement data is always obtained in some cycle of the rotating body 3 until the measurement signal completes all steps of its frequency switching operation.

The operation of releasing the reference excitation signal and the measurement excitation signal from the fixed station 2 while the mobile station 1 is in the period B can also be performed as follows. That is, based on the speed measurement data sent from the first data processor 209, the time required for the mobile station 1 to pass through the B section is determined, and the activation signal generator 208 generates an activation signal with a length equal to the determined time. and then send it. In such a configuration, the fixed station 2 only needs to receive the reference echo signal once when the mobile station 1 enters the B interval, and therefore the frequency switching speed of the measurement signal in the B interval is It is approximately twice as large as that of the above embodiment (in this case, the period and pulse width of the signal switching pulse used for frequency switching control of the measurement signal oscillator 202 and switching control of the signal switching switch 203 are made the same as those of the transmission/reception switching pulse, etc.). do.).

〔Effect of the invention〕

As explained above, the present invention adjusts the timing of transmitting and receiving measurement excitation signals and measurement echo signals between a sensor for measuring an event to be measured and a fixed station, and a second sensor provided in a mobile station together with the sensor. (A) Measurement of physical events and detection by sending and receiving a reference excitation signal and reference echo signal between Since the measurement of motion speed and the like can be performed simultaneously on the same time axis, the causal relationship between both measurement data (for example, the relationship between the rotation speed of the rotating shaft and the shaft temperature) can be clearly understood.

(B) Since the measuring means is a non-contact type, it does not adversely affect the movement of the moving object to be measured.

(C) Operation is extremely simple, as measurements can be made simply by setting the fixed station antenna or coupling coil along the mobile station's movement trajectory.

(D) Since no mechanical means is required as a synchronization means, there is no noise mixed into the measurement data, accurate data can be obtained, and it is also possible to measure moving objects moving at high speed.

Various benefits such as these can be enjoyed, and the present invention has extremely significant effects.

[Brief explanation of drawings]

The drawings all show embodiments of the present invention, and Fig. 1 is a block diagram, Fig. 2 is a circuit diagram showing a specific example of the configuration of a mobile station, Fig. 3 is a diagram explaining the operation method, and Fig. 4. is a time chart explaining the operation. Main symbols: 1...Mobile station, 101...First sensor, 102...Second sensor, 2...Fixed station, 201
...Reference signal oscillator, 202...Measurement signal oscillator, 2
08... Start signal generator, 209... First data processor, 210... Second data processor, 211... Controller.

Claims (1)

[Claims] 1. After a mobile station including a piezoelectric sensor is attached to a moving body to be measured, and an excitation signal of the piezoelectric sensor is transmitted from a fixed station to the mobile station, an excitation signal caused by residual vibration of the piezoelectric sensor is transmitted from a fixed station to the mobile station. By receiving the echo signal emitted from the mobile station at the fixed station,
In a telemeter designed to measure a moving object to be measured, a mobile station is provided with a first piezoelectric sensor whose vibration frequency is constant and a second piezoelectric sensor whose vibration frequency changes with changes in the event to be measured. At the same time, the coupling section between the mobile station and the fixed station is set so as not to cover the entire cycle of the movement of the moving object to be measured, and the fixed station always sends an excitation signal with a frequency equal to the vibration frequency of the first piezoelectric sensor. The echo signal is transmitted intermittently, and each time the coupling section arrives, the echo signal emitted from the first piezoelectric sensor is received, and the number of movements and/or the movement speed of the moving object to be measured is calculated based on the number of times the echo signal is received. Upon receiving the echo signal from the first piezoelectric sensor, the fixed station starts transmitting an excitation signal whose frequency changes within the range of variation of the vibration frequency of the second piezoelectric sensor. The sending of the excitation signal is continued intermittently throughout the entire coupling section, thereby receiving the echo signal emitted from the second piezoelectric sensor and measuring the event to be measured from the frequency thereof. Echo type mobile telemeter system. 2 The vibration frequency of the first piezoelectric sensor is set to a value outside the change range of the vibration frequency of the second piezoelectric sensor and close to the change range, and the first piezoelectric sensor and the second piezoelectric sensor are connected to each other. The echo type mobile telemeter system according to claim 1, which is connected in parallel. 3. The echo type mobile telemeter system according to claim 1 or 2, wherein the first piezoelectric sensor and the second piezoelectric sensor are crystal oscillators.