CN216012139U - Displacement measuring device - Google Patents
Displacement measuring device Download PDFInfo
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- CN216012139U CN216012139U CN202122139086.4U CN202122139086U CN216012139U CN 216012139 U CN216012139 U CN 216012139U CN 202122139086 U CN202122139086 U CN 202122139086U CN 216012139 U CN216012139 U CN 216012139U
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Abstract
The utility model discloses a displacement measuring device, which comprises a signal transmitting part and a signal receiving part; the signal transmitting part comprises a high-frequency oscillator, a transmitting antenna and a controller; the signal receiving part comprises a receiving antenna and a frequency counter; the signal receiving part returns to the signal transmitting part through a circulator; the frequency counter is used for measuring the frequency of the reflected wave; the controller controls the reflected wave received by the signal receiving section to turn on/off the return to the high-frequency oscillator according to the frequency output from the frequency counter to control the interference of the reflected wave with the frequency of the high-frequency oscillator. The utility model discloses among the measuring device, be provided with frequency counter in transmitting antenna to set up the switch on receiving part's returning, thereby can realize the adjustment to high frequency oscillator transmitting frequency under the non-interfering condition, whole scheme simple structure easily realizes, has solved the problem of interference, has realized the measurement of high accuracy.
Description
Technical Field
The utility model relates to a radar technical field specifically is a displacement measurement device based on radar.
Background
Conventional displacement measuring devices using microwave or millimeter wave in the prior art generally employ a pulse method, an FMCW method, a phase detection method, and the like.
In the impulse method, an impulse signal is transmitted to an object, and a distance and a displacement are measured by measuring a time difference between a reflected received pulse and a transmitted pulse.
The FMCW method continuously and linearly changes the frequency of a transmitted wave, and measures the difference between the frequency of the transmitted wave and the frequency of a reflected wave from an object. Since the frequency difference is proportional to the time delay caused by the distance to the object, the distance and the displacement can be measured.
The phase detection method synthesizes a transmission wave radiated toward an object and a reflection wave from the object, and detects a phase change due to a displacement of the object.
In the pulse method measuring apparatus, a high-speed and high-resolution pulse generating circuit and a time difference measuring circuit are required to measure a minute displacement, and the apparatus has a complicated structure and a high manufacturing cost.
In the FMCW method measuring apparatus, in order to realize measurement in the millimeter level (detection of displacement of 1 mm), a high-frequency oscillator and a frequency modulation circuit with high accuracy are also required, and the manufacturing cost of the apparatus is high.
In the prior art, in order to detect the phase change, the amplitude information of the radio wave needs to be measured, the influence of noise is easily caused, and the complexity of a circuit is improved in order to reduce the noise and ensure the precision.
As described above, the conventional measuring apparatus cannot measure the displacement of the object with high accuracy at a distance of several hundred meters by a low-cost, simple circuit configuration.
Disclosure of Invention
The utility model aims to solve the technical problem that a displacement measurement device and measuring method of simple structure, with low costs noise interference reduction is provided.
In order to solve the technical problem, the utility model discloses a technical scheme is:
a displacement measuring device includes a signal transmitting portion and a signal receiving portion; the method is characterized in that: the signal transmitting part comprises a high-frequency oscillator, a transmitting antenna and a controller; the signal receiving part comprises a receiving antenna and a frequency counter; the signal receiving part returns to the signal transmitting part through a circulator;
the high-frequency oscillator is used for sending out a high-frequency signal; the transmitting antenna is used for radiating the high-frequency signal generated by the high-frequency oscillator to form transmitting waves; the receiving antenna is used for receiving the reflected wave; the frequency counter is used for measuring the frequency of the reflected wave; the controller controls the reflected wave received by the signal receiving section to turn on/off the return to the high-frequency oscillator according to the frequency output from the frequency counter to control the interference of the reflected wave with the frequency of the high-frequency oscillator.
The signal receiving section further includes an amplifier for amplifying the received transmission wave and for turning on/off the reflected wave returned to the high-frequency oscillator.
The frequency converter is arranged in the transmitting antenna; for converting the frequency of the transmitted wave to an intermediate frequency LNB output frequency.
The controller performs the following control:
(1) when the measurement frequency of the frequency counter changes by a certain amount due to the displacement of the corner reflector, the controller stores the frequency after the change due to the interference of the reflected signal to the high-frequency oscillator;
(2) the controller controls the amplifier to turn off the reflected wave signal to eliminate interference, thereby returning the oscillation frequency of the high frequency oscillator to the original frequency;
(3) the controller controls the oscillation frequency of the high-frequency oscillator when the reflected wave signal stored in the step (1) is switched on, and the high-frequency oscillator is shifted to the frequency;
(4) the controller controls the amplifier to turn on the reflected wave signal;
(5) continuously measuring the continuous displacement of the corner reflector by repeating the steps (1) to (4).
A displacement measurement method is characterized by comprising the following steps:
acquiring the frequency of a reflected signal received by a receiving antenna after the displacement is changed;
the transmission frequency of the high-frequency oscillator is shifted to the frequency of the reflected signal, and the displacement is measured at the shifted frequency.
Compared with the prior art, the beneficial effects of the utility model are that:
the utility model discloses among the measuring device, be provided with frequency counter in transmitting antenna to set up the switch on receiving part's returning, thereby can realize the adjustment to high frequency oscillator transmitting frequency under the non-interfering condition, whole scheme simple structure easily realizes, has solved the problem of interference, has realized the measurement of high accuracy.
The utility model discloses receiving antenna and transmission are circular polarized antenna among the measuring device, have eliminated along the circular polarization and the linear polarization of different direction of rotation to only receive the reflection wave in the same direction of rotation with the radio wave of transmission.
When the right-hand circularly polarized wave is radiated from the transmitting antenna to the both-side corner reflectors of the present embodiment and reflected twice, the reflected wave returns together with the radiated right-hand circularly polarized wave. By receiving the reflected wave with a right-hand circularly polarized receiving antenna, the signal-to-noise ratio of the reflected wave with respect to surrounding radio noise can be improved.
Further, by using the corner reflector, the reflected wave returns in the direction of the transmitted wave, and therefore it is possible to easily adjust the reflection direction with the corner reflector as compared with the conventional planar reflection plate.
Drawings
Fig. 1 is a block diagram of the displacement measuring device of the present invention.
Fig. 2 is a top view of a corner reflector.
Detailed Description
The invention is described in detail below with reference to the accompanying drawings:
the displacement measuring device of the present invention, as shown in fig. 1, includes a high frequency oscillator 1, a circulator 2, a transmitting antenna 3, a receiving antenna 7, an amplifier 8, a frequency converter 9, a frequency counter 10, and a controller; the high-frequency oscillator 1 is used for sending out a high-frequency signal; the transmitting antenna 3 is used for radiating the high-frequency signal generated by the high-frequency oscillator 1 to form a transmitting wave; the frequency converter 9 is used for adjusting the frequency of the transmitted wave; the frequency counter 10 is used for measuring the frequency of the transmitted wave adjusted by the frequency converter 9; the receiving antenna 7 is used for receiving the transmitted wave; the amplifier 8 is used for amplifying the received transmission wave; the controller controls the amplifier 8 according to the frequency output from the frequency counter to turn on/off the reflected wave signal returned to the high frequency oscillator 1 to control the interference of the reflected signal with the high frequency oscillator frequency.
The signal from the high-frequency oscillator 1 is sent to the transmitting antenna 3 by the circulator 2 and radiated. The reflected wave 6 reflected by the corner reflector 5 is received by the receiving antenna 7, amplified by the amplifier 8, and then returned to the high-frequency oscillator 1 through the circulator 2. The controller may control the amplifier 8 according to the frequency output from the frequency counter 10 to turn on/off the reflected wave signal returned to the high frequency oscillator 1 to control the interference of the reflected signal with the high frequency oscillator frequency.
The frequency converter is arranged in the transmitting antenna 3; for converting the frequency of the transmitted wave 4 to an intermediate frequency LNB output frequency.
The controller adopts a computer 11, and the control of the computer 11 is realized by executing the following processes:
(1) when the corner reflector 5 is displaced, the frequency measured by the frequency counter 10 changes. When the measurement frequency of the frequency counter 10 changes by a certain amount, such as 1mm displacement, due to the displacement of the corner reflector 5, the computer 11 stores the frequency after the change due to the interference of the reflected signal to the high-frequency oscillator 1;
(2) the computer 11 controls the amplifier 8 to turn off the reflected wave signal to eliminate the interference so that the oscillation frequency of the high frequency oscillator 1 naturally returns to the original frequency;
(3) the computer 11 controls the oscillation frequency of the high-frequency oscillator 1 when the reflected wave signal stored in the step (1) is turned on, and shifts the high-frequency oscillator 1 to the frequency;
(4) the computer 11 controls the amplifier 8 to turn on the reflected wave signal;
(5) by repeating the steps (1) to (4), the continuous displacement of the corner reflector 5 is continuously measured.
As described above, the computer 11 can prevent the occurrence of frequency jump by controlling the frequency of the high-frequency oscillator 1 to the lock frequency by the computer, thereby improving the detection accuracy.
When the frequency of the oscillator and the other frequency are combined together, the frequency of the oscillator changes to approach the other frequency and causes the frequency of the oscillator itself to drift. This means that radio waves emitted from the oscillator are reflected back to the oscillator to automatically turn the oscillator into an easily oscillating state. That is, the oscillator itself automatically adjusts (locks) the oscillation frequency even without external control, and the phase of the radio wave generated by the oscillator and the phase of the reflected wave are in phase with each other at the portion entering the oscillator (to maintain a stable oscillation state). The phase of the returned reflected wave depends on the distance to the reflected object, and the frequency of the oscillator is stably locked in a range correlated with the distance to the object, so it is necessary to know the change in the frequency so that the change in the distance to the object can be detected with high accuracy. The relationship between the change Δ D in the distance from the object and the change Δ f in the frequency of the locked oscillator can be expressed by the following equation 1.
ΔＤ＝－（Ｄ／ｆ）・Δｆ
In formula 1, D is the distance between the oscillator and the object to be reflected, and f is the frequency of the oscillator. In addition, D > > Δ D and f > > Δ f, Δ D and Δ f are proportional.
The oscillator according to the present invention refers to an oscillator that oscillates in a UHF band (300 MHz to 3 GHz), a microwave band (3 to 30 GHz), and a millimeter wave band (30 to 300 GHz).
Further, in the present invention, there is no upper limit to the measurement distance in principle, but since the longer the measurement distance is, the smaller the frequency variation of the same displacement is, it is necessary to employ an LNB or a frequency counter of high accuracy. In practice, the actual distance range is about several meters to 500 meters, taking into account the variation of atmospheric characteristics such as humidity.
As the distance increases, the frequency change Δ f with respect to the displacement amount Δ D becomes small, and therefore, if the accuracy of the LNB or the resolution of the frequency counter is poor, it may be difficult to achieve millimeter resolution. In this case, the frequency variation Δ f can be increased by increasing the frequency f to increase the resolution. However, in the case of outdoors, it is also necessary to select a frequency that is not easily affected by rainfall (e.g., 10GHz band), and it is necessary to select an optimum frequency according to the purpose.
Fig. 2 shows the structure of the corner reflector. Various radio wave noises may exist in the detection environment. The results of the displacement measurement may be disturbed. To solve such a problem, the present application selectively receives only the reflected wave from the reflector by using linear polarization or circular polarization. The transmission signal is circularly polarized, and a radio wave radiated by right-hand circular polarization (or left-hand circular polarization) is reflected by the reflecting means to become right-hand without changing the rotational direction of the circular polarization. By the receiving antenna configuration that receives only circular polarization (or left-hand circular polarization) at the receiving end, circular polarization and linear polarization in different rotational directions are eliminated, and only reflected waves in the same rotational direction as the transmitted radio waves are received.
When the right-hand circularly polarized wave is radiated from the transmitting antenna to the both-side corner reflectors of the present embodiment and reflected twice, the reflected wave returns together with the radiated right-hand circularly polarized wave. By receiving the reflected wave with a right-hand circularly polarized receiving antenna, the signal-to-noise ratio of the reflected wave with respect to surrounding radio noise can be improved.
Further, by using the corner reflector, the reflected wave returns in the direction of the transmitted wave, and therefore it is possible to easily adjust the reflection direction with the corner reflector as compared with the conventional planar reflection plate.
Claims (4)
1. A displacement measuring device includes a signal transmitting portion and a signal receiving portion; the method is characterized in that: the signal transmitting part comprises a high-frequency oscillator, a transmitting antenna and a controller; the signal receiving part comprises a receiving antenna and a frequency counter; the signal receiving part returns to the signal transmitting part through a circulator;
the high-frequency oscillator is used for sending out a high-frequency signal; the transmitting antenna is used for radiating the high-frequency signal generated by the high-frequency oscillator to form transmitting waves; the receiving antenna is used for receiving the reflected wave; the frequency counter is used for measuring the frequency of the reflected wave; the controller controls the reflected wave received by the signal receiving section to turn on/off the return to the high-frequency oscillator according to the frequency output from the frequency counter to control the interference of the reflected wave with the frequency of the high-frequency oscillator.
2. The displacement measuring device according to claim 1, wherein the signal receiving section further comprises an amplifier for amplifying the received transmission wave and for turning on/off a reflected wave returned to the high-frequency oscillator.
3. The displacement measuring device according to claim 1, wherein the signal transmitting section further comprises a frequency converter for adjusting a frequency of the transmitted wave.
4. A displacement measuring device according to claim 3, characterized in that the frequency converter is arranged in the transmitting antenna for converting the frequency of the transmitted wave to an intermediate frequency LNB output frequency.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122139086.4U CN216012139U (en) | 2021-09-06 | 2021-09-06 | Displacement measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122139086.4U CN216012139U (en) | 2021-09-06 | 2021-09-06 | Displacement measuring device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216012139U true CN216012139U (en) | 2022-03-11 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202122139086.4U Active CN216012139U (en) | 2021-09-06 | 2021-09-06 | Displacement measuring device |
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| Country | Link |
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| CN (1) | CN216012139U (en) |
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2021
- 2021-09-06 CN CN202122139086.4U patent/CN216012139U/en active Active
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