Urban rail transit vehicle-mounted signal gap marking dynamic compensation method

Abstract

The application discloses a kind of urban rail transit vehicle-borne signal gap mark dynamic compensation method and system, it is related to rail transit signal control technical field.The present application obtains train operation, brake response, wheel-rail adhesion and signal delay data in real time by multi-source data acquisition unit for the problem of gap mark caused by PR4G / F@stnet radio signal transmission delay, brake system software and hardware imbalance, wheel-rail adhesion coefficient and environmental temperature fluctuation under ATO mode of Thales SelTrac™ CBTC system, and establishes signal transmission delay compensation model based on Kalman filter algorithm to calibrate ATO brake instruction time sequence;Combined with brake system software version and hardware state dynamic adjustment brake curve deceleration threshold and pressure distribution ratio, trigger secondary brake compensation through double closed-loop feedback control and environment-adhesion coefficient joint correction mechanism.Experiment verification shows that the present application can control the distance of gap mark within 0.1m, adapt to different brake software version and environmental scene, without large-scale hardware modification, significantly improve the precision of marking and operation safety, reduce operation and maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of urban rail transit signal control technology, specifically to a dynamic compensation technology for onboard signal overshoot and undershoot in Thales SelTrac™ CBTC systems. Background Technology

[0002] Thales signaling systems, as a mainstream solution for urban rail transit, have been applied to over 40 lines worldwide (data as of 2024). However, the issue of overshooting and undershooting in ATO mode still affects operational safety. Existing technology has the following shortcomings: 1. Signal transmission delay not specifically compensated: Thales PR4G series radios have millisecond-level delays in high-density operation scenarios, resulting in delayed execution of braking commands; 2. Imbalance between ATO algorithm and braking system: Braking force is improved after the braking software version is upgraded (e.g., from 3.7 to 4.0), but the ATO curve is not dynamically adapted; 3. Environmental and wheel-rail factors are overlooked: Low winter temperatures on underground lines cause a decrease in wheel-rail adhesion coefficient, and the existing system lacks a real-time correction mechanism; 4. Limited compensation methods: Existing solutions focus primarily on adjusting braking hardware (such as brake shoe clearance compensation), without forming coordinated control of signals, vehicles, and tracks. Summary of the Invention

[0003] Technical issues This invention addresses the issues of overshooting and undershooting caused by signal delay, brake mismatch, and wheel-rail adhesion fluctuations in the Thales signaling system under ATO mode, enabling precise alignment. Technical solution This invention constructs a dynamic compensation system through end-to-end optimization of the "sensing-computation-execution-feedback" process. 1. Multi-source sensing layer: Wheel-rail adhesion coefficient sensor: Based on optical detection principle, it collects the surface condition of the rail in real time with a resolution of 0.01. Braking response monitoring unit: Collects data on brake cylinder pressure (range 2.0-3.5 bar), brake shoe actuation timing, and deceleration. Signal delay detector: Monitors LTE / CBTC communication link delay with an accuracy of ±1ms. 2. Core Computing Layer: Transmission delay compensation: Kalman filtering algorithm is used to process PR4G radio delay data and dynamically adjust the ATO command transmission time; Braking curve adaptation: Establish a braking software version-braking force mapping table, and optimize the deceleration control during the electro-pneumatic transition phase for version 4.0 software; Adhesion coefficient correction: When the adhesion coefficient is below 0.3, the braking safety margin is automatically increased by 15% to prevent slippage. 3. Execution Feedback Layer: Dual closed-loop control: The outer loop adjusts the braking level based on the train's position deviation (overshoot is +, undershoot is -), while the inner loop monitors the braking performance. Secondary compensation mechanism: When the calibration deviation exceeds 0.2m, an emergency fine-tuning command is triggered, and the control accuracy reaches ±0.05m. Beneficial effects 1. Significantly improved alignment accuracy: The misalignment distance is controlled within 0.1m, reducing it by 80% compared to existing technologies; 2. Strong compatibility: Compatible with Thales TSTCBTC® 2.0 / 3.0 systems and PR4G / F@stnet radios, requiring no large-scale hardware modifications; 3. Excellent adaptive capability: It can cope with the effects of multiple factors such as braking software upgrades, temperature changes, and wheel and rail wear; 4. Low operation and maintenance costs: Fault tracing is achieved through the data storage module, reducing the parameter debugging cycle after maintenance. Hardware configuration Data acquisition module: installed on the train head and bogie, wheel-rail adhesion sensor fixed to the inside of the rail, brake monitoring unit connected to vehicle network system; Core control module: integrated into Thales vehicle-mounted ATP cabinet, adopts SCA architecture software radio, and supports GeoMux HD waveform; Communication interface: Compatible with DC11V door opening command signal, communicates with host computer via WIFI / Ethernet. Software process 1. System initialization: Read basic parameters such as braking software version and signal system model; 2. Data Acquisition: Real-time acquisition of data such as communication delay (≤50ms), adhesion coefficient (0.2-0.6), and brake cylinder pressure; 3. Delay compensation: Correct the ATO braking trigger time based on the Kalman filter output command calibration value; 4. Curve Adjustment: Adjust the deceleration threshold according to the braking software version; for version 4.0, set it to 1.2 m / s². 5. Deviation Correction: Compare the actual position with the PSP. When the deviation is >0.1m, output a secondary braking command; 6. Data storage: Record the benchmarking data each time to form a historical database for algorithm optimization. Experimental verification The Jinan Metro Line 1, which uses the Thales TSTCBTC® 3.0 system, was selected for 100 ATO (Automatic Train Operation) mode station entry tests using the system of this invention: Ambient temperature: -5℃~25℃ (covering low-temperature winter scenarios); Braking software version: 4.0; Test results: The maximum distance between the benchmark and the target was 0.08m, and the average distance was 0.03m. There was no need for secondary benchmarking, which met the operational standards.

Claims

1. A method for dynamic compensation of signal overshoot and undershoot in urban rail transit vehicles, characterized in that, include: Step 1: Construct a multi-source data acquisition unit to acquire real-time train operation status data, braking system response data, wheel-rail adhesion coefficient data, and signal transmission delay data; Step 2: Based on the communication protocol of the Thales SelTrac™ CBTC system, establish a signal transmission delay compensation model and perform timing calibration on the ATO braking command; Step 3: Based on the characteristics of the braking system software version and hardware status parameters, dynamically adjust the deceleration threshold and pressure distribution ratio of the ATO braking curve; Step 4: Through dual closed-loop feedback control, the deviation between the actual position of the train and the preset stopping point (PSP) is compared in real time, and a secondary braking compensation command is triggered; Step 5: Dynamically adjust the braking safety margin based on ambient temperature and wheel-rail adhesion coefficient to avoid alignment deviation caused by wheel spin or coasting.

2. The method according to claim 1, characterized in that: The multi-source data acquisition unit includes a wheel-rail adhesion coefficient sensor, a brake cylinder pressure sensor, a deceleration sensor, and an LTE communication delay detector, with a sampling frequency of not less than 100Hz.

3. The method according to claim 1, characterized in that: The signal transmission delay compensation model employs a Kalman filter algorithm and, based on real-time transmission delay data from the PR4G / F@stnet radio, performs ±50ms-level calibration on the timing of ATO command transmission.

4. The method according to claim 1, characterized in that: The braking curve adjustment includes adopting a graded braking strategy for the Thales TSTCBTC® 2.0 / 3.0 system. Under this graded braking strategy, when the braking system software version is 4.0 or above, the deceleration bulge compensation coefficient during the electro-pneumatic transition phase is set to 0.8-1.

2.

5. A dynamic compensation system for overshoot / undershoot in a Thales signaling system for rail transit, characterized in that, include: Data acquisition module: integrates wheel-rail adhesion coefficient detection unit, braking response monitoring unit and signal delay detection unit, and communicates bidirectionally with Thales on-board ATP / ATO system; Core control module: Based on software radio (SDR) architecture, running the dynamic compensation algorithm described in any of claims 1-4, and compatible with GeoMux HD waveform protocol; Execution feedback module: Connects to the train braking control system, receives compensation commands and provides real-time feedback on braking execution status, achieving precise control with a calibration deviation of ≤0.1m; Storage and interaction module: Records historical benchmarking data and compensation parameters, and supports data synchronization with the host computer operation and maintenance platform.

6. The system according to claim 5, characterized in that: The core control module adopts a dual MCU redundancy design, with a processing delay of ≤20ms, and has the functions of fault self-diagnosis and degraded operation.