Railway rail condition monitoring system

Abstract

The embodiment of the present disclosure provides a steel rail state monitoring system. The system comprises a plurality of trackside devices, a plurality of on-track devices and an indoor monitoring device; the trackside device comprises a sending device and a receiving device; the on-track device comprises a sending node and a receiving node; the sending device is connected with the corresponding sending node, and the receiving device is connected with the corresponding receiving node; the sending node and the receiving node are arranged adjacently; the sending device sends a signal to the corresponding sending node according to a set signal mode; the sending node sends the signal to the steel rail, so that the receiving node receives the signal; the receiving node receives the signal sent by the adjacent sending node; the adjacent sending node comprises an upstream sending node and a downstream sending node; the receiving device determines the steel rail state according to the signal of the corresponding receiving node; and the indoor monitoring device alarms according to the steel rail state, so that the steel rail state monitoring with low cost can be realized.

Description

Technical Field

[0001] This disclosure relates to the field of rail monitoring technology, and more particularly to a rail condition monitoring system. Background Technology

[0002] Rails are a crucial foundation for rail transit, and their health directly impacts railway transport and the safety of life and property. Rail condition is susceptible to factors such as temperature changes, train load pressure, and geological variations, leading to rail damage and breakage, severely affecting train operation safety. Track circuits are currently the primary equipment for rail breakage detection, but various scenarios still lack them, highlighting the urgent need for rail breakage detection solutions. For example, the 36,000 kilometers of semi-automatic block signaling sections, mainly concentrated on freight railways with low traffic volume and conventional railways with sparse passenger flow, often cannot accommodate track circuits due to operational cost constraints. Similarly, metro and urban rail transit, due to different signaling systems, often use axle counting, requiring rail breakage detection functionality—that is, monitoring rail condition—especially for lines that do not support manual inspection. Summary of the Invention

[0003] This disclosure provides a rail condition monitoring system that can monitor the condition of rails in a low-maintenance manner.

[0004] In a first aspect, embodiments of this disclosure provide a rail condition monitoring system, comprising: the system including multiple trackside devices, multiple rail-mounted devices, and indoor monitoring devices; the trackside devices including transmitting devices and receiving devices; the rail-mounted devices including transmitting nodes and receiving nodes; the transmitting devices connected to corresponding transmitting nodes, and the receiving devices connected to corresponding receiving nodes; the transmitting nodes and the receiving nodes arranged adjacent to each other; the transmitting devices being used to transmit signals to the corresponding transmitting nodes according to a set signal format; the transmitting nodes being used to transmit the signals to the rails so that the receiving nodes can receive the signals; the receiving nodes being used to receive signals transmitted by adjacent transmitting nodes; the adjacent transmitting nodes including upstream transmitting nodes and downstream transmitting nodes; the receiving devices being used to determine the rail condition based on the signals from the corresponding receiving nodes; and the indoor monitoring devices being used to issue an alarm based on the rail condition.

[0005] In this embodiment, the transmitting device sends a signal to the corresponding transmitting node according to a set signal format; the transmitting node sends the signal to the rail so that the receiving node receives the signal; the receiving node receives the signal sent by the adjacent transmitting node; the adjacent transmitting node includes an upstream transmitting node and a downstream transmitting node; the receiving device determines the rail status based on the signal from the corresponding receiving node; the indoor monitoring device issues an alarm based on the rail status, which can realize low-cost rail breakage inspection. Attached Figure Description

[0006] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0007] Figure 1 This is a schematic diagram of the rail condition monitoring system architecture provided in the embodiments of this disclosure;

[0008] Figure 2 This is a schematic diagram of another rail condition monitoring system architecture provided in an embodiment of the present invention;

[0009] Figure 3 A schematic diagram illustrating the effects of the first and second transmission systems provided in this embodiment of the invention;

[0010] Figure 4 This is a schematic diagram of the rail condition monitoring process provided in an embodiment of the present invention. Detailed Implementation

[0011] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0012] It should be understood that the steps described in the system implementation of this disclosure may be performed in different orders and / or in parallel. Furthermore, the system implementation may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.

[0013] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0014] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0015] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0016] It is understood that the data involved in this technical solution (including but not limited to the data itself, the acquisition or use of the data) shall comply with the requirements of relevant laws, regulations and related provisions.

[0017] Figure 1 This is a schematic diagram of the rail condition monitoring system architecture provided in this embodiment of the disclosure. This embodiment is applicable to situations where the condition of rails in a section is monitored, such as... Figure 1 As shown, the system includes multiple trackside devices, multiple rail-mounted devices, and indoor monitoring equipment. The trackside devices include transmitting and receiving devices. The rail-mounted devices include transmitting nodes and receiving nodes. Each transmitting device is connected to a corresponding transmitting node, and each receiving device is connected to a corresponding receiving node. The transmitting and receiving nodes are arranged adjacent to each other. The transmitting device transmits signals to the corresponding transmitting node according to a set signal format. The transmitting node transmits the signals to the rail so that the receiving node receives the signals. The receiving node receives signals transmitted by adjacent transmitting nodes. The adjacent transmitting nodes include upstream and downstream transmitting nodes. The receiving device determines the rail status based on the signals from the corresponding receiving node. The indoor monitoring equipment issues an alarm based on the rail status.

[0018] In this system, trackside equipment can function as both transmitting and receiving devices, and track-mounted equipment can function as both transmitting and receiving nodes. Transmitting devices correspond to transmitting nodes on the track-mounted equipment, and receiving devices correspond to receiving nodes on the track-mounted equipment. The transmitting and receiving nodes are arranged adjacent to each other, as are the transmitting and receiving devices. In practical applications, the nodes can be spaced 1 km apart. Depending on the specific circumstances, this system may include multiple transmitting nodes, multiple receiving nodes, multiple transmitting devices, and multiple receiving devices. This embodiment does not limit the specific number of transmitting nodes, receiving nodes, transmitting devices, and receiving devices. Figure 1 As shown, the number of nodes can be n, the corresponding number of track-mounted devices can be n, and the corresponding number of trackside devices can be n.

[0019] Specifically, the system also includes rail-mounted sensors located within the rail-mounted equipment. These sensors are used for signal transmission with the equipment. Each transmitting device sends electrical signals to its corresponding transmitting node according to a set signal format via the rail-mounted sensor. The corresponding transmitting node converts the electrical signals into vibration signals and transmits these signals to the rail, allowing the receiving node to receive them. The receiving node receives vibration signals from adjacent transmitting nodes; for example, receiving node 2 receives signals from adjacent transmitting nodes 1 and 3. For receiving node 2, transmitting node 1 can act as an upstream transmitting node, and transmitting node 3 as a downstream transmitting node. The receiving node converts the received vibration signals into electrical signals and transmits them to the corresponding receiving device via the rail-mounted sensor. The receiving device determines the rail status based on the electrical signals from the corresponding receiving node. The rail status includes normal and broken rail conditions. The indoor monitoring equipment monitors and issues alarms based on the rail status.

[0020] like Figure 2 As shown, Figure 2 This is a schematic diagram of another rail condition monitoring system architecture provided by an embodiment of the present invention. Optionally, the system further includes a power supply for supplying power to the trackside devices and the indoor monitoring equipment. The indoor monitoring equipment is also used to issue an alarm when the rail condition is a broken rail condition.

[0021] Figure 2 In this process, the indoor equipment may include an indoor monitoring host and an audible and visual alarm device. Specifically, the power supply provides power to each of the trackside devices and the indoor monitoring device.

[0022] The indoor monitoring equipment may include an indoor monitoring host and audible and visual devices. When the rail is in a broken rail condition, the indoor monitoring host can control the audible and visual devices to trigger an alarm.

[0023] Optionally, the transmitting nodes include a first odd-numbered transmitting node and a second odd-numbered transmitting node; the set signal mode includes a first transmission mode and a second transmission mode; the transmitting device is further configured to transmit a signal to the first odd-numbered transmitting node based on the first transmission mode, so that the first odd-numbered transmitting node transmits the signal according to the first transmission mode; the transmitting device is further configured to transmit a signal to the second odd-numbered transmitting node based on the second transmission mode, so that the second odd-numbered transmitting node transmits the signal according to the second transmission mode.

[0024] For example, since the nodes are arranged continuously and without interruption, a receiving node can receive waveforms sent by both upstream and downstream nodes. Therefore, the upstream and downstream transmitting nodes need to use different signal formats so that the receiving node can distinguish them. In this embodiment, odd-numbered nodes are transmitting nodes, and even-numbered nodes are receiving nodes. For example, nodes 2, 4, 6, 8, and 10 are receiving nodes, and nodes 1, 3, 5, 7, 9, 11, and 13 are odd-numbered transmitting nodes. Nodes 1, 5, 9, and 13 can serve as first odd-numbered transmitting nodes, which transmit signals using a first transmission format. Nodes 3, 7, 11, and 15 can serve as second odd-numbered transmitting nodes, which transmit signals using a second transmission format. Since there is a one-to-one correspondence between the transmitting devices and their corresponding nodes, with odd-numbered devices acting as transmitting devices and even-numbered devices as receiving devices, after the system powers on, the corresponding transmitting devices send signals to the corresponding first odd-numbered transmitting nodes based on the first transmission standard, causing the corresponding first odd-numbered transmitting nodes to transmit signals according to the first transmission standard. For example, transmitting device 1 sends a signal to corresponding transmitting node 1 based on the first transmission standard, causing transmitting node 1 to transmit signals to receiving node 2 according to the first transmission standard. The transmitting devices also send signals to the second odd-numbered transmitting nodes based on the second transmission standard, causing the second odd-numbered transmitting nodes to transmit signals according to the second transmission standard. For example, transmitting device 3 sends a signal to transmitting node 3 based on the second transmission standard, causing transmitting node 3 to transmit signals to receiving node 2 according to the second transmission standard. Each receiving node continuously receives signals sent by each transmitting node in real time. It should be noted that the first odd-numbered node can also be the second odd-numbered node, and the second odd-numbered node can also be the first odd-numbered node. For example, for receiving node 4, the adjacent sending nodes are node 3 and node 5. That is, node 3 can also be the first odd-numbered sending node, and node 5 can also be the second odd-numbered sending node.

[0025] Optionally, the first transmission mode is to excite according to a first set frequency and emit a first set number of wave groups, the duration of each wave group is a first set duration, and the pulse time interval is a second set duration; the second transmission mode is to excite according to a second set frequency and emit a second set number of wave groups, the duration of each wave group is a third set duration, and the pulse time interval is a fourth set duration; wherein, the first transmission mode and the second transmission mode are separated by a fifth set duration.

[0026] The first set frequency can be 0s / 30s per minute, meaning the transmission interval is 30s, starting from second 0 and repeating at second 30. The first set quantity is 3, and the first set duration is 330ms. The second set duration is 1s, and the second set frequency can be 15 / 45s per minute, meaning the transmission interval is also 30s, but starting from second 15 and repeating at second 45. The second set quantity can also be 3, the third set duration can be 330ms, the fourth set duration can be 2 seconds, and the fifth set duration can be 15 seconds.

[0027] For example, the first transmission mode: excitation every 0s / 30s per minute, emitting 3 sets of waves, each set lasting 330ms, with a pulse interval of 1s; the second transmission mode: excitation every 15 / 45s per minute, emitting 3 sets of waves, each set lasting 330ms, with a pulse interval of 2s. Figure 3 As shown, Figure 3 A schematic diagram illustrating the effects of the first and second transmission systems provided in an embodiment of the present invention.

[0028] Each transmitting node transmits according to a pre-set signal format. The receiving node works in real time, and the receiving device analyzes the transmitted signals and judges the condition of the rails based on the frequency and transmission interval, thus obtaining the rail condition information.

[0029] Optionally, the system includes a self-inspection mode, a monitoring mode, a vehicle passage mode, a coding mode, and a fault mode; wherein, the rail status corresponding to the self-inspection mode, the monitoring mode, the vehicle passage mode, and the coding mode is a normal state, and the rail status corresponding to the fault mode is a broken rail state.

[0030] The system is configured to enter the self-test mode after power-on; the self-test mode is configured to perform self-tests on the transmitting device and the receiving device, and to represent the rail status corresponding to the signal sent by the upstream transmitting node through a first flag bit, and to represent the rail status corresponding to the signal sent by the downstream transmitting node through a second flag bit.

[0031] Specifically, the self-test mode can be denoted as M0. In this mode, the system performs a self-test on both the transmitting and receiving devices, but the transmitting end has not yet started transmitting data. The first flag can be denoted as ST1, and the second flag as ST2. After system startup, both ST1 and ST2 are set to 0. Each time the receiving device detects an upstream or downstream signal, ST1 and ST2 are automatically incremented by 1. The system continuously monitors the duration T1 / T2 of ST1 / ST2 in a certain state (the duration of ST1 in a certain state is denoted as T1, and the duration of ST2 in a certain state is denoted as T2). When the duration of T1 / T2 exceeds the first set duration, meaning the upstream and downstream status of the rail has not been updated within the first set duration, the system alarms.

[0032] Optionally, the system is further configured to enter the monitoring mode when the self-test result of the self-test mode is a successful self-test; wherein, the monitoring mode is configured to continuously receive signals through the receiving device and determine parameter values ​​based on the received signals; if the duration of the rail status corresponding to the first flag bit and / or the second flag bit is greater than a first set duration, the system enters the fault mode; if the duration of the rail status corresponding to the first flag bit and / or the second flag bit is less than or equal to the first set duration, it is determined whether the parameter value meets a first threshold condition; if the parameter value meets the first threshold condition, the system enters the vehicle passage mode; if the parameter value does not meet the first threshold condition but meets the second threshold condition, the system enters the coding mode.

[0033] Specifically, in the monitoring mode, denoted as M1, after a successful self-test, the system switches from M0 to M1 mode, continuously receiving signals through the receiving device and determining parameter values ​​in real time based on the received signals. If the duration of the rail status corresponding to the first flag bit and / or the second flag bit is greater than a first set duration, the system enters the fault mode. The first set duration can be 5 minutes, 10 minutes, etc., and this embodiment does not impose any restrictions on this. If the duration of the rail status corresponding to the first flag bit and / or the second flag bit is less than or equal to the first set duration, it is determined whether the parameter value meets a first threshold condition. If the parameter value meets the first threshold condition, the system enters the vehicle passage mode. If the parameter value does not meet the first threshold condition but meets the second threshold condition, the system enters the encoding mode. If the parameter value does not meet either the first or second threshold condition, the corresponding rail status duration is incremented. When no signal is generated for the first set duration, the system enters the fault mode.

[0034] Optionally, the vehicle passage mode is used to continuously receive signals through the receiving device and determine parameter values ​​based on the received signals; if the parameter values ​​do not meet the first threshold condition, the rail states corresponding to the first flag bit and the second flag bit are counted and accumulated respectively to change the rail states corresponding to the first flag bit and the second flag bit, and then the monitoring mode is entered.

[0035] In this embodiment, in the train passage mode, which is denoted as M2, the receiving device continuously receives signals and determines parameter values ​​based on the received signals. At this time, the transmitting device stops transmitting signals of a specific frequency. If the parameter value does not meet the first threshold condition, it indicates that the train has left the section, the train passage ends, and the rail status corresponding to the first flag bit and the second flag bit is counted and accumulated to change the rail status corresponding to the first flag bit and the second flag bit, and then the monitoring mode is entered.

[0036] Optionally, the encoding mode is used to encode the signals sent by the upstream transmitting node and the downstream transmitting node to distinguish the signals received by the receiving device from the signals sent by the upstream transmitting node and the signals sent by the downstream transmitting node; and to count and accumulate the rail states corresponding to the first flag bit and the second flag bit respectively, so as to change the rail states corresponding to the first flag bit and the second flag bit, and enter the monitoring mode.

[0037] Specifically, in the encoding mode, denoted as M3, the system enters this encoding mode when it detects a signal of a specific frequency from the transmitting device to distinguish between upstream and downstream nodes. For example, the upstream transmission code is denoted as 10101, and the downstream transmission code is denoted as 12121, thereby determining whether the received data comes from upstream or downstream and distinguishing the rail status of upstream and downstream. The system also counts and accumulates the rail status corresponding to the first and second flag bits respectively to change the rail status corresponding to the first and second flag bits, and then enters the monitoring mode.

[0038] Optionally, the parameter values ​​include the centroid frequency and the wavelet packet entropy value; the first threshold condition is met when the centroid frequency is less than a set centroid frequency threshold and the wavelet packet entropy value is greater than a set entropy value threshold; the second threshold condition is met when the centroid frequency is greater than a set centroid frequency threshold and the wavelet packet entropy value is less than a set entropy value threshold.

[0039] The first threshold condition can be understood as the threshold condition for the vehicle passing signal, and the second threshold condition can be understood as the threshold condition for a specific frequency signal. The centroid frequency threshold can be set to 10kHz, and the entropy threshold can be set to 0.5. For example, the first threshold condition is: centroid frequency FC < 10kHz, and wavelet packet entropy H > 0.5; the second threshold condition is: centroid frequency FC > 10kHz, and wavelet packet entropy H < 0.5.

[0040] For example, the specific process of determining parameter values ​​based on the received signal is as follows: The receiving device continuously receives the signal with a sampling rate of 100kHz. Every 8192 points received are denoted as x(t). The centroid frequency and wavelet packet entropy value are calculated for x(t).

[0041] The steps for calculating the wavelet packet entropy are as follows:

[0042] First, the wavelet basis function db3 is selected, and the signal x(t) is decomposed into j-level wavelet packets to obtain 2j sub-signal sequences S1, S2…Sj with different frequency bands. k (k = 0 to 2j); the energy of the k-th subband at the j-th scale is E. j (k) is represented as: E j Let be the total energy at scale j, and let the ratio of the energy at the k-th sampling point to the total energy be denoted as:

[0043] The formula for calculating the wavelet packet entropy H is as follows:

[0044]

[0045] The received signal can be a signal of a specific frequency or a vehicle passing signal. Vehicle passing signals are random signals with greater uncertainty, and therefore have a higher entropy value. The signal from the system's transmitting device is a narrowband signal with a low entropy value, which can be distinguished by the wavelet packet entropy value H.

[0046] The centroid frequency (FC) describes the frequencies of the larger signal components in the signal spectrum, reflecting the distribution of the signal power spectrum. The formula for calculating the centroid frequency FC is as follows:

[0047]

[0048] Where S(k) is the power spectrum obtained with respect to x(t), f k This represents the frequency corresponding to the power spectrum. If the passing signal is concentrated at low frequencies, the center of gravity frequency is closer to the origin. Signals transmitted at specific frequencies are high-frequency, resulting in a higher calculated center of gravity frequency. The system mode can be determined using both the center of gravity frequency and the wavelet packet entropy value, which in turn indicates the rail condition.

[0049] like Figure 4 As shown, Figure 4 This is a schematic diagram of the rail condition monitoring process provided in an embodiment of the present invention. After the system is powered on, it enters the self-test mode; the self-test mode performs self-tests on the transmitting and receiving devices, and represents the rail condition corresponding to the signal sent by the upstream transmitting node through the first flag bit, i.e., through ST1, and sets it to 0, and represents the rail condition corresponding to the signal sent by the downstream transmitting node through the second flag bit, i.e., through ST2, and sets it to 0. When the self-test in self-test mode is successful, the system enters the monitoring mode. In this monitoring mode, the receiving device continuously receives signals and determines parameter values ​​based on the received signals. If the duration of the rail status corresponding to the first flag T1 and / or the second flag T2 is greater than a first set duration, the system enters a fault mode. If the duration of the rail status corresponding to the first flag T1 and / or the second flag T2 is less than or equal to the first set duration, it is determined whether the parameter value meets a first threshold condition. If the parameter value meets the first threshold condition, the system enters a vehicle passage mode. If the parameter value does not meet the first threshold condition but meets the second threshold condition, the system enters an encoding mode. If the parameter value does not meet either the first or second threshold condition, the system remains in monitoring mode. In vehicle passage mode, the receiving device continuously receives signals and determines parameter values ​​based on the received signals. If the parameter value does not meet the first threshold condition, it indicates the end of vehicle passage, and ST1+1 and ST2+1 are executed to change the rail status corresponding to the first and second flags, and the system enters the monitoring mode. The encoding mode encodes the signals sent by the upstream and downstream transmitting nodes, such as encoding the upstream transmitting node as 10101 and the downstream transmitting node as 12121, so as to distinguish the signals received by the receiving device from the signals sent by the upstream transmitting node and the signals sent by the downstream transmitting node; and executes ST1+1 and ST2+1 to change the rail status corresponding to the first flag bit and the second flag bit, and enters the monitoring mode.

[0050] This embodiment, from the perspective of practical engineering applications, designs the signal encoding system for transmission at different locations to avoid crosstalk between upstream and downstream signals, while overcoming environmental noise interference, vehicle interference, and other disturbances such as electromagnetic interference, thereby realizing low-power, long-distance real-time online rail monitoring based on acoustic wave detection.

[0051] In this embodiment, the transmitting device sends a signal to the corresponding transmitting node according to a set signal format; the transmitting node sends the signal to the rail so that the receiving node receives the signal; the receiving node receives signals sent by adjacent transmitting nodes; the adjacent transmitting nodes include upstream transmitting nodes and downstream transmitting nodes; the receiving device determines the rail status based on the signal from the corresponding receiving node; the indoor monitoring device issues an alarm based on the rail status, which can achieve low-cost rail breakage inspection, while minimizing the number of trackside devices and reducing operation and maintenance costs with minimal maintenance.

[0052] The system provided by this invention can be considered as a long-distance, highly reliable, easy-to-engineer, low-maintenance, and technically and economically efficient rail breakage inspection system.

[0053] Although the subject matter has been described using language specific to structural features and / or system logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A rail condition monitoring system, characterized in that, The system includes multiple trackside devices, multiple track-mounted devices, and indoor monitoring devices; the trackside devices include transmitting devices and receiving devices; the track-mounted devices include transmitting nodes and receiving nodes; the transmitting devices are connected to corresponding transmitting nodes, and the receiving devices are connected to corresponding receiving nodes; the transmitting nodes and the receiving nodes are arranged adjacent to each other. The transmitting device is used to send signals to the corresponding transmitting node according to a set signal format; The transmitting node is used to send the signal to the rail so that the receiving node can receive the signal; The receiving node is used to receive signals sent by adjacent transmitting nodes; the adjacent transmitting nodes include upstream transmitting nodes and downstream transmitting nodes. The receiving device is used to determine the rail status based on the signal from the corresponding receiving node; The indoor monitoring equipment is used to issue an alarm based on the condition of the rails; The transmitting nodes include a first odd-numbered transmitting node and a second odd-numbered transmitting node; the set signal mode includes a first transmitting mode and a second transmitting mode. The transmitting device is further configured to transmit a signal to the first odd-numbered transmitting node based on the first transmitting standard, so that the first odd-numbered transmitting node transmits the signal according to the first transmitting standard; The transmitting device is further configured to transmit a signal to the second odd-numbered transmitting node based on the second transmitting standard, so that the second odd-numbered transmitting node transmits the signal in accordance with the second transmitting standard.

2. The system according to claim 1, characterized in that, The first transmission mode is to excite according to a first set frequency and emit a first set number of wave groups, the duration of each wave group is a first set duration, and the pulse time interval is a second set duration; The second transmission mode is to excite according to a second set frequency, emit a second set number of wave groups, the duration of each wave group is a third set duration, and the pulse time interval is a fourth set duration; The interval between the first transmission mode and the second transmission mode is a fifth predetermined time.

3. The system according to claim 1, characterized in that, The system also includes a power supply for supplying power to the trackside equipment and the indoor monitoring equipment.

4. The system according to claim 3, characterized in that, The system includes a self-inspection mode, a monitoring mode, a vehicle passage mode, a coding mode, and a fault mode; wherein, the rail status corresponding to the self-inspection mode, the monitoring mode, the vehicle passage mode, and the coding mode is a normal state, and the rail status corresponding to the fault mode is a broken rail state. The system is configured to enter the self-test mode after power-on; the self-test mode is configured to perform self-tests on the transmitting device and the receiving device, and to represent the rail status corresponding to the signal sent by the upstream transmitting node through a first flag bit, and to represent the rail status corresponding to the signal sent by the downstream transmitting node through a second flag bit.

5. The system according to claim 4, characterized in that, The system is further configured to enter the monitoring mode when the self-test result of the self-test mode is a successful self-test; wherein, the monitoring mode is configured to continuously receive signals through the receiving device and determine parameter values ​​based on the received signals; if the duration of the rail status corresponding to the first flag bit and / or the second flag bit is greater than a first set duration, the system enters the fault mode; if the duration of the rail status corresponding to the first flag bit and / or the second flag bit is less than or equal to the first set duration, it is determined whether the parameter value meets a first threshold condition; if the parameter value meets the first threshold condition, the system enters the vehicle passage mode; if the parameter value does not meet the first threshold condition but meets the second threshold condition, the system enters the coding mode.

6. The system according to claim 5, characterized in that, The vehicle passage mode is used to continuously receive signals through the receiving device and determine parameter values ​​based on the received signals; if the parameter values ​​do not meet the first threshold condition, the rail states corresponding to the first flag bit and the second flag bit are counted and accumulated respectively to change the rail states corresponding to the first flag bit and the second flag bit, and then the monitoring mode is entered.

7. The system according to claim 5, characterized in that, The encoding mode is used to encode the signals sent by the upstream transmitting node and the downstream transmitting node, so as to distinguish the signals received by the receiving device into the signals sent by the upstream transmitting node and the signals sent by the downstream transmitting node. The system counts and accumulates the rail status corresponding to the first and second flag bits respectively, so as to change the rail status corresponding to the first and second flag bits and enter the monitoring mode.

8. The system according to claim 5, characterized in that, The parameter values ​​include the centroid frequency and the wavelet packet entropy value; the first threshold condition is met when the centroid frequency is less than a set centroid frequency threshold and the wavelet packet entropy value is greater than a set entropy value threshold; the second threshold condition is met when the centroid frequency is greater than a set centroid frequency threshold and the wavelet packet entropy value is less than a set entropy value threshold.

9. The system according to claim 1, characterized in that, The indoor monitoring equipment is also used to issue an alarm when the rail is in a broken rail condition.

Images