A rail detection system and node working method based on radio frequency energy supply

Abstract

The present invention belongs to the field of wireless sensing technology, and in particular relates to a wireless sensing system and a working method of a node based on radio frequency energy supply. It solves the problem that the existing technology is not only still expensive and has low inspection efficiency, but also requires the replacement of node batteries. A rail detection system based on radio frequency energy supply includes nodes, routers and coordinators. The nodes are arranged on the railway, and the routers and coordinators are arranged on the train. The nodes establish a wireless connection with the routers, and several routers are wirelessly connected to the coordinator. The coordinator has a wired data connection with the GSM-R communication system circuit arranged on the train, and the GSM-R communication system is wirelessly connected to the control center. The rail detection system proposed in the present invention realizes rail detection and data reporting completely driven by radio frequency energy through the cooperation of detection nodes, routers and coordinators. It does not require battery power supply and has the advantages of reliable operation, strong real-time detection, and maintenance-free.

Description

Technical Field

[0001] The present invention belongs to the field of wireless sensing technology, and in particular relates to a rail detection system and a node working method based on radio frequency energy supply. Background Art

[0002] Railways are an economical and environmentally friendly mode of land transportation. Travel demand and the need to alleviate traffic congestion have led to rapid growth in China's railway length over the past decade. However, over time, the stress and impact caused by the interaction between wheels and rails can deteriorate rail quality. As the foundation of train operation, uneven rails can cause vibration or damage to rolling stock, and may even lead to derailment or overturning. Therefore, regular inspection and reporting of rail conditions to promptly identify potential risks is crucial.

[0003] Current rail inspections rely primarily on inefficient, costly, and dangerous manual methods, as well as custom vehicles equipped with inspection systems. While these methods significantly expedite inspections, they also suffer from the high cost of occupying the tracks while the equipment is in operation, resulting in low inspection efficiency. IoT-based structural health monitoring is an effective strategy for timely detection of defects, minimizing costs while preserving the normal operation of the railway system.

[0004] Currently, IoT nodes are powered by lithium batteries or harvested solar energy. While IoT-based wireless sensor network systems offer advantages such as low cost and compact node size, they also require a large number of nodes and are widely distributed, leading to labor costs associated with replacing numerous node batteries. Energy harvesting to maintain node operation is susceptible to environmental influences. Due to the low frequency of track inspection needs, most track inspection systems utilize a standby mode to wake up nodes. However, this conventional standby mode consumes significant standby power. RF energy is a far-field wireless energy transmission method, but its development and utilization are currently limited. By placing RF energy transmitters on trains and building a system to power track inspection nodes with RF energy, the nodes can operate stably without batteries and independently of the environment, saving significant labor costs associated with replacing batteries due to damage or depletion.

[0005] Therefore, it is urgent to propose a rail detection system based on radio frequency energy supply to solve the above problems. Summary of the Invention

[0006] The present invention aims to address the high cost and frequent battery replacement issues inherent in existing technologies. A brief overview of the present invention is provided below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify key or important aspects of the present invention, nor is it intended to limit the scope of the present invention.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is a rail detection system based on radio frequency energy supply, including nodes, routers and coordinators. The nodes are deployed on the railway, and the routers and coordinators are deployed on the train. The nodes establish a wireless connection with the routers, and several routers are wirelessly connected to the coordinator. The coordinator has a wired data connection with the GSM-R communication system circuit installed on the train, and the GSM-R communication system is wirelessly connected to the control center.

[0008] Preferably, the nodes are evenly arranged on the railway, and several routers are evenly arranged on both sides of the train.

[0009] Preferably: the node includes a radio frequency antenna, a rectifier and matching circuit, a voltage multiplier, an energy storage capacitor, a power management circuit, a first load switch, an accelerometer, a microcontroller unit (MCU) with a built-in Zigbee module, a data transceiver antenna, a second load switch, and an ultra-low power analog-to-digital converter (ADC). The radio frequency antenna, the rectifier and matching circuit, the voltage multiplier, and the energy storage capacitor are electrically connected in sequence. The energy storage capacitor is respectively connected to the first load switch, the second load switch, and the MCU (1.3) through the power management circuit. The MCU is electrically connected to the first load switch, the second load switch, the ultra-low power ADC, the accelerometer, and the data transceiver antenna. The second load switch is electrically connected to the ultra-low power ADC. The ultra-low power ADC is electrically connected to the energy storage capacitor.

[0010] Preferably: the router includes a radio frequency antenna, an impedance matching circuit, a radio frequency power amplifier, a signal generating module, a vehicle-mounted power supply, a power management circuit, an MCU with a built-in Zigbee module, and a data transceiver antenna. The vehicle-mounted power supply is electrically connected to the power management circuit, the power management circuit is electrically connected to the signal generating module and the MCU respectively, the signal generating module, the radio frequency power amplifier, the impedance matching circuit, and the radio frequency antenna are electrically connected in sequence, and the MCU is electrically connected to the data transceiver antenna.

[0011] Preferably: the coordinator includes a data transceiver antenna, an MCU with a built-in Zigbee module, an on-board power supply, a power management chip (Power Management IC, hereinafter referred to as PMIC), and a GSM-R interface circuit; the on-board power supply, PMIC, and MCU are electrically connected in sequence, and the MCU is electrically connected to the GSM-R interface circuit and the data transceiver antenna respectively.

[0012] A method for operating a node of a rail detection system based on radio frequency energy supply comprises the following steps:

[0013] S1: The RF antenna in the node collects the RF energy emitted by the RF antenna in the router and powers on.

[0014] S2: node initialization;

[0015] S3: The MCU controls the second load switch to turn on, controls the ultra-low power ADC to collect the voltage of the energy storage capacitor and determine whether the battery is sufficient. If the battery is insufficient, the second load switch is turned off, and the MCU enters low-power mode. After waking up from low-power mode for a period of time, the second load switch is turned on again to collect the voltage of the energy storage capacitor to determine whether the battery is sufficient. If the battery is sufficient, the MCU turns off the second load switch and turns on the radio frequency function to start scanning the network through the data transceiver antenna. The router with the best signal quality is selected as the parent node through the algorithm to join the network;

[0016] S4: The MCU controls the first load switch to turn on, controls the accelerometer to turn on to collect data, and sends the data to the data transceiver antenna in the router through the data transceiver antenna, waits for the router to receive the data information and return a confirmation message to the MCU, and executes in a loop until the time the node waits for the confirmation message exceeds the preset time threshold or the remaining power is insufficient to complete the tasks of data collection, sending, and waiting for the router to return a confirmation message. It disconnects from the current router, enters low power mode, and re-executes S3. If the power is cut off during the execution of S4 and the train has not left, S2 is executed after the power is restored. After the train leaves, the node loses power and waits for the next train to arrive.

[0017] The present invention has the following beneficial effects

[0018] The present invention provides a rail inspection system and node working method based on radio frequency energy supply, which can detect defects in a timely manner, improve inspection efficiency, and provide an effective inspection strategy that does not affect the normal operation of the railway system and can reduce costs.

[0019] The node can operate stably without batteries and is not dependent on the environment, which can save a lot of labor costs for replacing batteries due to battery damage or exhaustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1This is a working diagram of a rail detection system based on radio frequency energy supply provided by the present invention.

[0021] Figure 2 This is a block diagram of a rail detection system node based on radio frequency energy supply provided by the present invention.

[0022] Figure 3 This is a block diagram of a rail detection system router based on radio frequency energy supply provided by the present invention.

[0023] Figure 4 This is a block diagram of a rail detection system coordinator based on radio frequency energy supply provided by the present invention.

[0024] Figure 5 This is a workflow diagram of a node of a rail detection system based on radio frequency energy supply provided by the present invention. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is described below by way of specific embodiments. However, it should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the present invention.

[0026] The connections mentioned in the present invention are divided into electrical connections and wireless connections. The electrical connections include but are not limited to wire connections, plug connections, terminal connections and snap connections. The wireless connections include but are not limited to conventional connection methods such as electromagnetic wave connections, infrared connections, signal connections and data connections. When the specific connection method is not clearly specified, it is assumed that at least one connection method can always be found among the existing connection methods to achieve the function. Those skilled in the art can choose according to their needs.

[0027] Specific implementation method 1: Combination Figure 1-5 This embodiment describes a rail detection system based on radio frequency energy supply, including a node 1, a router 2 and a coordinator 3. The node 1 is arranged on the railway, and the router 2 and the coordinator 3 are arranged on the train. The node 1 establishes a wireless connection with the router 2, and several routers 2 are wirelessly connected to the coordinator 3. The coordinator 3 is connected to the GSM-R communication system circuit set up on the train, and the GSM-R communication system 4 is wirelessly connected to the control center. It can easily adapt to the monitoring needs of rails of different lengths and different densities. By increasing or decreasing the number of nodes and routers, the system can easily expand or reduce its coverage.

[0028] Specific implementation method 2: Combination Figure 1This embodiment describes a rail detection system based on radio frequency energy supply, wherein nodes are evenly arranged on the railway, and a plurality of routers (2) are evenly arranged on both sides of the train, which facilitates communication and data transmission.

[0029] Specific implementation method three: Combination Figure 1-2 The present embodiment describes a rail detection system based on radio frequency energy supply, wherein the node 1 includes a radio frequency antenna 1.1, a rectifier matching circuit 4, a voltage multiplier 5, an energy storage capacitor 6, a power management circuit 1.2, a first load switch 7, an accelerometer 8, a microcontroller unit (hereinafter referred to as MCU) 1.3 with a built-in Zigbee module, a data transceiver antenna 1.4, a second load switch 9, and an ultra-low power analog to digital converter (Analog to Digital Converter). Converter (hereinafter referred to as ADC) 10, RF antenna 1.1, rectifier and matching circuit 4, voltage multiplier 5, and energy storage capacitor 6 are electrically connected in sequence. The energy storage capacitor 6 is respectively connected to the first load switch 7, the second load switch 9, and MCU 1.3 through the power management circuit 1.2. The MCU 1.3 is electrically connected to the first load switch 7, the second load switch 9, the ultra-low power ADC 10, the accelerometer 8, and the data transceiver antenna 1.4. The second load switch 9 is electrically connected to the ultra-low power ADC 10, and the ultra-low power ADC 10 is electrically connected to the energy storage capacitor 6 to achieve efficient energy utilization.

[0030] Specific implementation method four: Combination Figure 1-3 This embodiment describes a rail detection system based on radio frequency energy supply. The router 2 includes a radio frequency antenna 2.1, an impedance matching circuit 11, a radio frequency power amplifier 12, a signal generating module 13, an on-board power supply 2.6, a power management circuit 2.2, an MCU 2.3 with a built-in Zigbee module, and a data transceiver antenna 2.4. The on-board power supply 2.6 is electrically connected to the power management circuit 2.2, and the power management circuit 2.2 is electrically connected to the signal generating module 13 and the MCU 2.3 respectively. The signal generating module 13, the radio frequency power amplifier 12, the impedance matching circuit 11, and the radio frequency antenna 2.1 are electrically connected in sequence. The MCU 2.3 is electrically connected to the data transceiver antenna 2.4, and the data transceiver antenna 2.4 is electrically connected to the data transceiver antenna 1.4, which improves the efficiency and accuracy of data collection and provides strong support for the intelligence and automation of railway detection systems.

[0031] Specific implementation method five: Combination Figure 1-4This embodiment describes a rail track detection system based on radio frequency energy supply. The coordinator 3 includes a data transceiver antenna 3.4, an MCU 3.3 with a built-in Zigbee module, an on-board power supply 3.6, a power management chip (Power Management IC, hereinafter referred to as PMIC) 14, and a GSM-R interface circuit 15. The on-board power supply 3.6, the PMIC 14, and the MCU 3.3 are electrically connected in sequence. The MCU 3.3 is electrically connected to the GSM-R interface circuit 15 and the data transceiver antenna 3.4, respectively. The data transceiver antenna 3.4 is electrically connected to the data transceiver antenna 2.4. This improves the intelligence level of the railway detection system and also enhances the safety and efficiency of railway operations.

[0032] Specific implementation method six: combination Figure 1-5 This embodiment describes a method for operating a rail detection system node based on radio frequency energy supply, including the following steps:

[0033] S1: The RF antenna (1.1) in the node (1) collects the RF energy emitted by the RF antenna (2.1) in the router (2) and powers on;

[0034] S2: Node (1) initialization;

[0035] S3: MCU1.3 controls the second load switch 9 to turn on, controls the ultra-low power ADC 10 to collect the voltage of the energy storage capacitor 6 and determine whether the battery is sufficient. If the battery is insufficient, the second load switch 9 is turned off, and MCU1.3 enters low-power mode. After waking up from low-power mode for a period of time, the second load switch 9 is turned on again to collect the voltage of the energy storage capacitor 6 to determine whether the battery is sufficient. If the battery is sufficient, MCU1.3 turns off the second load switch 9 and turns on the radio frequency function to start scanning the network. Router 2 with the best signal quality is selected as the parent node to join the network through the algorithm;

[0036] S4: MCU1.3 controls the first load switch 7 to turn on, controls the accelerometer 8 to turn on and send data to router 2, waits for router 2 to return a confirmation message after receiving the data information, and executes the loop until the time node 1 waits for the confirmation message exceeds the preset time threshold or the remaining power is insufficient to complete the tasks of data collection, transmission, and waiting for router 2 to return a confirmation message. Then, node 1 disconnects from router 2, enters low-power mode, and re-executes S3. If the power is lost during the execution of S4 and the train has not left, node 1 will be powered on again and execute S2. After the train leaves, node 1 will lose power and wait for the next train to arrive.

[0037] Step S3 is to judge the amount of electricity according to formula (1), where C is the capacitance of the energy storage capacitor, U min1It is the lower limit of the capacitor's initial voltage that is sufficient to complete the process from controlling the ADC to collecting voltage, scanning the network, joining the network, collecting data, sending data, and receiving the router's confirmation message. L It is the lower voltage limit set by the power management circuit to allow the capacitor to discharge (the capacitor voltage will no longer discharge if it is lower than this voltage). t0 is the time when the ADC starts to collect the capacitor voltage, t1 is the time when the node receives the confirmation message returned by the router, and P1(t) is the real-time power during this period. By replacing the circuit before the energy storage capacitor with a constant voltage source with a constant voltage of U and measuring the current I1(t) of the power source during this period, the energy required for this process can be calculated. According to formula (1), U is obtained min1 When the node is working normally, if the ADC collects the voltage U ADC1 If formula (2) is satisfied, the battery is sufficient, otherwise the battery is insufficient.

[0038]

[0039] U ADC1 >U min1 (2)

[0040] The power determination in step S4 can be performed according to formula (3), where C is the capacitance of the energy storage capacitor, U min2 It is the lower limit of the capacitor initial voltage that is sufficient to complete the process from controlling the ADC to collecting voltage, collecting data at the node, sending data, and receiving confirmation messages from the router. L is the lower voltage limit set by the power management circuit to allow the capacitor to discharge (the capacitor will no longer discharge if the capacitor voltage is lower than this voltage). t2 is the time when the ADC starts to collect the capacitor voltage, t3 is the time when the node receives the confirmation message returned by the router, and P2(t) is the real-time power during this period. By replacing the circuit before the energy storage capacitor with a constant voltage source with a constant voltage of U and measuring the current I2(t) of the power source during this period, U can be obtained according to formula (3). min2 ; When the node is working normally, if the ADC collects the voltage U ADC2 If formula (4) is satisfied, the battery is sufficient, otherwise the battery is insufficient;

[0041]

[0042] U ADC2 >U min2 (4)

[0043] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0044] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutations and combinations. Therefore, the present invention will no longer describe the technical solutions after permutations and combinations one by one, but it should be understood that the technical solutions after permutations and combinations have been disclosed by the present invention.

[0045] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A rail detection system powered by radio frequency energy, characterized by: The system comprises a node (1), a router (2) and a coordinator (3), wherein the node (1) is arranged on the railway, the router (2) and the coordinator (3) are arranged on the train, the node (1) establishes a wireless connection with the router (2), several routers (2) are wirelessly connected with the coordinator (3), the coordinator (3) is connected to the GSM-R communication system circuit arranged on the train by a wired data connection, and the GSM-R communication system is wirelessly connected to the control center; The node (1) includes a radio frequency antenna (1.1), a rectifier matching circuit (4), a voltage multiplier (5), an energy storage capacitor (6), a power management circuit (1.2), a first load switch (7), an accelerometer (8), an MCU (1.3), a data transceiver antenna (1.4), a second load switch (9), and an ultra-low power ADC (10). The radio frequency antenna (1.1), the rectifier matching circuit (4), the voltage multiplier (5), and the energy storage capacitor (6) are electrically connected in sequence. The energy storage capacitor (6) is connected to the first load switch (7), the second load switch (9), and the MCU (1.3) through the power management circuit (1.2). The MCU (1.3) is electrically connected to the first load switch (7), the second load switch (9), the ultra-low power ADC (10), the accelerometer (8), and the data transceiver antenna (1.4). The second load switch (9) is electrically connected to the ultra-low power ADC (10). The ultra-low power ADC (10) is electrically connected to the energy storage capacitor (6). The router (2) includes a radio frequency antenna (2.1), an impedance matching circuit (11), a radio frequency power amplifier (12), a signal generating module (13), an on-board power supply (2.6), a power management circuit (2.2), an MCU (2.3) with a built-in Zigbee module, and a data transceiver antenna (2.4). The on-board power supply (2.6) is electrically connected to the power management circuit (2.2). The power management circuit (2.2) is electrically connected to the signal generating module (13) and the MCU (2.3) respectively. The signal generating module (13), the radio frequency power amplifier (12), the impedance matching circuit (11), and the radio frequency antenna (2.1) are electrically connected in sequence. The MCU (2.3) is electrically connected to the data transceiver antenna (2.4), and the data transceiver antenna (2.4) is electrically connected to the data transceiver antenna (1.4).

2. The rail detection system based on radio frequency energy supply according to claim 1, characterized in that: Nodes (1) are evenly arranged on the railway, and several routers (2) are evenly arranged on both sides of the train.

3. The rail detection system based on radio frequency energy supply according to claim 1, characterized in that: The coordinator (3) includes a data transceiver antenna (3.4), an MCU (3.3) with a built-in Zigbee module, an on-board power supply (3.6), a PMIC (14) and a GSM-R interface circuit (15). The on-board power supply (3.6), the PMIC (14) and the MCU (3.3) are electrically connected in sequence. The MCU (3.3) is electrically connected to the GSM-R interface circuit (15) and the data transceiver antenna (3.4) respectively. The data transceiver antenna (3.4) is electrically connected to the data transceiver antenna (2.4).

4. A method for operating a node of a rail detection system based on radio frequency energy supply according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: The RF antenna (1.1) in the node (1) collects the RF energy emitted by the RF antenna (2.1) in the router (2) and powers on; S2: Node (1) initialization; S3: MCU (1.3) controls the second load switch (9) to turn on, controls the ultra-low power ADC (10) to collect the voltage of the energy storage capacitor (6) and judge whether the power is sufficient. If the power is insufficient, the second load switch (9) is turned off, and the MCU (1.3) enters the low power mode. After a period of time in the low power mode, it wakes up and turns on the second load switch (9) again to collect the voltage of the energy storage capacitor (6) to judge whether the power is sufficient. If the power is sufficient, the MCU (1.3) turns off the second load switch (9) and turns on the radio frequency function to start scanning the network through the data transceiver antenna (1.4). The router (2) with the best signal quality is selected as the parent node to join the network through the algorithm; S4: MCU (1.3) controls the first load switch (7) to be turned on, controls the accelerometer (8) to be turned on to collect data, and sends the data to the data transceiver antenna (2.4) in the router (2) through the data transceiver antenna (1.4), waits for the router (2) to receive the data information and return the confirmation message to MCU (1.3), and executes the loop until the time the node (1) waits for the confirmation message exceeds the preset time threshold or the remaining power is insufficient to complete the task of data collection, sending and waiting for the router (2) to return the confirmation message, disconnects from the current router (2), enters the low power mode, and re-executes S3. If the power is lost during the execution of S4 and the train has not left, the power is restored and S2 is executed. After the train leaves, the node (1) loses power and waits for the next train to arrive.

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