JP2568991B2 - Measuring device for ground on automatic train stop - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a point control type automatic train stop system (ATS), and more particularly to an apparatus for measuring a resonance frequency and a Q of a ground child.

[0002]

2. Description of the Related Art In order to prevent a driver from overlooking a traffic light and causing a dangerous situation, an automatic train stop which gives a warning on the car when a red light or a speed limit is exceeded and applies an emergency brake when ignored. Equipment (ATS) is installed in many lines.

In the ATS, as a method of providing information on a vehicle, there is a point control type method in which a resonance frequency of a resonance circuit called a grounding element installed between rails is detected by an oscillator on the vehicle. FIG. 5 is a principle diagram of the point control type ATS. The capacitor of the grounding element 5 is switched according to the signal condition, and the oscillation frequency of the feedback oscillator 13 on the vehicle is pulled down to the resonance frequency only when the vehicle child passes over it.

The oscillation frequency of the feedback oscillator 13 is selectively detected by selection amplifiers 14, 14,.
.. Are given a trigger to the brake control device 15. The brake control device 15 includes selection amplifiers 14, 14,.
From the vehicle signal and the vehicle speed signal.

[0005] In order to maintain such a grounding element, a conventional measuring device as shown in FIG.
Had been measured. The feedback oscillator 13 supplies a signal to the coil of the vehicle upper child 4 and receives a feedback signal from the coil of the vehicle upper child 4.

When the vehicle arm 4 and the ground arm 5 are coupled, the feedback oscillator 13 oscillates at the resonance frequency of the earth arm 5. The frequency of the output signal of the feedback oscillator 13 is measured by the frequency counter 16, and its level is detected by the Q detector 17, and the Q is measured by converting the level into Q.

[0007]

In the above-mentioned conventional ground measuring device, the level is converted in the measurement of the Q, and the calculation is performed. However, this greatly varies depending on the distance between the ground and the vehicle. I do. Therefore, the swaying of the upper armature caused by the running of the train causes an error. Also, when measuring ground elements having different shapes, such as large and small ones, a method such as using a converted value calibrated to minimize the error is used for both.
It has been difficult to increase the measurement accuracy of.

[0008] Therefore, there is a limit in the improvement of the measurement error due to restrictions on facilities such as mounting the upper arm on a bogie with less fluctuation, and there is a problem in maintaining and managing the ground arm having a different shape in the future.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to reduce the resonance frequency and Q of a ground child of an automatic train stopping device in a short observation time, and to provide a ground child and a vehicle child. It is an object of the present invention to provide a measuring device capable of measuring with high accuracy without affecting the distance between the antennas and the size and shape of the grounding element.

[0010]

According to the present invention, there is provided an apparatus for measuring a ground contact of an automatic train stopping device, which applies a signal voltage having a flat spectrum to a predetermined frequency to a coil of a vehicle child, and connects the coil of the vehicle child with the ground. The signal generated in the child coil on the vehicle when the child coil is inductively coupled is amplified and passed through a bandpass filter, then converted to analog and digital and stored in memory. It is configured to calculate the resonance frequency and Q of the ground element from the discrete spectrum obtained by Fourier transform.

[0011]

According to the measuring device of the ground child of the automatic train stopping device of the present invention, the signal voltage of the flat spectrum applied to the coil of the vehicle child is the electromagnetic induction coupling between the coil of the vehicle child and the coil of the ground child. Then, a signal having a spectrum according to the resonance characteristics of the ground child is generated in the coil of the vehicle child.

This signal causes a level change at the initial stage of the electromagnetic induction coupling between the vehicle coil and the ground coil, and after detecting that the level exceeds the threshold value, the signal of the vehicle coil for a certain period of time. Is converted from analog to digital and stored in a memory, whereby a time-series discrete value of the signal can be obtained. By setting the clock frequency of the analog-to-digital conversion to twice the maximum frequency of the signal by the sampling theorem,
Analog signals are completely sampled as discrete values.

[0013] A discrete spectrum is obtained by performing a discrete Fourier transform on the signal sampled as described above. The difference between the obtained discrete value and the calculated value of the resonance characteristic using the resonance frequencies f ₀ and Q as parameters, that is, f ₀ and Q that minimize the sum of the squares of the residuals is calculated.

As described above, since the resonance frequency and Q are calculated from a large amount of data that has been converted from analog to digital, accurate measurement can be performed by sampling in a short time.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A ground probe measuring apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a ground measuring device of an embodiment. In the figure, reference numeral 1 denotes a multiple frequency generator. FIG. 2 shows the configuration of the multiplex frequency generator, which comprises N oscillators 1a and a synthesizer 1b.

The output signal of the multiplex frequency generator 1 is amplified by an amplifier 3 through a low-pass filter 2, and a discretely flat signal is output in a desired band as shown in FIG.

The output signal of the amplifier 3 is applied to the primary coil of the upper armature 4. A signal generated in the secondary coil of the upper armature 4 is amplified by the amplifier 6 and is converted into an analog / digital signal by the AD converter 8 to obtain digital discrete data.

The level detector 9 detects the level when the vehicle upper child 4 and the ground child 5 are coupled, and sends a write pulse signal to the buffer memory 10 when a signal exceeding a threshold value is input. .

The buffer memory 10 stores the data output from the AD converter 8 after the input of the write pulse signal into two.
Remember ⁿ . When 2 ⁿ data are stored in the buffer memory 10, the RS232C interface circuit 11
The data is sent to the personal computer 12 via the. The personal computer 12 performs an operation such as FFT (Fast Fourier Transform) on the transmitted data.

FIG. 4 is a flowchart showing the flow of the operation of the personal computer 12. First, step S
At 1, the AD converted data is written to the memory. Next, in step S2, the data at the beginning and end of sampling is corrected using a window function to correct the error of the Fourier transform due to the limited time domain.

Next, in step S3, an FFT operation is performed to calculate discrete spectrum values. Next, in step S4, the parameters of the equation indicating the resonance characteristic are determined from the obtained discrete spectrum values by the least square method, and the resonance frequency and Q are calculated in step S5.

In the above configuration, the multiple frequency generator 1
Are N oscillators 1a (F ₂ −F ₁ = F ₃ −F ₂ =...) Whose frequency interval is equal to the resolution of the FFT depending on the measurement time.
= F _N −F _N−1 = resolution) and a combiner 1b, and can generate a flat discrete spectrum in a desired band.

When the vehicle arm 4 is coupled to the ground arm 5, a signal appears in the secondary coil of the vehicle arm 4, which is similar to the signal passing through the resonance filter and has a ground spectrum of the ground arm. The signal passes through a band-pass filter 7 to generate an unnecessary low-frequency signal (commercial frequency 50/60 Hz).
) And high-frequency signals (aliasing noise, impulse noise, etc.) are removed to have a spectrum as shown in FIG.

The signal having such a spectrum is AD-converted by a clock (2 × 140 kHz) according to the sampling theorem. The AD converted data is written into the buffer memory 10 by 2 ⁿ from the time when the reception level exceeds the threshold value.

When the clock is 300 kHz and 512 (2 ⁹ )
When performing FFT operation on points, 1 / (300 × 10
³ ) × 512 × 1000 = 1.7 ms required data can be acquired. If there is enough time for the upper child and the lower child to be connected, the data is acquired several times and
The reliability can be improved by taking the average value by performing the FT operation.

The resolution of the FFT is limited by the measurement time,
If the measurement time is 1.7 ms, the resolution is 588 Hz. In order to increase the accuracy, it is necessary to supplement the data. Therefore, the least squares method is used.

The parameters f ₀ and Q for minimizing the difference between the obtained discrete value and the calculated value of the resonance characteristic shown in the following equation, ie, the sum of the squares of the residuals, are calculated.

I = E [1 / R + Q ² (f / f ₀ −f ₀ /
f) ² ] where I, E and R are the current, electromotive voltage and resistance of the ground element 5, respectively.

Although the embodiment is configured as described above, the invention is not limited to this. For example, instead of performing the FFT operation or the like on a personal computer, a dedicated DSP (digital signal processor) may be used.

Also, if only OK or NG determination is sufficient,
High accuracy is not required. In that case, the determination can be made in real time, and it can be shared with a normal ATS detector.

[0031]

According to the ground train measuring device of the automatic train stopping device of the present invention, the resonance frequency and Q of the ground train can be obtained with high accuracy in a short measuring time, so that a normal commercial vehicle can be used. The maintenance cost can be reduced, and if it is shared with the ATS detector, it can be used for a normal automatic train stop device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a ground probe measuring apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a multiple frequency generator according to the present embodiment.

FIG. 3 is a diagram showing a spectrum of a signal in the device.

FIG. 4 is a flowchart showing the operation of the apparatus.

FIG. 5 is a block diagram showing a configuration of a point control type ATS.

FIG. 6 is a block diagram showing a conventional ground detector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-frequency generator 1a Oscillator 1b Synthesizer 2 Low-pass filter 3 Amplifier 4 On-board element 5 Ground element 6 Amplifier 7 Band-pass filter 8 AD converter 9 Level detector 10 Buffer memory 11 RS232C interface circuit 12 Personal computer 13 Feedback oscillator 14 Selection Amplifier 15 Brake controller 16 Frequency counter 17 Q detector

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Kenichi Shiraishi, 2-17-5 Shibuya, Shibuya-ku, Tokyo Inside Kenwood Co., Ltd. (72) Shoichi Suzuki 2-17-5, Shibuya, Shibuya, Shibuya-ku, Tokyo Inside Kenwood

Claims (1)

(57) [Claims] 1. A signal voltage having a flat spectrum up to a predetermined frequency is applied to a coil of a vehicle upper child, and a signal generated in the vehicle upper child coil when the coil of the vehicle upper child and the coil of the ground child are electromagnetically inductively coupled to each other. After being amplified and passed through a bandpass filter, it is converted from analog to digital and stored in a memory, and the resonance frequency and Q of the ground element are determined from the discrete spectrum obtained by performing a discrete Fourier transform on the data thus stored in the memory. A measurement device for a ground child of an automatic train stop device configured to calculate.