JP2006160161A - Wayside coil sensing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable frequency type automatic train stopper (ATS) in which a normally oscillating circuit is formed from a positive feedback loop where a pick up coil is connected with an amplifier and sensing the signal is conducted while the normally oscillating frequency is changed to the wayside coil resonance frequency owing to electromagnetic coupling with the wayside coil, as improvement of the conventional technique which has required adjustment of the phase and gain characteristic of the amplifier including the wayside coil in order to sense another wayside coil frequency and an adjustment with the turbulence noise to be discriminated. <P>SOLUTION: A wayside coil sensing device uses a direct digital synthesizer (DDS) circuit as a signal source and emits repetitively frame signals of such a structure that slot signals based on a minimum constituent unit consisting of a plurality of wayside coil frequencies are laid in line and changed on the time series basis, in which the noise endurance is enhanced by making DC-AC detection on the signal receiving side to lead to elimination of necessity for adjustment with an offset circuit, and the judging method according to this arrangement enhances the reliability by incorporating the procedure to make multiple time judgement upon calculation of the spectrum from the IQ components based on the DC-AC detection. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an automatic train stop device (ATS), and more particularly, detection and reliability with improved noise resistance without adjustment in a process of detecting and determining a ground child frequency by electromagnetic coupling between a vehicle upper child and a ground child. The present invention relates to an improvement in a ground element detection device and a ground element determination method capable of performing highly reliable determination.

  As an automatic train stop device (ATS), a variable speed ATS is generally widely used. The variable speed ATS device includes an on-vehicle device and a ground element.

  FIG. 1 shows a configuration of a conventional variable speed ATS apparatus. In the on-board device, the coil of the on-board element 1 is connected as a feedback circuit of the amplifier 11, and an oscillation circuit 12 including the amplifier is configured. When the vehicle upper element 1 of the running train passes over the ground element 10, the oscillation frequency f1 of the signal output from the amplifier 11 is temporarily drawn to the ground element side and set to the ground element 10. The frequency f2 is changed. This change is called a frequency change, and the ground element is detected by this frequency change.

  Before the frequency change, a constant signal is output from the signal selection BPF 13a, but the output from the signal selection BPF 13a is stopped by the frequency change, and a signal is output from the signal selection BPF 13b. Here, the signal selection bands of the signal selection BPF 13a and the signal selection BPF 13b are different.

  In the conventional variable frequency ATS apparatus, the ground element is determined based on the level of the output signal from the signal selection BPF 13b having a different pass band from the signal selection BPF 13a. In recent years, adjustment of a feedback circuit, a BPF, and a discrimination circuit has become very difficult due to the addition of a frequency to be detected and an increase in disturbances such as vehicle noise.

  FIG. 2 shows an example of improvement of a conventional variable speed ATS device. In order to meet the above-described requirements, for example, as disclosed in Patent Document 1, it has been proposed to eliminate the adjustment of the feedback circuit. In the technique disclosed in Patent Document 1, signal oscillators 21a to 21d are individually provided, frequencies f1 to f4 are generated, added by a signal adder 22, and then multiplexed signals amplified by an amplifier 24 are converted into an on-board unit. 1 to send. The signal that resonates with the ground unit 10 is detected at a signal level via the signal selection BPFs 25a to 25d.

JP 10-304516 A

  However, in the prior art, harmonics are generated by adding the outputs of the oscillation circuits 21a to 21d, saturation distortion is generated due to the dynamic range limitation of the amplifier 24, and the discrimination ratio due to the resonance frequency shift of the ground element. There are problems such as reduction and difficulty in discrimination due to interference caused by panda graph separation noise.

  Even in the improvement of the above-described conventional variable speed ATS device, it is difficult to reduce the size of the device due to the necessity of equipment adjustment work, noise resistance problems, BPFs and detection circuits for the number of resonance judgments. There's a problem. Further, since the vehicle upper 1 has frequency characteristics, the center frequency fluctuates by ± 2 KHz due to the problem that the signal level and phase on the secondary side of the vehicle upper 1 change depending on the frequency, the secular change of the ground child 10 and the like. However, there is a problem that the signal level and phase on the secondary side of the vehicle upper body 1 fluctuate.

  Furthermore, there is a problem that the signal level and phase on the secondary side of the vehicle upper 1 change depending on the cable length connecting the vehicle upper 1 and the signal source side, and the distance between the vehicle upper 1 and the ground 10. However, there is a problem that the amplitude changes, and it is very difficult to perform adjustment in consideration of all of the above-described fluctuation factors.

  The present invention has been made in view of such a problem, downsizing the device, making no initial adjustment of equipment depending on the length of the vehicle core and the connection cable, and resistance to noise caused by external noise and harmonic distortion. Is to provide a ground element detection apparatus and a ground element determination method that improve the reliability of ground element frequency determination.

  In order to achieve such an object, the present invention provides a ground unit detection device that detects electromagnetic coupling between a vehicle top unit and a ground unit to determine the presence or absence of a ground unit frequency. Means for generating a signal having a constant amplitude at one of the ground element frequencies that can be combined with the ground element, and means for selecting a plurality of the signals and generating a frame signal continuously arranged in time series And detecting the electromagnetic coupling with the ground unit by transmitting the frame signal from the vehicle upper unit.

  The invention according to claim 2 is a ground element detection device that detects electromagnetic coupling between a vehicle element and a ground element to determine the presence or absence of a ground element frequency, and is one of the ground element frequencies that can be combined with the ground element. Means for storing signal data for generating a signal having a constant amplitude at one frequency; means for sequentially reading out the signal data stored in the storage means and generating frame signals arranged in time series; The signal having a constant amplitude at the one frequency is used as a slot of a minimum signal unit, and the frame signal is transmitted from the vehicle upper element to detect electromagnetic coupling with the ground element.

  According to a third aspect of the present invention, means for storing reference signal data for generating a reference signal 301 having an orthogonal relationship synchronized with the signal, and the reference signal data stored in the storing means are sequentially read out. And a means for generating the reference signal, wherein a quadrature detector 130 performs quadrature detection on the frame signal electromagnetically coupled to the ground unit and the reference signal.

  According to a fourth aspect of the present invention, there is provided means for performing quadrature detection of the frame signal and the reference signal 301 to discriminate and output an I component signal and a Q component signal, and the I component signal for each slot without a ground element. Means for storing a plurality of frames of amplitude data and amplitude data of the Q component signal, and reading the stored amplitude data to calculate average value data for a plurality of frames for each of the I component data and the Q component data Means for storing average value data and means for sequentially subtracting the stored average value data from I component data and Q component data are provided.

According to a fifth aspect of the present invention, means for sequentially calculating an amplitude spectrum value √ (I ² + Q ² ) from the discriminated I component signal, the I component data of the Q component signal, and the Q component data; The means for integrating for each slot and storing the integrated value, the means for calculating the average value of the power spectrum from the integrated values of a plurality of frames, and the average value of the power spectrum and the stored integrated value of the slot are compared. Means.

  The invention according to claim 6 determines the number of times corresponding to a frequency that is larger than the average value of the power spectrum and can be combined with the ground element, and is n times (n = 2 or more) continuously. When there are two slots larger than the power spectrum average value, it is determined that the frequency is the ground-child coupling frequency, and when a slot having a large absolute value is determined as the ground-child coupling frequency, there are three or more slots larger than the power spectrum average value. When the average value of the power spectrum is less than or equal to a threshold value, it is determined as noise.

According to the seventh aspect of the present invention, means for sequentially calculating the amplitude spectrum value √ (I ² + Q ² ) from the I component data and Q component data of the discriminated I component signal and Q component signal, and a threshold value or less Means for weighting and synthesizing the amplitude spectrum value with n (n = 2 or more) frames, and corresponding to a frequency that can be combined with the ground unit. The slot is determined as a coupling frequency with the ground unit.

According to an eighth aspect of the present invention, means for sequentially calculating an amplitude spectrum value √ (I ² + Q ² ) from the I component data and Q component data of the discriminated I component signal component and Q component signal component; Means for searching for a first maximum value slot and a second maximum value slot from among the first and second maximum value slots, and performing the search every n (n = 2 or more) frames; A slot that is a frequency that can resonate with a ground element in the same slot for n consecutive times (n = 2 or more) is determined as a ground element frequency.

  As described above, according to the present invention, it is possible to reduce the size of the apparatus by omitting a plurality of oscillators and filters by using a slot having a frequency that can resonate with the ground element and a transmission signal of a frame signal. . By simultaneously outputting the frame signal and the reference signal in time series in the DDS circuit and performing discrimination by synchronous detection in the quadrature detection circuit, the noise resistance of the discrimination circuit is improved. Further, by adopting a configuration in which the fluctuation characteristics are canceled by the offset circuit, it is possible to realize no adjustment of the apparatus.

  Further, based on the configuration in which the amplitude spectrum is calculated from the IQ value and processed and determined many times in time series, the first embodiment compares the value twice the weighted average spectrum of 4 frames with the spectrum value of each slot. By determining the same slot four times consecutively as the ground element detection frequency many times, the reliability of the determination of the ground element frequency is improved, and the ground element frequency determination with improved noise tolerance is possible.

  In the second embodiment, the maximum frequency slot is determined as the detection frequency by combining (multiplying) the spectrum of 4 frames, and thus the ground child frequency can be determined with high reliability.

  In the third embodiment, the first maximum value slot and the second maximum value slot are searched from the frame, and the slot having the maximum value continuously in the four frames is determined as the detection frequency.

  Accordingly, there are provided a ground element detection apparatus and a ground element frequency determination method that reduce the size of the apparatus, eliminate the need for initial adjustment, improve noise resistance, and improve the reliability of ground element frequency determination.

  It should be noted that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Example]
FIG. 7 is a diagram for explaining a first embodiment of the present invention. In the ground element detection device 100, the transmission signal control unit 110 is connected to the vehicle upper element 1, and the vehicle upper element 1 is connected to the input signal processing unit 120. The input signal processing unit 120 is further connected to the determination processing unit 140. The Sequencer 150 is connected to the external device control unit 180 via the CPU 170.

  FIG. 5 is a configuration diagram of the transmission signal control unit 110. The transmission signal control unit 110 is a DDS circuit 111 configured by a generally known MEMORY and a D / A converter. That is, the output of the Waveform ROM 113 is connected to the D / A converter 114, and is connected to the amplifier 112 through the LPF 115. An output signal from the amplifier 112 is supplied to the vehicle upper part 1 in FIG. 7 as a transmission signal 300 which is an output of the transmission signal control unit 110.

  FIG. 6A is a diagram for explaining the bit allocation of the Waveform ROM 113. In the Waveform ROM 113, bit portions from bit 0 to bit 9 forming the transmission signal 300 and bit portions from bit 12 to bit 15 forming the reference signal 301 used for quadrature detection are allocated.

  FIG. 6B is a diagram for explaining the memory space of the Waveform ROM 113. A plurality of different frequencies, which will be described later, are used as variable parameters, and the waveform data configuration is such that the frequency of the transmission signal 300 transmitted from the transmission signal control unit 110 is arranged.

Here, the configuration of the transmission signal 300 will be further described in detail.
3 and 4 are diagrams for explaining the configuration of the transmission signal 300, respectively. That is, the transmission signal 300 is configured with a slot as a minimum unit as shown in FIG. Furthermore, as shown in FIG. 4, the slots gather to constitute a frame signal.

  FIG. 8 is a diagram for explaining the configuration of the transmission signal 300 in more detail. The frame signal includes a dummy frequency of 130 KHz (f1), 90 KHz (d3), 108.5 KHz (f3), 140 KHz (d1), 123 KHz (f2), 85 KHz (d4), 103 KHz (f4), 98 KHz (d2). , Composed of eight slot signals. For the dummy frequencies 140 KHz (d1), 98 KHz (d2), 90 KHz (d3), and 85 KHz (d4), the amplitude is set to 0 so that the transmission power of each transmission signal 300 becomes 0. The amplitude difference between 103 KHz (f4) and 108.5 KHz (f3), and the amplitude difference between 123 KHz (f2) and 130 KHz (f1) are 6 dB, respectively. The frame signal waveform data is composed by superimposing the slot signal and the constant transmission oscillation frequency signal by combining the slot signal with the constant transmission oscillation frequency of 67 KHz and 103 KHz and storing the transmission signal data corresponding to the synthesized wave amplitude in the Waveform ROM 113. ing.

  By using the DDS circuit 111, the waveform phase can be made continuous by storing waveform data in which the waveform amplitude is continuous at the boundary between slots. Therefore, harmonic distortion is not generated in the transmission signal 300, and the discrimination performance of the ground element detection circuit is not deteriorated by the harmonic distortion unlike the conventional variable frequency ATS apparatus shown in FIG. . Also, since there is only one signal source, a plurality of signal oscillators, BPFs, and determination circuits are not required as in the prior art, which is effective in reducing the size of the apparatus.

  The dummy frequency refers to the slot frequency of the transmission signal 300 set to a frequency other than the ground frequency. Increasing the number of parameters of amplitude spectrum data for calculating a weighted average spectrum, which will be described later, has an effect of preventing erroneous determination due to noise. The reason why the amplitude difference is set to 6 dB is that the resonance characteristic due to the electromagnetic coupling of the actual ground element 10 is not a Q value of 6 dB / oct. This is because there is an effect of increasing the accuracy of determination by providing.

  Further, by arranging the dummy frequencies (d1 to d4) and the ground child frequencies (f1 to f4) alternately, the frequency arrangement has an effect of reducing erroneous determination of the ground child frequency due to noise due to the dispersion effect.

  A clock signal is supplied from the sequencer 150 to the transmission signal control unit 110, and a frame signal is transmitted from the DDS circuit 111 and a reference signal 301 is output simultaneously. The reference signal 301 is supplied to two quadrature detectors 130 to be described later, and includes a pair of orthogonal I reference signals and Q reference signals. The reference signal 301 is a rectangular wave signal whose amplitude is determined by the data of bits 12 to 15 of the Waveform ROM 113 as shown in FIG. In order to synchronize a reference signal 301 and an input signal to two quadrature detection circuits 130 described later, reference signal data is output from an address that takes into account the delay of the signal path from the DSS circuit 111 to the quadrature detector 130. As described above, the reference signal data is written in the Waveform ROM 113. There are two types of reference signals 301, that is, a reference signal used for detecting a ground element and a reference signal used for detecting a transmission oscillation frequency at all times, and each is output from the DSS circuit 111.

  The frame signal generated by the D / A converter 114 using the waveform data of the Waveform ROM 113 passes through the LPF 115 and is transmitted to the vehicle upper element 1 as a transmission signal 300 having a required power level by the amplifier 112. The time t of each slot is about 220 us, and the frame time is about 1.8 ms. The transmission signal 300 and the reference signal 301 configured as a frame signal are output from the DDS circuit 111 repeatedly.

  Next, the input signal processing unit 120 will be described below. As already described, the transmission signal 300 is configured as a frame signal shown in FIG. 4 with the slot shown in FIG. When there is no ground element 10, changes in the amplitude and phase of the transmission signal 300 due to the degree of coupling of the vehicle element 1 and the connection cable length appear on the secondary side of the vehicle element 1 and are input to the input signal processing unit 120. When the ground element 10 is electromagnetically coupled to one of the frequencies of the transmission signal 300, an amplitude and phase signal corresponding to the degree of coupling between the vehicle element 1 and the ground element 10 appears on the secondary side of the vehicle element 1. The amplitude changes according to the Q value of the ground element 10 and the distance between the vehicle upper element 1 and the ground element 10.

  Here, the signal from the secondary side of the vehicle upper arm 1 is input via the amplifier 121 with a limiter so that excessive maximum amplitude or surge is not input to the input signal processing unit 120 and is destroyed. Connected to the amplifier 122. The differential amplifier 122 generates forward and inversion signals, passes through the BPF 123, and is input to the quadrature detection circuit 130. Here, the quadrature detection circuit 130 will be described in detail.

  FIG. 9 shows a configuration of the quadrature detection circuit 130 in the input signal control unit 120. The input signal to the quadrature detection circuit 130 and the reference signal 301 from the DDS circuit 111 are synchronized. By turning the TG circuit on / off by the reference signal 301, the in-phase I component signal and the quadrature Q are output as a detection output. A component signal is output. The two reference signals 301 input to the quadrature detection circuit 130, that is, the I reference signal and the Q reference signal are orthogonal to each other, and are synchronized with the input signal to the input signal processing unit 120. Even slight changes in amplitude and phase due to the coupling of the upper element 1 and the ground element 10 can be detected. By synchronous detection with the reference signal 301, a large number of detection circuits and BPFs are not required as in the prior art of FIG.

  In addition, disturbance noise entering the vehicle upper unit 1 and the ground unit 10 is also detected by orthogonal detection with the reference signal 301, so that noise outside the band of the transmission center frequency ± 2.2 KHz of the transmission signal 300 is output from the LPF 124. It becomes an out-of-band signal. Therefore, disturbance noise is removed by the LPF 124, and noise resistance is improved. The quadrature detection circuit 130 is arranged on the circuit side for detecting the frequency that can be coupled to the ground unit 10 and on the circuit side for detecting the constant transmission oscillation frequency. The I component signal and the Q component signal of the quadrature detection circuit 130 for detecting the ground element 10 pass through a narrow band LPF 124 having a cutoff frequency fc = 2.2 kHz, respectively, and are sampled by the A / D converter 125. I component data and Q component data are output from the A / D converter 125 and input to the vehicle upper offset circuit 126.

  On the other hand, the output signal of the quadrature detector 130 that detects the constant transmission oscillation frequency passes through the LPF 131 having the cutoff frequency fc = 100 Hz, and is determined by the magnitude of the signal level of the constant transmission oscillation frequency detection circuit 132. The constant transmission oscillation frequency detection circuit 132 operates when an input signal to the input signal processing unit 120 cannot be detected due to an abnormality such as cable disconnection, and outputs the disappearance information of the input signal to the external control device 180.

  Next, the operation of the vehicle upper offset circuit 126 will be described below. The vehicle upper offset circuit 126 uses the data detected by the electromagnetic coupling with the ground child 10 to obtain basic fluctuation data based on the cable length that changes depending on the coupling degree of the vehicle upper 1 and the mounting position of the vehicle upper 1 on the train vehicle. This is a circuit that realizes no adjustment of the ground element detection device 100 by subtraction. Therefore, first, the reference SW 190 is turned on in the absence of the ground element 10 and the ground element detection device 100 is activated, so that the I and Q signals of 4 frames (32 slots) input to the vehicle element offset circuit 126 are displayed. Amplitude data is written into the EEPROM 160. Thereafter, until the data is written again in the EEPROM 160, basic fluctuation data based on the coupling degree of the vehicle upper member 10 and the cable length is stored in the EEPROM 160. This operation of turning on the Reference SW 190 is executed when the vehicle upper member 10, the cable connecting the vehicle upper child 10 and the ground child detecting device 1 is replaced or newly installed.

  When the reference SW 190 is turned off after the writing is completed and the ground detector 100 is restarted, the average value is calculated for each slot by the sequencer 150 from the I and Q amplitude data for four frames stored in the EEPROM 160. Then, 1 frame length (8 sets) of I and Q average value data is written in the Reference Memory 128 for each slot. Thereafter, the I and Q average value data stored in the Reference MEMORY 128 is subtracted in synchronization with the input signal, and the basic fluctuation characteristics depending on the vehicle arm 1 and the cable length are offset. It is possible to detect the electromagnetically coupled signal.

  Also, IQ amplitude data input from the A / D converter 125 to the vehicle upper offset circuit 126 is always written in the DPRAM 191 and, if necessary, the IQ amplitude data is operated by an operation from the external device (PC) 183. ) Can be output to 183. The data stored in the EEPROM 160 can be output to the external device (PC) 183 in the same manner.

Using the IQ amplitude data subtracted in the above-described vehicle upper offset circuit 126 as an address, data in the Magnet ROM 127 is read. The Magnitude ROM 127 stores the calculation result of the amplitude spectrum √ (I ² + Q ² ) of the IQ amplitude data, and the ground element 10 can be detected by any change in the in-phase component signal (I value) and the quadrature component signal (Q value). It is possible to detect the fluctuation of the transmission signal 300 due to the combination with

  The amplitude spectrum data output from the Magnitude ROM 127 of the input signal processing unit 120 is input to the determination processing unit 140. Next, the operation of the determination processing unit 140 will be described in detail.

  FIG. 10 shows the ground child coupling frequency determination process of the first embodiment. The amplitude spectrum data input to the determination processing unit 140 is processed, processed, and determined as follows. That is, the slot power spectrum calculation unit 141 integrates the amplitude spectrum data of each slot and stores and holds it as power spectrum data. Further, the frame average power spectrum calculation circuit 142 adds the power spectrum data of each slot described above to calculate a four-frame weighted average spectrum AVE. The determination circuit 143 compares the value twice the weighted average spectrum AVE with the power spectrum data stored in each slot, and finds a slot larger than the value twice the weighted average spectrum AVE from each frame. Next, when the searched slot is the same slot for four consecutive frames, the majority decision circuit 144 decides the frequency corresponding to the slot as the ground frequency.

  If there are two or more slots having a value equal to or greater than twice the weighted average spectrum AVE, a slot having a large power spectrum value and a ground child frequency is determined as the ground child frequency. If many slots are larger than twice the weighted average spectrum AVE, all slots are determined as noise. Even when a value twice the weighted average spectrum AVE is equal to or less than a certain threshold value, it is determined as noise. The threshold value is a power spectrum value due to coupling with the ground unit 10 and is a residual noise of the entire system including fluctuations in electromagnetic coupling state due to structures such as rails around the vehicle unit 1 and the ground unit 10. This is a power spectrum value for determining whether or not there is a value greater than twice the weighted average spectrum AVE. That is, it means a minimum value that can be determined as a power spectrum due to the coupling with the ground unit 10. Here, the threshold value is a power spectrum value when the determination condition is the worst, such as when the distance between the vehicle upper element 1 and the ground element 10 becomes the maximum and the signal level decreases.

  Also, slots larger than the weighted average spectrum AVE may occur irregularly due to disturbance noise or the like. Noise is generated in a short period, but is distributed to slots apart from each other on the time frame of 4 frames. If the slot of the dummy frequency signal is inserted in the frame signal in a timely manner, the dispersion effect is further enhanced. Since the amplitude and phase of the noise signal changes only in a specific slot mixed with noise, there is a clear difference between the behavior of the noise spectrum and the behavior of the original amplitude spectrum detected by combining with the ground element. Can be discriminated. As described above, the noise resistance and reliability of the ground child frequency determination are improved by performing the determination many times using the spectrum obtained by weighted averaging of the ground child frequencies over four frames as a reference.

  The sequencer 150 performs timing control of signal transmission / reception between the transmission signal 300 from the transmission signal control unit 110 and the input signal processing unit 129 and the determination processing unit 140. The transmission signal control unit 110 is controlled to repeatedly transmit a frame signal, and the input signal processing unit 120 is always controlled to transmit a reference signal at a transmission oscillation frequency, and to receive detection interrupts due to disconnection, Child offset data transmission / reception control, control of writing IQ amplitude data after quadrature detection to DPRAM 191, and determination processing unit 140 are input with slot / frame timing control and majority determination result.

  The CPU 170 performs an interface with an external device (PC) 183. Data output to an external device (PC) 183, transmission of vehicle top offset data, control of start / stop of detection operation of the ground unit detection device 100, and external notification of detection information are performed.

  The external device control unit 180 includes an LED group 181 and an external device (PC) 183. The external device (PC) 183 is connected to the CPU 170 via the RS232C interface 182. The external device control unit 180 is equipped with a control program for the ground unit detection device 100, starts / stops the detection operation of the ground unit detection device 100, stores and browses I, Q amplitude data, vehicle top unit offset data, ground unit It has a function to display time series display of detection frequency, spectrum display, and ground-son detection frequency. The LED 181 displays a detection frequency, an abnormality, an operation state, and the like.

  In general, the vehicle upper 1 is attached to a train that moves at a high speed, and travels at a maximum speed of 160 km / hour on a conventional line. If the ground element 10 is installed in the middle of the rail, the distance between the ground element 10 and the vehicle element 1 is 100 to 260 mm, the response distance is 400 mm, and the time of the frame signal is 1.8 ms, the minimum is 5 There is time to receive one frame. Since the ground element detecting device according to the present invention is synchronous and the coupling with the ground element is asynchronous, it is necessary to prevent a lack of determination many times due to the coupling timing. The reception sensitivity can be set by setting the transmission power of the transmission signal 300 and the gain of the differential amplifier 122 so that the response distance corresponds to five frame times.

  Compared with the conventional technique, the adjustment of the ground detector is unnecessary, and determination is made from data from the frame many times, and at the same time, noise tolerance can be improved and reliability can be improved.

  In this embodiment, the case of the signal configuration of the transmission signal 300 in which one frame is composed of eight slots has been described. However, the maximum vehicle speed to be applied, the distance between the vehicle upper element 1 and the ground element 10, the response Depending on the distance, it can be applied to other signal configurations. Also, the ground frequency and the dummy frequency can be changed. In this embodiment, the weighted average spectrum is calculated from the I and Q amplitude data for four frames, but can be changed according to the frame signal configuration method.

  FIG. 11 is a diagram for explaining a second embodiment of the present invention. In the ground child detection apparatus 100, the structure of the determination process part 140 is shown. Other configurations than the determination processing unit 140 are the same as those in the first embodiment.

FIG. 12 is a diagram illustrating an example of determination processing according to the second embodiment. To the determination processing unit 140, amplitude spectrum data of √ (I ² + Q ² ) calculated by the Magnitude ROM 127 of the input signal processing unit 120 is input. A multiplication spectrum is obtained by multiplying four amplitude spectrum data of the same slot for every four frames in time series in the synthesis circuit 145. Here, when the amplitude spectrum data is a value equal to or smaller than the threshold value, the amplitude spectrum data is multiplied by zero. Even when noise is input to an unspecified slot, if the same slot of another frame is amplitude spectrum data equal to or less than the threshold value, 0 is multiplied. As a result, the multiplication spectrum becomes 0, so that the noise can be canceled. In the determination circuit 143, the frequency of the slot which is the highest value among the multiplication spectrum results and can be combined with the ground unit 10 is determined as the ground unit frequency. The threshold value in this case is the amplitude spectrum when the relationship between the vehicle upper element 1 and the ground element 10 is the worst. In the above embodiment, the process is performed every four frames, but can be changed according to the method of configuring the slot and frame signals.

  FIG. 13 is a diagram illustrating an example of determination processing according to the third embodiment. The configuration of the ground unit detection apparatus 100 is the same.

  The power spectrum data from the Magnitude ROM 127 calculated by the input signal processing unit 120 is input, and the first maximum value slot and the second maximum value slot are searched from the frame data. This is performed every four frames, and when either the first or second slot is a frequency that can resonate with the ground unit in the same slot for four consecutive times, this slot is determined as the ground unit frequency. is there. In this embodiment, the determination is made every four frames, but can be changed depending on the slot and frame signal configuration.

It is a block diagram of the conventional variable speed ATS apparatus. It is the block diagram which improved the conventional variable speed type | formula ATS apparatus. It is a figure which shows the minimum structural unit of the transmission signal of this invention. It is a figure which shows the frame structure of the transmission signal of this invention. It is a figure which shows the structure of the transmission signal control part of this invention. (A) is a figure which shows bit allocation of Waveform ROM which is a memory element of a DDS circuit, (b) is a figure which shows the structure of Waveform ROM of the memory element of the DDS circuit of a present Example. 1 is a configuration diagram of Example 1. FIG. It is a figure which shows the transmission signal of Example 1. FIG. 1 is a diagram illustrating a quadrature detection circuit according to a first embodiment. It is a figure which shows the determination process of Example 1. FIG. 6 is a diagram illustrating a configuration of Example 2. FIG. It is a figure which shows the determination process of Example 2. FIG. It is a figure which shows the determination process of Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car top 10 Ground unit 11 Amplifier 12 Oscillator 13a, 13b Signal selection BPF
21a to 21d signal oscillator 22 signal adder 24 amplifier 25a to 25d signal selection BPF
DESCRIPTION OF SYMBOLS 100 Ground unit detection apparatus 110 Transmission signal control part 111 DDS circuit 112 Amplifier 113 Waveform ROM
114 D / A converter 115 LPF
120 Input Signal Control Unit 121 Amplifier with Limiter 122 Differential Amplifier 123 BPF
124 LPF fc = 2.2KHz
125 A / D converter 126 Vehicle upper offset circuit 127 Magnet ROM
128 Reference Memory
130 Quadrature detection circuit 131 LPF fc = 100 Hz
132 Constant Transmission Oscillation Frequency Detection Circuit 140 Determination Processing Unit 141 Slot Power Spectrum Calculation Circuit 142 Frame Average Power Spectrum Calculation Circuit 143 Determination Circuit 144 Majority Determination Circuit 145 Synthesis Circuit 146 Average Processing Circuit 150 Sequencer
160 EEPROM
170 CPU
180 External device control unit 181 LED group 182 RS232C control circuit 183 External device (PC)
190 Reference SW
191 DPRAM
192 OSC
300 Transmission signal 301 Reference signal

Claims (8)

A ground unit detection device that detects electromagnetic coupling between a vehicle top unit and a ground unit to determine the presence or absence of a ground unit frequency,
Means for generating a signal of constant amplitude at one of the ground child frequencies that can be combined with the ground child;
Means for selecting a plurality of the signals and generating frame signals continuously arranged in time series,
A ground unit detection device, wherein the frame signal is transmitted from a vehicle top unit to detect electromagnetic coupling with the ground unit. A ground unit detection device that detects electromagnetic coupling between a vehicle top unit and a ground unit to determine the presence or absence of a ground unit frequency,
Means for storing signal data for generating a signal having a constant amplitude at one of the ground child frequencies that can be combined with the ground child;
Means for sequentially reading out the signal data stored in the storage means and generating frame signals arranged continuously in time series;
A ground unit detection apparatus, wherein a signal having a constant amplitude at one frequency is used as a slot of a minimum signal unit, and the frame signal is transmitted from a vehicle unit to detect electromagnetic coupling with the ground unit. Means for storing reference signal data for generating a reference signal in an orthogonal relationship synchronized with the signal;
Means for generating the reference signal by sequentially reading the reference signal data stored in the storage means;
3. The ground element detection apparatus according to claim 2, wherein the frame signal electromagnetically coupled to the ground element and the reference signal are subjected to quadrature detection. Means for orthogonally detecting the frame signal and the reference signal to discriminate and output an I component signal and a Q component signal;
Means for storing a plurality of frames of amplitude data of the I component signal and amplitude data of the Q component signal for each slot in the absence of a ground element;
Means for reading the stored amplitude data, calculating average value data for a plurality of frames for each of I component data and Q component data, and storing the average value data;
The ground unit detecting device according to claim 3, further comprising means for successively subtracting the stored average value data from the I component data and the Q component data. Means for sequentially calculating an amplitude spectrum value √ (I ² + Q ² ) from the discriminated I component signal, the I component data of the Q component signal, and the Q component data;
Means for integrating the amplitude spectrum value for each slot and storing the integrated value;
Means for calculating an average value of a power spectrum from the integrated values of a plurality of frames;
5. The ground unit detection device according to claim 4, further comprising means for comparing the average value of the power spectrum with the stored integral value of the slot.   The slot corresponding to the frequency that is larger than the average value of the power spectrum and can be combined with the ground element is determined many times, and when it is the same continuously n times (n = 2 or more), it is determined as the ground element coupling frequency, When there are two slots larger than the power spectrum average value, a slot having a large absolute value is determined as a ground-son coupling frequency, and when there are three or more slots larger than the power spectrum average value and the power spectrum average value is a threshold value. 6. The ground element detection device according to claim 5, wherein if it is below, it is determined as noise. Means for sequentially calculating an amplitude spectrum value √ (I ² + Q ² ) from the I component data and Q component data of the discriminated I component signal and Q component signal;
Means for weighting and synthesizing the amplitude spectrum value equal to or less than a threshold value with n (n = 2 or more) frames.
5. The ground element detection apparatus according to claim 4, wherein a slot corresponding to a frequency that can be combined with a ground element is the largest value among the weighted values and is determined as a combined frequency with the ground element. Means for successively calculating an amplitude spectrum value √ (I ² + Q ² ) from the I component data and Q component data of the discriminated I component signal component and Q component signal component;
Means for searching for a first maximum value slot and a second maximum value slot from the frame;
The search is performed every n (n = 2 or more) frames, and either the first or the second slot is a frequency that can resonate with the ground element in the same slot for n times (n = 2 or more) continuously. The ground element detecting device according to claim 4, wherein the ground element frequency is determined as a ground element frequency.

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