JPH01295191A - Discrimination device for moving direction of moving body - Google Patents

Abstract

PURPOSE:To reduce the size of the device and to reduce the time and labor for the adjustment of an optical system by discriminating a Doppler beat signal according to laser output light which is used when the speed of the moving body is measured. CONSTITUTION:The Doppler beat signal outputted by a beat detecting means 1 is amplified (signal 1') by a rate level controller ALC7. Then a differentiating circuit 8 differentiates the signal 1' (signal 2') so as to compare the time of the rising slope of a saw-tooth wave with the time of the falling slope. This signal 2' is compared by a comparing circuit 9A with a reference level REF and then a rectangular wave (signal 3') which becomes high in level while the signal 1' has the rising slope is obtained. Similarly, the inversion of the signal 2' is compared by the other comparing circuit 9B with the REF and then a rectangular wave (signal 4) which becomes high while the signal has the falling slope is obtained. Then, signals 5' and 6' passed through LPFs 5A and 5B are compared by a comparator 6 to discriminate the moving direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a moving direction determining device for a moving object, and particularly to a moving object determining device that functions suitably when measuring speed using the laser Doppler effect.

[Conventional technology]

2. Description of the Related Art A device for determining the direction of movement of a moving object has traditionally been considered important as a means for simultaneously specifying the direction of movement of the moving object when measuring the speed of the object.

Determination of the moving direction of a moving object in a laser Doppler velocimeter will be explained based on a known reference light method.

Now, as shown in FIG. 33, there are two optical paths ffi,,I!
.

An optical frequency thick l01 is arranged in one of the optical paths 11 of the optical path I! , I is given a frequency shift fR and is used as a reference light. On the other hand, the moving object is irradiated with another laser beam that does not undergo any frequency shift, and the scattered light that has undergone the Doppler frequency shift fS is used as signal light. Then, the reference light and the scattered light are detected by the photodetector 200 to obtain 'f++ fs J and the above-mentioned 'f
A method has been adopted in which the direction is determined by comparing the ``R'' and ``R''.

Here, the code 100 indicates a light source section, and the code 102.10
3 represents a half mirror, and 1°4 represents a reflecting mirror. Further, V indicates the traveling direction and traveling speed of the moving object M.

[Problem to be solved by the invention]

However, in such a conventional example, it is essential to set up two optical paths and equip one of the optical paths with a frequency thick 101, which results in a great loss of equipment, and especially if the optical system is Moreover, it is necessary to equip a relatively large and expensive optical system with a frequency filter, which not only increases the size of the entire device but also requires a lot of time and effort to adjust the optical system. was there.

[Purpose of the invention]

The present invention improves the disadvantages of the conventional example, and in particular, the moving direction of a moving object can be identified very easily by signal processing a laser Doppler signal detected during velocity measurement. The purpose is to provide a discrimination device.

[Means to solve the problem]

Therefore, the present invention provides a detection means for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on laser output light used when measuring the speed of a moving object, and a detection means for determining the moving direction of the moving object based on the Doppler beat signal. direction determining means. The direction determining means includes a waveform conversion circuit section that converts the Doppler beat signal into a predetermined timing signal, and a signal processing circuit section that forms two waveforms with different duty ratios based on this timing signal according to a certain standard. , two low-pass filters that equalize each output of the signal processing circuit, and two signals output from each low-pass filter with different levels, one of which is used as a reference to determine the level of the other signal. Along with calculating the difference.

The present invention is constructed by comparing and determining means for determining the direction of movement of a moving object based on the size thereof, and thereby attempts to achieve the above-mentioned purpose.

[First Embodiment of the Invention] A first embodiment of the invention will be described below with reference to FIGS. 1 and 2.

The embodiment shown in FIGS. 1 and 2 is a detection means 1 for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on a laser output light used when measuring the speed of a moving object M.
and a direction determining means 2 for determining the moving direction of the moving object based on the Doppler beat signal.

The direction determining means 2 includes a waveform conversion circuit section 3 that converts the Doppler beat signal into a predetermined timing signal, and a signal processing circuit section 4 that forms two waveforms with different duty ratios according to a certain standard based on this timing signal. Two low-pass filters 5A each equalize each output of the signal processing circuit section 4.

5B and each low bass wave)
Comparison that calculates the level difference between two signals of different levels output from I'5A and 5B, using one signal as a reference, and determines the direction of movement of the moving object M based on the magnitude of the difference. It is constituted by a comparator 6 as a determination means.

The waveform conversion circuit section 3 includes a level adjustment circuit (ALC; auto level controller) 7 that amplifies the Doppler beat signal to a predetermined level, and a differentiation circuit 8 that differentiates the output signal of the level adjustment circuit 7.

The signal processing circuit section 4 has one comparison circuit 9A that outputs a rectangular wave of a predetermined level in synchronization with a predetermined timing signal output from the differentiating circuit 8, and a comparison circuit 9A that outputs the same timing signal as the other comparison circuit 9A. It is constituted by an inverter 1o that inputs and outputs a signal that is an inversion of the output signal of one comparison circuit 9A, and a series circuit consisting of the other comparison circuit 9B. Each comparison circuit 9A, 9B is provided with a reference signal generation circuit (REF) 9a, 9b, respectively, on its human axis.

Next, the operation of the above embodiment will be explained.

First, the output signal from the beat detecting means 1 is amplified by an ALC (auto level controller) 7 to a measurable level waveform (signal ■). To compare the upslope time (ΔTr) and the downslope time (ΔTf) of the sawtooth wave, the signal ■ is differentiated (signal ■). When this signal (2) is compared with the reference level by one comparison circuit 9A, a rectangular wave (signal (2)) which is at a high level during the rising slope (ΔTr) of the signal (2) is obtained. Similarly, when the inversion of the signal ■ is compared with the reference level in the other comparator circuit 9B, a rectangular wave (signal ■) becomes high level during the downward slope (ΔTf).
is obtained.

Low pass filter (LPF) 5A and low pass filter (
When signals ■ and ■ are averaged by LPF)'5B, Δ
A voltage proportional to Tr and ΔTf is obtained from the signals ■ and ■. The comparator 6 compares the magnitudes of the signals (1) and (2), and depending on whether the output is at a high level or a low level, it is possible to determine the direction of the sawtooth wave, that is, the speed direction.

The direction determining device constructed and operated in this manner is incorporated into the device shown in FIG. 31.

The apparatus shown in FIG. 31 includes a laser light source 91 that outputs coherent light, a laser output light 91a output from the laser light source 91, and a reflected and scattered light 91b from an object to be measured M directed toward the laser light source 91. A laser drive circuit 93 is provided to drive the laser light source 91. Then, the laser light source 91 receives a Doppler beat signal formed by the reflected and scattered light 91b.

beat detection means 1 for separating and extracting the beat signal Db from a laser light source 91, a speed calculation means 90 for calculating the moving speed or rotational speed of the object to be measured M based on the dop beat signal Db detected by the beat detection means 1, and a direction determination means. 6.

Of these, the laser light source 91 is driven by a laser drive circuit 93 to operate. In this embodiment, a semiconductor laser is used as the laser light source 91, which outputs coherent light 91a that irradiates the object to be measured (moving object) M by stimulated emission. In this case, reflected return light 91b scattered by the object to be measured M and subjected to Doppler frequency shift.
When the light returns to the semiconductor laser, a self-mixing effect occurs inside the resonator with coherent light that has not undergone Doppler shift, generating Doppler beats. Then, a sawtooth wave signal corresponding to the beat frequency is superimposed on the semiconductor laser drive current.

As the condensing means 92, an optical lens is used in this embodiment. This condensing means 92 is disposed between the laser light source 91 and the object to be measured M, and is mounted on a holding mechanism (31st (omitted in the figure). The condensing means 92 has a function of condensing the laser irradiation light 91a emitted from the laser light source 91 and efficiently irradiating the object M to be measured. At the same time, it has a function of condensing the reflected return light scattered by the object to be measured M and making it incident on the end surface a of the semiconductor laser light source 91.

As the beat detection means 1, a signal detection amplifier is used in this embodiment. This signal detection amplifier is installed at the output end of the laser drive circuit 93, and has the function of extracting and outputting a Doppler beat signal that approximates a sawtooth wave superimposed on the drive current that drives the laser light source 91. It is equipped with

Then, the sawtooth wave detected by the beat detection means 1 and containing certain information is transmitted to the direction determination means 1 as described above.
The signal is processed at

[Second Embodiment] Next, a second embodiment will be described based on FIGS. 3 and 4.

This embodiment attempts to determine the direction by focusing on the difference between the time of one cycle of the input sawtooth wave and the time of the specified slope.

In the second embodiment shown in FIG.
1 is a waveform conversion circuit section 3 that converts the Doppler beat signal detected by the beat detection means 1 into a predetermined timing signal, and a signal that forms two waveforms with different duty ratios based on this timing signal according to a certain standard. It is composed of a processing circuit section 22 and a waveform equalizing circuit section 5 including two low-pass filters 5A and 5B that equalize each output of the signal processing circuit section 22.

Of the two signals with different levels output from each low-pass filter (LPF) 5A, 5B, the level difference between the other signal is calculated using the - signal as a reference, and the movement of the moving object is determined based on the magnitude of the difference. A comparator 6 is provided as a comparison/judgment means for determining the direction.

The waveform conversion circuit section 3 includes a level adjustment circuit (ALC) that amplifies the Doppler beat signal sent from the beat detection means 1 to a predetermined level as in the case of the first embodiment described above.
7 and a differentiating circuit 8 for differentiating the output of this ALC 7.

Further, the signal processing circuit unit 22 includes one waveform shaping circuit 22A that outputs a rectangular wave of a predetermined level synchronized with the fall of a predetermined timing signal output from the differentiating circuit, and one waveform shaping circuit 22A that is identical to the other waveform shaping circuit 22A. The other waveform shaping circuit 22B inputs a timing signal, inverts it, rectifies it, and outputs a rectangular wave having the same level as the output of the aforementioned one waveform shaping circuit 22A and a different duty ratio. ing.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of the above embodiment will be explained based on FIG. 4.

First, the Doppler beat signal detected by the beat detection means 1 is adjusted to a predetermined level by the level adjustment circuit 7 (signal ■). The output of this level adjustment circuit 7 is input to a differentiating circuit 8, which outputs a timing signal synchronized with the rising and falling edges of the waveform (signal 2).

This timing signal is transmitted to the waveform shaping circuits 22 of one side and the other side.
It is sent to A and 22B.

One of the timing signals is converted into a pulse train (2) synchronized with the falling edge by one waveform shaping circuit 22A. The period of this pulse train (3) is twice the period T of the sawtooth wave, and the frequency is 1/2. Therefore, the duty ratio with respect to the rectangular wave converted to the frequency of the sawtooth wave is 50%, and it can be considered equivalent to a reference triangular wave whose uphill and downhill times are equal. Therefore, when the pulse train (2) is averaged by the LPF 5A, a voltage value corresponding to one period of the sawtooth wave is obtained (signal (2)).

The signal {circle around (2)} is the average voltage value of the reference triangular wave whose upward and downward slopes are equal, as described above.

The other signal is inverted by the waveform shaping circuit 22B and then averaged by the low pulse filter (LPF) 5B, and has a voltage value corresponding to the time of the downward slope of the sawtooth wave (signal ■).

In addition, in Fig. 4, comparing the voltage values of signal ■ and signal ■ with the comparator corresponds to comparing the peak position of the manual sawtooth wave with the peak position of the reference triangular wave, and the downward slope When the time is long, the output is high level, and when it is short, the output is low level. As a result, it is possible to determine whether the time of the downward slope is longer or shorter than the half period of the sawtooth wave, and the direction of velocity can be determined.

Note that although this embodiment focused on a downward slope, direction determination using an upward slope can also be realized in a similar manner.

[Third Embodiment] Next, a third embodiment will be described based on FIGS. 5 and 6.

In the embodiment shown in FIG. 5, the direction determining means 24 includes a waveform converting circuit section 25 that converts the Doppler beat signal detected by the beat detecting means 1 into a predetermined timing signal, and a waveform converting circuit section 25 that has a different duty ratio based on this timing signal. A waveform equalization circuit section 27 that includes a signal processing circuit section 26 that forms two waveforms, and two low-pass filters 27A and 27B that equalize each output of the signal processing circuit section 26 separately.
and a comparator 6 for determining the moving direction of the moving object as described above based on the outputs of the filters 27A and 27B.

Of these, the waveform conversion circuit section 25 includes a level adjustment circuit 7 that amplifies the Doppler beat signal to a predetermined level, and a Schmitt trigger that converts the output signal of the level adjustment circuit 7 into a square wave of a predetermined level by setting a certain dead zone. circuit 25A
It is composed of.

Further, the signal processing circuit section 26 includes a first signal output circuit 2 that outputs the output of the Schmidts 1-trigger circuit 25A as it is.
6A, and a second signal output circuit 26B that inverts and outputs the output of the Schmitt trigger circuit 25A.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of the third embodiment shown in FIG. 5 will be explained.

As in the case of each embodiment described above, the dots plaby 1 to signal detected by the beat detection means 1 is sent to the Schmitt circuit 25A via the level adjustment circuit 7 (signal
).

This Schmitt circuit 25A outputs the input signal (2) only when it is higher or lower than the dead zone level. As a result, rectangular waves (2) with different duty ratios are obtained. This duty ratio, in terms of whether it is larger or smaller than 1, tends to match the ratio of the up-slope time and down-slope time of the sawtooth wave.

The signal ■ and the inversion of the signal ■ (signal ■) are passed through a low-pass filter (
When averaged by LPF) 27A and 27B, the voltage proportional to the duty of signal ■ becomes signal ■.

■ Obtained by binding. The comparator 6 compares the magnitudes of the signals (1) and (2), and it is possible to determine whether the output is at a high level or a low level.The direction of the sawtooth wave, that is, the speed direction, can be determined.

[Fourth Example] Next, a fourth example will be described based on FIGS. 7 and 8. □ This fourth embodiment creates a triangular wave that matches the period of the sawtooth wave (the time ratio of the uphill slope and downhill slope is equal), and compares the uphill (downward) slope of the sawtooth wave with that of the triangular wave in time. This method determines the direction by

In the embodiment shown in FIG. 7, the direction determining means 30 includes a waveform conversion circuit section 31 that converts the Doppler beat signal detected by the beat detecting means 1 into a predetermined timing signal;
A waveform equalization circuit that includes a signal processing circuit section 32 that forms two waveforms with different duty ratios based on this timing signal, and two low-pass filters 33A and 33B that equalize each output of this signal processing circuit 26. Part 33
and a comparator 6 that specifies the moving direction of the moving object based on the outputs of these two low-pass filters 33A and 33B.

Among these, the waveform conversion circuit section 31 includes a first waveform conversion circuit 3 that converts the Doppler beat signal into a predetermined timing signal.
1A, and a second waveform conversion circuit 31B that outputs a predetermined reference timing signal synchronized with the Doppler beat signal.

The signal processing circuit unit 32 includes a first pulse control circuit 32A that inverts the output signal of the first waveform conversion circuit 31A and outputs a rectangular wave signal that is adjusted to a constant level;
and a second pulse control circuit 32B that inverts the output signal of the waveform conversion circuit 31B and outputs a reference signal with a duty ratio [50%].

Furthermore, the first waveform conversion circuit 31A described above includes a level adjustment circuit (ALC) 7 that amplifies the Doppler beat signal to a predetermined level, and a first differential circuit that converts the output signal of the level adjustment circuit 7 into a predetermined timing signal. It is composed of a circuit 8.

The second waveform conversion circuit 31B also includes a frequency counter 31 that counts the frequency of the Doppler beat signal, and a frequency counter 31 . A triangular wave oscillation circuit 31 inputs each output of the level adjustment circuit 7 and outputs a reference triangular wave signal.
2, and a second differentiator circuit 313 that converts the output signal of the triangular wave oscillation circuit 31□ into a predetermined reference timing signal.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of this fourth embodiment will be explained.

First, the output signal (2) of the beat detection means 1 is divided into two as shown in FIG.
Sent to 31B.

Among these, in the first waveform conversion circuit 31A, the sawtooth wave as an input signal is set to a predetermined level by the level adjustment circuit 7, and then sent to the differentiating circuit 8, where the peak position of the sawtooth wave is determined. (signal ■).

In the second waveform conversion circuit 31B, the frequency of the sawtooth wave which is the input signal is measured by the frequency counter 31. After counting at
The information is sent to the triangular wave oscillation circuit 31□. This triangular wave oscillation circuit 312 also receives a sawtooth wave of a predetermined level as a reference from the level adjustment circuit 7 described above.

In the triangular wave oscillation circuit 31□, the frequency counter 31
．． oscillates a triangular wave synchronized with the sawtooth wave based on the reference level (signal ■). Differentiate this to detect the peak position of the triangular wave (signal ■).

When the signals ■ and ■ are respectively passed through the pulse control circuits (inverters) 32A and 32B of the signal processing circuit section 32, pulse trains ■ and ■ corresponding to the respective times required for the signal level to change from the lowest value to the highest value are obtained. It will be done. Here, in the pulse train (2), the steeper the rising slope of the sawtooth wave, the larger the duty of the pulse, and the gentler the rising slope, the smaller the duty.

These are filtered by the low-pass filter 33 of the waveform equalization circuit section 33.
By comparing the averaged signals A and 33B with the comparator 6, it can be determined whether the rise of the manual sawtooth wave is steeper or more gradual than that of the reference triangular wave. Therefore, the direction can be determined.

Direction can be easily determined in a similar manner by focusing on the downward slope of the sawtooth wave.

[Fifth Example] Next, a fifth example will be described based on FIGS. 9 and 10.

In the embodiment shown in FIG. 9, the direction determining means 35 includes a waveform conversion circuit section 3 that converts the aforementioned Donpla beat signal into a predetermined timing signal, and a positive peak value and a negative peak value of the output of this waveform conversion circuit section 3. A positive peak value detection circuit 36 and a negative peak value detection circuit 3 each separately detect the values and output a voltage signal of a predetermined level corresponding to the detected value
7, and an addition determining means 38 which adds the output signals of each of the detection circuits 36 and 37 and determines the moving direction of the moving object based on the result.

In this case, the positive peak value detection circuit 36 and the negative peak value detection circuit 37 function in the same manner as the waveform equalization circuit section 5 in the first embodiment described above.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of the fifth embodiment will be explained based on FIG. 1.0.

The sawtooth wave detected by the beat detection means 1 is amplified by the level adjustment circuit 7 to a measurable predetermined level waveform (signal ■).

The sum (D) of the upward and downward slopes of one cycle of the sawtooth wave (2) changes to be positive or negative depending on the direction of the sawtooth wave. This is clear from the following equation due to the nature of the sawtooth wave.

D=(ΔA/ΔTr)−(ΔA/Δ'rr)=ΔA(Δ
T, -ΔT,)/(ΔTr·ΔT,) where ΔA is the amplitude, and ΔTr and ΔT are the up-slope time and the down-slope time.

,', D>O→ΔT,>ΔT1 D<0→ΔTt<ΔTr In order to know the slope of the sawtooth wave (■), it is differentiated by the differentiating circuit 8 (signal (■)). A positive peak value detection circuit 36 and a negative peak value detection circuit 37 have functions such as sampling and holding the positive peak value [Vl] and negative peak value (■2) of the signal ■.
When detected using the signal ■1. ■ is obtained. This is added by an adding circuit 38, and the direction of the sawtooth wave, that is, the speed direction, can be determined depending on whether the obtained output is positive or negative.

[Sixth Example] Next, a sixth example will be described based on FIGS. 11 and 12.

This sixth embodiment relates to a direction discrimination method that utilizes the difference in the sawtooth wave gradient depending on the direction.

In the embodiment shown in FIG. 11, the direction determining means 40 is
A waveform conversion circuit section 3 that converts the Doppler beat signal detected by the beat detection means 1 into a predetermined timing signal, and a signal processing circuit section 41 that forms two waveforms with different duty ratios based on this timing signal according to a certain standard.
, a latch circuit 42 that latches one of the two output signals of the signal processing circuit section 41 with the other as a reference, and direction determining means 43 that determines the moving direction of the moving object based on the output of this latch circuit. It is made up of.

Of these, the waveform conversion circuit section 3 includes a level adjustment circuit 7 that amplifies the Doppler beat signal to a predetermined level, and converts the output signal of the level adjustment circuit 7 into a predetermined timing signal, as in the case of the first embodiment described above. and a differentiating circuit 8 for conversion.

Further, the signal processing circuit section 41 inputs the timing signal outputted from the waveform conversion circuit section 3 described above, forms a rectangular wave signal of a constant level using a threshold value of a predetermined level, and outputs the signal. 41A and the output of the level adjustment circuit 7, the duty ratio is set to 50 [corresponding to the positive and negative signals].
%] square wave.

In this case, the latch circuit 42 has the same function as the waveform equalization circuit 5 in the first embodiment described above.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of the embodiment shown in FIG. 11 will be explained based on FIG. 12.

First, the Doppler beat signal detected by the beat detection means 1 is amplified by the level adjustment circuit 7 to a waveform of a measurable level (signal ■).

The positive peak value ■+ of the differential waveform ■ of the signal ■ and the positive peak value when the direction of the sawtooth wave is different is V°+ (<V+), and the reference of the first comparator circuit 41A is determined by the following conditional expression. When the voltage V rQf is determined and the signal ■ is input, the signal ■ is obtained.

When V rof is set in this manner, a signal (2) whose output differs depending on the direction of the sawtooth wave is obtained.

Here, rV'+<V, ,<V+J.

The second comparator circuit 41B generates a rectangular wave (2) corresponding to the positive and negative sides of the signal (2). Due to the rising edge, a signal is given at the edge■
By latching , it is possible to determine the direction of the sawtooth wave, that is, the speed direction, depending on whether the output ■ is at a high level or a low level. This determination is made by the direction determining means 43.

Note that the reference voltage V r of the first comparison circuit 41A
It is also possible to similarly determine the speed direction by setting e f as in the following conditional expression and latching the signal ■ at the falling edge of the signal ■.

V+-<Vr,,<V,.

However, ■-1■+-, the negative peak value (v, -1v'-) of two waveforms with different directions of sawtooth waves.

[Seventh Embodiment] Next, a seventh embodiment will be described based on FIGS. 13 and 14.

This seventh embodiment attempts to determine the direction of a moving object by measuring the gradient change time of the Doppler beat signal.

In the seventh embodiment shown in FIG.
consists of a waveform conversion circuit unit 3 that converts a Doppler beat signal into a predetermined timing signal, and a signal processing circuit that forms two rectangular waves, one of which has a repetition period twice that of the other, based on this timing and according to a certain standard. a latch circuit 47 that latches one of the two output signals of the signal processing circuit 46 as a reference; and a direction determination unit 47 that determines the moving direction of the moving object based on the output of the latch circuit 47. means 48.

As in the case of the first embodiment described above, the waveform conversion circuit section 3 includes a level adjustment circuit 7 that amplifies the Doppler beat signal to a predetermined level, and a differential circuit that converts the output signal of the level adjustment circuit 7 into a predetermined timing signal. It is composed of a circuit 8.

The signal processing circuit unit 46 directly inputs the output of the level adjustment circuit 7 and a first comparator 46A that receives the above-mentioned timing signal and forms and outputs a rectangular wave signal of a constant level using a zero level threshold. = 42- A second comparator 46B outputs a rectangular wave with a duty ratio of 50% corresponding to the positive/negative signal, and is synchronized with the rise and fall of the signal output from the second comparator 46B. frequency doubling circuit 4 that outputs a rectangular wave with twice the repetition period
6C.

In this case, the latch circuit 47 has the same function as the waveform equalization circuit 5 in the first embodiment described above.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of this seventh embodiment will be explained based on FIG. 14.

The Doppler beat signal detected by the beat detection means 1 is
The signal is adjusted (amplified) to a predetermined level by the level adjustment circuit 7 (signal ■).

When the signal ■ is input to the first comparator 46B and compared with the ground, the duty is 5 with the same phase and frequency as the sawtooth wave.
Obtain a 0% square wave ■. The frequency doubling circuit 46C generates twice the frequency in synchronization with the rectangular wave (signal).
. The period of the signal ■ is T.

When the time taken for the potential to reach a positive peak from 0 is Tp, the direction of the sawtooth wave can be determined using the following conditional expression.

Tp<(T/4) Tp>(T/4) Therefore, it is sufficient to know "Tp" and rT/4J.

The time rT/4J has elapsed since the sawtooth wave changed from negative to positive can be determined from the signal ■. Furthermore, when the signal (2) is differentiated and compared with the ground by the first comparator B, the signal (2) is obtained. Since the timing of the positive peak of the sawtooth wave can be obtained at the fall of the signal (2), if the signal (2) is latched using this signal, the above conditional expression can be determined. Depending on whether this latch signal (2) is positive or negative, the direction of the sawtooth wave, that is, the speed direction can be determined.

Incidentally, even if the signal (2) is latched at the rising edge of the signal (2), it is possible to determine the velocity direction using the same concept.

[Eighth Example] Next, an eighth example will be described based on FIGS. 15 and 16. In the eighth embodiment, the direction is determined by comparing the period and slope of the sawtooth wave over time.

In the eighth embodiment shown in FIG. 15, the direction determining means 50 includes a waveform converting circuit section 3 that converts the Doppler beat signal into a predetermined timing signal, and a waveform converting circuit section 3 that converts the Doppler beat signal into a predetermined timing signal, and a waveform converting circuit section 3 that converts the Doppler beat signal into a predetermined timing signal. A signal processing circuit section 51 that forms two waveforms, a gate circuit section 52 that separately controls the output of clock signals that are input separately based on two timing signals, and this gate circuit section 5.
a counting circuit unit 53 that counts the pulses of the two pulse trains outputted from the Doppler beat signal separately within a time corresponding to one cycle of the Doppler beat signal; and this counting circuit unit 53.
and a direction calculation circuit unit 54 which compares and calculates each output and determines the moving direction of the moving object based on the magnitude thereof.

Of these, the signal processing circuit section 51 includes a gate control circuit 51A as a first control signal output circuit that converts two periods of the timing signal output from the differentiating circuit 7 into a rectangular wave signal with one period = 45-. , and a gate control circuit 51B serving as a second control signal output circuit that inverts the timing signal and then outputs the positive side portion thereof as a rectangular wave signal of a predetermined level.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of this eighth embodiment will be explained based on FIG. 16.

This eighth embodiment focuses on the time difference between the period of the sawtooth wave and a specific slope, and is characterized in that the extracted time difference is expressed by the number of pulses.

That is, in this eighth embodiment, the signal ■ which creates the pulse train of the time corresponding to the - period and the downward slope, respectively.
, ■), it compares and calculates whether the time of the downward slope is longer or shorter than the half cycle of the sawtooth wave, and the velocity direction is determined from the result.

[Ninth Embodiment] Next, a ninth embodiment will be described based on FIGS. 17 and 18. This embodiment uses two analog switches that are open during the rising and falling slopes of the sawtooth wave to charge or discharge a capacitor, and by observing the tendency of the potential appearing on the capacitor based on the time difference, the direction of speed can be determined. It is something to do.

In the ninth embodiment shown in FIG. 17, the direction determining means 55 includes a waveform conversion circuit section 3 that converts the Doppler beat signal into a predetermined timing signal, and a waveform conversion circuit section 3 that converts the Doppler beat signal into a predetermined timing signal, and A signal processing circuit unit 56 that simultaneously outputs a rectangular wave signal and its inverted signal separately; a capacitor charging/discharging circuit 57 that is activated by the output of the signal processing circuit unit 56 and continues charging and discharging simultaneously; It is comprised of a direction calculation circuit section 58 that detects the charging potential of the capacitor charging/discharging circuit 57 and determines the moving direction of the moving object based on this.

Of these, the signal processing circuit unit 56 includes a comparator 56A that forms a constant level rectangular wave signal synchronized with the timing signal based on the timing signal and outputs it as one switch drive signal, and a comparator 56A that outputs the signal as one switch drive signal. and an inverter 56A that inverts the signal and outputs it as the other switch drive signal.

In addition, the capacitor charging/discharging circuit 57 includes a capacitor 57A whose one end is grounded, and the other end of which is connected to the potential of "+■ [v]" via a resistor R and an analog switch AS1. It is constituted by one power supply circuit 57B and the other power supply circuit 57C, which is also connected to the other end of the capacitor through a resistor R and an analog switch AS2 and has a potential of '-V(v)J.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of this embodiment will be explained based on FIG. 18.

The Doppler beat signal detected by the beat detection means 1 is amplified to a predetermined level by the level adjustment circuit 7 (signal ■). By passing the differential waveform (2) of this signal (2) through a comparator 56A, a rectangular wave (2) which is at a high level during an upward slope and at a low level during a downward slope is obtained. This signal {circle around (2)} opens and closes the analog switch AS. At this time, the analog switch AS is opened and opened by the inverted signal of the signal (2).

Two analog switches AS++' ASz (first
When one capacitor C is charged and discharged by (see Figure 7), if the duty of the rectangular wave (2) is not 50%, the charging/discharging balance is disrupted and a positive or negative potential constantly appears in the capacitor C (signal (2)).

This signal (2) is compared with the ground level by a comparator 56B, and the comparison/determination circuit 58 determines whether the signal is positive or negative, thereby determining the direction. In this case, the period of the measurement frequency is rRC
/2J is set to ungrooved.

[Tenth Embodiment] Next, a tenth embodiment will be described based on FIGS. 19 and 20. This tenth embodiment uses a Schmitt trigger circuit to determine direction.

In the tenth embodiment shown in FIG. 19, the direction determining means 60 includes a level adjustment circuit 7 for amplifying the Doppler beat signal outputted from the beat detecting means 1 to a predetermined level;
A signal processing circuit section 61 that forms two waveforms with different duty ratios according to a certain standard based on the output signal of the level adjustment circuit 7, and two low-pass circuits that equalize each output of the signal processing circuit section 61. Filters 62A, 62
Among the two signals with different levels outputted from the waveform equalization circuit section 62 equipped with a waveform equalizing circuit section 62 and each of the low-pass filters 62A and 62B, one signal is used as a reference to calculate the level difference between the other signal and its value. and a comparison/discrimination means 63 for discriminating the moving direction of the moving object based on the size of the moving object.

Here, the signal processing circuit unit 61 includes a Schmitt trigger circuit 61A that sets a certain dead zone for the output signal of the level adjustment circuit 7, converts it into a square wave of a predetermined level, and outputs the output signal, and a Schmitt trigger circuit 61A that converts the output signal of the level adjustment circuit 7 into a square wave of a predetermined level. A comparator 61B converts the signal into a rectangular wave with a ratio of 50% and outputs it.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of the tenth embodiment will be explained based on FIG. 20.

First, the Doppler beat signal detected by the beat detection means 1 is amplified to a predetermined level by the level adjustment circuit 7 (signal ■) and then sent to the signal processing circuit section 61.

In the signal processing circuit section 61, when the signal ■ is passed through the Schmitt trigger circuit 61A and outputted only when it is higher or lower than the dead band level, a rectangular wave ■ with a different duty ratio is generated.
is obtained. On the other hand, the output of the comparator 61B, which is the signal (2), is always a rectangular wave with a duty of 50% because the comparison potential is grounded. When signal ■ and signal ■ are passed through low-pass filters (LPF) 62A and 62B, ■
Signals (1) and (2) averaged to 1 and (2) are obtained.

Due to the direction of the sawtooth wave, the duty of signal ■ is 50%.
], the voltage (2), which is the average of the signal (2), also changes. Since the voltage (2) is constant regardless of the direction of the sawtooth wave, the magnitude of (1) and (2) is determined by the comparing and determining means 6.
3, and the direction of the sawtooth wave, that is, the speed direction, is determined depending on whether the output is high level or low level.

[Eleventh Embodiment] Next, an eleventh embodiment will be described based on FIGS. 21 and 22. The eleventh embodiment is characterized in that the characteristics of the waveform are captured only by the comparator without differentiating the input signal, and the direction is determined by time comparison.

In the eleventh embodiment shown in FIG. 21, the direction determining means 65 includes a level adjustment circuit 7 and a signal processing circuit section 6 that processes the signal output from the level adjustment circuit 7.
6, a waveform equalization circuit section 67 that equalizes each of the two output signals output from the signal processing circuit section 66, and a waveform equalization circuit section 67 that compares and moves the two signals output from the waveform equalization circuit section 67. It is composed of a comparator 68 that determines the direction of an object.

The signal processing circuit section 66 includes a first comparator 66A that forms a rectangular wave of a predetermined level from the output signal of the level adjustment circuit 7 based on a certain reference value, and also inverts the output signal of the level adjustment circuit 7. It has a signal inverting circuit 66H and a second comparator 66B which inputs the output of the signal inverting circuit 66H and forms a rectangular wave of a predetermined level using a reference value of the same level as the first comparator 66A. Equipped with a rectangular wave output circuit 66C that detects the rise of the output of the first and second comparators 66A and 66B and generates a rectangular wave, and further outputs a rectangular wave with a duty ratio of 50% from the level adjustment circuit 7. The third comparator 66D is configured to separately output two rectangular waves having different duty ratios.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of the eleventh embodiment shown in FIG.
This will be explained based on the diagram.

First, the Tonpra beat signal (2) sent from the beat detection means 1 is amplified to a predetermined level by the level adjustment circuit 7, divided into three parts, and sent to the signal processing circuit section 66.

One of the three divided Doppler beat signals is detected by the first comparator 66A having a predetermined reference voltage REF for a time width Tun in which the sawtooth wave has a value equal to or higher than the reference voltage (signal ■).

The other signal is inverted, and the second comparator 66B similarly detects a time width Tiu in which the sawtooth wave has a value greater than the reference voltage (signal ■).

A rectangular wave is generated by detecting the rising edge of each pulse train of the signals (■) and (2). Let T5 be the high level time of this rectangular wave (signal ■). This time Ts varies depending on the shape of the sawtooth wave.

The other remaining signal detects the half period T r e f of the sawtooth wave with reference to the ground potential (signal ■).

Therefore, when the signals ■ and ■ are respectively averaged by the two low-pass filters 67A and 67B of the waveform equalization circuit section 67, and the signals ■, ■) are compared by the third comparator 66D, from the magnitude relationship between T r G f and Ts, It can be determined whether the peak position of the sawtooth wave is earlier or later than a half cycle, and the direction can be determined.

[Twelfth Embodiment] Next, a twelfth embodiment will be described based on FIGS. 23 and 24.

This embodiment focuses on the fact that sawtooth waves are synthesized by superimposing trigonometric waves, and applies the fact that the shape characteristics depend on the phase relationship between the fundamental wave and harmonics.

In the twelfth embodiment shown in FIG.
is a reference signal output circuit 71 that outputs a reference signal having a frequency twice the fundamental wave component of the Doppler beat signal based on the Doppler beat signal detected and sent by the beat detection means 1, and a reference signal output circuit 71 that outputs a reference signal having a frequency twice the fundamental wave component of the Doppler beat signal, and a second harmonic component from the Doppler beat signal. a measurement signal output circuit 72 that extracts and outputs the signal, and a circuit that inputs the two signals output from each of these signal output circuits and detects the phase shift of the measurement signal with respect to the reference signal to determine the moving direction of the moving object. Phase difference detection means 7
3.

Here, the reference signal output circuit 71 includes a free-running oscillator 71A that outputs a sine wave signal of twice the frequency of the fundamental wave component related to the Doppler beat signal, and a component that divides the output of the free-running oscillator 71A into 1/2. The frequency divider 71B is input with the output signal of the frequency divider 71B and the fundamental wave component related to the Doppler beat signal, and the phase difference between these two sine wave signals is detected, and the phase shift of the free-running oscillator output signal is detected. The phase detection circuit 71C performs correction control.

The measurement signal output circuit 72 also includes a voltage control filter 7 that extracts and outputs the second harmonic component from the Doppler beat signal.
2A, and a frequency stabilizing circuit 7' 2B that stabilizes the frequency of the second harmonic component of the output signal of the voltage control filter 72A.

A frequency-voltage (F-V) conversion circuit 72C is attached to the voltage control filter 72A, and its operation is controlled by its output.

In this embodiment, the voltage control filter (VCF) 72A uses a bypass filter (HPF) whose characteristics change depending on the input voltage value.

Next, the operation of this twelfth embodiment will be explained based on FIG. 25.

First, the sawtooth wave (2) as a Doppler beat signal outputted from the beat detection means 1 is divided into three parts, and each is inputted to a phase detection circuit (VCO) 71A, an F-V conversion circuit 72C, and a voltage control filter 72A. VCO71A, 1/2
The function of the reference signal output circuit 71, which is a loop block formed by the frequency divider 71B and the phase detection circuit 71C, outputs a signal whose phase is synchronized with the fundamental wave of the sawtooth wave.

On the other hand, harmonic components of the sawtooth wave signal input to the voltage control filter 72A are extracted, and the frequency stabilization circuit (PL)
L) Generate a signal {circle around (2)} whose phase is synchronized with the harmonic (mainly the second harmonic) forming a sawtooth wave at 72A. In this case, if the phase difference output is zero, it means that the moving object is approaching. Furthermore, if the phase difference output is not zero, it means that the moving object is moving away.

The phase detection circuit 71C detects the phase difference between ■ and ■ and determines the direction.

Incidentally, in the above description, an example in which the VCF is realized by an HPF is shown, but the same operation can be easily obtained by using a band pass filter (BPF).

Further, in this embodiment, the output of the F--(2) conversion is used as the control voltage of the VCF, but the same operation can be easily obtained by using the output (2) from the VCO. Further, when the speed of the object to be measured is almost constant and changes are small, a general HPF or BPF may be used.

[Thirteenth Embodiment] Next, a thirteenth embodiment will be described based on FIGS. 25 and 26.

In the embodiment of FIG. 25, the detected analog signal is
The goal is to obtain speed by converting the signal into a digital signal using a D converter, loading it into a memory, and then performing numerical operations using a computer such as a microprocessor.

In this 13th embodiment, as shown in FIG.
A low-pass filter 76 with a sampling period of /2 or less, a sampling bold circuit 77 that holds the data sampled by the low-pass filter 76 at each sampling time, and converts this sample-and-held signal into a digital signal. an A-D conversion circuit 78,
A memory 79 that temporarily stores the output of this A-D conversion circuit 78, and a direction calculation circuit 80 that performs predetermined calculations based on the large and small digital signals stored in this memory and determines the moving direction of the moving object. It is made up of.

Here, the direction arithmetic circuit 80 has an arithmetic separation function that takes the difference of the digital signal, which is discrete data, and divides it into two sets of positive and negative, and also has an arithmetic separation function that takes the average of the difference between the data divided into each set and calculates its absolute value. It is characterized in that it is equipped with an arithmetic determination function that compares values and determines the moving direction of the moving object.

The other configurations are the same as those of the first embodiment described above.

Next, the operation of this thirteenth embodiment will be explained based on FIG. 26.

In this embodiment, the Doppler beat signal input through the beat detection means 1 and the level adjustment circuit 7 is sampled and held at every sampling time T through a low-pass filter 76, and converted into a digital value through an A-D conversion circuit 78. Ru.

Here, the low-pass filter 76 has the ability to remove frequency signals of 1/2T or more, since waveforms with a period shorter than 2T are not reproducible according to the sampling theorem, and in order to remove noise. Therefore, the sampling period T must be less than or equal to 1/2 of the period of the signal under measurement.

The signal thus converted into a digital value is stored in the memory 79, and the direction calculation circuit 80 determines the speed direction.

In this case, in the 13th embodiment, the velocity direction is determined by taking the difference between the discrete data converted into digital values, dividing the differences into positive and negative groups, and comparing the averaged absolute values. It is.

The velocity direction can be determined by comparing the magnitude of the absolute value of the slope of the upward slope of the sawtooth wave, but it is also possible to determine the velocity direction by dividing the difference of discrete data sampled at a constant period T into positive and negative, and then calculating the magnitude of the absolute value. The same thing can be done by comparing.

Now, as shown in FIG. 26, if the number of data where the difference value between adjacent data is positive is Nr, and the number of data where the difference value is negative is Nr, then the slope of the upward slope ``Lr'' and the slope of the downward slope are It is expressed by the following formula.

Lr-(1/T) ・(ΔArn++ΔAr+21
+...+ΔA,. ) /Nr Lr = (1/T) ・ (ΔArL1++ΔAr
rz++...+ΔArLt+)/Nt Therefore, by comparing the average value of the positive difference values and the average value of the negative difference values, the velocity direction can be determined.

Here, in order to determine the velocity direction, it is necessary to perform sampling at a cycle of 174 or more due to the nature of the sawtooth wave.

[Fourteenth Embodiment] Next, a fourteenth embodiment will be described based on FIGS. 27 and 28.

This 14th embodiment is an improved version of the 13th embodiment described above. That is, in this embodiment, the difference between discrete data is taken, and this is divided into positive and negative groups.
The velocity direction is determined by comparing the number of data.

In this 14th embodiment, the direction calculation circuit 80A has a calculation separation function that calculates the difference between digital signals, which are discrete data, and divides the difference into two groups, positive and negative, and counts the number of data divided into each group. , is equipped with an arithmetic determination function that determines the moving direction of a moving object by comparison.

The other configurations are the same as those of the thirteenth embodiment described above.

In the fourteenth embodiment, due to a change in the direction of the sawtooth wave, the ratio of time occupied by the upward slope (ΔTr) and the downward slope -62=(8T) is reversed. The fact that the data difference value is positive or negative is equivalent to indicating that the slope is uphill or downhill. Considering that the data is collected by sampling at a constant period T, it is possible to determine the velocity direction by comparing the positive number P and the negative number N of the difference values.

ΔTr; ΔT, =P-T:N-T=P:
NP>N, P<N When the number of data is small, the direction can be determined by finding the maximum and minimum values and comparing the positive and negative data numbers of the difference values between them.

In addition, although the above-mentioned embodiment explained the case where the intensity of the scattered return light is sufficiently weak, the above-mentioned method of self-mixing the returned light falls within the scope of the present invention even when the intensity of the scattered return light is strong. Of course, it goes without saying that any device that exhibits a phenomenon similar to that of a semiconductor laser in the above description falls within the scope of the invention.

[Fifteenth Embodiment] Next, a fifteenth embodiment will be described based on FIGS. 29 and 30.

In this embodiment, the direction is determined by paying particular attention to the steep slope and slow slope of the Doppler beat signal.

In the fifteenth embodiment shown in FIG. 29, the direction determining means 85 includes the waveform conversion circuit section 3 and
a signal processing circuit section 86 that processes the Doppler beat signal that is the output of the signal processing circuit section 86 under predetermined conditions; and a comparator 87 that serves as a comparison and judgment means that compares the output of the signal processing circuit section 86 with the zero level as a reference and determines the direction. It is composed of.

Of these, the signal processing circuit section 86 is composed of an amplitude limiting circuit (limiter) 86A and a low-pass filter 86B as a waveform equalizing circuit.

The other configurations are the same as those of the first embodiment described above.

Next, the operation in the embodiment shown in FIG. 29 will be explained based on FIG. 30.

First, the Doppler beat signal (2) detected by the beat detection means 1 is converted into a predetermined timing signal (2) by the waveform conversion circuit section 3. In this case, the differentiating circuit 8 of the waveform conversion circuit section 3 obtains a signal (2) depending on the sharpness of the slope. This signal ■ is sent to limiter 86A. Here, the limiting voltage of the limiter 86A is set to .

In this limiter 86A, the voltage of the differential signal corresponding to the steep slope is limited because the voltage level is high, but the voltage of the signal corresponding to the gentle slope is not limited (signal ■). When this signal is passed through the low-pass filter 86B, a signal with a steep slope is softened by averaging, so that an output corresponding to a gentle slope is obtained (signal ■). Based on this output, the comparator 87 determines the direction.

In the above embodiment, an example was shown in which the amplitude limiting circuit 86A was used as a method for limiting the level, but the same result can be obtained by amplifying the differential signal up to the power supply voltage of the amplifier circuit using an amplifier with a large gain instead of this circuit. results.

〔Effect of the invention〕

Since the present invention is configured and functions as described above, according to this, the direction of a moving object is converted into a signal such as positive or negative, positive or zero by the action of a waveform equalization circuit or a circuit that functions equivalently. Based on this, the moving direction of the moving object can be determined very easily by a comparison/judgment means or a circuit that functions equivalently. This is an unprecedented and excellent moving object that can reliably determine the direction of a moving object with relatively simple equipment. A moving direction determining device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the first embodiment of the present invention, FIG. 2 is an explanatory diagram showing output signals of each part of FIG. 1, and FIG.
FIG. 4 is an explanatory diagram showing the output signals of each part in FIG. 3, FIG. 5 is a block diagram showing the third embodiment, and FIG. 6 is an explanatory diagram showing the output signals of each part in FIG. 5. 7 is a block diagram showing the fourth embodiment, FIG. 8 is an explanatory diagram showing output signals of each part in FIG. 7, FIG. 9 is a block diagram showing the fifth embodiment, and FIG. is an explanatory diagram showing output signals of each part in FIG. 9, FIG. 11 is a block diagram showing the sixth embodiment, FIG. 12 is an explanatory diagram showing output signals of each part in FIG.
3 is a block diagram showing the seventh embodiment, and FIG. 14 is a block diagram showing the 13th embodiment.
FIG. 15 is a block diagram showing the eighth embodiment. FIG. 16 is an explanatory diagram showing the output signals of each part in FIG. 15. FIG. 17 is a block diagram showing the ninth embodiment. FIG. 18 is an explanatory diagram showing the output signals of each part in FIG. 17, FIG. 19 is a block diagram showing the tenth embodiment, and FIG.
21 is a block diagram showing the 11th embodiment. FIG. 22 is an explanatory diagram showing the output signals of each part in FIG. 21. 24 is an explanatory diagram showing the output signals of each part in FIG. 23, FIG. 25 is a block diagram showing the 13th embodiment, and FIG. 26 is an explanation showing the operation of FIG. 25. Figure, 2nd
7 is a block diagram showing the 14th embodiment, and FIG. 28 is a block diagram showing the 2nd embodiment.
7 is an explanatory diagram showing the operation, FIG. 29 is a block diagram showing the 15th embodiment, FIG. 30 is an explanatory diagram showing the output signals of each part in FIG. FIGS. 32(1) and 32(2) are explanatory diagrams each showing a Doppler beat signal, and FIG. 33 is an explanatory diagram showing a conventional example. 1...Beat detection means, 2, 21, 24, 30
゜35.40, 45, 50, 55, 60, 65, 70.
75,81.82...Direction determining means, 3.25
．． 31... Waveform conversion circuit section, 4, 22, 26° 32.41.46, 51, 56, 61.66...
- Signal processing circuit section, 5. ．． 27, 33, 62.67...
... Waveform equalization circuit section, 5A, 5B, 27A, 27
B, 33A, 33B, , 62A, 62B, 67A. 67B, 76...Low pass filter, 6.5B
. 63.68...Comparison/discrimination means, 7...
Level adjustment circuit, 8, 313...Differential circuit, 9
A: one comparison circuit, 9B: the other comparison circuit, 22A, 22B: waveform shaping circuit, 25A, 61A: Schmitt trigger circuit,
31.・・・・・・Frequency counter, 31□・・・・・・
- Triangular wave oscillation circuit, 38...Addition circuit, 43.
48...Direction determining means, 54, 58, 63°6
B, 80.80A... Direction calculation circuit section, M...
...Moving object. Patent applicant: Suzuki Motor Co., Ltd. Agent Patent attorney: Isamu Takahashi
-□2Figure ■O□ ■O□ History ■ [Yes] O■ [Yes] ■ '-> S ()((Ri■ @ ■ ■ ■ ℃ (effect -7Saichi I I J Mother ■ @ ■ ■ [Phase] ○ 0 [Phase] ■ [Phase] ■ ■ L -J ○ ■ ■ O■ lyo 8.. 5 too o (L
J.S.
c> o () c
b Fusuma ■0○ ■ 0 ] (0(4■00■[
phase] ■■ [Yes] ■ 罎((Q (

Claims (26)

[Claims] (1) beat detection means for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on laser output light used to measure the speed of a moving object; and detecting the moving direction of the moving object based on the Doppler beat signal. a waveform conversion circuit section that converts the Doppler beat signal into a predetermined timing signal; A signal processing circuit unit that forms a waveform, two waveform equalization circuit units that equalize each output of this signal processing circuit unit, and two waveform equalization circuit units that output two different levels from each waveform equalization circuit unit. A moving object characterized by comprising: a comparison and determination means that calculates a level difference between one of the two signals using the other signal as a reference, and determines the moving direction of the moving object based on the magnitude thereof. Movement direction determination device. (2) The waveform conversion circuit section is configured by a level adjustment circuit that amplifies the Doppler beat signal to a predetermined level, and a differentiation circuit that differentiates the output signal of this level adjustment circuit. The device for determining the moving direction of a moving object as described above. (3) one comparison circuit that outputs a rectangular wave of a predetermined level in synchronization with a predetermined timing signal output from the differentiating circuit; and a timing signal that is the same as that of the one comparison circuit; 2. The direction of movement of the moving object according to claim 1, further comprising an inverter at the input stage that outputs a signal in the form of an inverted version of the output signal of one of the comparison circuits. Discrimination device. (4) The signal processing circuit section includes one waveform shaping circuit that outputs a rectangular wave of a predetermined level synchronized with the fall of a predetermined timing signal output from the differentiating circuit, and one waveform shaping circuit. The other waveform shaping circuit inputs the same timing signal, inverts it, rectifies it, and outputs a rectangular wave having the same level and different duty ratio as the output of the one waveform shaping circuit. The moving object moving direction determining device according to claim 1. (5) The waveform conversion circuit section includes a level adjustment circuit that amplifies the Doppler beat signal to a predetermined level, and a Schmitt that converts the output signal of the level adjustment circuit into a square wave of a predetermined level by setting a certain dead zone. a first signal output circuit that outputs the output of the Schmitt trigger circuit as it is; and a second signal output circuit that inverts and outputs the output of the Schmitt trigger circuit. 2. The device for determining the moving direction of a moving object according to claim 1, further comprising a circuit. (6) The waveform conversion circuit unit includes a first waveform conversion circuit unit that converts the Doppler beat signal into a predetermined timing signal, and a second waveform conversion circuit unit that outputs a predetermined reference timing signal synchronized with the Doppler beat signal. a waveform conversion circuit section, and the signal processing circuit section is configured with a first signal processing circuit that inverts the output signal of the first waveform conversion circuit section and outputs a rectangular wave signal adjusted to a constant level. , and a second signal processing circuit that inverts the output signal of the second waveform conversion circuit section and outputs a reference signal with a duty ratio of 50%. movement direction determination device. (7), the first waveform conversion circuit unit includes a level adjustment circuit that amplifies the Doppler beat signal to a predetermined level;
a first differentiation circuit that converts the output signal of the level adjustment circuit into a predetermined timing signal, and the second waveform conversion circuit section includes a frequency counter that counts the frequency of the Doppler beat signal; It is composed of a triangular wave oscillation circuit which receives the outputs of the frequency counter and the level adjustment circuit and outputs a reference triangular wave signal, and a second differentiation circuit which converts the output signal of the triangular wave oscillation circuit into a predetermined reference timing signal. 7. The moving object moving direction determining device according to claim 6. (8) beat detection means for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on the laser output light used when measuring the speed of the moving object; a waveform conversion circuit unit that converts the Doppler signal into a predetermined timing signal; and a waveform conversion circuit unit that converts the Doppler signal into a predetermined timing signal, and a positive peak value and a negative peak value of the output of the waveform conversion circuit unit, respectively. A positive peak value detection circuit and a negative peak value detection circuit detect the moving object and output a voltage signal of a predetermined level corresponding to the detected value, and add the output signals of the respective detection circuits and detect the moving object based on the addition result. and an addition determination circuit for determining the direction of movement of a moving object. (9) beat detection means for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on the laser output light used when measuring the speed of the moving object; and detecting the moving direction of the moving object based on the Doppler beat signal. a waveform conversion circuit section that converts the Doppler beat signal into a predetermined timing signal; A signal processing circuit unit that forms a waveform, a latch circuit that uses one of the two output signals of this signal processing circuit unit as a reference and latches the other, and determines the moving direction of a moving object based on the output of this latch circuit. 1. A moving direction determining device for a moving object, comprising a direction determining circuit. (10) The waveform conversion circuit section is configured by a level adjustment circuit that amplifies the Doppler beat signal to a predetermined level, and a differentiation circuit that converts the output signal of the level adjustment circuit into a predetermined timing signal, The processing circuit section includes a first comparator circuit which inputs the timing signal and forms and outputs a rectangular wave signal of a constant level according to a threshold value of a predetermined level, and a first comparator circuit which inputs the output of the level adjustment circuit and determines whether the signal is positive or negative. 10. The moving object moving direction determining device according to claim 9, further comprising a second comparison circuit that outputs a rectangular wave with a duty ratio of 50% corresponding to the second comparison circuit. (11) Beat detection means for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on laser output light used when measuring the speed of a moving object, and detecting the moving direction of the moving object based on the Doppler beat signal. a waveform conversion circuit section that converts the Doppler beat signal into a predetermined timing signal;
A signal processing circuit unit that forms two rectangular waves with a repetition period of /2 times, a latch circuit that latches one of the two output signals of this signal processing circuit unit with reference to the other, and this latch circuit. 1. An apparatus for determining the moving direction of a moving object, comprising: a direction determining circuit that determines the moving direction of the moving object based on the output of the moving object. (12) The waveform conversion circuit section is configured by a level adjustment circuit that amplifies the Doppler beat signal to a predetermined level, and a differentiation circuit that converts the output signal of the level adjustment circuit into a predetermined timing signal, The processing circuit section includes a first comparator that inputs the timing signal and forms and outputs a rectangular wave signal of a constant level based on a zero level threshold, and a first comparator that inputs the output of the level adjustment circuit and generates a signal. A second comparator that outputs a rectangular wave with a duty ratio of 50% corresponding to the positive and negative sides of 12. The device for determining the moving direction of a moving object according to claim 11, further comprising a frequency doubling circuit that outputs a rectangular wave having a period of 1. (13) Beat detection means for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on laser output light used when measuring the speed of a moving object, and detecting the moving direction of the moving object based on the Doppler beat signal. a waveform conversion circuit section that converts the Doppler beat signal into a predetermined timing signal; A signal processing circuit section that forms a waveform, a gate circuit section that outputs and controls the clock signals that are input separately based on the two timing signals, and a gate circuit section that controls the output of the two pulse trains that are output from the gate circuit section. a counting circuit unit that counts each output separately within a period of time corresponding to one cycle of the Doppler beat signal; and a calculation/discrimination circuit unit that compares and calculates each output of the counting circuit and determines the moving direction of the moving object based on the magnitude of the output. A device for determining the moving direction of a moving object, characterized in that it is configured by: (14) The waveform conversion circuit section is configured by a level adjustment circuit that amplifies the Doppler beat signal to a predetermined level, and a differentiation circuit that converts the output signal of the level adjustment circuit into a predetermined timing signal, a first control signal output circuit that converts the processing circuit section into a rectangular wave signal in which one period is two periods of the timing signal output from the differentiating circuit; and a first control signal output circuit that inverts the timing signal and is located on the positive side thereof. 14. The apparatus for determining the moving direction of a moving object according to claim 13, further comprising a second control signal output circuit that outputs the part as a rectangular wave signal of a predetermined level. (15) beat detection means for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on the laser output light used when measuring the speed of the moving object, and detecting the moving direction of the moving object based on the Doppler beat signal. a waveform converting circuit unit that converts the Doppler beat signal into a predetermined timing signal; and a rectangular shape of a certain level synchronized with the timing signal based on the timing signal. A signal processing circuit that simultaneously outputs a wave signal and its inverted signal separately, a capacitor charging/discharging circuit that is activated by the output of this signal processing circuit and continues charging and discharging simultaneously, and a charging circuit for this capacitor charging/discharging circuit. What is claimed is: 1. A device for determining the moving direction of a moving object, comprising a comparison and determining circuit that detects an electric potential and determines the moving direction of the moving object based on the electric potential. (16) The signal processing circuit includes a comparator that forms a constant level rectangular wave signal synchronized with the timing based on the timing signal and outputs it as one switch drive signal, and an output of the comparator that is inverted. 16. The device for determining the moving direction of a moving object according to claim 15, further comprising an inverter that outputs the signal as another switch drive signal. (17) The capacitor charging/discharging circuit includes a capacitor whose one end is grounded, and a potential of "+V[
It consists of one power supply circuit with a potential of "V]" and the other power supply circuit with a potential of "-V [V]" which is also connected to the other end of the capacitor via a resistor and an analog switch. 16. The moving object moving direction determining device according to claim 15. (18) beat detection means for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on laser output light used when measuring the speed of a moving object, and detecting the moving direction of the moving object based on the Doppler beat signal. a level adjustment circuit that amplifies the Doppler beat signal to a predetermined level; and a level adjustment circuit that amplifies the Doppler beat signal to a predetermined level; a signal processing circuit section that forms one waveform; a waveform equalization circuit section that includes two low-pass filters that equalize each output of the signal processing circuit section; The moving object is characterized by comprising a comparative judgment means for calculating the level difference between the two signals using one signal as a reference and for determining the moving direction of the moving object based on the magnitude of the difference in level of the other signal. A device for determining the moving direction of an object. (19) The signal processing circuit unit includes a Schmitt trigger circuit that converts the output signal of the level adjustment circuit into a square wave of a predetermined level by setting a certain dead zone, and outputs the output signal of the level adjustment circuit. 19. The moving object moving direction determining device according to claim 18, further comprising a comparator that converts the signal into a rectangular wave with a duty ratio of 50% and outputs the signal. (20), the signal processing circuit section includes a first comparator that forms a rectangular wave of a predetermined level from the output signal of the level adjustment means based on a certain reference value; A second comparator that forms a rectangular wave of a predetermined level using an inverted input and a reference value of the same level as the first comparator.
and is equipped with a rectangular wave output means for detecting the rising edge of each of the first and second comparator outputs to generate a rectangular wave, and at the same time adjusting the duty ratio from the level adjusting means to 50%.
Claim 18, further comprising: a third comparator that outputs a rectangular wave, whereby two rectangular waves with different duty ratios are output separately.
The device for determining the moving direction of a moving object as described above. (21) Beat detection means for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on laser output light used when measuring the speed of a moving object, and detecting the moving direction of the moving object based on the Doppler beat signal. a reference signal output circuit that outputs a reference signal having a frequency twice the fundamental wave component of the Doppler beat signal based on the Doppler beat signal; A measurement signal circuit extracts and outputs the second harmonic component from the beat signal, and the two signals output from each of these signal output circuits are input, and the phase shift of the measurement signal with respect to the reference signal is detected. 1. An apparatus for determining the moving direction of a moving object, comprising phase difference detection means for determining the moving direction. (22) The reference signal output circuit includes a free-running oscillator that outputs a sine wave signal with a frequency twice the fundamental wave component of the Doppler beat signal, and an output of the free-running oscillator that is halved.
A frequency divider that divides the frequency, and the output signal of this frequency divider and the fundamental wave component related to the Doppler beat signal are inputted, and the phase difference between these two sine wave signals is detected and the free-running oscillator outputs. 22. The moving object moving direction determining device according to claim 21, further comprising a phase detection circuit that corrects and controls a phase shift of a signal. (23) The measurement signal output circuit includes a voltage control filter that extracts and outputs the second harmonic component of the Doppler beat signal, and stabilizes the frequency of the second harmonic component of the output signal of the voltage control filter. 22. The device for determining the moving direction of a moving object according to claim 21, further comprising a frequency stabilizing circuit that causes the moving object to move. (24) beat detection means for detecting a predetermined Doppler beat signal consisting of a sawtooth wave based on the laser output light used when measuring the speed of the moving object; and detecting the moving direction of the moving object based on the Doppler beat signal. a low-pass filter having a sampling period of 1/2 or less of one period of the Doppler beat signal; and data sampled by the low-pass filter. A sampling and holding circuit that holds the sampled and held signal at each sampling time, an A-D conversion circuit that converts this sampled and held signal into a digital signal, and this
- It is composed of a memory that temporarily stores the output of the D conversion circuit, and a direction calculation circuit that performs predetermined calculations based on the large and small digital signals stored in this memory and determines the moving direction of the moving object. Features: A device for determining the moving direction of a moving object. (25) The direction arithmetic circuit has an arithmetic separation function that takes the difference between the digital signals, which are discrete data, and divides the difference into two sets of positive and negative, and takes an average of the differences between the data divided into each set. 25. The moving object moving direction determining device according to claim 24, further comprising an arithmetic determining function for determining the moving direction of the moving object by comparing the absolute values thereof. (26) The direction arithmetic circuit calculates and compares the number of data divided into each group with an arithmetic separation function that calculates the difference between the digital signal, which is discrete data, and divides the difference into two groups, positive and negative. 25. The moving object moving direction determining device according to claim 24, further comprising an arithmetic determining function for determining the moving direction of the moving object.