JPS6167196A - Pressure measuring/recording apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the use of a piezoelectric device whose oscillation frequency is modulated by the action of pressure through an object.

[Prior Art] Generally, a piezoelectric element such as a crystal resonator in an oscillating state has a characteristic that its excavation frequency changes due to the action of pressure through an object, for example.

Therefore, various devices have been proposed that can measure pressure itself, acceleration, etc. by utilizing the characteristics of such piezoelectric elements.

By the way, in the above IT measurement, what is actually detected is a physical quantity (hereinafter referred to as measurement data) corresponding to the change in the oscillation frequency of the piezoelectric element based on pressure action, and in order to analyze pressure etc., the above measurement data must be recorded. It is necessary to do so.

Conventionally, a device for measuring pressure and recording the measurement data as described above has a configuration as shown in FIG. 4, for example. In the figure, 10 is a measurement system, and this measurement system 1o basically consists of a crystal oscillator 12 (piezoelectric element) that receives pressure from a weight 11, and this crystal oscillator 12.
The oscillation circuit 13 that holds the light in the oscillating state
It consists of an amplifier circuit 14 that amplifies the oscillation signal of the crystal resonator 12 via the circuit 13. On the other hand, 20 is a recording system, and this recording system 20 is connected to the measurement system 10 by a coaxial cable 3, etc., and its sample configuration is as follows:
0 (from the amplifier circuit 14)
OL signal (information) that can record the oscillation signal caused by the oscillation of
The demodulation circuit 21 includes a demodulation circuit 21 that converts the signal into a signal, and a recording circuit 22 such as a data recorder that records the output signal from the demodulation circuit 21. In the above configuration, the measurement system 1
The oscillation frequency information (measurement data) from the crystal oscillator 12 at o is sequentially recorded in the recording circuit 22 in the recording system 20, and in the process, the oscillation frequency of the crystal oscillator 12 is modulated by the pressure action via the weight 11. Then, information (measurement data) corresponding to the modulated frequency is recorded in the recording circuit 22.

[Problems to be Solved by the Invention] - By the way, for example, in measuring the acceleration of a flying object, it is conceivable to utilize the characteristics of the piezoelectric element as described above. That is, the lifting platform on which the acceleration α acts on the weight 11 in FIG.
A pressure of M·α (M: mass of the weight 11) acts on 'f12, and the change in the oscillation frequency in the crystal camera 12 at that time is utilized.

However, especially for relatively small flying objects that fly in the atmosphere, mounting a pressure measurement and recording device as shown in FIG. Therefore, as a practical matter, it is impossible.

Therefore, for example, as shown in FIG.
It is equipped with a measurement system 10 as shown in the figure, and a transmission system 30 consisting of a telemeter etc. that transmits the measurement data from this measurement system 10 to the ground, and the measurement data from this transmission system 30 is installed on the ground. It is conceivable to record on the recording system 2o via a receiving device (not shown).

However, as described above, even if the recording system 20 is installed on the ground, the flying object 1 must be equipped with the transmitting system 30 consisting of a telemeter etc. together with the measuring system 10, and the There was a limit to the size and weight reduction of on-board equipment.

[Means for Solving the Problems] In view of the above problems, the present invention aims to provide a smaller and lighter pressure measurement recording device. a first piezoelectric element device whose oscillation frequency is modulated by pressure action; a second piezoelectric element device which outputs oscillation at a reference frequency;
The present invention is configured to include a demodulator that creates a beat frequency signal of each oscillation signal from the piezoelectric device, and a solid-state memory element that stores information corresponding to the frequency of the beat frequency signal from the demodulator.

[Embodiments of the invention] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing an example of a pressure measurement and recording device according to the present invention, and this example is assumed to measure the acceleration of a flying object.

In FIG. 1, 101 is a weight, 102 is a first crystal resonator (piezoelectric element) that receives pressure from the weight 101, and 103 is under the same environment as the crystal resonator 102 (temperature, wet polishing, The first crystal oscillator 102 is held in an optical signal state by the transmitter circuit 104, and the second crystal oscillator 102 is
The crystal camera 103 is maintained in a reference oscillation state by an oscillation circuit 105. 106 is
A balanced modulation circuit that superimposes an oscillation signal from the first crystal oscillator 102 via the oscillation circuit 104 and a reference oscillation signal from the second crystal oscillator 103 via the R/oscillation circuit 105. , 107 is a demodulator for extracting the envelope signal of the output signal from the balanced modulation circuit 106, that is, the beat frequency signal of the oscillation signal from the first crystal oscillator 102 and the oscillation signal from the second crystal oscillator 103. It is a circuit. here,
The first and second crystal oscillators 102.1o3, oscillation circuits 104.105, balanced modulation circuit 106, and demodulation circuit 10
7 constitutes a measurement system.

On the other hand, 108 is a memory circuit that stores the beat frequency information based on the beat frequency signal from the demodulation circuit 107, and this memory circuit 108 has a solid-state memory element configured as a half-fathom body as its memory section. ing. Also, 10
Reference numeral 9 denotes a trigger circuit for timing the operation of the memory circuit 108. Then, the storage circuit 108 converts the output signal from the demodulation circuit 107 into a pulse signal at a predetermined threshold value vth or more and less than a predetermined threshold value vth, and each time the trigger signal from the trigger circuit 109 is output, the pulse signal at that time becomes H level. If the bit information is “1P”, the same pulse signal is “L”.
If it is the level, the bit information II O+3 is sequentially written into the solid-state memory element as measurement data. Further, 110 is a backup power source (for example,
This is a holding circuit for holding measurement data until it is analyzed by a solid-state storage element in the storage circuit 108 using a large capacitor (capacitor, etc.). Here, the storage circuit 108.1 including the solid-state storage system mentioned above to the trigger circuit 109 and the holding circuit 110 constitute a recording system.

For example, as shown in FIG.
, oscillation circuits 104, 105, balanced modulation circuit 106, and demodulation circuit 107.
While the memory circuit 1 is housed in the
08, the recording system composed of the trigger circuit 109 and the holding circuit 110 is housed in the recording section case 100b together with its power supply 112 (including a backup power source for the solid-state memory element). , 100
They are connected by a pin connector 113 provided at the joint part b. Then, the measuring unit case 100a and the recording unit case 100b joined as described above are mounted on a flying object whose acceleration is to be measured. Note that the reference numeral 114 in FIG. 2 is a pin connector used when reading information from the solid-state memory element in the memory circuit 108.

Next, the operation of this device will be explained.

For example, when launching a flying object, the first crystal oscillator 1
02 is subjected to a pressure action of M·α (M: mass of the weight 101) from the weight 101 due to the acceleration α at that time, and its oscillation frequency is modulated (see FIG. 1 (a)). This signal waveform f1 is fl = V1 - cos ω1.The second crystal oscillator 103 outputs a reference oscillation signal (see Fig. 1(b)), and this signal waveform c2 is expressed as +2 = V2- cos ω2. shall be.

The signals of waveforms f1 and [2 as described above are transmitted to the balanced modulation circuit 10
When 6 is input, the output waveform r3 becomes as shown in Fig. 1 (C), and the amplitude of this signal waveform ``3'' is Vl = V
2 = VO, then V3 = VO-cos ωl
+VO-cos co2=2VO-CO3ωp
1 cos w.

ωp = (ω1 + ω 2)/2 ω0 = (ω1-ω2)/2, and the signal waveform from the first and second crystal oscillators 102. Then, the signal from the balanced modulation circuit 107 having the above waveform [3] is converted by the demodulation circuit 107 into the 1g number of the envelope waveform f4 of the waveform r3 (the first (See Figure (d)) Here, the frequency of the waveform [4 is the heat frequency of each output fn'?j frequency from the first and second crystal oscillators 102 and 103.

In this way, the memory circuit 10
8, for example, as shown in FIG.
- Every time the trigger signal from the reset circuit 109 goes down, if the pulse signal at that time is at H level, the bit information is "1'", and if the same pulse signal is at L level, the bit information is 11011. are sequentially written into the solid-state memory element as measurement data. For example, in the example shown in FIG. 3, before time t1, from time t2 to (3), and after time t4, bit information II OI+ is written in the solid-state memory element every time the trigger signal is input, and
Bit information "1" is written from time tl to t2 and from time t3 to (4).

As described above, after the flying object equipped with the pressure measurement and storage device consisting of a measurement system and a recording system completes a predetermined flight, the recording system housed in the recording unit case 100b is recovered from the flying object. (Disconnect the bin connector 113). At this time, the solid-state memory element in the memory circuit 108 receives battery backup due to the action of the holding circuit 110, and retains the stored information.

Thereafter, the circular information in the solid-state 1n element is read out via the pin connector 114, and the acceleration is analyzed based on this information. Specifically, for example, data from the first and second crystal oscillators 102 and 103 is based on the bit string read out from the solid-state memory element (stored data in FIG. 3) and the tricycle period at the time of writing. While calculating the beat frequency of each output signal, the relationship between the pressure acting on the first crystal resonator 102 and the beat frequency is determined in advance, and based on this relationship and the calculated beat frequency, the flight The pressure P acting on the first crystal camera 102 while the body is flying is determined. Then, since the quality (2) of the weight 101 is M, the acceleration α is determined according to P=M·α.

As described above, according to this embodiment, the output signal from the first crystal oscillator 102 whose oscillation frequency is modulated by the pressure action caused by the acceleration of the flying object via the weight 101 and the output signal from the second crystal oscillator Since the beat frequency signal with the output signal of the reference frequency from 103 is used as the measurement data, the amount of data is reduced compared to the case where the output signal from the crystal oscillator 102 of direct use 1 is used as the measurement data. Since the beat frequency signal is binarized at a predetermined slice level and this binarized data is written to the solid-state storage element at a predetermined timing, the processing in step a3 at 108 in the storage circuit becomes extremely simple. Furthermore, since the first and second crystal oscillators 102 and 103 are affected by the same environmental conditions, it is not necessary to perform environmental compensation such as temperature compensation and humidity compensation for each crystal oscillator. Measurement data will be obtained. Furthermore, in conjunction with the reduction in the amount of data described above, the recording system can be made extremely compact because the measurement data is occupied by the solid-state storage element.

Note that a non-volatile memory that does not require battery backup can also be used as the solid-state memory element.

Further, although the above embodiment assumes acceleration measurement, the present invention can of course be applied to a measurement and recording device for pressure itself.

[Effects of the Invention] As explained above, the present invention has 4. This consists of a first piezoelectric element device whose oscillation frequency is modulated by pressure action through an object, and a second piezoelectric device that oscillates at the wind wall frequency.
Since the information obtained by changing the constitutional frequency of the beat frequency signal of each output signal from the electronic element device is stored in the solid-state memory element, it is especially possible to use a compact and lightweight recording system that uses the solid-state memory element as a core element. For example, it becomes possible to realize a pressure measurement and recording device for measuring acceleration that can be mounted on a relatively small flying object flying in the atmosphere.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a pressure measurement and recording device according to the present invention intended for acceleration measurement, and FIG.
Figure 3 is an explanatory diagram showing an example of a female body mounted on the same fly gamma 114i, Figure 3 is a timing chart showing an example of a specific operation of the memory circuit in a3 in Figure 1, Figure 4 is Figure 5 shows an example of a conventional pressure measurement and recording device.
It is a Brookcock diagram. 101...To way 1 102...First crystal oscillator 103...Second crystal oscillator 104.105...Oscillation circuit 106...Balanced modulation circuit 107...Demodulation circuit 108.・Memory circuit (including solid state memory element) 109・
...Trigger circuit 110...Holding circuit

Claims (1)

[Claims] A first piezoelectric element device whose oscillation frequency is modulated by pressure action through an object, a second piezoelectric element device which outputs oscillation at a reference frequency, and each of the first and second piezoelectric device devices. A pressure measurement and recording device comprising: a demodulator that creates a beat frequency signal of an oscillation signal; and a solid state memory element that stores information corresponding to the frequency of the beat frequency signal from the demodulator.