JPS6118988B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring the traveling speed of a crane, a bogie, a vehicle, a train, etc. traveling on a fixed traveling path at a fixed ground station (hereinafter referred to as a ground station).

Conventionally, there are various methods for measuring the speed of a moving object, including optical methods, electromagnetic wave methods, ultrasonic methods, electromagnetic coupling methods, inductive coupling methods, and mechanical methods, each with its own characteristics, depending on the purpose of use. One or more combinations of these methods have been put into practice.
Among these, the inductive coupling method in particular has the excellent feature of being non-contact and usable even in environments with a lot of dust, rain, snow, and dirt, so various types are in practical use. Furthermore, among these, to measure on the road side (ground station), two loop coils are installed at a certain distance on the road, and a signal wave of a specific frequency is sent from the mobile object to these and combined, and the ground station receives this signal. The method detects the signal, measures the time required to pass between two loops, and calculates the speed. However, since signal detection at the loop point is determined based on the amplitude component, it is difficult to detect changes in the distance between the moving object and the traveling route (loop) and noise. If there is contamination, there is a problem of a lack of reliability, such as large fluctuations in the position detection error of the moving object and false detections. The present invention was made to eliminate such drawbacks, and will be explained in detail below using Examples.

FIG. 1 is a diagram showing an example of the basic configuration of a traveling speed measuring device according to the present invention, in which a cross-shaped parallel two-wire guide wire 1 is laid in a speed measuring section along a traveling path of a moving object, and a coupler 4 is installed at one end of the wire. A speed measuring device 6 connected via
It consists of a terminating resistor 3 connected to the other end of the guide wire, an antenna ₈ mounted on a moving body, and transmitters 1 and ₂ which output appropriate outputs of two-frequency modulated signals. Note that ₁ and ₂ are actually selected from the induction radio frequency band.

FIG. 2 is a basic configuration diagram of another embodiment of the present invention, which is configured so that data transmission from the mobile unit to the ground station is performed at the same time, and the symbols are the same as those in FIG. 1. Note that 2 is a parallel two-wire guide wire that does not intersect within this speed measurement section and is laid parallel to the guide wire 1. 5 is a coupler, 7 is a speed measuring device including a data demodulator, and 10 is a two-frequency signal transmitter on the moving object side, which uses data signals such as π-phase phase shift keying (PSK) frequency _{1 and unmodulated frequency 1} . The appropriate output of each of the _two waves is sent to the guide wires 1 and 2 through the antenna 8. Between ₁ and ₂ , m ₁ /(m-
1) = ₂ , and m is an integer of 2 or more. (Speed measurement sections may be provided at any number of locations along the running route, and the guide line 2 can be shared by all locations.) Figure 3 shows the circuit of the speed measurement device shown as 7 in Figures 1 and 2. In the configuration example diagram, the portion indicated by a broken line is not included in 6 in FIG. 11 and 12 are bandpass filters (BPF) that separate and extract _two waves and _one wave from the input, 13 and 14 are amplification and amplitude limiters (A/L), 15 is a frequency doubler, and 16 is a phase discriminator. (PD), 17 is a square wave converter (W),
18 is a clock (pulse) generator (C), 19 is a clock counter (referred to as a counter), 20 is a speed information output device, 21 is a data demodulator, V _put is a speed information output, D _io is a data input, D _put is data demodulation output.

FIG. 4 is an operation waveform diagram of each part in the configurations of FIGS. 1 and 2, and the operations of FIGS. 1 to 3 will be explained using this chart. _First , from the moving object side,
₂ is guided and transmitted to the ground station via the guide wires 1 and 2, but since the guide wire 1 is crossed at two fixed points S ₁ and S ₂ , the speed measuring device 6 or The phase of the input signal wave to the antenna 7 differs by 180 degrees each time the antenna 8 passes through the positions S ₁ and S ₂ , that is, the phase is reversed. Further, such phase inversion due to the position of the antenna does not occur in the input to the speed measuring device 7 through the guide wire 2 shown in FIG.

Next, in Figure 3, the input from guide wire 1 is
Consider the case in Figure 2 where the input from guide wire 2 is input to BPF 11 and BPF 12, but in the case of Figure 1, the input from guide wire 1 is input to BPF 11 and BPF 12.
12. BPF1 in both cases
1 receives the _2- wave component from the input, BPF12 receives the 2-wave component from the input.
Each of the _first wave components is selectively extracted to obtain the outputs of waveforms b and a in Figure 4, which are used in the next stage A and A.
The signal is amplified at L13 and A/L14 and limited to a constant amplitude. Figure 3 shows the case where m = 2, and _one wave of the output of A.L14 is made 2 ₁ by the frequency doubler 15, and the output that becomes 2 ₁ = ₂ is used as a reference for one input of the phase discriminator PD 16. Sent as a phase wave. This is shown in FIG. 4 as waveform c. As mentioned above, the _single wave input to the multiplier 15 has a phase change of 180° (π phase) at each point S ₁ and S ₂ , but by doubling the frequency, it becomes a continuous phase wave. Since it can be changed, this is used as the reference phase wave. Note that even if m is other than 2,
If the difference frequency between ₂ and ₁ is extracted and multiplied by m, it can be used as a reference phase wave.

Now, the two inputs of the phase discriminator PD16 are this c
Phase discrimination between these two inputs is performed using the waveform and _{the two} waves from A and L13, and if they are in phase, for example, negative,
If the phase is opposite, a positive output is sent to the next stage W17. Although this output is shown as a waveform in FIG. 4, the polarity may be reversed. In addition, BPF11, 12 in Figure 3,
Since A/L13, 14, etc. have a unique amount of phase rotation that cannot be predicted, it is necessary to install a phase correction circuit at the input of PD16 and perform correction to obtain ideal discrimination results. Needless to say. The d waveform from PD16 is converted to square wave converter W17.
A counter 19 and a speed information output device 20 output the e-waveform converted into a backward waveform passed through a low-frequency wave generator.
Output to. The counter 19 has a clock generator 1.
The clock pulse is input from 8 and the e waveform is H.
Count clocks between levels. This is the j waveform in FIG. The counter 19 is configured to detect the rising edge (L→H) transition point of the e waveform, reset it, and then count the clocks.
On the other hand, the speed information output device 20 detects the falling edge of the e waveform (H
→L) Detect the conversion point, read the count value of the counter 19, calculate the speed of the moving object from these using the distance value set in advance between S ₁ and S ₂ , and calculate the speed of the moving object from these Km/
A speed value V _put expressed as H, etc. is output. The g waveform in FIG. 4 shows the output operation when the moving body moves in the right direction Sr in FIG. 1, and the h waveform shows the output operation when the moving object moves in the left direction in the Sl direction.

The difference between the device in Fig. 1 and the device in Fig. 2 is that only _one guide wire or one or two guide wires are provided in parallel depending on whether one wave is unmodulated or PSKed with a data signal. In the case of FIG. 1, it is not a necessary condition that _one wave be unmodulated, but it is also possible to perform amplitude modulation and use it for telephone calls, for example. In addition, in the case of Fig. 2, only _two unmodulated waves are sent from the mobile side to both guide lines, and on the ground station side, the coupling between guide line 1 and 2 is at the intersection of S ₁ and S ₂ , so they are canceled out. Taking advantage of the fact that the output becomes zero, that is, no guidance, _two- wave components are extracted separately from each output of the guide wires 1 and 2, and the _two- wave output from the non-crossing guide wire 2 is made constant in amplitude and used as a reference phase signal wave. From intersecting guide line 1
Even if the phase difference between _{the two-} wave output with a constant amplitude is discriminated and the processing from W17 onwards in Figure 3 is performed to measure the time required between S ₁ and S ₂ , the The speed gains are obvious.

As is clear from the above explanation, according to the present invention, the speed of a moving object can be measured and monitored on the ground side, so there is no need to measure the speed on the moving object side and transmit the measured value. High-precision measurement is possible up to high speeds. In addition, since the phase detection method is used to detect intersections, that is, fixed points, the amplitude limiting function can minimize errors even if the distance between the mobile antenna and the guide wire changes, and it is effective against noise interference. However, the noise suppression effect due to continuous signal waves can be obtained. Furthermore, when a ground station uses this device to verify speed commands from a travel control device of a moving object, it is possible to directly detect speed abnormalities and runaway. Conventionally, speed detection on the moving object side has been based on measuring the number of rotations of the wheels, but this method involves errors due to wear on the outer circumference of the wheels, etc., whereas the device of the present invention eliminates the occurrence of such errors. There are none. Furthermore, in the present invention, ₂ = m ₁ /(m-
1) Two frequency signals having the following relationship are used, and this effect can be explained as follows. As mentioned above, it can be used for transmitting and receiving telephone calls by amplitude modulating _one wave, but when m = 2, it can also be used for data transmission with a two-phase (180°) phase shift. . At this time
The phase of ₁ is inverted by 180° according to the data of 1 and 0. Furthermore, when a moving object passes through the crossing point of the guiding wires, there is a 180° phase change in the guiding wire output before and after that point, so if these two occur at the same time, there will be a 360° phase change, and the receiving side 2 in Figure 3. A _two- wave phase reference signal can be obtained at the output of the multiplier 15.
Further, by setting m=4, ₂ =4 _1/3 , and multiplying ( ₂ − ₁ ) by 4 on the receiving side, frequency ₂ can be obtained. On the other hand, even if _one wave is shared for data transmission and data transmission is performed by the above-mentioned two-phase or four-phase phase shift keying, data transmission due to π phase or (π/2) × n phase change and cross position passing. π
Even if there is a phase change, if the reception side multiplies the signal by 2×2=4, _two waves of continuous phase can be obtained as the phase reference wave. It is clear that amplitude modulation of _one wave can be used for telephone calls in this way, and also for data transmission using two-phase or four-phase phase shift keying.

As described above, from the perspective of operational (transmission) frequency, the ground measuring device for measuring the speed of a mobile object according to the present invention shares _one wave for other purposes such as telephone calls and data transmission, so only _two waves are dedicated to speed measurement. You can say that. In other words, in practice, if there is _one wave used for telephone calls or data transmission, it is sufficient to allocate another wave as a frequency dedicated to speed measurement.

Also, the frequency relationship between ₁ and ₂ is ₂ = m ₁ /
(m-1), and the respective transmission bands ₁ and ₂ should be the required band of the modulation method according to the operational purpose, or the equipment selected to transmit each of the minimum band if no modulation is used. Since the devices for the other purposes mentioned above can use a common transmission path, significant economical effects can be obtained for all the devices.

[Brief explanation of the drawing]

1 and 2 are configuration example diagrams of the device of the present invention, FIG. 3 is a circuit configuration diagram of a speed measuring device, and FIG.
The figures are operation waveform diagrams of each part in FIGS. 1 to 3. 1, 2... Induction wire, 3... Terminating resistor, 4, 5
...Coupler, 6,7...Speed measuring device, 8...Antenna, 9,10...Transmitter, 11,12...
BPF, 13, 14...Amplification and amplitude limiter (A/
L), 15... Frequency doubler, 16... Phase discriminator (PD), 17... Square wave converter (W), 18
...Clock generator, 19...Counter, 20...
...Speed information output device, 21...Data signal demodulator.

Claims (1)

[Scope of Claims] 1. A cross-type parallel two-wire guide wire extending over a speed measurement section along a moving vehicle travel path and crossing two lines at a constant interval, and a speed sensor connecting an input side to one end of the cross-shaped parallel two-wire guide wire. ₂ = m ₁ / (m-1) (m
is an integer greater than or equal to ₂ ), and the speed measuring device is equipped with a transmitter that outputs two frequencies, 1 and ₂ , which are in the relationship of 1 and 2 (integer greater than or equal to 2), and the speed measuring device separately extracts each frequency component of ₁ and ₂ from the input from the guide wire. A circuit that limits the amplitude to a constant amplitude after amplification, and the output of the difference frequency between ₂ and ₁ obtained from these circuits is multiplied by m to have a frequency equal to ₂ as a reference phase wave, and the phase difference with the above _two waves with constant amplitude is A circuit that generates a square wave of high and low or positive and negative levels based on the phase difference.The output of this square wave controls the on-off of a constant clock pulse counter, and the speed of the moving object is determined by the count value while the moving object is traveling in the above-mentioned crossing section. A ground measuring device for measuring the speed of a moving object, characterized in that it includes a circuit for extracting information. 2. The first guide line of the intersecting parallel two-wire system, which is spread out in the speed measurement section along the moving vehicle travel path and intersects at regular intervals, and the first guide line, which is parallel to this and does not cross within this section. ground-side equipment consisting of a parallel two-wire second guide wire and a speed measuring device that receives a signal input from one end of each of these guide wires through a coupler; one or more antennas to couple to and
Only non-modulated waves with frequency ₂ in the relationship ₂ = m ₁ / (m-1) (where m is an integer greater than or equal to 2),
Alternatively, the speed measuring device is equipped with a transmitter that transmits _two unmodulated waves and _one frequency wave that is unmodulated or phase-shift keyed using a digital signal, and the speed measuring device is provided with an input from the first guiding wire. From, the frequency
The frequency of _{the second} component is also calculated from the input from the second guiding wire.
After extracting and amplifying ₁ , a circuit limits the amplitude to a constant amplitude, and the difference frequency between ₂ and ₁ obtained from these circuits is multiplied by m, and the output with a frequency of ₂ is used as a reference phase wave from the first guide line above. A circuit that discriminates the phase difference between _two constant amplitude waves of A ground measuring device for the speed of a moving object, characterized in that the device includes a circuit for extracting the counting position while traveling in the crossing section as speed information.