JPS5941614B2 - Mobile object position detection device capable of data transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When an automated system controls the travel of a mobile object such as a crane that moves on a fixed travel path, it is necessary to constantly monitor the position of the mobile object and to monitor the position of the mobile object and the ground control device (
It is necessary to be able to exchange control and monitoring data between the ground side (hereinafter referred to as the ground side).

The present invention relates to a position detection and data communication device that can exchange data at any time in this case and can detect the current position of a moving object on the ground side. Conventional position detection devices connect a pulse generator that generates pulses as the vehicle rotates to the running wheels of a moving object or a rotating shaft engaged with the wheels, and count the number of pulses generated by the movement of the moving object. There are devices that constantly calculate the distance from a constant reference position, but such devices provide information from the reference position to the current position (
In this case, it is troublesome to have to input the number of pulses) and to memorize the calculation results while moving.Also, once the power to the device is turned off, the memory is lost, so the current It is necessary to input location information or take measures against power outages. A further drawback is that errors are likely to occur due to slippage of the running wheels. In addition, various so-called induction-type position detection devices have been proposed in which a guide wire is extended along the running route and a signal current is passed through it or the induced voltage of the signal sent from the moving object is received. This system is dedicated to detecting the position of a moving object, and in order to transmit data between the moving object and the ground side, it is necessary to separately install data transmission equipment, which is economically disadvantageous.

The present invention eliminates the above-mentioned drawbacks and makes it possible to transmit data at the same time as detecting the position of a moving object.
In order to guide and receive the transmitted waves, the position of the moving object is determined using a guiding wire (antenna) extended along the moving path of the moving object and fixed equipment on the ground connected to one end of the track. It is characterized by being able to detect absolute positions based on the addresses of the sections given to each section into which the travel route is divided, and to be able to receive data at the same time. The present invention will be explained in detail below using the drawings. FIG. 1 is a diagram showing the principle of construction of the apparatus of the present invention.

Symbol 1 in the figure is a parallel two-line guide line, which intersects at each division point of the position division sections A, B, C, and D along the travel route. 3 is a terminal resistor thereof, 4 is a coupler, 2 is a position detection/data receiver for a moving object, 5 and 6 are equipment mounted on the moving object, 5 is a two-frequency signal transmitter or a two-frequency data transmitter, 6 is a transmitting antenna or antenna coil.

a is the travel path of the antenna 6 when the moving body moves, and the guide line 1
It is assumed that the antenna moves so that the degree of coupling of the antenna to the plane of is approximately constant. 2 waves from transmitter 5 are sent to antenna 6
The induced voltage is generated in the guiding wire 1, but this phase is reversed at each intersection point and is transmitted to the coupler 4 when the moving object is in section A or C and when it is in section B or D. The phase of the voltage or current is different by 180 degrees. Next, each part will be explained in more detail.

First, the transmitter 5 on the mobile side has two frequencies f1 and F.
The antenna 6 includes an oscillator, an amplifier, and a modulator that performs phase modulation (PM) of the f1 wave using data, and both the f1 wave PMed with data and the unmodulated F2 wave are radiated from the antenna 6. However, in this explanation, a practical example in which the frequency relationship 2f,=F2 is maintained is taken up, but in addition to this, (m-1)F2/m-f1 (m is an integer of 2 or more)
Sometimes I choose. Ground side position detection and data receiver (
The configuration example of 2) in FIG. 1 is as shown in FIG. 2, and FIGS. 3 and 4 are signal waveform diagrams of each part for explaining the operation. In FIG. 2, reference numerals 21 and 27 denote bandpass filters (BPF), which selectively extract the induced components of the f1 wave and the F2 wave of the transmitted wave from the mobile body. 22, 28 are frequency f1 and F, respective amplifiers (A,, A2), 23, 29 are amplitude limiters (
L,,L2), 24 is a double frequency multiplier (X), 25
is a phase discriminator (PD), 26 is a square wave converter (DC
), 30 is a phase modulation signal detector (DTC).

Note that 24(X) outputs a double frequency signal synchronized with the zero phase of the f1 wave. Also, since the amount of phase rotation inherent in each of the BPF, amplifier, and amplitude limiter cannot be predicted, a manually adjusted shifter is used in this circuit to first perform phase correction so that the PD input is optimal. It is provided. Next, the operation of the circuit will be explained.

The explanation will be given with reference to FIGS. 2 and 3, assuming that there is no data and the f1 wave is not modulated by a data signal and the signal "0" is continuous. In this case, the transmitting antenna 6
The transmitted signal has the relative phase of each section and is input to the position detection/data receiver 2 via the combiner 4, and as shown in Fig. 2, the f1 component and F2 component are separated and processed, but the signal for each section is The process is illustrated in FIG. That is, FIG. 3 is a signal waveform diagram of each part explaining the operation of FIG. 2, and the symbols at the left end of the diagram correspond to the symbols in FIG. First, c is the phase change in the output of the F wave amplitude limiter 23 (solid line) when the mobile antenna moves on the a line, and d is the phase change in the output of the F wave amplitude limiter 29 (solid line). It is. As shown in the C and d waveforms, the phases are reversed at each point on the travel path. Furthermore, C,
The envelope shown by the broken line in d is the amplitude characteristic of each output of C and d, and the induced voltage becomes zero at the intersection point. It should be noted that the c output is output by the multiplier 24 at a frequency of 2f1, and as shown in FIG. 3e, the phase change is continuous, unlike the c waveform. D
．． (The phase difference between the two outputs of 5e is detected by the phase discriminator (PD) 25, and if the two outputs are in phase, for example +E,
In the case of reverse phase, a binary output of -E is generated. Note that the zero output of the PD 25 also coincides with the input of d and e when the induced voltage of the induction wire is zero (phase cancellation at the intersection point). This output zero point of g is given the output from the PD and is also the conversion point for the high and low levels (H, L level) of the output of the square wave converter (DC) 26 that converts the waveform into a square wave. , D.C.
26, +E of the g waveform is converted to H level and E to L level, as shown in h of FIG. 3, and the level change point correctly coincides with the dividing point. This H and L two value output represents one bit of the address code. Next, the operation in a state where the f1 wave is modulated with a data signal and data transmission is performed will be described.

A detailed configuration example of the phase modulation signal detector (DTC) 30 in FIG. 2 is shown in FIG. This is a 1-bit time delay circuit (DL). Although there are many types of phase modulation, in order to simplify the explanation, a differential phase keying (DPSK) system will be used here. [In DPSK, in the case of two-phase modulation, when the input modulation signal is "0", the phase is not shifted (shifted), and when the signal is "1°", the phase shift of the π phase is phase-modulated in units of 1 bit and transmitted. On the receiving side, a phase discriminator detects the O-phase or π-phase phase shift of the preceding bit signal delayed by 1 bit time and the subsequent bit, bit by bit.
If it is 0 phase, it is converted to "O" and if it is π phase, it is converted to each bit code of "1". Now, position detection in this state will be explained with reference to FIG. 4. FIG. 4 shows sections A and B in FIG. This is an enlarged view of the vicinity of the dividing point.The symbols on the left end of the figure correspond to the symbols of the signal waveforms of each part in FIGS. ) is the input data signal.Also, assuming that the moving speed of the moving object and the data speed are constant, if the data signal Z is ゜"bi, there is a phase shift of π, and if it is "0", there is no phase shift. The f1 wave transmission signal from the transmitting antenna 6 of No. 1 is as shown in Tz, and the induced voltages of the f1 wave and F wave have the relative phase of each section of the traveling road and are sent through the coupler 4 to be used for position detection and data. Input to receiver 2. Here, as shown in Figure 2, F,
The F2 component and the F2 component are separated, and the modulated f1 wave signal outputs the c waveform in FIG. 4 from the amplitude limiter 23, and the unmodulated (continuous) F wave signal outputs the d waveform in FIG. Output. Since the phases of both Cd waveforms are reversed at the division points of A and B, the amplitude becomes zero at the division points as shown by the envelope shown by the broken line. The output c is multiplied by the frequency 2f1 by the doubler 24, and the output e has a continuous phase as shown in the waveform of FIG. 4e. D,! :． The two signals of e are phase discriminator (PD)
The phase difference is detected at 25 and becomes the g output (FIG. 3), which is further converted at DC 26 into a square wave h waveform with the output zero of the PD 25 as the border. In this example, A like the h waveform
The H level is output in the section, and the L level is output in the B section as the position detection information. Note that the intersection point of the guide line and the level change point of the h waveform serving as the position detection signal are exactly the same as when the f1 wave is not modulated. Next, data is obtained from the F, wave input c using the DTC 3O in FIG. 2, but in FIG. In this example, when h is at the H level, the C waveform remains unchanged, but when the h level is at the L level, it is inverted and the output 1 of the inverter 31 becomes the i waveform in FIG. 4. This means that the inverter 31 is the one whose phase is reversed at the intersection of the guide wires.
This means that the signal is further inverted and restored to the phase state of the signal transmitted from the moving object. Output 1 is sent to a phase discriminator (PD2) 32 and a delay circuit (DL) 33, where it is delayed by 1 bit time and output to PD.
232 to another input. The PD 232 detects the phase difference between these two input signals and outputs the j waveform in FIG. 4. That is, if the leading bit and the succeeding bit are in phase, the level output corresponds to O, and if they are in opposite phase, the output level corresponds to π. The j waveform signal is restored to a square wave data signal through an integration circuit (not shown). The above is an explanation of the configuration principle diagram of the present invention shown in FIG.
, B, C, D, . . . , one guiding line can represent only one bit of the address code as shown in FIG. 1. The number of sections is 2n (
For example, for 8 sections (23), it is necessary to use an n-bit address code, so n guide wires are laid in parallel to each other, and the mobile antenna is connected to one to two guide wires so that it is almost equally coupled to all of these guide wires. Multiple pieces. Furthermore, the n guide lines intersect as shown in Figure 6 according to the change in each bit of the address code given to that section with the code of the adjacent section, but in this case, the code given to the address is The well-known gray (G) code in which only one bit of the code changes each time
ray) code, it is possible to set the intersections so that the intersections do not overlap between the guide lines and only one intersection of the n guide lines coincides with the dividing point of the travel route. By detecting the phase between F, , f22 frequencies with a position detector as shown in Fig. 2 installed at one end of each of the n guiding wires, each bit of the 2n binary code can be is detected as the output h of the wave converter. This output h can therefore be displayed, for example, as an address in decimal code on a suitable display. Incidentally, FIG. 6 shows the crossing situation of the guide lines by the 4-bit Gray code. The reason why Gray code is used for address codes is that if there are two or more level inversion bits at a division point, there is generally a slight difference in the timing of the inversion! )≦There is a risk of incorrect detection. Next, in data reception, as shown in the i waveform of FIG. 4, the signal output becomes zero at the intersection of the guide lines, and a correct bit signal cannot necessarily be obtained, so it is desirable to use the double-combined reception method shown in FIG. Further, an encoded signal capable of error detection or a encoded signal capable of error detection and correction may be used for the data. Now, in FIG. 7, symbols 34 and 35 are both data receiving and position detectors whose configuration is shown in FIG.
n-1 from each coupler 4. Here, the guide line 2n represents the guide line corresponding to the 2n-th bit of the address code. 36 and 37 are envelope detectors (Dl,
D2) 38 is a level comparator (CMP), and 39 is a data switch (G3).

As mentioned above, the address code has a 2n-bit configuration, so n guide wires are used, but in data reception, the f1 wave 1
Since it is only a channel reception, the amplitude level of the F wave input from any two guide wires, for example, 2n and 2n-1, and the data receiving/position detector connected to one end of the F, wave input can be compared and the level can be determined. Select and output the data on the larger side.
To explain this with reference to FIG. 7, the f1 wave signal from each guide line 2n,'/n-1 is input from each amplifier A 34, 35 to envelope detectors 36, 37, and envelope detection is performed. and sent to comparator 38. By the way, since the guide line crossing for position detection follows the Gray code which does not overlap in the same section, one of the outputs of 36 and 37 (DlD2) does not always become zero even at the crossing point.
Therefore, the level comparator 38 compares the levels of Dl and D2 and selects the data with the larger level ("
The data alarm device 39 (G
3) Output. Data outputs Jn-1 and Jn (signal outputs obtained by shaping the waveform in FIG. 4J) from 34 and 35 are input to G3, and the data signal with a higher level among them becomes the output DO. That is, even if one input is a small input at the intersection point or its vicinity, the other input is sufficiently large and the data will not be erroneous. Further, when the two inputs are not at a crossing point but are substantially equal, the output can be output from either side, and G3 can be switched to either side.
Furthermore, from the previous explanation, since only two guide wires are used for data transmission, the position detection and data receiver connected to the guide wires other than the two guide wires is the position detection device excluding DTC3O from Figure 2. It is clear that a container is sufficient. As explained in detail above, the device of the present invention can detect with high accuracy the address of the road on which a moving object currently exists, and can simultaneously send and receive data from the moving object, resulting in significant practical effects.

[Brief explanation of drawings]

FIG. 1 is a diagram of the configuration principle of the device of the present invention, FIG. 2 is a block diagram of an example configuration of the position detection and data receiver in FIG. 1, and FIGS. 3 and 4.
is a signal waveform diagram of each part for explaining the operation of Fig. 2, and Fig. 5 is a diagram of Fig. 2.
Figure 6 shows an example of the configuration of the phase modulation signal (DPSK) detector in
7 is a diagram showing an example of crossover of guide lines for address codes, and FIG. 7 is a diagram showing a configuration example of a double composite reception system for data reception. 1... Guide wire, 2... Moving body position detection and data receiver, 3... Terminating resistor, 4...
...Coupler, 5...Two-frequency data transmitter, 6.
...Transmission antenna, 21,27...Band filter, 22,28...Amplifier, 23,29...
... Amplitude limiter, 24 ... Frequency multiplier, 25, 32 ... Phase discriminator, 26 ...
・Square wave converter, 30... Phase modulation signal detector (DTC), 31... Signal inverter (inverter), 33... Delay circuit, 34, 35...・
...Same as 2, 36, 37. ．． ．． ... Envelope detector, 38 ... Comparator, 39 ... Data switcher.

Claims (1)

[Claims] 1 Divide the travel path of a moving object, give a position address using a gray code to each divided section, extend parallel two-wire guide wires in a number equal to the number of bits of the code, and extend each guide wire along the travel path. Crossover is performed at the dividing point of the divided section according to the code of the above address, and one side has twice the frequency of the other, and one side is phase-modulated with a data transmission signal, and the other side is not modulated. A two-frequency transmitter and a transmitting antenna for inductively coupling its output to each of the above-mentioned guide wires are provided,
In addition, at one end of each of the guide wires, the induced two-frequency signal is separated and amplified for each frequency, limited to a constant amplitude, and only the lower frequency component of the two-frequency signal is converted to twice the frequency. Connecting a moving body position detector that discriminates the phase difference and outputs each bit of the address code as a binary output,
For any two adjacent points in the guide line, a data receiving circuit that reproduces a data signal from the output of the amplitude limiter of the phase modulated wave in the moving body position detector and the output of both data receiving circuits are combined. A mobile object position detection device capable of transmitting data, characterized in that a circuit is added to detect the position of the mobile object and to receive data from the mobile object on a fixed ground side.