JP3361999B2 - Moving distance detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a small displacement of a surface layer (slope), an amount of snow, etc., in a region at risk of landslide, etc., from a remote point with high accuracy for advance prediction and warning of a landslide disaster. The present invention relates to a moving distance detecting device using microwave means.

[0002]

2. Description of the Related Art The applicant has proposed a moving distance detecting device using microwave means in Japanese Patent Application No. 10-121432 "Ground surface displacement detecting device". Since the present invention relates to an improvement of this prior application, the outline and problems of this prior application technology will be described below as prior art.

FIG. 8 is an overall configuration diagram of a surface layer displacement detecting device. 1 is a safe immovable area, 2 is a dangerous area where landslides in the direction of arrow P are predicted, and 3 is a crack or a terrain conversion point at the boundary between both areas. 4 is a pile driven into the dangerous area 2. Reference numeral 5 is a monitor means fixed to the immovable area 1 (safety area) via a support base 6, and reference numeral 7 is a transmission / reception antenna formed integrally with the housing of the monitor means 5.

Reference numeral 8 denotes a radio wave reflecting means fixed to the top of the pile 4 driven into the surface layer displacement area (hazardous area 2), and L indicates a distance between the radio wave reflecting means 8 and the transmitting / receiving antenna 7. The monitor means 5 transmits a transmission wave of frequency F (for example, a microwave of 10.525 GHz) ft in the form of a beam to the radio wave reflection means 8 via the transmission / reception antenna 7, and transmits / receives the reflected wave fr from the radio wave reflection means 8 again. It is received via the antenna 7 and combined with the transmitted wave ft.

Considering that the phase is reversed when the transmitted wave ft is reflected by the radio wave reflection means 8, 2L = (1/2). (N + 1) .lambda. (.Lambda .: wavelength .lambda. =
C / F C: speed of light), the transmitted wave ft and the reflected wave fr are in phase at the position of the monitor means 5, and the combined amplitude is the sum of the two. On the other hand, 2L
In the case of = (n / 2) λ, the transmitted wave ft and the reflected wave fr have opposite phases, and the combined wave has a difference between them.

Therefore, when the combined wave output amplitude V of the transmitted wave ft and the reflected wave fr is taken, it becomes a sine wave that changes from the maximum value to the minimum value during λ / 4, as shown in FIG. For example, in FIG.
If the distance between the monitor means 5 and the radio wave reflection means 8 is set in advance so as to become point A (voltage VA), the operating point is point B (VB), C due to the radio wave reflection means 8 moving a minute distance.
It changes to a point (VC) and the moving distance can be detected from the change value of the combined amplitude. In other words, this converts the relative phase of the reflected wave fr into a voltage.

Here, for example, F = 10.525 GHz
(Λ = 28.5 mm), λ / 4 = 7.12 mm. During this period, the combined amplitude changes from the maximum value to the minimum value (full scale), so that it is possible to detect a distance change of about 3 mm (1/8 full scale) of 1 mm in the measurement resolution of this amplitude.

FIG. 10 is a block diagram showing the electrical construction of the monitor means 5. A microwave oscillating unit 9 oscillates a microwave having a predetermined frequency F and supplies it to the coupler 11 via the buffer amplifier 10. Coupler 1
Reference numeral 1 is for dividing the microwave into two, one of which is supplied to the circulator 13 via the power amplifier 12 and the other of which is supplied to the mixer 14. The circulator 13 is a switch, and supplies the microwave supplied from the power amplifier 12 to the antenna 7 and the received microwave supplied from the antenna 7 to the mixer 14.

The antenna 7 transmits and receives microwaves, and the microwave ft transmitted in a beam form from the antenna is reflected by the radio wave reflection means 8 and the reflected microwave fr is received by the same antenna 7. And is supplied to the mixer 14 via the circulator 13.

The mixer 14 receives the transmission wave f from the coupler 11.
t (transmission microwave) and the reflected wave fr (reception microwave) from the circulator 13 are combined, and the DC level V of the output amplitude of the combined wave is within λ / 4 of the radio wave reflection means 8 as described with reference to FIG. Transmitted wave ft and reflected wave fr due to fluctuations
It changes from maximum to minimum depending on the phase difference of (reception microwave).

Reference numeral 15 denotes a DC amplifier for amplifying the DC component of the composite wave output amplitude V and setting the span, and its output V0 is, for example, 1 when the radio wave reflecting means 8 changes from 0 to λ / 4. Span set to vary from ~ 5 volts.

Reference numeral 16 denotes a signal processing unit, which uses the output V0 of the DC amplifier as an input signal, and outputs an alarm by comparing it with an alarm set value, a change record in units of one day or one week, and digital conversion as necessary. After that, more complicated data management is executed by computer processing. Reference numeral 17 denotes an on-site indicating instrument which operates at the output of the signal processing unit 16, and S denotes an analog or digital transmission signal which is also output from the signal processing unit 16 and transmitted to a remote monitoring center or the like.

Generally, since the radio wave reflecting means 8 is limited in practical size, the reflected wave fr is extremely weak as compared with the transmitted wave ft. In addition, reflection naturally occurs not only from the reflector but also from the surrounding soil and sand, trees, etc. Considering the movement of water flow, gravel, etc., there is always a fluctuation of about 1 mm. As a method of extracting only the reflected wave from the installed radio wave reflection means 8 by eliminating the influence of the background, it is effective to remove the background noise in the frequency domain by modulating the reflection means.

In FIG. 8, reference numeral 18 denotes a reflectance control circuit for intermittently controlling the reflection of the radio wave reflecting means 8 with a signal of a constant frequency. Such reflectance control can be easily realized by using a so-called Luneberg lens which has been put into practical use as a radar radio wave reflection means for confirming the buoy position on the sea with a radar. The processing of the received signal in this case is
The envelope output of the modulation frequency component is extracted from the composite wave via the filter means, and the displacement can be detected in the same manner as in FIG. 9 by the change in the amplitude.

The frequency of the modulating AC signal fm is set sufficiently higher than the frequency of the fluctuation of sand and gravel due to the fluctuation of the tree due to the wind and the change of the rainwater flow, and the component modulated by the signal fm from the composite wave by the filter means. Can be extracted to obtain a fluctuation signal of only the radio wave reflection means in which background noise is cut.

In the configuration example of FIG. 11, the purpose is to simplify the configuration of the radio wave reflection means by applying modulation on the transmission side, and the background noise in the surroundings is small,
Suitable for an environment with a good reflected wave-to-noise ratio. Further, this configuration is characterized in that the monitor means 5 is separated into a transmission unit 5a and a reception unit 5b and has an independent configuration. 7a is a transmitting antenna and 7b is a receiving antenna.

In the transmitting unit 5a, 19 is a modulation circuit, which is, for example, 10 times the output of the microwave oscillating unit 9.
Amplitude modulation is performed with the signal fm of kHZ. Therefore, the transmission wave ft from the transmission antenna 7a becomes a microwave amplitude-modulated by 10 KHZ.

In the receiving unit 5b, the receiving antenna 7b receives the reflected wave fr from the radio wave reflecting means 8 and the direct wave ft 'that wraps around the ground from the transmitting antenna 7a, and is synthesized by the nonlinear element 20 such as a diode. Is
A composite wave output fm is generated. Reference numeral 21 is a high frequency amplifier, which amplifies an alternating current component of the composite wave output. Reference numeral 22 is a bandpass filter having a center frequency of the modulated AC signal fm,
The envelope output ve of the signal modulated at the frequency of the modulated AC signal fm of the combined signal is extracted.

Reference numeral 23 is a rectifying / smoothing circuit for the envelope output ve, which converts it into a DC signal v proportional to the amplitude of the envelope output ve. The configurations of 15 to 17 are the same as in the case of FIG. FIG. 12 shows that the movement of the radio wave reflection means can be measured in exactly the same way as in FIG. 9 by the change in the amplitude v of the envelope output of the received wave modulated by the modulated AC signal fm.

[0020]

The problems of the microwave detecting device having such a configuration are as follows: (1) The fluctuation of the output amplitude of the microwave oscillating unit 9 becomes the fluctuation of the amplitude of the composite wave or the envelope output, which causes a measurement error. It becomes a factor. Therefore, it is necessary to provide an amplitude stabilizing unit in the microwave oscillating unit 9, but the high frequency makes the structure complicated and expensive, which causes a cost hindrance to the system. (2) The attenuation of radio waves in the space where microwaves propagate is affected by meteorological conditions (water vapor amount, temperature, atmospheric pressure, etc.) and becomes a measurement error factor. The correction of this factor requires various weather sensors, which imposes a system cost obstacle and is not practical. The present invention has been made under such a background, and an object of the present invention is to provide a moving distance detecting device which is not influenced by a variation in microwave output and an error factor due to weather conditions.

[0021]

SUMMARY OF THE INVENTION The present invention has been made under such circumstances, and an object of the present invention is to provide a detection apparatus which is not affected by these error factors.
The first structural feature of the present invention is to provide a monitor means that is periodically movable in a reciprocating direction of a radio wave so as to be able to reciprocate periodically, and a radio wave reflection object that is a movement detection target separated by a predetermined distance from the monitor means. The monitor means comprises a transmitting means for transmitting a radio wave having a predetermined wavelength toward the radio wave reflecting means, a receiving means for receiving a reflected wave from the radio wave reflecting means, and the transmitting wave in the receiving means. Mixer means for synthesizing the received wave, a level detecting means for detecting the displacement of the radio wave reflecting means as a change in the composite wave output of the mixer means, and the composite wave output for each reciprocating movement cycle of the monitor means. Means for holding the position information of the monitor means at the timing when the peak is obtained, and the movement detection target is moved based on the held value of the position information in each reciprocating movement cycle. Distance lies in the fact to be detected.

The second characteristic is a monitor means installed so as to periodically reciprocate a fixed distance in a radio wave transmission / reception direction,
The radio wave reflecting means, which is a movement detection target separated by a predetermined distance from the monitor means, and the periodically varying reflectance ratio means formed on the radio wave reflecting means, the monitor means predetermines toward the radio wave reflecting means. Transmitting means for transmitting a radio wave having a wavelength, receiving means for receiving a reflected wave from the radio wave reflecting means, mixer means for synthesizing the transmitting wave and the receiving wave in the receiving means, and a composite wave output of the mixer means Envelope detecting means for extracting more variable period components, level detecting means for detecting displacement of the radio wave reflecting means as a change in the output of the envelope detecting means, and peak of the envelope output within each reciprocating movement cycle of the monitoring means. And means for holding the position information of the monitor means at the timing at which Lies in detecting a moving distance of the moving detection object based on.

The third characteristic is a monitor means installed so as to periodically reciprocate a fixed distance in a radio wave transmission / reception direction,
The monitor means is a radio wave reflecting means that is a movement detection target separated from the monitor means by a predetermined distance, and the monitor means transmits a radio wave of a predetermined wavelength amplitude-modulated at a constant period toward the radio wave reflecting means. , Receiving means for receiving the reflected wave from the radio wave reflecting means, mixer means for synthesizing the transmitting wave and the receiving wave in the receiving means, and envelope detection for extracting a variable period component from the synthetic wave output of the mixer means Means, a level detecting means for detecting the displacement of the radio wave reflecting means as a change in the output of the envelope detecting means, and a position of the monitor means at a timing at which a peak of the envelope output is obtained in each reciprocating movement cycle of the monitor means. A holding stage for holding information, and a moving distance of the movement detection target based on a holding value of the position information in each reciprocating movement cycle. To the point that detects certain.

A fourth characteristic is a monitor means installed so as to periodically reciprocate a fixed distance in a radio wave transmission / reception direction,
The monitor means is a movement detection target separated from the monitor means by a predetermined distance, and the monitor means transmits a radio wave of a predetermined wavelength amplitude-modulated at a constant cycle toward the radio wave reflection means, and the transmitter. Is a receiving means which is independently installed at a certain distance and receives a reflected wave from the radio wave reflecting means, a mixer means for combining the transmitting wave and the receiving wave in the receiving means, and a combined wave output of the mixer means. Envelope detecting means for extracting a variable period component, level detecting means for detecting displacement of the radio wave reflecting means as a change in output of the envelope detecting means, and output of the envelope detecting means within each reciprocating movement cycle of the monitor means. Means for holding the position information of the monitor means at the timing at which the peak of Based on the value held in location information in that it detects the moving distance of the moving detection object. The fifth feature is
The point is that the movement distance of the movement detection target is detected based on the number of peak occurrences of the composite wave output or the output of the envelope detection means in each reciprocating movement cycle and the held value of the peak position information.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The moving distance detecting device according to one embodiment of the present invention is characterized in that the conventional device measures the voltage change of the composite wave output or the envelope output by periodically reciprocating the monitor means to reciprocate the composite wave output or the envelope. The point is to measure the peak position of the output and detect the amount of movement of the radio wave reflection means based on the change in the peak position.

FIG. 2 is a diagram showing the basic concept of measurement by the moving distance detecting apparatus according to one embodiment of the present invention. The monitor means is set so that the reference position L0 at which the measurement starts becomes the peak P0. V1 is a composite wave output waveform in the first measurement cycle, P1 is its peak value, and L1 is peak P1.
The position of the monitor means in FIG. Next, V2 is a composite wave output waveform in the second measurement cycle, P2 is its peak value, and L2 is the position of the monitor means at the peak P2. Therefore, the moving position of the monitor means is L2 with L0 as the reference position, and the moving amount of the radio wave reflecting means in one measurement cycle is ΔL = L2-L1.

As described above, in one embodiment of the present invention, the position of the monitor means for holding the peak value of the composite wave output in each measurement cycle is held, and the position of the radio wave reflecting means is held based on the change of the held value. And the amount of movement is detected. As a result, the peak position does not change even if the amplitude of the composite wave or the envelope output fluctuates as shown in FIG. 2 due to fluctuations in the output of the microwave oscillator and weather conditions, so that measurement that is not affected by disturbance can be performed.

Next, a moving distance detecting device according to an embodiment of the present invention will be described with reference to the drawings. In the block diagram of FIG. 1, 24 is a connecting member for connecting the transmitting units 5a and 5b described in FIG.
Is a pulse motor means, and its rotation output shaft 26 is engaged with the connecting member 24 via a rack and pinion mechanism.

The pulse motor means 25 includes a position control section 27.
The forward and reverse rotations are controlled by the clock pulse CL from the pulse generating means 28 inside, and the connecting member 26 is moved forward from the initial position by a certain distance in the microwave emission direction as shown by an arrow Q in each measurement cycle, and then the initial position. Return to. In this case, the moving distance is set to the microwave frequency of 10.525 GHz.
(Λ = 28.5 mm), moving distance = λ / 2 = 14.
It is 25 mm. The clock pulse CL advances the connecting member by, for example, 100 pulses c1, c2, ... C100,
In the retracting design, the moving amount of the connecting member 26 per pulse is 0.1425 mm.

A position counter means 29 holds the position (movement amount from the initial position) of the connecting member 26 in each measurement cycle by the count value of the clock pulse CL. Three
Reference numeral 0 is a peak position latch unit, which is operated by a voltage latch control signal LT described later at a timing when the peak value of the combined signal output V0 is detected in each measurement cycle.
Captures and holds the location information of.

Information held in the peak position latch section 30 is stored in the peak position latch section 30 after the peak position detection is completed in each measurement cycle.
Latch shift signal L from timer 32 before the next measurement cycle
It is moved to and held by the peak position latch section (holding means) 31 last time by S. The movement distance of the peak position during one measurement cycle, that is, the movement distance of the radio wave reflection means 8 is determined by the difference between the held information (current measurement value) Ln of the peak position latch unit 30 and the held information Ln-1 of the previous peak position latch unit 31. Can be measured.

The timer 32 controls the sequence of each measurement cycle, regulates the operation of the pulse generating means 28 in the position control section 27 for each measurement cycle, and after the position measurement is completed in each measurement cycle. A latch shift signal LS for transferring the information held in the peak position latch unit 30 to the previous peak position latch unit 31 before the next measurement cycle is generated.

The time charts shown in FIGS. 3 (A) to 3 (E) represent the sequence of the measurement period of two cycles.
(A) is a sequence signal of the timer 32. Each measurement cycle T1, T2 ... Is set to, for example, 65 seconds, and 5 seconds (T11, T21 ...) From the start timing t0 of each cycle.
Is the measurement period, and 60 seconds (T2
1, T22 ...) is the waiting period.

FIG. 3B shows the waveform of the clock pulse CL from the pulse generating means 28 in each measurement cycle, and 100 forward pulses C in 5 seconds of the measurement period.
1, C2 ... C100 are generated, and the connecting member 26 is advanced by λ / 2 from the initial position via the pulse motor means 25. Further, the pulse motor 25 is reversely rotated by the same number of negative direction clock pulses C1 ', C2' ... C100 'within the standby period of the same measurement period to return the connecting member 26 to the initial position. Such a reciprocating operation is repeated in each measurement cycle.

FIG. 3D shows timings t1, t2, ... At which the peak position is detected in each measurement period, and at this timing, the position information L1, L of the position counter means 29 is detected.
2 are taken into the peak position latch section 30 and held.

FIG. 3E shows the latch shift signal LS generated by the timer 32 at the timing of the end of each measurement period.
The peak position latch unit 3 is shown at this timing.
The holding information of 0 is shifted to L1, L2 ...

Next, returning to FIG. 1, the configuration and operation of the peak position detecting section 33 for the composite wave output or the envelope output V0 will be described. An A / D converter 34 digitally converts the composite wave output V0 given as an analog voltage, and supplies the converted output VD to the voltage latch 35 and the comparator 36.

The voltage latch unit 35 and the comparison unit 36 receive the clock pulse CL of the pulse generating means 28 in the measurement period of each measurement cycle, and the voltage latch unit 3 at the rising edge thereof.
Reference numeral 5 latches VD and supplies the latch voltage VL to the comparison unit 36. Next, VL and VD are compared with each other at the falling edge of this clock pulse CL. If VL> VD, the comparison is performed with the latch by the next clock pulse.

If the comparison result is VL≤VD, it is determined that V0 is the peak value, the comparison unit 36 issues the voltage latch control signal LT to release the latch of the voltage latch unit 35, and the peak of the position control unit. By controlling the position latch unit 30, position counter information of peak timing, that is, the connecting member 24.
The position information of is taken into 30. 3C shows the timing of comparison with the voltage latch synchronized with the clock pulse CL, and FIG. 3D shows the generation timing of the voltage latch control signal LT transmitted at the peak position of V0 in each measurement period. Is shown.

Reference numeral 37 is a position calculation / display unit. Reference numeral 38 denotes a movement amount calculation unit, which calculates a difference ΔL = Ln−Ln−1 between the holding value Ln of the peak position latch unit 30 of the position control unit 27 and the holding value Ln−1 of the previous peak position latch unit 31. It is given to the position calculation unit 39. The position calculation unit 39 inputs the movement information ΔL of the radio wave reflection means within λ / 2 and its polarity, and the peak number information N from the peak number detection unit 41, and moves the movement direction including the movement direction of the radio wave reflection unit. Calculate information or position information. The calculation result is displayed on-site by the display unit 40 or transmitted to an external monitoring system or the like by the transmission signal S.

The peak number detecting section 41 has a function of counting the peak number N of V0 generated in each measurement period when the radio wave reflecting means 8 moves beyond λ / 2.
Reference numeral 43 is a VD differentiating means, and 44 is a differentiating counter means, which counts and holds the number of times the polarity of the differential value is inverted, and a latch shift signal LS generated at the end of the measurement period
The count value is cleared with. By providing this function, it is possible to reduce the λ
It is possible to detect the amount of movement until the movement exceeds / 2.

Next, the operation procedure of position measurement will be described with reference to the flow chart of FIG. 4 and the time chart of FIG. When the sequence by the timer is started by the reset signal RS, the position counter becomes 1 by the clock from the pulse generation after waiting for the waiting time of 60 seconds, and the pulse motor means advances one step. The voltage measurement of V0 is executed at this timing, and this measurement loop is executed every 100 steps of the clock CL.

During the loop period of 100 steps, the peak position is detected and the movement information is held. When the loop of 100 steps is completed, the pulse motor means is returned to the initial position, the content of the position counter means is set to 0, and the timer is also initialized to return to the start.

Next, the operation procedure of peak position measurement will be described with reference to the flowchart of FIG. 5 and the time chart of FIG.
A / D conversion output V for each step forward of the pulse motor means
D is compared with the voltage latch output VL, and if VL> VD, the pulse motor means is advanced by one step and the comparison is continued. If the peak point is judged when VL ≧ VD, the information of the position counter means is latched.

The position information is latched as the previous position information at the timing of the completion of 100 steps of the clock pulse, and in the next step, the movement amount calculation based on the difference from the previous position information is executed. At the end timing of 100 steps of the clock, the position information of this measurement is latched as the previous position information, the display calculation of the movement information is performed, and the process returns to the start. Further, the A / D conversion output VD is applied to the differential operation and differential counter means to detect the peak number signal N and supplied to the display operation means.

Next, referring to FIG. 6, the λ / 2 of the radio wave reflecting means 8 will be described.
A specific operation procedure for detecting the movement position or the movement amount of the movement exceeding the distance will be described. All the functions in FIG. 1 are reset by the reset signal RS, the connecting member 24 is manually operated, and the position L0 at which V0 takes the peak value P0 is set as the initial position of the measurement start, and the measurement is started. At this time, the content of the differential counter means 42 is zero.

P1, P2, and P3 are peak positions of V0 in the first, second, and third measurement cycles, and since the change amounts are all within λ / 2, the moving amount L1 from the reference position of the monitor means, L2 and L3 are detected as the movement amount from L0. When the n-th peak position is Pn, this peak appears as a peak Pn ′ at a position of an amount Ln exceeding λ / 2, as indicated by a dotted arrow W, and the apparent measured value is Ln.

In such a case, since the polarity reversal of the differential value of V0 occurs once or more within the measurement cycle, if the number of occurrences N is detected by the count value of the differential counter means, Pn The actual movement position L of L is L = Ln + N
It can be calculated by * λ / 2. Furthermore, the radio wave reflector 8
The movement amount calculation means 3 determines the movement direction from the reference position of
It is easy to check the polarity of the output ΔL of 8 in the position calculating section 39.

In order to realize the determination of the number of times exceeding λ / 2 by a method not using the differential counter means, ΔL of each measurement cycle
It is also possible to check the increase tendency from the previous time and judge that the measured value exceeds λ / 2 when the increase reverses the decrease.

FIG. 7 shows an embodiment of a snow cover meter to which the present invention is applied. The snow cover amount Ls of the snowfall 44 at the monitoring point 43 is measured. 45 is a supporting column higher than the maximum expected snow cover level,
Reference numeral 5 is an electric circuit unit of the monitor means fixed to the top of the support pillar, and 7 is a transmission / reception antenna unit fixed to a member extended from this unit, and this antenna unit is periodically reciprocally controlled. 46 is an antenna for a wireless telemeter. The snowfall amount Ls can be obtained from the difference Ls between the initial position L0 from the reference level (ground surface) at the start of measurement to the antenna unit 7 and the measured value Ld.

Although one embodiment of the present invention has been described above with reference to FIG. 1, the monitor means 5 may have an independent unit structure as in the embodiment, and may also have the structure of the transmission / reception integrated type described in FIG. 10 of the conventional example. The modulation means for the microwave may be the modulation of the microwave oscillating section, and the reflectance control of the radio wave reflector 8 by the Luneberg lens means or the like. In addition, the timer 32
The sequence period of is selected to a value that ensures sufficient measurement accuracy in accordance with the moving speed of the radio wave reflection means 8 that is the measurement target.

Note that the radio wave reflecting means 8 is provided with a special reflector as shown in FIG. 8 in addition to the case where a special reflector is installed on the moving object. In the case where the body cannot be installed, an embodiment is also possible in which the reflected waves of the microwaves that are directly beam-irradiated on the monitoring target are received.

[0053]

As described above, the following effects can be expected in the moving distance detecting device of the present invention which follows the change of the peak position, as compared with the conventional system. (1) Even if the fluctuation of the output amplitude of the microwave oscillating section causes the fluctuation of the amplitude of the composite wave or the envelope output, it does not cause a measurement error. Therefore, the amplitude stabilizing means of the microwave oscillating section can be simplified. A highly accurate system can be realized at low cost. (2) Even if the attenuation of radio waves is affected by changes in the weather conditions in the space where microwaves propagate, it does not cause a measurement error, so correction by various weather sensors is unnecessary, and a low-cost and highly accurate system can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a moving distance detecting device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a basic concept of a moving distance detecting apparatus according to the same embodiment.

FIG. 3 is a time chart explaining the operation of the moving distance detecting apparatus according to the same embodiment.

FIG. 4 is a flowchart illustrating an operation procedure of position measurement in the movement distance detection device according to the same embodiment.

FIG. 5 is a flowchart illustrating an operation procedure of peak position measurement in the movement distance detecting apparatus according to the same embodiment.

FIG. 6 is a diagram illustrating an operation when a movement exceeding λ / 2 is detected in the movement distance detection device according to the same embodiment.

FIG. 7 is a configuration diagram in the case where the movement distance detection device according to the same embodiment is applied to a snow cover meter.

FIG. 8 is a diagram showing an overall configuration of a conventional ground displacement detection device.

FIG. 9 is a diagram showing a waveform of a composite wave output in a conventional ground displacement detection device.

FIG. 10 is a diagram showing an electrical configuration of a monitor means in a conventional ground displacement detection device.

FIG. 11 is a diagram showing an electrical configuration of a monitor means when modulation is applied on the transmitting side in the conventional ground displacement detecting device.

12 is a diagram showing a waveform of an envelope output in the conventional ground surface displacement detection device of FIG.

[Explanation of symbols]

5a Transmission unit 5b receiving unit 7a transmitting antenna 7b receiving antenna 8 Radio wave reflection means 24 Connecting member 25 pulse motor means 26 rotation output shaft 27 Position controller 32 timer 33 Peak position detector 37 Position calculation / display 41 Peak number detector

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-11-325864 (JP, A) JP-A-11-316140 (JP, A) JP-A-11-303093 (JP, A) JP-A-3- 272488 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01S ⁷ /00-7/42 G01S 13/00-13/95 G01B 21/32 G01D 21/00

Claims (5)

(57) [Claims] 1. A monitor comprising: a monitor means installed so as to periodically reciprocate a fixed distance in a radio wave transmission / reception direction; and a radio wave reflection means which is a movement detection target and is separated from the monitor means by a predetermined distance. The means includes a transmitting means for transmitting a radio wave having a predetermined wavelength toward the radio wave reflecting means, a receiving means for receiving a reflected wave from the radio wave reflecting means, and a synthesizing the transmitted wave and the received wave in the receiving means. The mixer means, the level detecting means for detecting the displacement of the radio wave reflecting means as a change of the composite wave output of the mixer means, and the timing at which the peak of the composite wave output is obtained within each reciprocating movement cycle of the monitor means. Means for holding the position information of the monitor means, and detects the movement distance of the movement detection target based on the held value of the position information in each reciprocating movement cycle. Moving distance detecting apparatus according to claim Rukoto. 2. A monitor means installed so as to periodically reciprocate a fixed distance in a radio wave transmission / reception direction, a radio wave reflection means which is a movement detection target separated from the monitor means by a predetermined distance, and the radio wave reflection means. The monitoring means includes a transmitting means for transmitting a radio wave having a predetermined wavelength toward the radio wave reflecting means, and a receiving means for receiving a reflected wave from the radio wave reflecting means. Mixer means for synthesizing the transmission wave and the reception wave in the receiving means, an envelope detecting means for extracting a variable period component from a composite wave output of the mixer means, and a displacement of the radio wave reflecting means for the envelope detecting means. Of the output of the envelope detecting means within each cycle of the reciprocating movement of the monitor means. And means for holding the position information of the monitoring means in timing, a moving distance detecting device and detecting a moving distance of the moving detection object based on a value held in the position information in each reciprocation cycle. 3. The monitor comprises: monitor means installed so as to periodically reciprocate a fixed distance in a radio wave transmission / reception direction; and radio wave reflection means, which is a movement detection target, separated from the monitor means by a predetermined distance. The means includes a transmitting means for transmitting a radio wave of a predetermined wavelength amplitude-modulated at a constant cycle toward the radio wave reflecting means, a receiving means for receiving a reflected wave from the radio wave reflecting means, and the transmitting wave in the receiving means. Mixer means for synthesizing a received wave, an envelope detecting means for extracting a variable period component from a composite wave output of the mixer means, and a level detection for detecting a displacement of the radio wave reflecting means as a change in the output of the envelope detecting means. Means and the monitor means at the timing at which the peak of the output of the envelope detection means is obtained within each reciprocating movement cycle of the monitor means. And means for holding location information, moving distance detecting device and detecting a moving distance of the moving detection object based on a value held in the position information in each reciprocation cycle. 4. A monitor means installed so as to be capable of periodically reciprocating a fixed distance in a radio wave transmission / reception direction, and a movement detection target separated by a predetermined distance from the monitor means. Transmitting means for transmitting a radio wave of a predetermined wavelength, which is amplitude-modulated at a constant cycle toward the reflecting means, and receiving means for independently receiving the reflected wave from the radio wave reflecting means, which is independently installed at a constant distance from the transmitting means. Mixer means for synthesizing the transmitted wave and the received wave in the receiving means, an envelope detecting means for extracting a variable period component from a composite wave output of the mixer means, and a displacement of the radio wave reflecting means for the envelope detecting means. The level detecting means for detecting the change in the output and the timing for obtaining the peak of the output of the envelope detecting means in each reciprocating movement cycle of the monitor means. And means for holding the position information of the monitoring means in ring moving distance detecting device and detecting a moving distance of the moving detection object based on the holding value of the peak position information at each reciprocation cycle. 5. The movement distance of the movement detection target is detected based on the number of peak occurrences of the composite wave output or the output of the envelope detection means and the held value of the peak position information in each reciprocating movement cycle. Claims 1 to 4
The moving distance detection device according to any one of 1.