WO2020252881A1 - Axle counting system - Google Patents

Abstract

An axle counting system, comprising: a shaping module (22); a waveform detection module (82); a determining module (83); and an interference signal filtering module (84). The shaping module (22) which is connected to sensing units (111, 112, 121, 122) of wheel sensors (11, 12) is configured to shape sensing signals to generate shaping signals, waveform characteristic data is extracted according to two pulse signals of the shaping signals, and whether a first pulse signal and a second pulse signal satisfy an axle counting signal feature is determined according to the waveform characteristic data to identify an abnormal interference pulse signal. The axle counting accuracy is improved.

Description

Axle counting system Technical field

The invention relates to the technical field of railway signals, in particular to an axle counting system.

Background technique

Railway transportation has become our main long-distance transportation tool. Therefore, the railway transportation process requires precise monitoring. In the railway transportation system, the use status of the section must be monitored accurately in real time. When the occupancy status of the section is detected, the section can be closed to prevent other trains from entering the running section. How can the section start the section when it is idle? Use of segments. In order to check the occupancy/vacancy status of the track section, an axle counting system is introduced. By checking the number of axles between the axle counting points in the section, it is judged whether there is car occupancy in the section.

The principle of the axle counting system is to set up two axle counting points in the interval, and set a wheel sensor on the track of each axle counting point. The sensor signal of the wheel sensor is used to sense whether there is a car passing by, and then the number of wheels in the interval is counted. Judge the occupancy of the section, when the train is occupied, the train moves in, and when the section is free, the running train leaves.

During the operation of the axle counting system, due to external interference, abnormal pulses are often generated. The continuous waveform formed by the train passing through the sensor is shown in Figure 18. The waveforms at the two ends in Figure 18 are generated by the induction plate, and the two waveforms in the middle are The interference waveform of the charging blade. The above situation causes the output of the axle counting equipment to be abnormally occupied, especially in the signal control system of the tram. The train is powered by the battery. When the train stays at the station, the battery is charged, and the charging blade interferes with the axle counting sensor , The probability of forming an abnormal pulse is very high.

In view of this, to overcome the above-mentioned defects in the prior art, a new axle counting system is provided to analyze the waveform difference formed by the induction plate and the charging blade by processing the shaft pulse signal and interference signal, and then filter the charging blade And other similar interference signals, correctly identify shaft pulses and interference pulses.

In view of this, overcoming the above-mentioned shortcomings in the prior art and providing a new axle counting system has become an urgent technical problem in this field.

Summary of the invention

The purpose of the present invention is to provide an axle counting system in view of the above-mentioned defects of the prior art.

The purpose of the present invention can be achieved through the following technical measures:

The present invention provides an axle counting system, which includes:

The shaping module connected to the wheel sensor is configured to generate shaping signals according to the sensing signals of the wheel sensors, and the shaping signals include a first pulse signal and a second pulse signal;

The waveform detection module is used to generate waveform characteristic data according to the first pulse signal and the second pulse signal of the shaping signal;

A judging module, judging whether the first pulse signal and the second pulse signal meet a preset condition according to the waveform characteristic data;

The interference signal filtering module, when the judgment result is yes, extract the first pulse signal and the second pulse signal as effective shaping signals and output to the processing module; otherwise, the first pulse signal and the second pulse signal Filter as an interference signal.

Preferably, the waveform characteristic data includes the pulse widths of the first pulse signal and the second pulse signal; the preset condition is that the pulse width of the first pulse signal and the pulse width of the second pulse signal are both greater than the fourth preset threshold ；

Or, the waveform characteristic data includes the overlap range of the first pulse signal and the second pulse signal; the preset condition is that the overlap range of the first pulse signal and the second pulse signal is greater than the second time threshold;

Or, the waveform characteristic data includes the overlap range of the first pulse signal and the second pulse signal, and the pulse width of the first pulse signal and the second pulse signal; the preset condition is the first pulse signal and the second pulse signal The overlap range of is greater than the second time threshold, and the pulse width of the first pulse signal and the pulse width of the second pulse signal are both greater than the fourth preset threshold.

Preferably, the shaping module includes: a shaping unit, a first output port, and a second output port that are arranged in one-to-one correspondence with the sensing unit of the wheel sensor, one end of the shaping unit is connected to the sensing unit, and the other end Are respectively connected to the first output port and the second output port, the shaping unit is used to generate a shaping signal or a fault signal according to the sensing signal of the wheel sensor, the shaping signal is output from the first output port, and the The fault signal is output from the second output port;

The axle counting system further includes: a processing module connected to the shaping module, the processing module includes: two processing units, each processing unit is connected to the first output port, and the two processing units are connected in communication The processing unit is configured to detect the waveform of the shaping signal, and when the two processing units detect that the shaping signal conforms to the shaft pulse rule, output the shaping signal as the shaft pulse signal; when the two processing units When it is detected that the pulse width of the shaping signal is greater than the second preset threshold, outputting the first occupation signal; and

An isolated output module respectively connected to the second output port of the processing module and the shaping module, and the isolated output module is used to output the fault signal to the axle counter and output the axle pulse signal to the axle counter Board, and output the first occupancy signal to the output board;

The first output port of the shaping module is connected to the waveform detection module, and each processing unit of the processing module is connected to the interference signal filtering module.

Preferably, each shaping unit includes: four voltage comparison circuits, each of the voltage comparison circuits is provided with a voltage threshold, each of the voltage comparison circuits includes a first output terminal and a second output terminal, and the four voltage comparison circuits The voltage comparison circuit is sequentially connected through the first output terminal, and the second output terminals are all connected to the processing module,

The first voltage comparison circuit receives the sensing signal, and when the voltage of the sensing signal is higher than the first threshold voltage, it outputs a fault signal and the isolation output module; otherwise, it outputs the sensing signal Voltage to the second voltage comparison circuit; when the voltage of the sensing signal is lower than the second threshold voltage, output the fault signal to the isolation output module, otherwise, output the voltage of the sensing signal to the third voltage Comparing circuit; when the voltage of the sensing signal is lower than the third threshold voltage, the output is idle to the processing module, otherwise, the voltage of the sensing signal is output to the fourth voltage comparing circuit; when the sensing signal is The voltage is higher than the fourth threshold voltage, and the occupied pulse is output to the processing module,

Wherein, the first threshold voltage is higher than the fourth threshold voltage, the fourth threshold voltage is higher than the third threshold voltage, and the third threshold voltage is higher than the second threshold voltage.

Preferably, the first voltage comparison circuit is provided with the first threshold voltage 9.95V for detecting the disconnection state of the sensing unit;

The second voltage comparison circuit is provided with the second threshold voltage 5.04V, which is used to detect the off-rail state of the sensing unit;

The third voltage comparison circuit is provided with the third threshold voltage 8.25V, which is used to detect the idle state of the sensing unit;

The fourth voltage comparison circuit is provided with the fourth threshold voltage 8.45V for detecting the occupancy state of the sensing unit.

Preferably, the axle counting system further includes: a compensation device arranged between the wheel sensor and the shaping module for detecting the first moment when the first wheel induction signal has a pulse and the second wheel induction signal has a pulse At the second time, the time difference between the first time and the second time is determined; according to the time difference, a compensation value is determined according to a preset first compensation strategy to compensate for the pulse width of the second wheel induction signal.

Preferably, the first compensation strategy is: when the time difference is less than or equal to the first time threshold, the compensation value is 2×the time difference; when the time difference is greater than the first time threshold, the compensation value is the second time value.

Preferably, the compensation device is also used to obtain the pulse width of the second wheel induction signal; when the pulse width of the second wheel induction signal is less than or equal to a third preset threshold, the compensation of the second wheel induction signal The pulse width is compensated; when the pulse width of the second wheel induction signal is greater than the third preset threshold, the pulse width of the second wheel induction signal is not compensated.

Preferably, the isolated output module includes a first photocoupler, a second photocoupler, and a third photocoupler, and the first photocoupler is connected to the axle counter board for isolating and outputting the axle pulse Signal; the second photocoupler is connected to the axle counter board for isolating and outputting the fault signal; the third photocoupler is connected to the output board for isolating and outputting the occupancy signal.

Preferably, the axle counting system further includes:

The axle counter is used to identify the running direction of the train and calculate the number of wheels according to the axle counting signals of the wheel sensors, and to judge whether the section is occupied or free according to the number of wheels of the two wheel sensors. When the judgment result is occupied, the second occupancy signal is output , When the judgment result is idle, output an idle signal, where the axle counting signal of the wheel sensor includes the axle pulse signals corresponding to the two sensing units;

The output board is used to control the closing or opening of the section according to the first occupation signal, the second occupation signal or the idle signal;

And/or, an internal power supply module connected to the four sensing units for providing a constant current source for the sensing units;

And/or, a zero reset board, which is connected to the axle counter board and the output board;

And/or, a power supply board, including a first power supply module and a second power supply module, the first power supply module provides 12V direct current for the amplifying board, the axle counter board, the zero reset board and the output board, The second power supply module provides 24V direct current for the axle counter board, the zero reset board and the output board.

In the axle counting system of the present invention, a shaping module connected to the induction unit of the wheel sensor is arranged to shape the sensing signal to generate a shaping signal, extract the waveform characteristic data according to the two pulse signals of the shaping signal, and then judge according to the waveform characteristic data Whether the first pulse signal and the second pulse signal meet the characteristics of axle counting signals to identify abnormal interference pulse signals and improve axle counting accuracy.

Description of the drawings

Fig. 1 is a schematic structural diagram of an axle counting system according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of the structure of the magnifying plate in the axle counting system of the embodiment of the present invention.

3 is a schematic diagram of the structure of the magnifying plate shaping module in the axle counting system of the embodiment of the present invention.

4 is a schematic diagram of the structure of the shaping unit of the shaping module in the axle counting system of the embodiment of the present invention.

Fig. 5 is a schematic structural diagram of the isolated output module of the amplifying board in the axle counting system of the embodiment of the present invention.

Fig. 6 is a schematic diagram of the internal power module structure of the amplifier board in the axle counting system of the embodiment of the present invention.

Fig. 7 is a schematic diagram of the structure of the axle counter plate in the axle counter system of the embodiment of the present invention.

Fig. 8 is a schematic diagram of the structure of the output plate in the axle counting system of the embodiment of the present invention.

Fig. 9 is a schematic diagram of the formation of the sensor signal of the wheel sensor in the present invention.

Fig. 10 is a waveform acquisition diagram of the sensor signal of the wheel sensor in the present invention when the axle is lost.

Fig. 11 is a pulse diagram when the sensor signal of the wheel sensor loses axle in the present invention.

Fig. 12 is a schematic structural diagram of an axle counting system according to a preferred embodiment of the present invention.

Fig. 13 is a structural block diagram of a compensation device in an axle counting system according to an embodiment of the present invention.

Fig. 14 is a schematic diagram of the signal pulse width compensation of the wheel sensor in the present invention.

Fig. 15 is a structural block diagram of the first preferred embodiment of the compensation device in the axle counting system of the embodiment of the present invention.

Fig. 16 is a schematic diagram of the axle pulse formed when the wheel passes the wheel sensor and then reverses in the present invention.

Fig. 17 is a structural block diagram of a second preferred embodiment of the compensation device in the axle counting system of the embodiment of the present invention.

Fig. 18 is a waveform acquisition diagram when the signal of the wheel sensor in the present invention has interference.

Fig. 19 is a structural block diagram of a filter device in an axle counting system according to an embodiment of the present invention.

Fig. 20 is a waveform diagram of the interference signal of the wheel sensor in the present invention.

Fig. 21 is a waveform diagram of a signal of a wheel sensor.

[Corrected according to Rule 91 on 17.10.2019]

Detailed ways

In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention.

In order to make the description of the present disclosure more detailed and complete, the following provides an illustrative description of the embodiments and specific embodiments of the present invention; this is not the only way to implement or use the specific embodiments of the present invention. The implementation manners cover the characteristics of a number of specific embodiments and the method steps and sequences used to construct and operate these specific embodiments. However, other specific embodiments can also be used to achieve the same or equal functions and sequence of steps.

As shown in Fig. 1, Fig. 1 shows a structural diagram of an axle counting system according to an embodiment of the present invention. The axle counting system includes outdoor equipment and indoor equipment. The outdoor equipment includes wheel sensors 11 and 12 on the two axle counting track rails of the section, which are used to detect train wheels. The wheel sensors 11 and 12 include two sensing units, the sensing units 111, 112, 121, 122 respectively generate a sensor signal. The indoor equipment includes an amplifier board 2 connected with the wheel sensors 11 and 12; an axle counter board 3 connected with the amplifier board 2; an output board 4 connected with the axle counter board 3 and the amplifier board 2 respectively; and the axle counter board 3 and the output board 4 The connected zero reset board 5; the power supply board 6 used for the amplifier board 2, the axle counter board 3, the output board 4 and the zero reset board 5.

The sensor unit of the wheel sensor can generate a sensor signal according to the passing of the wheel. The sensor signal includes the first wheel sensor signal and the second wheel sensor signal respectively generated by the two sensor units. The shaping module in the amplifying board 2 senses The signal is reshaped to generate a reshaped signal or obstacle signal, and the fault signal is output to the axle counter board. The waveform of the reshaped signal is detected by the detection module to generate the first occupancy signal and the shaft pulse signal. The first occupancy signal is directly output to the output board. Eliminate the abnormal occupation of the induction unit (except for the occupation caused by the train entering the station), input the axis pulse signal generated by the normal occupation of the induction unit to the axle counter for axle counting, judge the train running direction and the section occupied or idle, and output the first Second, the occupied signal and the idle signal are sent to the output board, and the output board closes the section for use according to the second occupied signal, prohibits the train from entering the station, and opens the section for use according to the idle signal, allowing the train to enter the station. The axle counting system of the present invention can react sensitively to the faults of the wheel sensor (including short circuit, open circuit and derailment), and can effectively eliminate the abnormal occupation of the induction unit (for example, the induction unit has sundries close to it). The normal occupancy is calculated to determine the occupancy and vacancy of the interval.

As shown in Fig. 2, Fig. 2 both show the structure diagram of the enlarged board of the embodiment of the present invention. The amplifying board 2 includes a shaping module 22, as shown in FIG. 3, which is a structural diagram of the shaping module of the amplifying board according to the embodiment of the present invention. The shaping module 22 includes shaping units 221-224 connected to the sensing units 111, 112, 121, 122 in one-to-one correspondence, a first output port 225 and a second output port 226, a processing module 23 connected to the first output port 225, and The isolated output module 25 connected to the second output port 226 and the processing module 23, an internal power module 24 for supplying power to the sensing units 111, 112, 121, 122; and a prompt module 21 for detecting whether the working state of the amplifier board is normal .

Among them, each shaping unit includes a voltage comparison circuit 2201-2204, the first, second, and third voltage comparison circuits include a first output terminal A and a second output terminal B, and the fourth voltage comparison circuit includes a first output terminal A. . As shown in Fig. 4, Fig. 4 shows a structural diagram of an enlarged plate shaping unit according to an embodiment of the present invention. The shaping unit includes a first voltage comparison circuit 2201, a second voltage comparison circuit 2202, a third voltage comparison circuit 2203, and a fourth voltage comparison circuit 2204 that are sequentially connected through a second output terminal B. The first output terminal A is used to output the Fault signal and shaping signal.

The first voltage comparison circuit 2201 is used to detect the disconnection status of the sensing units 111, 112, 121 and 122, and is provided with a first threshold voltage of 9.95V. When the voltage of the sensing signal is higher than the first threshold voltage of 9.95V, the An output terminal A outputs a fault signal to the isolation output module, otherwise the voltage of the sensing signal is output to the second voltage comparison circuit 2202 through the second output terminal B;

The second voltage comparison circuit 2202 is used to detect the off-rail state of the sensing units 111, 112, 121 and 122, and is provided with a second threshold voltage of 5.04V. When the voltage of the sensing signal is lower than the second threshold voltage of 5.04V, the first The output terminal A outputs the fault signal to the isolated output module, otherwise the voltage of the sensing signal is output to the third voltage comparison circuit through the second output terminal B;

The third voltage comparison circuit 2203 is used to detect the occupancy status of the sensing units 111, 112, 121, and 122, and is provided with a third threshold voltage of 8.25V. When the voltage of the sensing signal is lower than the third threshold voltage, it passes through the first output terminal A The output is idle to the detection module, otherwise the sensing signal is output to the fourth voltage comparison circuit 2204 through the second output terminal B.

The fourth voltage comparison circuit 2204 is used to detect the occupancy status of the sensing units 111, 112, 121, and 122, and is provided with a fourth threshold voltage of 8.45V. When the voltage of the sensing signal is higher than the fourth threshold voltage, it passes through the first output terminal A , Output the occupied pulse to the detection module.

In order to further determine whether the wheel sensor is in an occupied or idle state, the state of the sensing signal is determined according to the change trend of the sensing signal voltage. The voltage of the sensing signal is between 8.25V-8.45V, indicating that the sensing units 111, 112, 121, and 122 are in the state transition process. When the voltage of the sensing signal is in an upward trend, it indicates that the sensing units 111, 112, 121, and 122 are in the process of transitioning from idle to occupied state. When the voltage of the sensing signal is in a downward trend, it indicates that the sensing unit is in an occupied state. Idle state transition process.

The present invention includes 4 voltage comparison circuits in the shaping unit, and each voltage comparison circuit is provided with a threshold voltage corresponding to the threshold voltage values of 9.95V, 5.04V, 8.25V and 8.45V respectively. When the sensing unit is in a short circuit/disconnection state, the sensing signal voltage detected by the shaping unit is higher than 9.95V, and the shaping unit outputs a fault signal; when the sensing unit is off rail, the sensing signal voltage detected by the shaping unit is low At 5.04V, the shaping unit outputs a fault signal; when the sensing unit is in an idle state, the shaping unit detects that the voltage of the sensing signal is between 5.04V and 8.25V, and the shaping unit outputs idle; when the sensing unit is in an occupied state, it detects When the voltage of the sensing signal is between 8.45V and 9.95V, the shaping unit outputs a single pulse with a certain pulse width, which is an occupied pulse.

In the absence of faults (short circuit, open circuit and derailment), if there is no car in the interval, it will always output idle. If there is a car in the interval, the output will be idle-occupied-idle, which is a complete The axis pulses of, can output the shaping signal through the first output port 225 to the processing module 23 for waveform detection.

In the event of a fault (short circuit, open circuit and off-rail), the output is a fault signal. If a fault occurs, the signal can be directly output to the axle counter through the second output port 226.

The shaping module of the present invention can directly output the fault signals generated by the short circuit, open circuit and derailment of the induction unit during the axle counting process, and quickly respond to the fault, thereby ensuring the safety of the train during running.

The processing module 23 includes a processing unit 231 and a processing unit 232. The processing unit 231 and the processing unit 232 can respectively receive four groups of shaped signals, detect and identify the waveforms of the shaped signals, and generate corresponding pulse signals according to the detection results. The processing unit 231 and the processing unit 232 may both be CPUs. When the processing unit 231 and the processing unit 232 both detect that the shaping signal is a complete pulse waveform and the pulse width is less than the first preset threshold, it indicates that the induction unit is normally occupied by the train, and the shaping signal is output as an axle pulse signal (AZ signal), The axis pulse signal is a regular pulse; when the processing unit 231 and the processing unit 232 both detect that the pulse width formed by the shaping signal waveform exceeds the second preset threshold (for example, 500ms), it indicates that the sensing unit has been disturbed. Normally occupied (that is, the sensing unit is occupied by other than the train), output the first occupied signal (AK signal). There is a communication connection between the processing unit 231 and the processing unit 232, and the AZ signal or the AK signal is redundantly output only when the detection results of the two processing units are consistent.

The processing module 23 in the embodiment of the present invention adopts a two-out-of-two architecture. Through two CPUs, each CPU independently detects the waveforms of the 4 shaping signals output by the shaping unit, and independently generates 4 sets of pulse signals, and compares the two sets. Whether the CPU detection results are consistent (that is, whether they are all AZ signals or all AK signals), if so, the CPU detection results are redundantly output. The two out of two architecture can ensure the accuracy of the waveform detection process.

As shown in Fig. 5, Fig. 5 shows the structure diagram of the isolated output module of the amplifier board according to the embodiment of the present invention. The isolated output module 25 includes photocouplers 251-253. Both the photocoupler 251 and the photocoupler 252 are connected to the axle counter board 3, the photocoupler 253 is connected to the output board 4, and the axle counter board 3 is connected to the output board 4. The photocoupler 251 can output the axle pulse signal to the axle counter board 3, the photocoupler 252 can output the fault signal to the axle counter board 3, and the photocoupler 253 can output the first occupation signal to the output board 4.

As shown in Fig. 6, Fig. 6 shows the structure diagram of the internal power module of the amplifier board according to the embodiment of the present invention. The internal power supply module 24 includes an overcurrent protection fuse 240 for accessing 12VDC and a power converter 241 connected to the fuse 240; it is used to convert one 12V DC voltage into four relatively independent 12V DC voltages to ensure the generation of power supply and External 12V power supply isolation; the voltage regulator 242～245 connected to the power converter 241, model LP2951, is used to generate a 10VDC 5mA constant current source from a 12V DC voltage, and the internal power module 24 generates four independent constant current sources 246- 249: One-to-one correspondence supplies power to the sensing units 111, 112, 121, and 122.

The internal power module of the amplifying board of the present invention can provide four independent constant current sources to respectively supply the corresponding four sensing units, without being interfered by external power sources, and can reflect the impedance change of the sensing unit as a voltage change.

The amplifying board also includes a prompt module 21, which includes an LED display board, including a RUN indicator, which is always on to indicate that the amplifying board is working normally, and off to indicate that the amplifying board is not working; FUA indicator, which is always on to indicate that the amplifying board is running incorrectly, and is off. The amplifier board is fault-free; the CAN indicator light connected to the CAN bus of the amplifier board flashes to indicate that the CAN bus has data exchange, and goes out to indicate that the CAN bus function is not used; the ER indicator connected to the wheel sensor includes four one-to-one corresponding induction units 111 , 112, 121 and 122 red LED lights, always on to indicate the corresponding sensor unit, may detect: connection cable open circuit, connection cable short circuit and wheel sensor installation loose; corresponding to the sensor units 111, 112, 121 and 122 one-to-one S1.1, S1.2, S2.1, S2.2 buttons. Press the S button to simulate the occupancy of the corresponding sensor unit, and release the S button to restore the idle state of the sensor unit; and the OC indicator light connected to the sensor units 111, 112, 121, and 122. The steady light indicates that the corresponding sensor unit is occupied (sensor If sensing object, sensor open circuit, sensor short circuit, sensor looseness are detected on the upper part, the light off indicates that the corresponding sensor unit is idle. Through the prompt module, the operating status of the axle counting system can be observed intuitively. If there is an error status, it can be checked and repaired in time to avoid potential safety hazards.

As shown in Fig. 7, Fig. 7 shows the structure diagram of the axle counter plate according to the embodiment of the present invention. The axle counter 3 includes a first judgment module 31 and a second judgment module 32. The first judgment module 31 and the second judgment module 32 are connected through the output terminal C of the first judgment module 31, and the output terminal of the second judgment module 32 D Connect output board 4. The first judgment module 31 is used to identify the running direction of the train and calculate the number of wheels according to the axle counting signal of the wheel sensor, wherein the axle counting signal of the wheel sensor includes the axle pulse signals of the two sensing units of the wheel sensor; the second judgment module 32 According to the number of wheels, determine the occupancy/idle state of the section.

The axle counting board 3 axle counting process: When the first judgment module 31 receives the axle pulse signal, it compares the time sequence of the axle pulse signals (AZ signals) generated by the two sensing units of the wheel sensor to judge the direction of train movement, and The number of wheels is calculated according to the number of axle pulse signals of the wheel sensor, and then the number of wheels is output to the second judgment module 32 through the output terminal C.

The second judgment module 32 judges the occupied/idle state of the section according to the number of wheels. For example, when the number of wheels meets the preset number, the section is in the occupied state, and the output terminal D outputs the second occupancy signal to the output board 4; otherwise, the section is in the idle state and outputs the idle signal to the output board 4.

The output board 4 is connected with the amplifier board 2 and the axle counter board 3, as shown in FIG. 8, which shows the structure diagram of the output board in the embodiment of the present invention. The output board 4 can receive the first occupancy signal generated by the abnormal occupancy of the amplifying board 2, and can also receive the second occupancy signal/idle signal output by the axle counter board 3 according to the axle counter signal to determine the interval occupancy/idle state. The judgment and selection module 41 of the output board 4 can trigger the first drive 42 to close the use of the section according to the first and second occupancy signals, prohibit other trains from entering the station, or can trigger the second drive 43 to open the section according to the idle signal Normal use, allowing trains to enter the station.

In addition, the axle counting system also includes a zero-resetting board 5, which is connected to the axle-counting board 3 and the output board 4, and the data of the axle-counting board 3 and the output board 4 can be cleared through the zero-resetting board 5. For example, when the number of wheels on the axle counter output board changes to meet the conditions, the zero reset board 5 automatically clears the data on the axle counter 3 and the output board 4, or you can manually control the reset board 5 to control the axle counter 3 and output The data of board 4 can be cleared. For example, after the axle counting system has eliminated the fault, it can be cleared manually.

The axle counting system also includes a power supply board 6. The power supply board 6 is a two-in-one power supply, including two power supplies of 12VDC and 24VDC. It provides 12V DC for the amplifier board 2, the axle counting board 3, the output board 4 and the zeroing board 5, and also Provide 24V direct current for axle counter 3, output board 4 and zero reset board 5.

When the wheel crosses the wheel sensor, the two sensing units SI and SII respectively induce and form pulse signals. Since the train wheels pass through the two magnetic heads of the wheel sensor one after another, the two pulse signals must meet the characteristics of overlap in order to be considered as a valid sensor signal of the wheel sensor. As shown in Figure 9, the two pulse signals The phase relationship of represents the direction of wheel movement, and the system uses this to identify the direction of wheel movement.

In the process of listing and operation, it was found that the wheel sensor shaft was lost. The waveform formed by the wheel sensor when the axle was measured is shown in Figure 10 and Figure 11. The rising edge and falling edge of the SI pulse in the formed sensing signal waveform The SII pulse is completely covered. If the superposition rule of the two pulse signals in the sensor signal of the wheel sensor in Figure 9 is not met, the axle will be lost.

In order to prevent the occurrence of the aforementioned axle loss, please refer to FIGS. 12 and 13, the axle counting system of the embodiment of the present invention further includes a compensation device 70 arranged between the wheel sensors 11, 12 and the shaping module 22. The compensation device 70 It includes: a signal acquisition module 71, a detection calculation module 72, and a compensation module 73. The signal acquisition module 71 is used to acquire the first wheel sensing signal and the second wheel sensing signal of the two sensing units of the wheel sensor; the detection calculation module 72 uses When detecting the first moment when the pulse of the first wheel induction signal appears and the second moment when the pulse of the second wheel induction signal appears, the time difference between the first moment and the second moment is determined; the compensation module 73 is used for For the time difference, a compensation value is determined according to a preset first compensation strategy to compensate the pulse width of the second wheel induction signal.

In this embodiment, the first wheel sensing signal and the second wheel sensing signal are both pulse signals, and the two partially overlap.

Please refer to FIG. 14, the pulse widths of the first wheel sensing signal and the second wheel sensing signal are T ₁ and T ₂ , respectively, and the detection calculation module 72 is used to detect pulses of the first wheel sensing signal and the second wheel sensing signal. At the first time t ₁ and the second time t ₂ , the time difference T ₃ =t ₂ -t _{1 is} calculated.

The compensation module 73 is used for substituting the time difference T ₃ into the first compensation strategy to calculate the compensation value T ₅ , and to compensate the pulse width of the second wheel induction signal. The compensated pulse width is T ₂ +T ₅ to avoid being affected by the first wheel The induction signal is completely covered, and after compensation, it complies with the superposition rule of two pulse signals in the axle counting signal of the wheel sensor to avoid the phenomenon of axle loss.

Specifically, the first compensation strategy is: when the time difference T _{3 is} less than or equal to the first time threshold, the compensation value T ₅ is 2×the time difference T ₃ ; when the time difference T _{3 is} greater than the first time threshold, The compensation value T ₅ is the second time value.

Further, the first time threshold value is 50 milliseconds, and the second time value is 100 milliseconds.

On the basis of the above embodiments, please refer to FIG. 15, the compensation device 70 includes: a signal acquisition module 71, a detection calculation module 72, a compensation module 73, and a pulse width detection module 74, where the signal acquisition module 71 is used for Obtain the first wheel sensing signal and the second wheel sensing signal of the two sensing units of the wheel sensor; the detection calculation module 72 is used to detect the first moment when the pulse of the first wheel sensing signal appears and the second wheel sensing signal appearing The second moment of the pulse is used to determine the time difference between the first moment and the second moment; the pulse width detection module 74 is used to obtain the pulse width of the second wheel induction signal; the compensation module 73 is used to detect the second wheel induction signal When the pulse width is less than or equal to the third preset threshold, according to the time difference, the compensation value is determined according to the preset first compensation strategy to compensate the pulse width of the second wheel induction signal; when the second wheel induction signal When the pulse width of is greater than the third preset threshold, the pulse width of the second wheel induction signal is not compensated.

Please refer to Figure 16. Considering that the train has not rolled over the wheels and the train reverses, when the above situation occurs, the second wheel induction signal that appears later is also subjected to pulse width compensation, which is prone to misjudgment. Therefore, a pulse width detection module 40 is further provided in the compensation device 70 to obtain the pulse width of the second wheel induction signal before performing the pulse width compensation on the second wheel induction signal. When it is less than or equal to the third preset threshold value, it is judged that the train speed is normal, and the train decelerates, stops, or reverses. The pulse width of the second wheel induction signal can be compensated; when the second wheel induction signal pulse When the width is greater than the third preset threshold, it is determined that the train is decelerating, stopping, or going backwards, and the pulse width of the second wheel induction signal is not compensated.

Further, the third preset threshold value is 600 milliseconds. When the pulse width of the wheel sensing signal is 600 milliseconds, the speed of the train is about 2 km/h.

On the basis of the above embodiments, please refer to FIG. 17, the compensation device 70 includes: a strategy formulation module 75, a signal acquisition module 71, a detection calculation module 72, and a compensation module 73, wherein the strategy formulation module 75 is used to respond When the operating state of the wheel sensor changes, the first compensation strategy is detected and determined according to the operating data of the wheel sensor; the signal acquisition module 71 is used to acquire the first wheel sensing signal and the second wheel sensing signal of the two sensing units of the wheel sensor Wheel induction signal; the detection calculation module 72 is used to detect the first time when the first wheel induction signal has a pulse and the second time when the second wheel induction signal has a pulse, and determine the difference between the first time and the second time Time difference; the compensation module 73 is configured to determine a compensation value according to the time difference according to a preset first compensation strategy, so as to compensate the pulse width of the second wheel induction signal.

Specifically, the strategy formulation module 75 includes: an acquisition unit 7501, a first detection calculation unit 7502, a second detection calculation unit 7503, and a statistics and formulation unit 7504. The monitoring unit 7501 is configured to respond to changes in the operating state of the wheel sensors, The first wheel sensing signal and the second wheel sensing signal of the two sensing units of the wheel sensor are acquired through the signal acquisition module 71; the first detection calculation unit 7502 is used to detect the pulse width of the first wheel sensing signal and the second The pulse width of the wheel induction signal determines the pulse width difference between the first wheel induction signal and the second wheel induction signal; the second detection and calculation unit 7503 is used to detect the first moment when the first wheel induction signal appears pulse and the first time The second moment when the pulse of the two-wheel induction signal appears to determine the time difference between the first moment and the second moment; the statistics and formulation unit 7504 is used to perform statistical analysis on the pulse width difference and the time difference, and determine according to the statistical analysis result The first compensation strategy.

By collecting two pulse signals in the axle counting signal of each wheel sensor, calculating the time difference and pulse width difference of the two pulse signals, and performing statistical analysis on the time difference and pulse width difference, the applicant found that the axle counting signals of all wheel sensors The pulse width difference of the two pulse signals is less than 2×time difference.

Therefore, the first compensation strategy is determined as follows: when the time difference T _{3 is} less than or equal to the first time threshold, the compensation value T ₅ is 2 × the time difference T ₃ ; when the time difference T _{3 is} greater than the first time threshold, the compensation value T ₅ is the second time value. Further, the first time threshold value is 50 milliseconds, and the second time value is 100 milliseconds.

During operation, abnormal pulses are often generated due to external interference. The continuous waveforms formed by the train passing the wheel sensors are shown in Figure 18. The waveforms at the two ends in Figure 18 are generated by the induction plate, and the two waveforms in the middle are the charging blades. The above situation causes the output of the axle counting system to be abnormally occupied, especially in the signal control system of the tram. The train is powered by the battery. When the train stays at the station, the battery is charged, and the charging blade interferes with the axle counting sensor. The probability of abnormal pulses is very high.

In order to prevent the occurrence of the above interference, please refer to FIG. 12 and FIG. 19. The axle counting system of the embodiment of the present invention further includes a first output port 225 provided in the shaping module 22 and processing units 231, 232 of the processing module 23. Between the filtering device 80, the filtering device 80 includes a waveform detection module 82, a judgment module 83 and an interference signal filtering module 84, wherein the shaping signal output by the shaping module 22 includes the first pulse signal and the second pulse signal; the waveform detection module 82 is used to generate waveform characteristic data according to the first pulse signal and the second pulse signal; the judgment module 83 is used to judge whether the first pulse signal and the second pulse signal meet preset conditions according to the waveform characteristic data; The signal filtering module 84 is used to extract the first pulse signal and the second pulse signal as valid shaping signals and output to the processing module 23 when the judgment result is yes; otherwise, the first pulse signal and the second pulse signal The pulse signal is filtered as an interference signal.

When the induction plate or the charging blade approaches the magnetic head of the wheel sensor, it causes the magnetic field of the magnetic head to change. The induction circuit connected to the magnetic head generates an induction signal corresponding to the magnetic field change. The shaping module 22 generates a pulse signal according to the induction signal. Specifically, the shaping module 22 At least one threshold voltage is set inside. When the voltage value of the sensing signal is greater than or equal to the threshold voltage, a pulse is generated; when the voltage value of the sensing signal is less than the threshold voltage, no pulse is generated. Therefore, the corresponding voltage value of the pulse part is greater than or equal to The sensing signal of the threshold voltage.

Since the train wheels pass the two magnetic heads of the wheel sensor one after another, the two pulse signals must meet the characteristics of overlap in order to be considered as an effective shaping signal of the wheel sensor. As shown in Figure 9, the two pulse signals The phase relationship represents the direction of movement of the wheel, and the system uses this to identify the direction of the wheel. The interference pulse signals generated by the charging blades approaching the two magnetic heads in turn are shown in Fig. 20, and there is no overlap range of the two interference pulses.

As shown in FIG. 20, the interference pulse signal generally has a very short duration. Therefore, in the first preferred embodiment, the waveform characteristic data includes: the pulse width of the first pulse signal and the second pulse signal. Please refer to FIG. 21, the waveform detection module 82 is used to obtain the pulse width t ₁₂ -t _{11 of the} first pulse signal and obtain the pulse width t ₂₂ -t _{21 of the} second pulse signal. In the judging module 83, the preset condition is that the pulse width of the first pulse signal and the pulse width of the second pulse signal are both greater than the fourth preset threshold. Therefore, the judging module 83 is used to obtain the first pulse signal from the waveform detection module 83. The pulse width t _12- t _{11 of the} pulse signal and the pulse width t _22- t _{21 of the} second pulse signal determine whether the first pulse signal and the second pulse signal meet a preset condition.

In the second preferred embodiment, the waveform characteristic data is the overlap range of the first pulse signal and the second pulse signal. Specifically, referring to FIG. 21, the waveform detection module 82 is used to obtain the appearance time t ₁₁ and disappearance time t ₁₂ of the pulse edge of the first pulse signal, and obtain the appearance time t of the pulse edge of the second pulse signal. ₂₁ and the disappearing time t ₂₂ ; the overlapping range t ₁₂ -t _{21 of the} first pulse signal and the second pulse signal is determined according to the disappearing time t _{12 of} the first pulse signal and the appearance time t _{21 of the} second pulse signal. In the judgment module 83, the preset condition is that the overlap range of the first pulse signal and the second pulse signal is greater than the second time threshold. Therefore, the judgment module 83 is used to determine the overlap range t ₁₂ -t ₂₁ obtained by the waveform detection module 82 It is determined whether the first pulse signal and the second pulse signal meet a preset condition. Preferably, the second time threshold is 2 ms.

Further, in the third preferred embodiment, the waveform characteristic data includes: (i) the overlap range of the first pulse signal and the second pulse signal, and (ii) the pulse width of the first pulse signal and the second pulse signal. Please refer to FIG. 21, the waveform detection module 82 is used to obtain the appearance time t ₁₁ and disappearance time t ₁₂ of the pulse edge of the first pulse signal, and obtain the appearance time t ₂₁ and disappearance time of the pulse edge of the second pulse signal. Time t ₂₂ ; then, obtain the pulse width t _12- t _{11 of the} first pulse signal, and obtain the pulse width t _22- t _{21 of the} second pulse signal; then, according to the disappearance time t _{12 of} the first pulse signal and the The occurrence time t _{21 of the} second pulse signal determines the overlap range t ₁₂ -t _{21 of the} first pulse signal and the second pulse signal. In the judgment module 83, the preset condition is that the overlap range of the first pulse signal and the second pulse signal is greater than the second time threshold, and the pulse width of the first pulse signal and the pulse width of the second pulse signal are both greater than the fourth preset threshold , Then, the judging module 83 is used for the overlap range t ₁₂ -t ₂₁ obtained by the waveform detection module 82, the pulse width of the first pulse signal t _12- t ₁₁ , and the pulse width of the second pulse signal t _22- t ₂₁ It is determined whether the first pulse signal and the second pulse signal meet a preset condition.

In the fourth preferred embodiment, specifically, the waveform detection module 82 may further include a waveform diagram generation unit and a feature extraction unit, and the waveform diagram generation unit is configured to perform the processing on the first pulse signal and the second pulse signal respectively. Waveform detection to obtain a first waveform diagram and a second waveform diagram respectively; the feature extraction unit is used for extracting waveform feature data according to the first waveform diagram and the second waveform diagram.

The interference signal filtering module 84 extracts the first pulse signal and the second pulse signal as effective shaping signals and outputs them to the processing module 23 when the preset conditions are met; when the preset conditions are not met, the first The pulse signal and the second pulse signal are filtered as interference signals.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be included in the protection of the present invention. Within range.

Claims (10)

1. An axle counting system, characterized in that the axle counting system includes:

   The shaping module connected to the wheel sensor is configured to generate shaping signals according to the sensing signals of the wheel sensors, and the shaping signals include a first pulse signal and a second pulse signal;

   The waveform detection module is used to generate waveform characteristic data according to the first pulse signal and the second pulse signal of the shaping signal;

   A judging module, judging whether the first pulse signal and the second pulse signal meet a preset condition according to the waveform characteristic data;

   The interference signal filtering module, when the judgment result is yes, extract the first pulse signal and the second pulse signal as effective shaping signals and output to the processing module; otherwise, the first pulse signal and the second pulse signal Filter as an interference signal.
2. The axle counting system according to claim 1, wherein the waveform characteristic data includes the pulse width of the first pulse signal and the second pulse signal; the preset condition is the pulse width of the first pulse signal and the second pulse signal. The pulse width of the pulse signal is greater than the fourth preset threshold;

   Or, the waveform characteristic data includes the overlap range of the first pulse signal and the second pulse signal; the preset condition is that the overlap range of the first pulse signal and the second pulse signal is greater than the second time threshold;

   Or, the waveform characteristic data includes the overlap range of the first pulse signal and the second pulse signal, and the pulse width of the first pulse signal and the second pulse signal; the preset condition is the first pulse signal and the second pulse signal The overlap range of is greater than the second time threshold, and the pulse width of the first pulse signal and the pulse width of the second pulse signal are both greater than the fourth preset threshold.
3. The axle counting system according to claim 1, wherein the shaping module comprises: a shaping unit, a first output port, and a second output port arranged in a one-to-one correspondence with the sensing unit of the wheel sensor, and the shaping module One end of the unit is connected to the sensing unit, and the other end is respectively connected to the first output port and the second output port. The shaping unit is used to generate a shaping signal or a fault signal according to the sensing signal of the wheel sensor. The signal is output from the first output port, and the fault signal is output from the second output port;

   The axle counting system further includes: a processing module connected to the shaping module, the processing module includes: two processing units, each processing unit is connected to the first output port, and the two processing units are connected in communication The processing unit is configured to detect the waveform of the shaping signal, and when the two processing units detect that the shaping signal conforms to the shaft pulse rule, output the shaping signal as the shaft pulse signal; when the two processing units When it is detected that the pulse width of the shaping signal is greater than the second preset threshold, outputting the first occupation signal; and

   An isolated output module respectively connected to the second output port of the processing module and the shaping module, and the isolated output module is used to output the fault signal to the axle counter and output the axle pulse signal to the axle counter Board, and output the first occupancy signal to the output board;

   The first output port of the shaping module is connected to the waveform detection module, and each processing unit of the processing module is connected to the interference signal filtering module.
4. The axle counting system according to claim 3, wherein each shaping unit comprises: four voltage comparison circuits, each of the voltage comparison circuits is provided with a voltage threshold, and each of the voltage comparison circuits includes a first An output terminal and a second output terminal, the four voltage comparison circuits are connected in sequence through the first output terminal, and the second output terminals are all connected to the processing module,

   The first voltage comparison circuit receives the sensing signal, and when the voltage of the sensing signal is higher than the first threshold voltage, it outputs a fault signal and the isolation output module; otherwise, it outputs the sensing signal Voltage to the second voltage comparison circuit; when the voltage of the sensing signal is lower than the second threshold voltage, output the fault signal to the isolation output module, otherwise, output the voltage of the sensing signal to the third voltage Comparing circuit; when the voltage of the sensing signal is lower than the third threshold voltage, the output is idle to the processing module, otherwise, the voltage of the sensing signal is output to the fourth voltage comparing circuit; when the sensing signal is The voltage is higher than the fourth threshold voltage, and the occupied pulse is output to the processing module,

   Wherein, the first threshold voltage is higher than the fourth threshold voltage, the fourth threshold voltage is higher than the third threshold voltage, and the third threshold voltage is higher than the second threshold voltage.
5. The axle counting system according to claim 4, wherein the first voltage comparison circuit is provided with the first threshold voltage 9.95V for detecting the disconnection state of the sensing unit;

   The second voltage comparison circuit is provided with the second threshold voltage 5.04V, which is used to detect the off-rail state of the sensing unit;

   The third voltage comparison circuit is provided with the third threshold voltage 8.25V, which is used to detect the idle state of the sensing unit;

   The fourth voltage comparison circuit is provided with the fourth threshold voltage 8.45V for detecting the occupancy state of the sensing unit.
6. The axle counting system according to claim 1, wherein the axle counting system further comprises: a compensation device arranged between the wheel sensor and the shaping module for detecting the presence of pulses in the first wheel sensor signal Determine the time difference between the first time and the second time when the pulse of the second wheel induction signal appears; according to the time difference, determine the compensation value according to the preset first compensation strategy to The pulse width of the second wheel induction signal is compensated.
7. The axle counting system according to claim 6, wherein the first compensation strategy is: when the time difference is less than or equal to the first time threshold, the compensation value is 2×the time difference; when the time difference is greater than the first time At the time threshold, the compensation value is the second time value.
8. The axle counting system according to claim 6, wherein the compensation device is also used to obtain the pulse width of the second wheel induction signal; when the pulse width of the second wheel induction signal is less than or equal to a third preset When the threshold is set, the pulse width of the second wheel sensing signal is compensated; when the pulse width of the second wheel sensing signal is greater than the third preset threshold, the pulse width of the second wheel sensing signal is not compensated.
9. The axle counting system according to claim 3, wherein the isolated output module includes a first photocoupler, a second photocoupler, and a third photocoupler, the first photocoupler and the counter The shaft plate is connected to output the shaft pulse signal; the second photocoupler is connected to the shaft counter plate to output the fault signal; the third photocoupler is connected to the output plate Connected to output the occupied signal in isolation.
10. The axle counting system according to claim 3, wherein the axle counting system further comprises:

    The axle counter is used to identify the running direction of the train and calculate the number of wheels according to the axle counting signals of the wheel sensors, and to judge whether the section is occupied or free according to the number of wheels of the two wheel sensors. When the judgment result is occupied, the second occupancy signal is output , When the judgment result is idle, output an idle signal, where the axle counting signal of the wheel sensor includes the axle pulse signals corresponding to the two sensing units;

    The output board is used to control the closing or opening of the section according to the first occupation signal, the second occupation signal or the idle signal;

    And/or, an internal power supply module connected to the four sensing units for providing a constant current source for the sensing units;

    And/or, a zero reset board, which is connected to the axle counter board and the output board;

    And/or, a power supply board, including a first power supply module and a second power supply module, the first power supply module provides 12V direct current for the amplifying board, the axle counter board, the zero reset board and the output board, The second power supply module provides 24V direct current for the axle counter board, the zero reset board and the output board.

Images