JP2003270333A - Measurement signal detector and measurement signal detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measurement signal detector capable of detecting a measurement signal without committing erroneous detection even if the reflectivity of a physical object drastically changes on a time basis. <P>SOLUTION: This measurement signal detector comprises a sample-hold part 40 for acquiring first sampled values by sampling input signals at prescribed points of time and then acquiring second sample values by further sampling input signals, an estimation part 42 for generating corrective signals proportional to time by time-integrating differences between the first sampled values and the second sampled values, and an addition part 44 for finding detection threshold values by adding up at least the first sampled values and the corrective signals. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measurement signal detection device and a measurement signal detection method for correcting a detection threshold value according to an input signal and detecting the measurement signal from the input signal using the corrected detection threshold value.

[0002]

2. Description of the Related Art A pulse radar device for measuring the distance to an object reflecting the measurement signal from the time difference between the time when the measurement signal such as a pulse signal is transmitted and the time when the measurement signal is detected from the received signal. Is widely used. The pulse radar device requires a measurement signal detection device used to detect a measurement signal from the received signal.

FIG. 3 shows a block diagram of the configuration of a high-frequency pulse radar device which is a typical pulse radar device. The pulse radar device includes a receiving antenna 10 and a transmitting antenna 1.
2, a high frequency amplifier 14, a trigger generator 16, a high frequency generator 18, a high frequency switch (high frequency SW) 20, and a measurement signal detection device 22.

A high frequency signal is generated by the high frequency generator 18. The high frequency signal output from the high frequency generator 18 is blocked from the transmitting antenna 12 by the high frequency SW 20. The high frequency switch 20 has a trigger generator 16
Upon receiving the pulse-shaped trigger signal from, the high frequency generator 18 and the transmission antenna 12 are connected by the pulse time width. As a result, the measurement signal which is a high frequency pulse is transmitted from the transmission antenna 12. The measurement signal is reflected by an object located in front of the transmitting antenna 12 and received by the receiving antenna 10. The received signal is amplified by the high frequency amplification unit 14 and input to the measurement signal detection device 22. The measurement signal detection device 22 selectively detects and outputs the measurement signal from the input signal that has been input. From the time difference between the time when the trigger signal is output from the trigger generator 16 and the time when the measurement signal is output from the measurement signal detection device 22, the distance between the pulse radar device and the object can be obtained.

However, in the high frequency pulse radar device as described above, the high frequency signal generated by the high frequency generator 18 cannot be completely blocked by the high frequency SW 20, so that the trigger signal is not output. A leaky wave is transmitted from the transmitting antenna 12.

FIG. 4 shows aspects of a transmission signal and a reception signal in the high frequency pulse radar device. The transmission signal is sent as a signal in which a measurement signal when the high frequency SW 20 is in the passing state and a leak wave when the high frequency SW 20 is in the blocking state are superimposed. The received signal is proportional to the value obtained by multiplying the transmitted signal by the reflectance of the object. The reflectance of the object often changes with time, and the received signal is received as a high frequency signal whose amplitude gradually changes, as shown in FIG.

FIG. 5 shows a block diagram of the configuration of a conventional measurement signal detecting device. The measurement signal detection device 22 of the present technology,
The detection unit 24, the reference signal unit 26, and the signal comparison unit 28 are basically configured. FIG. 6 shows the detection operation of the measurement signal from the received signal in the present technology.

The reception signal input to the measurement signal detection device 22 is converted by the detection section 24 into a detection signal obtained by taking the envelope of the high frequency peak section. The detected signal is compared with a reference signal having a constant detection threshold output from the reference signal unit 26 in the signal comparison unit 28. The binarized signal discriminated between the case where the detection signal has the intensity equal to or higher than the detection threshold and the case where the detection signal has the intensity smaller than the detection threshold are output.

However, in the measurement signal detecting device of the present technology, when the leak wave increases due to the influence of the reflectance of the object, the detection signal exceeds the detection threshold value even when there is no measurement signal, There was a problem that caused erroneous detection.

FIG. 7 shows a block diagram of the configuration of another conventional measurement signal detecting device. Measurement signal detection device 22 of the present technology
Further includes a sample hold section (SH section in the figure) 30 and an addition section 32. FIG. 8 shows the detection operation of the measurement signal from the received signal in the present technology.

The received signal is converted by the detection section 24 into a detection signal having an envelope. Sample hold unit 30
Performs sampling on the detected signal to obtain a sampling value. The timing of sampling (shown as SH in the drawing) is, for example, the trigger generation unit 22.
The trigger signal is received and the time is set to a time when the measurement signal is not superimposed. In addition section 32, sampling section 30
And the reference signal of constant intensity from the reference signal unit 26 are added to obtain the detection threshold value. In the signal comparison unit 28, the detected signal and the detection threshold are compared,
The binarized signal discriminated between the case where the detection signal has the intensity equal to or higher than the detection threshold and the case where the detection signal has the intensity smaller than the detection threshold are output.

However, as shown in FIG. 9, when the temporal change of the reflectance of the object with respect to the sampling interval by the sampling unit 30 is rapid, there is a risk of being affected by leaky waves and causing erroneous detection. There is.

[0013]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the present invention detects a measurement signal without erroneous detection even when the reflectance of an object changes rapidly with time. It is an object of the present invention to provide a measurement signal detection device and a measurement signal detection method that can be performed.

[0014]

SUMMARY OF THE INVENTION The present invention for solving the above-mentioned problems is a measurement signal detecting apparatus for detecting a measurement signal exceeding a detection threshold value from an input signal, and sampling the input signal at a predetermined time. To obtain a first sampling value and then further sample the input signal to obtain a second sampling value, and a time integration of a difference between the first sampling value and the second sampling value. It is characterized by including an estimating unit for generating a correction signal proportional to time, and an adding unit for adding at least the first sampling value and the correction signal to obtain the detection threshold value.

Further, in the adding section, a reference signal having a pulse signal is further added during a time from the sampling time of the first sampling value to the sampling time of the second sampling value to obtain the detection threshold value. It is more suitable.

Further, the present invention is a measurement signal detecting method for detecting a measurement signal exceeding a detection threshold value from an input signal, wherein the input signal is sampled at a predetermined time to obtain a first sampling value, and thereafter, A sample and hold step of further sampling the input signal to obtain a second sampling value, and a time-integrated difference between the first sampling value and the second sampling value to generate a correction signal proportional to time. The method is characterized by including an estimation step and an addition step of adding at least the first sampling value and the correction signal to obtain the detection threshold value.

In the adding step, a reference signal having a pulse signal may be further added during the time from the sampling time of the first sampling value to the sampling time of the second sampling value to obtain the detection threshold value. It is more suitable.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a block diagram of the configuration of a measurement signal detecting device according to an embodiment of the present invention. The measurement signal detection device according to the present embodiment includes a detection unit 24, a reference signal unit 46, a signal comparison unit 28, and a sample hold unit 4.
0, the estimation unit 42 and the addition unit 44 are included.

FIG. 2 illustrates the operation of the measurement signal detecting device according to this embodiment. Hereinafter, the operation of the measurement signal detection device according to the present embodiment will be described with reference to FIGS. 1 and 2. It should be noted that, in FIG. 1, components having the same operations as those of the conventional measurement signal detecting device are designated by the same reference numerals and will be briefly described.

The detection section 24 generates a detection signal from the input signal. The detected signal is output to the sample hold unit 40 and the signal comparison unit 28.

The sample hold unit 40 samples the detected signal to obtain a sampling value. In this embodiment, sampling is performed at a short time interval of 2
Is done once. First, at timing SH1, the first
A sampling value (SH1 value) is acquired. After acquiring the first sampling value, the second sampling value (SH2 value) is acquired at timing SH2. Sampling is performed, for example, at the time when the trigger signal from the trigger generation unit of the pulse radar device is received and the measurement signal is not superimposed on the input signal. Further, it is preferable that the sampling timings SH1 and SH2 be set in advance as at least a time interval in which no measurement signal is received.

The estimation unit 42 obtains the difference between the first sampling value and the second sampling value obtained by sampling twice as a sampling difference (SH difference). At this time, the intensity is set to zero during the period from the sampling timing SH1 to the timing SH2.

Further, in the time from the timing SH2 to the timing SH1 of the next sampling, a correction signal proportional to the time is generated. For example, by integrating the sampling difference with time using an integrating circuit,
A triangular wave having a slope proportional to time can be generated. When the intensity change of the detection signal from the timing SH1 to SH2 is large, the sampling difference between the first sampling value and the second sampling value is also large, and the slope of the correction signal obtained by integrating them is large. Therefore, by appropriately adjusting the gain of the integrating circuit, it is possible to obtain a correction signal equal to the time change of the detection signal.
This is because if the sampling interval is made sufficiently short with respect to the change of the reflectance of the object with time, the reflectance of the object changes substantially in proportion to time.

In the adding section 44, the first sampling value (S
H1 value), the correction signal obtained by the estimation unit 42, and the reference signal output from the reference signal unit 46 are added to obtain the detection threshold value. The reference signal can be a signal having a constant intensity as in the conventional measurement signal detecting device. Further, as shown in FIG. 2, it is more preferable to use a reference signal in which a pulse signal having a signal intensity sufficiently larger than the maximum intensity of the measurement signal is superimposed in the time from sampling timing SH1 to SH2.

The signal comparison unit 28 compares the detection signal received from the detection unit 24 with the detection threshold value received from the addition unit 44 to generate a binarized signal. That is, the generated binarized signal is discriminated depending on whether the detection signal is equal to or higher than the detection threshold value or smaller than the detection signal. At this time, in the reference signal unit 46, by superimposing the pulse signal on the reference signal, it is possible to completely avoid erroneous detection between the timings SH1 and SH2.

As described above, according to the present embodiment, even if the reflectance of the object changes abruptly with time, the measurement signal can be accurately detected without erroneous detection. Therefore, by applying the measurement signal detection device according to the present embodiment to a pulse radar device that causes leakage of high-frequency signals, it is possible to measure the distance to the object without erroneous measurement.

[0027]

According to the present invention, a measurement signal detecting device and a measurement signal detecting method capable of detecting a measurement signal without erroneous detection even when the reflectance of an object changes rapidly with time. Can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram of a configuration of a measurement signal detection device according to an embodiment of the present invention.

FIG. 2 is a diagram showing the operation of measurement signal detection in the embodiment of the present invention.

FIG. 3 is a block diagram of a configuration of a high frequency pulse radar device.

FIG. 4 is a diagram showing a transmission wave and a reception wave of a high frequency pulse radar.

FIG. 5 is a block diagram of a configuration of a conventional measurement signal detection device.

FIG. 6 is a diagram showing an operation of detecting a measurement signal in a conventional measurement signal detecting device.

FIG. 7 is a block diagram of a configuration of another conventional measurement signal detection device.

FIG. 8 is a diagram showing the operation of measuring signal detection in another conventional measuring signal detection device.

FIG. 9 is a diagram showing an operation of detecting a measurement signal when the reflectance changes abruptly.

[Explanation of symbols]

10 receiving antenna, 12 transmitting antenna, 14 high frequency amplifying section, 16 trigger generating section, 18 high frequency generating section,
20 high-frequency switch (high-frequency SW), 22 measurement signal detection device, 24 detection unit, 26 reference signal unit, 28 signal comparison unit, 30 sample hold unit, 32 addition unit, 40
Sample hold unit, 42 estimation unit, 44 addition unit,
46 Reference signal section.

Claims (4)

[Claims] 1. A measurement signal detection device for detecting a measurement signal exceeding a detection threshold value from an input signal, the first signal being sampled at a predetermined time.
A sampling and holding unit that acquires a sampling value and then further samples the input signal to acquire a second sampling value, and integrates the difference between the first sampling value and the second sampling value with respect to time. The measuring signal detecting apparatus includes: an estimating unit that generates a proportionally proportional correction signal; and an adding unit that adds at least the first sampling value and the correcting signal to obtain the detection threshold value. 2. The adding section further adds a reference signal having a pulse signal in a time period from the sampling time of the first sampling value to the sampling time of the second sampling value to obtain the detection threshold value. The measurement signal detection device according to claim 1, which is characterized in that. 3. A measurement signal detection method for detecting a measurement signal exceeding a detection threshold value from an input signal, wherein the input signal is sampled at a predetermined time, and
A sampling and holding step of obtaining a sampling value and then further sampling the input signal to obtain a second sampling value, and integrating a difference between the first sampling value and the second sampling value with respect to time. And a correction signal generating a proportional correction signal, and an addition step of adding at least the first sampling value and the correction signal to obtain the detection threshold value. 4. In the adding step, a reference signal having a pulse signal is further added in a time period from the sampling time of the first sampling value to the sampling time of the second sampling value to obtain the detection threshold value. The measurement signal detection method according to claim 3, wherein the measurement signal detection method is used.