Railway line row identification device and method

Abstract

The invention discloses a railway line row identification device and method. The railway line row identification device comprises a signal acquisition module, a signal processing module, a microcontroller and an output module, the signal acquisition module performs signal acquisition by sensing a current signal in a track circuit; the signal processing module is used for sequentially carrying out low-pass filtering, signal amplification and voltage bias processing on the acquired signal and outputting a signal adaptive to the analog-to-digital conversion unit; the microcontroller executes frequency domain analysis based on the acquired digital signals, including performing fast Fourier transform on the signals, extracting target frequency and amplitude characteristics thereof, and judging row attributes and track types of track signals; and the output module outputs the detected railway line row information according to the judgment result of the microcontroller. Noise interference is cleared through a digital filtering algorithm, and the signal purity is improved. The frequency, amplitude and phase information of the track circuit signal is extracted, and the source and characteristics of the signal are identified based on a built-in algorithm. And multi-system track signals are compatible, and automatic identification and output are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of track signal processing, and the present invention relates to a railway line identification device and method. Background Art

[0002] With the rapid development of railway transportation, the safety of train operation and the maintenance quality of equipment are particularly important. Operators often go on the track to maintain equipment. There have been many accidents in which operators mistakenly identify the line type, causing personal injury and stopping normally running trains, which poses a great labor safety risk. At present, when confirming the line type, railway maintenance personnel can only use the method of sealing the track circuit and contacting the station liaison to confirm the track circuit status to confirm the railway line type. This practice has the risk of missealing, increases the workload of the station liaison and is prone to manual misidentification. This has caused great obstacles to the judgment of line type information. At present, there is no relevant detection equipment on the market, which not only increases the labor intensity of operators, but also greatly reduces the personal safety of operators. In addition, the track circuit formats used on different lines are often different. Summary of the invention

[0003] The purpose of the present invention is to provide a railway line identification device and method, which further removes noise interference through digital filtering algorithm and improves signal purity. It extracts the frequency, amplitude and phase information of the track circuit signal, and identifies the source and characteristics of the signal based on the built-in algorithm. It is compatible with multi-standard track signals and automatically identifies and outputs them.

[0004] The technical solution to achieve the purpose of the present invention is:

[0005] A railway line identification device comprises a signal acquisition module, a signal processing module, a microcontroller and an output module;

[0006] The signal acquisition module performs signal acquisition by sensing the current signal in the track circuit;

[0007] The signal processing module performs low-pass filtering, signal amplification and voltage bias processing on the collected signal in sequence, and outputs a signal suitable for the analog-to-digital conversion unit;

[0008] The microcontroller performs frequency domain analysis based on the collected digital signal, including fast Fourier transform of the signal, extracting the target frequency and its amplitude characteristics, and determining the line attribute and track type of the track signal;

[0009] The output module outputs the detected railway line information according to the judgment result of the microcontroller.

[0010] In a preferred technical solution, the signal acquisition module adopts an electromagnetic coil induction unit, the number of turns of the induction coil is 50 to 100 turns, it is made of high-conductivity copper wire, and is provided with an anti-interference shielding layer.

[0011] In a preferred technical solution, the signal processing module adopts a low-pass filter designed with a Hamming window, and the cut-off frequency is 3000 Hz.

[0012] In a preferred technical solution, the probe part of the signal acquisition module is made of high temperature resistant and corrosion resistant materials.

[0013] In the preferred technical solution, a 5V voltage regulator clamp protection amplifier is arranged between the probe and the analog amplifier of the signal processing module, and positive and negative voltages are used for power supply. The positive voltage is output by TPS54335, and the negative voltage is output by TL7660. The signal is filtered and amplified by the OP07 analog amplifier and the CD4051 eight-way selector to adapt to the analog-to-digital conversion range, and is adjusted to the voltage range required by the digital sampling module through the bias circuit.

[0014] In a preferred technical solution, the method for determining the line attribute and track type of the track signal includes:

[0015] S01: Perform low-pass filtering on the collected digital signal x[n], and the cut-off frequency of the low-pass filter is f c The frequency is 3000Hz, and the low-pass filter formula used is:

[0016]

[0017] in:

[0018]

[0019] w[k] is the Hamming window function:

[0020]

[0021] y[n] is the filtered digital signal, x[n] is the input digital signal, h[k] is the impulse response of the filter, and M is the order of the filter. The impulse response window function is calculated as:

[0022] h[k]=h_ideal[k]*w[k]

[0023] where h_ideal[k] is the impulse response of the ideal low-pass filter, f s is the sampling frequency, k is the time index;

[0024] S02: Use fast Fourier transform to convert the filtered time domain signal y[n] into a frequency domain signal Y[d]. The conversion formula is as follows:

[0025]

[0026] Where Y(d) is the dth frequency component of the frequency domain signal, and N is the number of sampling points;

[0027] S03: Analyze the corresponding frequency component in the frequency domain signal Y[d] and calculate the amplitude G of the frequency to be detected. When the frequency component amplitude G> the set amplitude P, determine the row attribute and track type of the track signal according to the d value.

[0028] In the preferred technical solution, the method for calculating the amplitude G of the frequency to be detected includes:

[0029] Calculate the spectrum resolution. The formula for spectrum resolution is:

[0030]

[0031] Where Δf is the spectrum resolution, f s is the sampling frequency, N is the number of sampling points;

[0032] The subscript d corresponding to the frequencies of 550Hz, 750Hz, 1700Hz, 2300Hz, 650Hz, 850Hz, 2000Hz, and 2600Hz is calculated, namely d=75, 102, 232, 314, 88, 116, 273, and 355, respectively. The amplitude of the adjacent frequency components is added during the judgment, namely:

[0033] G=|Y[d-1]|+|Y[d]|+|Y[d+1]|

[0034] Substitute the d value to calculate the amplitude G of the frequency to be detected.

[0035] The present invention also discloses a railway line identification method, using any of the railway line identification devices described above, the identification method comprises the following steps:

[0036] S11: Collect digital signal x[n];

[0037] S12: Perform low-pass filtering on the collected digital signal x[n], and the cut-off frequency of the low-pass filter is f c The frequency is 3000Hz, and the low-pass filter formula used is:

[0038]

[0039] in:

[0040]

[0041] w[k] is the Hamming window function:

[0042]

[0043] y[n] is the filtered digital signal, x[n] is the input digital signal, h[k] is the impulse response of the filter, and M is the order of the filter. The impulse response window function is calculated as:

[0044] h[k]=h_ideal[k]*w[k]

[0045] where h_ideal[k] is the impulse response of the ideal low-pass filter, f s is the sampling frequency, k is the time index;

[0046] S13: Use fast Fourier transform to convert the filtered time domain signal y[n] into a frequency domain signal Y[d], and the conversion formula is as follows:

[0047]

[0048] Where Y(d) is the dth frequency component of the frequency domain signal, and N is the number of sampling points;

[0049] S14: Analyze the corresponding frequency component in the frequency domain signal Y[d] and calculate the amplitude G of the frequency to be detected. When the frequency component amplitude G>threshold amplitude P, determine the row attribute and track type of the track signal according to the d value.

[0050] In the preferred technical solution, the method for calculating the amplitude G of the frequency to be detected includes:

[0051] Calculate the spectrum resolution. The formula for spectrum resolution is:

[0052]

[0053] Where Δf is the spectrum resolution, f s is the sampling frequency, N is the number of sampling points;

[0054] The subscript d corresponding to the frequencies of 550Hz, 750Hz, 1700Hz, 2300Hz, 650Hz, 850Hz, 2000Hz, and 2600Hz is calculated, namely d=75, 102, 232, 314, 88, 116, 273, and 355, respectively. The amplitude of the adjacent frequency components is added during the judgment, namely:

[0055] G=|Y[d-1]|+|Y[d]|+|Y[d+1]|

[0056] Substitute the d value to calculate the amplitude G of the frequency to be detected.

[0057] Compared with the prior art, the present invention has the following significant advantages:

[0058] (1) The invention uses electromagnetic coils to sense current signals in the rails, which fundamentally ensures the stability and high sensitivity of signal acquisition. The electromagnetic coil can effectively sense the weak current signal in the rails. After the signal is sensed, the system removes interference components through a filtering circuit, and uses a signal amplification circuit to amplify the effective signal amplitude, and then performs voltage bias processing to ensure that the signal is adapted to the subsequent digital sampling unit. The conditioned signal is sampled at high resolution through the ADC module of the microcontroller, thereby ensuring the accuracy and real-time nature of the sampling. The entire process has a high degree of automation and can continuously and accurately detect the type of railway line in a dynamic and complex environment, ensuring the reliability and recognition efficiency of the instrument.

[0059] (2) The invention uses frequency domain analysis methods to analyze sampled data. Traditional frequency detection methods, such as direct input capture technology, are usually limited by external interference, such as environmental electromagnetic waves or equipment vibrations, resulting in unstable detection results. The invention innovatively introduces frequency domain analysis technology, which significantly improves the robustness and accuracy of detection through digital filtering and fast Fourier transform (FFT) of sampled data. Specifically, the filtering process can remove high-frequency and low-frequency noise interference, while FFT analysis can quickly and accurately extract the main frequency components in the signal to achieve in-depth analysis of track signals. This method not only improves detection accuracy, but also greatly improves anti-interference capabilities. In particular, in railway environments with strong electromagnetic interference and complex signals, it can effectively identify signal changes and provide reliable data support for subsequent judgment of railway line types.

[0060] (3) The coil probe design of this invention is centered on convenience, completely abandoning the cumbersome fixtures or complex deployment requirements of traditional detection equipment. The probe is compact and lightweight, and can be easily carried to any line environment. In actual operation, the user only needs to simply place the probe on the track surface, and can quickly start detection without additional installation or adjustment. This "place and use" design not only reduces the labor intensity of the operator, but also greatly shortens the detection preparation time and improves overall work efficiency. In addition, the coil probe itself has high durability and adaptability, and can maintain stable performance in harsh environments such as high temperature, low temperature, humidity, and vibration. It is suitable for various railway maintenance scenarios, including emergency treatment and daily maintenance.

[0061] (4) The invention has been deeply optimized in terms of signal recognition. In modern railway systems, different lines may use different track circuit formats, which poses a huge challenge to the compatibility of detection equipment. The invention can simultaneously identify multiple track circuit format signals without switching equipment or performing additional configuration. Its core algorithm can accurately determine the source, frequency, amplitude and other characteristics of the signal. This multi-track signal recognition capability enables the invention to maintain high accuracy in the complex electromagnetic environment of railway lines, further expanding its scope of application and making it suitable for different lines. It provides railway operators with a highly flexible and reliable line detection tool, ensuring the labor safety of operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 is a principle block diagram of the railway line identification device of this embodiment;

[0063] Figure 2 is a circuit diagram of the railway line identification device of this embodiment;

[0064] Figure 3 It is a flow chart of the railway line identification method of this embodiment. DETAILED DESCRIPTION

[0065] The principle of the present invention is to further clean up noise interference and improve signal purity through digital filtering algorithm. It can extract the frequency, amplitude and phase information of track circuit signals and identify the source and characteristics of signals based on built-in algorithms. It is compatible with multi-standard track signals and can automatically identify and output them.

[0066] Embodiment 1:

[0067] like Figure 1 As shown, a railway line identification device includes a signal acquisition module, a signal processing module, a microcontroller and an output module;

[0068] The signal acquisition module acquires signals by sensing the current signal in the track circuit;

[0069] The signal processing module performs low-pass filtering, signal amplification and voltage bias processing on the collected signal in sequence, and outputs a signal suitable for the analog-to-digital conversion unit;

[0070] The microcontroller performs frequency domain analysis based on the collected digital signal, including fast Fourier transform of the signal, extracting the target frequency and its amplitude characteristics, and determining the line attributes and track type of the track signal;

[0071] The output module outputs the detected railway line information according to the judgment result of the microcontroller.

[0072] In a preferred embodiment, the signal acquisition module adopts an electromagnetic coil induction unit to achieve high stability and high sensitivity signal acquisition by sensing the weak current signal in the track circuit. The coil structure is optimized, the number of turns of the induction coil is 50 to 100 turns, it is made of high conductivity copper wire, and is provided with an anti-interference shielding layer. It adapts to different track signal frequency ranges. It ensures that in the multi-track circuit format, it can produce efficient induction of weak current signals in the track.

[0073] The device supports multi-standard track signal recognition, including low-frequency standards (such as 550Hz and 750Hz) and high-frequency standards (such as 2000Hz and 2600Hz).

[0074] The probe part of the signal acquisition module is made of high temperature resistant and corrosion resistant materials, suitable for long-term use in complex railway environments.

[0075] In a preferred embodiment, the signal processing module uses a low-pass filter designed with a Hamming window and a cut-off frequency of 3000 Hz to suppress high-frequency noise.

[0076] The output module adopts dual output mode of LED screen and buzzer, providing visual and auditory prompts respectively, enhancing the user's perception of the results.

[0077] For the induced current signal processing reference Figure 2 , a 5V voltage regulator clamp is used at the signal acquisition point to protect the amplifier from being destroyed by high voltage pulses. For complete sampling signals, positive and negative voltages are used for power supply. The positive voltage is output by TPS54335, and the negative voltage is output by TL7660. The weak signal is filtered and amplified by the OP07 analog amplifier and the CD4051 eight-way selector to adapt to the ADC range, and is adjusted to the voltage range required by the digital sampling module through the bias circuit to ensure the accuracy of the signal amplitude for subsequent processing.

[0078] The microcontroller uses a high-performance microcontroller based on stm32f103C8T6, and uses fast Fourier transform (FFT) to perform frequency domain analysis on the collected track circuit signals. The digital filtering algorithm is used to further clean up noise interference and improve signal purity. The frequency, amplitude and phase information of the track circuit signal are extracted, and the source and characteristics of the signal are identified based on the built-in algorithm. For multi-standard track signals, the output is automatically identified.

[0079] The probe adopts a compact modular design, is lightweight, and has a flexible material contact layer at the bottom to ensure efficient coupling with the track. The operator only needs to place the probe on the track surface, and the detection can be automatically started without complicated installation or adjustment.

[0080] This invention innovatively introduces frequency domain analysis technology, which significantly improves the robustness and accuracy of detection through digital filtering and fast Fourier transform (FFT) of sampled data. Specifically, the filtering process can remove high-frequency and low-frequency noise interference, while FFT analysis can quickly and accurately extract the main frequency components in the signal to achieve in-depth analysis of track signals. This method not only improves detection accuracy, but also greatly improves anti-interference capabilities, especially in railway environments with strong electromagnetic interference and complex signals. It can effectively identify signal changes and provide reliable data support for subsequent judgment of railway line types.

[0081] Specifically, the track signal recognition algorithm is as follows: Figure 3 As shown, the following steps are included:

[0082] Signal sensing: A highly sensitive electromagnetic coil is used as the signal sensing unit to sense the weak current signal in the track circuit to achieve high stability and high sensitivity signal acquisition.

[0083] Signal processing: The collected signal is subjected to noise suppression and amplitude amplification through the filtering circuit, and then the signal range is adjusted through the bias circuit to adapt to the subsequent analog-to-digital conversion (ADC). The low-pass filter designed with the Hamming window has a cutoff frequency of 3000Hz, which effectively filters out high-frequency noise. The signal amplification and voltage bias module adjusts the amplitude of the filtered signal to adapt it to the input range of the analog-to-digital conversion module.

[0084] (1) Input the time series x[n] of the acquired digital signal, where n is 2048 (sequence length is 2048), and the sequence contains noise and target signal.

[0085] (2) The collected digital signal x[n] is low-pass filtered to suppress high-frequency noise. In order to retain the frequencies that need to be detected, including 550 Hz, 750 Hz, 1700 Hz, 2300 Hz, 650 Hz, 850 Hz, 2000 Hz, and 2600 Hz (the signal frequencies emitted by tracks of different standards and directions), the design cutoff frequency fc of the low-pass filter is 3000 Hz. The low-pass filter formula used is:

[0086]

[0087] in:

[0088]

[0089] w[k] is the Hamming window function:

[0090]

[0091] y[n] is the filtered digital signal, x[n] is the input digital signal, h[k] is the impulse response of the filter, and M is the order of the filter, which is set to 3. The impulse response window function (Hamming window) is calculated as:

[0092] h[k]=h_ideal[k]*w[k]

[0093] Where h_ideal is the impulse response of the ideal low-pass filter, f c is the cut-off frequency (3000Hz), f s is the sampling frequency (3000*5=15KHz), k is the time index, and w[k] is the formula of the Hamming window;

[0094] After digital filtering, we obtain smoothed data y[n] that suppresses high-frequency noise;

[0095] (3) Then use the fast Fourier transform (FFT) to convert the filtered time domain signal y[n] into the frequency domain signal Y[k], and the conversion formula is as follows:

[0096]

[0097] Where Y(d) is the dth frequency component of the frequency domain signal, and N is the number of sampling points.

[0098] (4) Finally, we analyze the frequency components corresponding to (550 Hz, 750 Hz, 1700 Hz, 2300 Hz, 650 Hz, 850 Hz, 2000 Hz, 2600 Hz) in the frequency domain signal Y[d]. First, we need to calculate the spectrum resolution. The formula for the spectrum resolution is:

[0099]

[0100] Where Δf is the spectrum resolution, f s is the sampling frequency (15000), N is the number of sampling points (2048), and the formula is used to calculate that Δf = 15000 / 2048 is approximately equal to 7.3; then the subscript d corresponding to the frequencies of 550Hz, 750Hz, 1700Hz, 2300Hz, 650Hz, 850Hz, 2000Hz, 2600Hz, etc. is calculated, namely d = 75, 102, 232, 314, 88, 116, 273, 355, respectively. Since there is a certain error in the detected frequency signal, the amplitude of the adjacent frequency component will be added when judging, namely:

[0101] G=|Y[d-1]|+|Y[d]|+|Y[d+1]|

[0102] Then substitute the d value and calculate the amplitude G of the frequency to be detected. By setting a fixed amplitude value P (threshold constant), when the frequency component amplitude G> the set amplitude P and d is 75, 102, 232, 314, the downlink is output, and when d is 88, 116, 273, 355, the uplink is output. And the track type corresponding to the frequency is output. Low-frequency format (such as 550Hz and 750Hz) and high-frequency format (such as 2000Hz and 2600Hz).

[0103] The algorithm extracts key characteristics of the signal, such as frequency and amplitude, to achieve high-precision signal recognition. The device is equipped with a multi-standard track signal recognition algorithm that can automatically adapt to different track circuit types, avoiding the need to frequently change equipment or configurations, and maintaining stability and efficiency in complex environments with multiple parallel lines. The coil probe adopts a lightweight design and does not require complex installation. It only needs to be placed on the track surface to start detection. The casing and structure are made of high-strength materials and are resistant to high and low temperatures, shock and water, and are suitable for various harsh environments. The system implements a highly automated detection process, can sense track signals in real time in a dynamic environment, and quickly output results, providing reliable data support for subsequent railway line identification.

[0104] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement modes and shall be included in the protection scope of the present invention.

Claims

1. A railway line identification device, characterized in that: It includes a signal acquisition module, a signal processing module, a microcontroller and an output module; The signal acquisition module performs signal acquisition by sensing the current signal in the track circuit; The signal processing module performs low-pass filtering, signal amplification and voltage bias processing on the collected signal in sequence, and outputs a signal suitable for the analog-to-digital conversion unit; The microcontroller performs frequency domain analysis based on the collected digital signal, including fast Fourier transform of the signal, extracting the target frequency and its amplitude characteristics, and determining the line attribute and track type of the track signal; The output module outputs the detected railway line information according to the judgment result of the microcontroller.

2. The railway line identification device according to claim 1, characterized in that: The signal acquisition module adopts an electromagnetic coil induction unit, the number of turns of the induction coil is 50 to 100 turns, it is made of high-conductivity copper wire, and is provided with an anti-interference shielding layer.

3. The railway line identification device according to claim 1, characterized in that: The signal processing module adopts a low-pass filter designed with a Hamming window, and the cut-off frequency is 3000 Hz.

4. The railway line identification device according to claim 2, characterized in that: The probe part of the signal acquisition module is made of high temperature resistant and corrosion resistant materials.

5. The railway line identification device according to claim 2, characterized in that: A 5V voltage regulator clamp protection amplifier is arranged between the probe and the analog amplifier of the signal processing module. It uses positive and negative voltage power supply. The positive voltage is output by TPS54335 and the negative voltage is output by TL7660. The signal is filtered and amplified by the OP07 analog amplifier and the CD4051 eight-way selector to adapt to the analog-to-digital conversion range, and is adjusted to the voltage range required by the digital sampling module through the bias circuit.

6. The railway line identification device according to claim 1, characterized in that: The method for determining the line attribute and track type of the track signal includes: S01: Perform low-pass filtering on the collected digital signal x[n], and the cut-off frequency of the low-pass filter is f c The frequency is 3000Hz, and the low-pass filter formula used is: in: w[k] is the Hamming window function: y[n] is the filtered digital signal, x[n] is the input digital signal, h[k] is the impulse response of the filter, and M is the order of the filter. The impulse response window function is calculated as: h[k]=h_ideal[k]*w[k] where h_ideal[k] is the impulse response of the ideal low-pass filter, f s is the sampling frequency, k is the time index; S02: Use fast Fourier transform to convert the filtered time domain signal y[n] into a frequency domain signal Y[d]. The conversion formula is as follows: Where Y(d) is the dth frequency component of the frequency domain signal, and N is the number of sampling points; S03: Analyze the corresponding frequency component in the frequency domain signal Y[d] and calculate the amplitude G of the frequency to be detected. When the frequency component amplitude G> the set amplitude P, determine the row attribute and track type of the track signal according to the d value.

7. The railway line identification device according to claim 6, characterized in that: Methods for calculating the amplitude G of the frequency to be detected include: Calculate the spectrum resolution. The formula for spectrum resolution is: Where Δf is the spectrum resolution, f s is the sampling frequency, N is the number of sampling points; The subscript d corresponding to the frequencies of 550Hz, 750Hz, 1700Hz, 2300Hz, 650Hz, 850Hz, 2000Hz, and 2600Hz is calculated, namely d=75, 102, 232, 314, 88, 116, 273, and 355, respectively. The amplitude of the adjacent frequency components is added during the judgment, namely: G=|Y[d-1]|+|Y[d]|+|Y[d+1]| Substitute the d value to calculate the amplitude G of the frequency to be detected.

8. A railway line identification method, characterized in that: Using the railway line identification device according to any one of claims 1 to 7, the identification method comprises the following steps: S11: Collect digital signal x[n]; S12: Perform low-pass filtering on the collected digital signal x[n], and the cut-off frequency of the low-pass filter is f c The frequency is 3000Hz, and the low-pass filter formula used is: in: w[k] is the Hamming window function: y[n] is the filtered digital signal, x[n] is the input digital signal, h[k] is the impulse response of the filter, and M is the order of the filter. The impulse response window function is calculated as: h[k]=h_ideal[k]*w[k] where h_ideal[k] is the impulse response of the ideal low-pass filter, f s is the sampling frequency, k is the time index; S13: Use fast Fourier transform to convert the filtered time domain signal y[n] into a frequency domain signal Y[d], and the conversion formula is as follows: Where Y(d) is the dth frequency component of the frequency domain signal, and N is the number of sampling points; S14: Analyze the corresponding frequency component in the frequency domain signal Y[d] and calculate the amplitude G of the frequency to be detected. When the frequency component amplitude G> the set amplitude P, determine the row attribute and track type of the track signal according to the d value.

9. The railway line identification method according to claim 8, characterized in that: Methods for calculating the amplitude G of the frequency to be detected include: Calculate the spectrum resolution. The formula for spectrum resolution is: Where Δf is the spectrum resolution, f s is the sampling frequency, N is the number of sampling points; The subscript d corresponding to the frequencies of 550Hz, 750Hz, 1700Hz, 2300Hz, 650Hz, 850Hz, 2000Hz, and 2600Hz is calculated, namely d=75, 102, 232, 314, 88, 116, 273, and 355, respectively. The amplitude of the adjacent frequency components is added during the judgment, namely: G=|Y[d-1]|+|Y[d]|+|Y[d+1]| Substitute the d value to calculate the amplitude G of the frequency to be detected.

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