JPS6016643B2 - Moving body forward and backward movement detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides for automatic operation or operation control of mobile objects such as cranes, trolleys, trains, etc. that travel on a fixed traveling path, and for the safety of the movement of the mobile objects. The present invention relates to a device that performs detection on the side of a moving body.

When controlling the operation of a mobile object such as the one described above, the subordinate method involves controlling the travel control section of the mobile object using command signals sent from the ground station, and furthermore, returning the operation results to the ground station as controlled information. However, in the event of a failure of the control system, including communication between the control side and the controlled side, it is insufficiently reliable in terms of safety. Reversing when stopped can occur even when the control system is operating normally, whereas conventional detection of forward or backward movement of a moving object is based on the rotation of the wheels or axles of the moving object, or from the rotation of the moving object's wheels or axles. This is done based on data obtained from the vehicle's vehicle detection on the road the vehicle is traveling on, so when the wheel rotates gradually, the number of revolutions per second is too low, making detection difficult; The disadvantage is that it is unsuitable for detecting unexpected regressions in practice, as it is detected only after the vehicle has grown large.

The present invention aims to improve the reliability and detection function, which are the drawbacks of the conventional diamond counterfeiting, and provides a device that can quickly detect short-distance movement of a moving object at a ground station. This has a significant effect on ensuring the safety of driving control.

Furthermore, the reinstallation of the present invention has the advantage of being highly economical, since the guide lines, transmitting and receiving equipment, and operating frequencies used for data transmission and position detection between the ground station and the mobile body can be shared. The present invention will be explained in detail below using examples. First, a method for detecting the position of a moving body using a guide line will be explained. FIG. 1 is a diagram illustrating an example of the configuration of a position detection device, in which only one intersecting parallel two-wire guide wire (symbol 6) is installed on a moving path. In the figure, 1 is a two-frequency (frequency Na and Na 2) transmitter, 4 is a coupler, and 5 is a terminating resistor.
This ground-side transmitter 1 uses phase shift keying (P
Two signal currents, a transverse wave (referred to as SK) and a non-modulated N2 wave with a frequency different from the N wave, are connected via a coupler 4 to an inductive wire 6.
Output to. However, Na, waves are not related to position detection, and Na2
Just think about the waves. 2 and 3 are installed on a moving object, 3 is an antenna, and 2 is a fixed point detector. Antenna 3 moves while connected to a guide line, and detector 2 is mounted on a fixed point on the running road, that is, a fixed point detector. The point where the conducting wires 6 are crossed is detected.

This means that the phase of the two waves in the signal induced in antenna 3 is
There is a 1800 difference between the case where the moving object is in section a or c in Figure 1 and the case where it is in section b or d, and the intersections A, B,
This is because the signal phase changes by 180 degrees when the antenna 3 passes through C, etc., so the fixed point position can be detected by detecting the phase change. Note that the intervals between the intersections are arbitrary, but if they are set at equal intervals, it is convenient for detecting the speed and relative position of the moving object from counting the phase change points. Next, FIG. 2 is a diagram showing an example of the basic configuration of a communication device embodying the present invention.

In this figure, 7 is a transmitter for transmitting data and signal waves for position detection installed on the fixed ground side (hereinafter referred to as ground station), 8 is a coupler, and 9, 10, and 11 are transmitters installed along the mobile vehicle travel path. Parallel 2, both laid parallel across the section.
Wire guide wire, 9 is non-crossing type for data transmission, 10, 11
are equally spaced cross-type sensors for position detection and direction detection. 1
2 is a terminating resistor for each guide wire, 13 and 14 are devices mounted on the moving body, 13 is an antenna, and 14 is a receiving device, which receives data and detects the position and running direction or forward/backward movement of the moving body. .

It is assumed that the antenna 13 is configured to move in conjunction with each concession line. Further, the distance between the intersections of the guide lines 10 and 11 is L, but the positions of the intersections are shifted by L2L/pillow from each other. Further, Din, Ut'ma data input and output, p is a position detection output, and s is a running direction detection output. Now, the signal transmitter 7 has three oscillators of different frequencies, 〆, 〆2, and 〆3, and their output amplifiers and data (binary code) input. A modulator for phase shift keying (PSK) the waves is included, and the MKed waves are sent out to a non-crossing guiding wire 9 via a coupler 8.

Also, for "2 waves and 3 waves,", = (m-1)〆n
/m [here, n is 2 and 3, m is an integer of 2 or more, and is expressed as n2 kina3]. 11. In the following explanation, for convenience, it is assumed that m=2 for Na2 and m=4 for Me3, but the same operation can be obtained even if other numbers of m are selected. When m=2, na2=2na・, m=
4, Na3=4Na,/3. Next, FIG. 3 is a block diagram of a configuration example of the mobile side receiving device 14. As shown in FIG.

The reception input picked up by the mobile antenna 13 from each of the guide lines 9 to 11 is transmitted to the bandpass filter (BPF) 15, 16, 1.
7, the BPF 15 extracts the 3 components, the BPF 2 components, and the BPF 17 extracts the 2 components. 18, 19, and 20 are all amplifiers and amplitude limiters (A
- In L), each wave component extracted by the BPF is amplified and then limited to a constant amplitude.

Of these, the wave from the A/L 20 is divided into three parts and output, one of which is demodulated into a data code by the PSK demodulator (DTC) 21 and output as Dout. One is the frequency doubler (X2) (in the case of "2 = 2 na")
22, and the output of 2na,=na2 is inputted to a phase discriminator (PD) 25 as a reference phase signal. By the way, the waves are whistled. (The Matsu K at this time uses two-phase phase shift keying that shifts the phase by 18, so the 6th
As shown in the figure, when the data code is “1”, it is 1 from the preceding phase.
Differential phase modulation (abbreviated as DPSK) is usually used, in which the signal is shifted by 800 radians and is not shifted when the data code is "0". ) For this reason, for example, the phase state when the code is "0" is doubled. This double wave can also be thought of as a wave whose amplitude changes only in the positive direction with respect to the original sine wave, as shown in Figure 6b), and since the code "1" comes next, it is shifted by 18 pi. The phase obtained by doubling the phase is the same as the phase difference of 1800 as shown in Figure 6a before multiplication, and it becomes a continuous phase wave with no modulation (of spots K), so it is the reference phase. Can be used as a signal.
Next, the output of A.L20 is also sent to the frequency converter (skin X) 23, where the difference frequency (
Outputs 3 na,). In this example, in terms of frequency, it is 3:4 na, '3 is the orbit) ra na 3-na. = 0, and the next stage frequency 4 transmitter 24 makes it match 4〆,/3=na3. On the other hand, looking at the phase, 〆, is a K-modulated wave shifted by 1800 due to the 1 and 0 of the data code as described above, and since 〆3 uses the guiding wire 11 as a transmission path, the wave before and after the crossing of this guiding wire ( Antenna 1 at left and right in Figure 2)
The change in phase of Na3 obtained by inductive coupling with Na3 is 1
Each has a certain amount of shift, such as 8 pins. Therefore, the phase change of the difference frequency (Na3-Na.) wave is a quantitative shift of oo or 180o. In this way, the rhombus frequency has a frequency of 0.00 or 1.3 and a phase shift of 0.00 or 18.0, so it is input to the quadruple multiplier in the next stage (24 in Figure 3) and the frequency is multiplied by 4 (actually 2 x 2). ), the frequency is 4 na,
/3 and a continuous phase wave can be obtained. This output is sent to one input of the phase discriminator PD26 as a reference phase signal. Now, the other input of PD26 is na3 from A/L18.
Here, it is detected whether it is in phase with the reference phase wave or in reverse phase and sent to the next stage square wave converter (W) 27.

W27 has a low frequency wave generator at its input and outputs a and a. This a output has a waveform as shown in FIG. 4 a. Fourth
The figure shows an example of the operation waveforms of each part in FIG. 3, and the a waveform is the phase difference (
m phase) is output. Note that a in Figure 3
is the inverted waveform output of the a waveform. On the other hand, the other input to the PD 25 is the N2 wave from the A/LI 9, and its phase is discriminated.

The next stage square wave converter W28 has the same configuration as W27, and its output has a waveform as shown in FIG. 4b. b waveform is lead wire 10
The phase difference between each intersection of is output, but it can be seen that there is a shift of a distance equal to that of the a waveform and L. Furthermore, PD25, PD
In order for a phase discriminator such as 26 to operate satisfactorily, it is necessary to
, "3 Of each transmission line, especially BPF, A.L.
etc., there is an inherent phase rotation, and the phase difference between the two input signals of the phase discriminator is not in a state where ideal characteristics can be obtained. For example, when the phase difference between the two signals of the discriminator is 00, the maximum positive output is output, when the phase difference is 180o (shore), the maximum output is negative, and when the phase difference is 900 and 270, the maximum output is negative.
0 (m/2 and 1 digit/2) have a phase difference discrimination characteristic that obtains zero output, so if the reference signal is set in phase either before or after the crossing of the guiding wires, the crossing of the guiding wires can be avoided. Ideal characteristics in which the front and back phase change is 180 degrees can be obtained. Therefore, in order to offset and correct the phase rotation due to the transmission line, for example, a CL or RC circuit is inserted on the input side of the phase discriminator to correct the phase difference to obtain ideal characteristics. Now, the a and b outputs of W27 and W28 are input to the position detection output device 29 (actually an exclusive OR circuit) on the one hand, and the P waveform shown in FIG. 4 is output. It is clear that the polarity of the p waveform is reversed every L2=L/2 along the running speed, so it is used for position detection every L2. Next, a description will be given of a moving body forward/reverse motion detection circuit, which is the main focus of the present invention.

Reference numerals 30 to 38 in FIG. 3 are parts added to the above-mentioned position detection device, and can be said to be a front and reverse detection circuit. Now, in Fig. 4, the moving direction of the moving object is set to the right direction as Sr and the left direction as SI, and the conversion point pulse generators P30 and P
It is assumed that 31 generates pulses separately at the rising conversion point and the falling conversion point of pulse b and pulse a, respectively. Therefore, if we represent the rising side of the conversion point by u and the falling side by d, from P30 we can obtain the law and bd, and from P31 we can obtain a
Since the u and ad pulses are output from separate terminals, if the running direction is Sr, the a waveform will be au, ad, and the b waveform will be b.
Each pulse of u and bd is generated as shown in the middle part of Fig. 4,
As shown in FIG. 4, in the SI direction, the u and d forces occur at opposite positions to the case of Sr. Each AND of the next stage
Circuits 32 to 35 (each including two 2-input AND gates, whose common gate signal inputs are a, a, b, b
W27, W28, P30,
The respective outputs of P31 are inputted in a combination as shown in FIG. 3. For example, in AND32, a bd pulse is output in the Sr direction when the a waveform is at H level, and a bu pulse is output in the SI direction. The same applies to other AND circuits, and the presence or absence of their output pulses can be collectively expressed as shown in the following table. However, r indicates output when moving in the Sr direction, and 1 indicates output when moving in the SI direction.

If you move in the direction of moving body force Sr in this way, OR gate 3
If the r pulse train in Fig. 4 moves from 7 in the SI direction, O
One pulse train shown in FIG. 4 is outputted from the R gate 36, respectively, and drives the flip-flop of the running direction signal output device 38 at the next stage to output a direction signal of, for example, 1 or 0 to its output S.

Note that it is easy to display or record the moving direction of the moving object from this signal, or to detect movement of the moving object in an unexpected direction and generate an alarm or control signal. The direction detection ability of the above method is expressed as a numerical sequence. For example, if the guide line intersection interval L is 500 ribs, then L2=L/2=2
If the moving body moves overboard by 25W at 50 ribs, a direction signal is generated and the direction of movement can be detected. The above example shows the three frequencies, guided wires, and
By sharing a transmitter, a receiving device, etc. and adding a small direction detection circuit, the device can detect the direction of movement within a small fixed distance even if the moving object is moving slowly. It is clear that for detection, the presence or absence of modulation of the wave, that is, the data transmission wave, does not matter. FIG. 5 is a diagram showing an example of the configuration of the mobile receiver 14 using a method different from that described above.

In this case, instead of the three frequencies Na, ~ Na3, the two frequencies ', and '2 are used, and the fact that the ground station sends the Na wave to the guide line 9 remains the same, but the Na2 wave is It is divided and sent out alternately to two parallel transfer wires 10 and 11, and the moving body side performs phase discrimination of the guided outputs obtained from the guided wires 10 and 11, and also outputs phase discrimination in synchronization with the switching of the guiding wires on the transmitting side. The feature is that the waveform b shown in FIG. 4 is output when the guide wire 10 is selected, and the a waveform is output when the guide wire 11 is selected.This will be explained in detail next with reference to FIG. 16, 17, 20, 21, 22, 25, 28, 29 in the figure
is the same as in Figure 3.

39 is an amplifier, 40 is an amplitude limiter, and 41 is an ON/OFF signal detection circuit (A/D) since ON/OFF amplitude modulation is used as a synchronization signal in this example.

42 is a timing synchronization and timing pulse generation circuit, 43 and 44 are phase discrimination output storage circuits (M), 45 is a running direction detection circuit consisting of 30 to 38 in FIG. 3, and S is a running direction signal output.

The signal transferred from each guide wire to the antenna 13 is BPF1
6 and BPF 17, the N2 wave and N2 wave are extracted, respectively.

Of these, na. The component is amplified in the A/L2 river, limited to a constant amplitude, and then divided into two parts. One is a data demodulator (D
TC) 21 and is demodulated and output as a data output Dout. The other one becomes a 2〆 wave by the frequency doubler 22, and this 2n, =n2 wave becomes a reference phase signal and is input to the phase discriminator PD25. On the other hand, the N2 wave component extracted by BPF16 is amplified by A39 and then divided into two parts.
One is input to the A/D 41 and amplitude modulation detection is performed. Note that when the signal transmission side alternately switches and transmits the 2-wave to the two parallel guide wires 10 and 11, a switching transmission is performed in which a time period in which no signal is transmitted to any of the guide wires is inserted. No two waves are received by the antenna 13. In addition, the speed of this switching is such that when the moving object is at its maximum speed, the guide wires 10 and 1
It is only necessary that a sufficiently high-speed switching is performed within the time it takes to pass between each intersection of 1, and in this case, the error in the intersection position is small. Switching is normally performed within approximately 1/10 of the transit time between each intersection. FIG. 7 is a diagram illustrating the above explanation, in which the current 1 in the guiding wire 10 is shown. and the current 1, . This figure shows the temporal change in , and the resulting change in the induced voltage of the antenna 13, and shows that the voltage of the antenna 13 is turned off at the time of switching. The detection output of A/D41 is sent to the next stage timing synchronization and timing pulse generation circuit (SYN) 42.
Control is performed to synchronize the phase of the generated pulse with the switching of the guiding wire output on the transmitting side, that is, a timing clock synchronized with the switching of the signal current of each concession wire.

However, this output is the phase discrimination output storage circuit (M) 4 of the next stage.
3 and 44 are turned on alternately. Figure 5 A3
Another output from 9 is input to amplitude limiter L40,
The one limited to a constant amplitude is sent to the phase discriminator PD25.

The PD 25 also receives the double output of the Na wave as a reference phase signal, and outputs the phase difference between these two input signals by discriminating it. In addition, in the transmission line up to the PD 25 for the two-wave signal on the transmitting side, the y and z of the coupler 8 and the guide wire 1 shown in FIG.
Although the transmission path is switched between 0 and 11, the shift in the signal phase is almost concentrated in the BPF and is minute in the transmission path, so simply inserting a phase correction circuit at the input of the PD 25 poses no practical problem. The output of the PD 25 is converted into a square wave by a square wave converter (W) 28 in the next stage, and becomes an input to each of phase discrimination memory circuits (M) 43 and 44 in the next stage. M4
The other input of 3 and M44 is the timing clock, which is input from SYN42 and is connected to M43 and M4 as described above.
Turn on 4 alternately. Concession wire 10 when M43 is on
If you memorize the phase detection output for the intersection position of
M44 is turned on at the next timing clock, but at this time, since the output of W28 is detecting the phase of the guide wire 11, M44 stores the phase signal. In this way, each time the antenna 3 passes the intersection of the guide wires, the M43
The memory of M44 is rewritten, and the waveforms a and b in FIG. 4 are respectively output. In addition, in the above case, the transmitting side is the transfer line 1.
M43 memorizes the detection phase of 10 when the current is being supplied, and 1 when the current is being supplied to the guide wire 11.
In the example, M44 memorizes the detection phase of 1.
The synchronization of the SYN circuit 42 is reversed (because only the timing is synchronized, the switching output of the transfer lines 10 and 11 on the transmitting side and the SY
This is because synchronization with the output of the N circuit 42 is determined by the synchronization pull-in operation at the initial stage of operation. However, once determined, it will continue as long as transmission and reception synchronization continues. ), the phase detection of the guide wire 10 is stored in M44, and the phase detection of the guide wire 11 is stored in M43, and the waveforms shown in FIGS. 4a and 4b are output. In Figure 5, the output a of M43 and M44
, a, b, b are running direction detection circuits (including 30 to 38)
45, the running direction (r, 1) is determined and the direction signal S is output as described in the operation description of FIG. 4 above. In addition, even if the above-mentioned transmission side conductor switching output and input switching of M43 and M44 are synchronized, the crossing positions of the guiding wires 10 and 11 are performed alternately (interval L), so the a waveform and the b waveform M43 regardless of whether the guide wire is 10 or 11.
is output from M44, and a pulse (a
Since the pulses caused by SI (ad, bu, M) and SI have different pulse generation states with respect to the a and b waveforms, they are discriminated as described above. The following running direction detection operation is shown in Figure 3.
It is the same as FIG. In this way, it is possible to detect the running direction using the two frequencies Na, 2, and 2. As explained above, in the device of the present invention, in addition to data transmission from a ground station to a mobile body using two or three frequencies and self-position detection of the mobile body, the mobile body side detects the running direction and detects the movement from a stopped state. It is possible to detect forward and backward movement, increasing the safety of autonomous driving and driving control of moving objects.

In addition, since the phase discrimination method is used to detect the yield line intersection, even if the coupling loss between the guide line and the antenna changes greatly as the moving object moves, it can be detected accurately without any effect.
It will be appreciated that the system is highly reliable and economical since it can be added to a multi-purpose device.

[Brief explanation of drawings]

FIG. 1 is a configuration example diagram of a position detection device, FIG. 2 is a basic configuration example diagram of a communication device implementing the present invention, FIGS. 3 and 5 are configuration examples of a mobile side receiving device, and FIG. 4 is an example of the operation waveform of each part in FIGS. 3 and 5, FIG. 6 is a diagram showing the phase change state 'a' of the wave according to the data code, and the waveform of its double wave, and FIG. 7 is the guide line. FIG. 3 is a diagram showing the relationship between turtle current switching and antenna voltage. 1, 7...Transmitter, 2...Mobile object position detector, 3,1
3...Antenna, 4,8...Coupler,
5, 12... terminal resistance, 6, 9, 10, 11...
...Concession line, 14...Mobile receiving device,
15, 16, 17... BPF, 18, 19, 2
0... Amplifier and constant amplitude limiter, 21...
- Phase-shifted wave (MK) demodulator, 22... Frequency doubler, 23... Frequency converter, 24...
Frequency quadrupler, 25, 26...phase discriminator,
27.28... Square wave converter, 29... Exclusive OR circuit, 30, 31... Conversion point pulse generator, 32-35... AND circuit, 36 ,37...O
R circuit, 38... Traveling direction signal output device, 39...... Amplifier, 40...... Amplitude limiter, 41...... Amplitude modulation detector, 42...... Timing synchronization, Timing pulse generation circuit, 43, 44... Phase discrimination output storage circuit, 45... Comprehensive circuit of 30-38. Figure 2 Figure 3 Figure 4 Figure 5 Diamond number 6 Figure Tsutomu 7

Claims (1)

[Scope of Claims] 1. A parallel two-wire first guide line laid along a fixed traveling path of a moving body, and a parallel two-wire first guide line laid over a required section in parallel with this guide line and intersecting at a fixed interval L_1. A guide wire group consisting of a second guide wire and a third guide wire of a crossed parallel two-wire system in which mutual intersections are shifted by a distance of 1/2 of the intersection interval L_1, and the above guide wire The output of the first frequency f_1, which is provided at one end of the group and is unmodulated or subjected to phase shift keying using a data signal, is sent to the first guiding wire, and the output of the first frequency f_1 and f_n=mf_1/( m-1) [Here, n is 2 and 3, m is 2 when n=2, and 4 when n=3
), and the unmodulated second frequency f
A ground-fixed transmitter that sends the output of _2 and the output of a third frequency f_3 to the second guide wire and the third guide wire, respectively, and a guide wire coupling antenna and a receiving device mounted on a moving body. However, in the mobile receiver, the received input from the antenna is separated and extracted for each frequency component, and after making the amplitude constant, frequency 2f_1, which is obtained by doubling the first frequency f_1, is used for phase discrimination of the second frequency f_2. The reference phase signal is the difference frequency f_3- between the first frequency and the third frequency.
The frequency (4f_1/3) obtained by multiplying f_1 by 4 is used as the reference phase signal for the phase discrimination of the third frequency, and the second
, a circuit that performs phase discrimination on each of the third frequency outputs and generates a square wave output whose level is inverted at each intersection of the second and third guide lines when the moving body moves; A pair of conversion point pulse generators that separately generate conversion point pulses at each rising and falling point as each square wave output runs, and each of the rising and falling conversion points generated by the generators. 4 types of pulses corresponding to the above, 4 sets of AND gates each using a square wave as a gate pulse for the intersection of the other guide lines, and the above set of AND gates is applied to the positive output b of the above f_2 square wave. Therefore, the falling pulse ad of the f_3 square wave is converted into the rising pulse au of the f_3 square wave by the inverted output ■ of the f_2 square wave.
When the positive output a of the f_3 square wave extracts the rising pulse bu of the f_2 square wave, and the falling pulse bd of the f_2 square wave is extracted by the inverted output ■ of the f_3 square wave, both pulses are allowed to pass. A pair of the first OR gate that outputs a unidirectional running direction pulse and the AND gate generates the rising pulse au of the f_3 square wave by the positive output b of the f_2 square wave, and the inverted output of the f_2 square wave ■
The falling pulse ad of the f_3 square wave is determined by the positive output a of the f_3 square wave, and the falling pulse b of the f_2 square wave is determined by the positive output a of the f_3 square wave.
d, and when the rising pulse bu of the f_2 square wave is extracted by the inverted output ■ of the f_3 square wave, a second OR gate that passes any of the pulses and outputs a running direction pulse in the opposite direction to the above; What is claimed is: 1. A forward and backward motion detection device for a moving body, comprising a traveling direction signal output device that stores pulse inputs from the first and second OR gates and outputs a traveling direction identification signal. 2 Parallel two-wire first guide line laid along the fixed travel route of the moving object, laid parallel to this guide line over the required section, intersecting at a fixed interval L_1 and at the intersections of each other. A guide wire group consisting of second and third guide wires of a cross-parallel two-wire system shifted by a distance of 1/2 of the crossing interval L_1, and a phase shift that is provided at one end of the guide wire group without modulation or by a data signal. The output of the shifted first frequency f_1 is sent to the first guiding wire, and the output of the first frequency f_2 is transmitted to the first guiding wire.
= 2f_1, and is mounted on a ground-fixed transmitter and a mobile body that alternately sends out an unmodulated second frequency output to both the second and third guide lines by time-division switching. The mobile receiving device includes circuits that separate and extract the received input from the antenna into each frequency component and amplify the frequency components to a constant amplitude.
a circuit that uses a signal made equal to a second frequency f_2 by multiplying the first frequency f_1 as a reference phase signal, performs phase discrimination from the second frequency output to generate a square wave output; an amplitude modulation detector that detects the on/off amplitude modulated wave of the output separately taken out by the amplifier circuit of the frequency reception input, and the on/off signal output from this detector synchronized with the division switching cycle of the transmitting side. a timing pulse generation circuit that generates a switching pulse; and a pair of first and second pulse generators that switch the square wave output using the switching pulse and store phase changes depending on the crossing positions of the second and third guide wires, respectively. A phase discrimination memory circuit and four types of pulses corresponding to respective conversion points at each point of rise and fall of each square wave output from the phase discrimination memory circuit for each guide line according to the traveling direction of the moving body. a pair of conversion point pulse generators that generate , four sets of AND gates whose respective gate inputs are the square waves of the four types of conversion point pulses and the outputs of the pair of phase discrimination memory circuits; The square wave positive output b of the pair of phase discrimination memory first circuits receives the falling pulse of the square wave output of the other phase discrimination memory second circuit, and the falling pulse of the square wave output of the second phase discrimination memory circuit The rising pulses of the circuit outputs are respectively extracted, and the rising pulses of the first circuit output are extracted at the square wave positive output a of the second circuit, and the rising pulses of the first circuit output are extracted at the square wave inverted output of the second circuit. When each falling pulse of The square wave positive output b of the first circuit is used to transmit the rising pulse of the other second circuit output to the first circuit.
The falling pulses of the second circuit output are extracted at the square wave inverted output (2) of the circuit, and the falling pulses of the first circuit output are extracted at the square wave positive output (a) of the second circuit. When each of the rising pulses of the first circuit output is extracted by the square wave inversion output (■) of the circuit, a second OR gate that passes any of the pulses and outputs a running direction pulse in the opposite direction to the above-mentioned direction; A forward/backward motion detection device for a moving body, comprising a traveling direction signal output device that stores pulse inputs from both the first and second OR gates and outputs a traveling direction identification signal.