JPH1152051A - Radio wave sensor detecting very near distance target - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease a wrong detection probability and correctly detect a very near distance target approaching at high speed, by constituting a plurality of distance gates and judging an order and a combination of outputs of the distance gates. SOLUTION: At a transmission system, carrier waves output from a high-frequency oscillator 1 are mixed by a mixer 3 with an M series code, a GOLD series code or an optional series code output from a code generator 2, amplified by a power amplifier 4 and transmitted from a transmission reception antenna 6 through a circulator 5. At a reception system, waves to be modulated which are reflected from a very near distance target approaching at high speed and wave interferences of a frequency near a frequency of the oscillator 1, etc., are received by the antenna 6, mixed with the output of the oscillator 1 by a mixer 7 through the circulator 5. A low-frequency signal is amplified by an amplifier 8 and distributed by a distributor 9 to at least two or more kinds of signals. In the meantime, the series code output from the generator 2 is delayed by a delay array 10. As a result, at least two or more kinds of distance gates are constituted and mixed with an output of the distributor 9 by an array 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave sensor for detecting a very short distance target, and a radio wave for a very short distance target capable of detecting a target object approaching a very short distance in front of an antenna at a high speed with a low false detection probability. About the sensor.

[0002]

2. Description of the Related Art In a conventional radio wave sensor, it is possible to detect an approaching very short distance target as a target object in a situation without radio wave interference. However, in the presence of radio interference, there is no function to remove radio interference, so the probability of erroneous detection of a non-target object as a target object by mistake is high. Improvements are needed to accurately detect target objects.

[0003] In view of the above-mentioned conventional problems, the present invention comprises a plurality of distance gates, determines the order and combination of outputs of the respective distance gates of the plurality of distance gates, and reduces the probability of false detection based on the determination result. It is an object of the present invention to accurately detect a very short distance target approached at high speed. Further, when the low-frequency signal is monitored and a narrow-bandwidth signal is detected, a low-frequency signal from which the narrow-bandwidth signal has been removed is output, thereby suppressing an increase in noise at the output of the distance gate. It is an object of the present invention to reduce the detection probability and detect a very close target at high speed.

[0004]

In order to achieve the above-mentioned object, a radio sensor for detecting an extremely short-range object according to the present invention modulates the output of a high-frequency oscillator by one sequence code by phase shift keying. A transmission system for transmitting a modulated wave (radio wave);
The modulated wave reflected from the target object at a very close distance at high speed is mixed with the output of the high-frequency oscillator and converted into a low-frequency signal.
A receiving system in which one sequence code is delayed by a plurality of delay amounts and substantially mixed with a plurality of sequence codes, and the order and combination of a plurality of gate outputs after the mixing are determined to reduce the probability of false detection. And an identification system that detects a target object at a very short distance approached at high speed and outputs a detection signal to a subsequent mechanism or device.

The radio wave sensor for detecting a very short-range target according to the present invention has a structure in which the frequency of the radio wave returned from the reflector and a signal of a frequency in the vicinity thereof are mixed with the output of the high-frequency oscillator, in addition to the above-mentioned radio wave sensor. Then, the low-frequency signal after mixing is monitored, and when a narrow-bandwidth signal is detected, a low-frequency signal from which the narrow-bandwidth signal has been removed is output.

Further, the radio wave sensor for detecting a very short distance target according to the present invention is a simplified version of the above-described radio wave sensor, and has a simplified configuration with one type of distance gate. With such a configuration, in the radio wave sensor for detecting a very short distance target of the present invention, a very short distance target approached in the absence of radio wave interference, that is, a moving target when the radio wave sensor is stationary is represented. When the radio wave sensor is moving, it not only detects a moving target or an approaching target representing a stationary target such as the ground, but also monitors the output status of a plurality of distance gates even in the presence of radio interference. It is possible to detect a very short-distance target approached at high speed while keeping the false detection probability low. In addition, by providing a function capable of removing a narrow-band radio wave interference wave component, it is possible to detect a very short-distance target approached at high speed while maintaining a low false detection probability.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a radio wave sensor for detecting a very short distance target according to the present invention will be described below with reference to the drawings. In the present invention, a radio wave (PSK-CW system) modulated by phase shift keying is used. FIG. 1 is a block diagram of a radio wave sensor for a very short distance target having a plurality of distance gates according to the first embodiment of the present invention.

In the transmission system, a carrier (transmission signal) output from the high-frequency oscillator 1 is mixed with an M-sequence, a GOLD-sequence or an arbitrary sequence code output from the code generator 2 by the mixer 3, and the power amplifier 4 Amplified by the circulator 5
Is transmitted from the transmission / reception antenna 6 via. The circulator 5 is a duplexer that separates a transmission wave and a reception wave.

In the receiving system, the modulated wave and the radio interference wave having a frequency close to the frequency of the high-frequency oscillator 1 which are reflected and returned from the extremely short-distance target approaching at high speed are received by the antenna 6 and are transmitted to the circulator 5. , And is mixed with the output of the high-frequency oscillator 1 by the mixer 7. The mixed low-frequency signal is amplified by the amplifier 8 and distributed by the distributor 9 to at least two types. On the other hand, the sequence code output from the code generator 2 is delayed by at least two types in the delay unit array 10, that is,
At least two or more types of distance gates are configured and mixed with the output of the distributor 9 by the mixer array 11. Note that a dotted line with an arrow represents a bus line obtained by combining a plurality of lines.

If the output of the mixer array 11 is not a signal due to an interference wave or the like, it is output in accordance with the relative distance to the target. The computer 12 monitors this signal and determines that it is a correct target. Alternatively, a detection signal is output to the device 13. It should be noted that a circuit constituted by an analog device or the like may be used instead of the computer 12 in order to cope with an ultra-high-speed target.

FIG. 2 is a block diagram of a radio sensor according to a second embodiment of the present invention for detecting an extremely short-range target having a plurality of distance gates. In the present embodiment, a distributor 16, an interference wave detector 14, and a notch filter 15 are added to the configuration of FIG. 1 to provide a function capable of removing a radio wave component of an interference wave having a narrow bandwidth. As is apparent from the figure, the transmission system is the same as the operation in FIG.

In the receiving system, the radio wave received by the antenna 6 is mixed with the output of the high-frequency oscillator 1 by the mixer 7 via the circulator 5, and the mixed low-frequency signal is converted by the amplifier 8
The amplified low-frequency signal is distributed by the distributor 16, and a part of the signal is input to the interference wave detector 14. The interference wave detector 14 monitors whether a narrow band radio wave due to the radio wave interference wave, for example, a CW system radio wave is received, and when the radio wave of this system is detected, this signal is tracked and set in the notch filter 15. The frequency information is sent, and the notch filter 15 outputs to the distributor 9 a low frequency component from which the radio wave component of the CW system has been removed. The operation after the distributor 9 is the same as in FIG. Note that the notch filter is a band elimination filter showing a steep drop characteristic.

FIG. 3 is a block diagram of a radio sensor according to a third embodiment of the present invention for detecting a very short distance target having one distance gate. This embodiment is a block diagram in which a plurality of distance gates in the configuration of FIG. 2 are used as one type. That is, the delay unit array 10 of FIG. 2 is replaced with a delay unit 17 and is constituted by one type of distance gate. As a result, the mixer array 11 of FIG. Further, an analog comparator 19 is used in place of the computer shown in FIG. As is apparent from the figure, the transmission system is the same as the operation in FIG.

In the receiving system, the radio wave received by the antenna 6 is mixed with the output of the high-frequency oscillator 1 by the mixer 7 via the circulator 5 as described above, and the low-frequency signal after mixing is amplified by the amplifier 8 and amplified. The low frequency signal is distributed by the distributor 16, and a part of the signal is input to the interference wave detector 14. The interference wave detector 14 monitors whether a narrow-band radio wave such as a radio wave interference wave, for example, a CW radio wave is received, and when this radio wave is detected, this signal is tracked and set in the notch filter 15. The frequency information is sent, and the notch filter 15 outputs the low frequency component from which the radio wave component of the CW system has been removed to the mixer 18.

On the other hand, the sequence code output from the code generator 2 is delayed by the delay unit 17, that is, one type of distance gate is formed, and is mixed with the output of the notch filter 15 by the mixer 18. If the output of the mixer 18 is not a signal due to interference or the like, it is output corresponding to the relative distance to the target. If the comparator 19 determines that the target is correct, the detection signal is sent to another mechanism or device 13 at the subsequent stage. Is output.

With such a configuration, the function of reducing the probability of false detection based on the relative distance information is deleted, and the circuit configuration is simplified.

[0017]

As described above, according to the radio wave sensor for detecting a very short distance target according to the present invention, a low speed erroneous detection of a very short distance target object approached at high speed even in the presence of radio interference. There is an effect that can be detected with probability.

[Brief description of the drawings]

FIG. 1 is a block diagram of a radio sensor according to a first embodiment of the present invention for detecting a very short-range target having a plurality of distance gates.

FIG. 2 is a block diagram of a radio sensor for detecting a very short distance target having a plurality of distance gates according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a radio wave sensor for detecting a very short distance target having one distance gate according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... High frequency oscillator 2 ... Code generator 3, 7, 18 ... Mixer 4 ... Power amplifier 5 ... Circulator 6 ... Transmitting / receiving antenna 8 ... Amplifier 9, 16 ... Distributor 10 ... Delayer array 11 ... Mixer array 12 ... Computer DESCRIPTION OF SYMBOLS 13 ... Other mechanism or apparatus 14 ... Interference wave detector 15 ... Notch filter 17 ... Delay device 19 ... Comparator

Claims (3)

[Claims] 1. A radio wave sensor for detecting a very short-range target, a transmitting means for transmitting a modulated wave obtained by modulating a high-frequency signal by phase shift keying with a pseudo-noise sequence code or a different sequence code toward a target object; Receives the modulated wave reflected from the target object, mixes the received modulated wave with a high-frequency signal, amplifies the mixed low-frequency signal, and distributes the amplified low-frequency signal to at least two or more types of signals. A distributing unit; an extracting unit configured to form a plurality of distance gates by respectively mixing respective sequence codes delayed to at least two types of the sequence codes and extracting only a Doppler component of a target object; and the Doppler component. The relative distance of the target object is detected based on the detected relative distance information, monitoring is performed to reduce the probability of false detection based on the detected relative distance information, and the target object is determined. Telecommunications sensor for detecting a very-short-distance target, characterized by comprising detecting means for outputting a detection signal. 2. A signal of a frequency of a modulated wave reflected from the target object and a signal of a frequency in the vicinity thereof are mixed at a high frequency, a low-frequency signal after the mixing is monitored, and when a signal having a narrow bandwidth is detected, the narrow band is detected. The radio wave sensor according to claim 1, further comprising an output unit that outputs a low-frequency signal from which a signal of a bandwidth has been removed. 3. The apparatus according to claim 1, wherein said extracting means forms one type of distance gate by mixing the sequence codes delayed by one type of said sequence codes, and extracts only the Doppler component of the target object. A radio sensor that detects the short-range target described.