Method for dynamically adjusting train operation interval in rainy and snowy weather

Abstract

This invention discloses a control method for dynamically adjusting train intervals in rainy and snowy weather, comprising: an ATS system receiving environmental change information from multiple input sources, integrating the information, and displaying environmental change information for a specific line area and range; the ATS system making a comprehensive judgment based on the environmental change information for the specific line area and range, setting corresponding GEBR values, and sending them to the onboard controller and the trackside area controller; the onboard controller recalculating the safety braking model and adjusting the operation control curve and stopping point for trains entering the specific line area and range according to the received GEBR values; and the trackside area controller providing updated stopping point protection distance lengths for trains operating within its jurisdiction that have already had their updated GEBR values ​​implemented. This invention addresses the safety risks caused by using fixed GEBR values ​​for train interval protection control under poor weather conditions such as rain and snow, and improves the operational safety of the train operation control system under slippery track conditions.

Description

Technical Field

[0001] This invention relates to the field of rail transit control, and more particularly to a control method for dynamically adjusting train intervals in rainy or snowy weather. Background Technology

[0002] In urban rail transit signal control CBTC (Communication-Based Automatic Train Control) systems, standard safety braking models are used to implement automatic train protection functions. The Guaranteed Emergency Brake Rate (GEBR), determined during project execution, is used as the core parameter for train interval protection under the most unfavorable conditions. The GEBR determined in the early stages of project execution with the vehicle specialists is a fixed value, which is guaranteed in non-slippery track environments such as tunnels. However, for elevated and open ground areas, although some systems can define a smaller GEBR value for protection design, it still cannot fully meet the requirements of extremely slippery tracks, icy rails, or oily wheels and rails under sudden severe conditions. When wheel-rail adhesion is severely insufficient, if the actual emergency braking rate cannot be guaranteed and exceeds the GEBR value used in the system's safety braking protection model, insufficient train protection distance may occur, posing a risk of train collisions or other train-tracking safety accidents. While existing implementation plans can mitigate operational risks in rainy and snowy weather by imposing temporary speed limits, reducing acceleration, and lowering braking rates, these measures significantly impact operational efficiency and do not fundamentally guarantee safety from the perspective of the ATP (Automatic Train Protection) safety braking principle. Research on how to effectively optimize train operation control under rainy and snowy weather conditions has been conducted for many years by various institutions in China, for example:

[0003] Chinese patent CN105549587B describes a method and system for automatic train control in rainy and snowy weather. This invention determines rainy or snowy weather by statistically analyzing the proportion of slippage experienced by trains operating on the main line. It then sends a stop command and a preset mode to all trains, allowing them to operate under preset traction and / or braking force limits, thus changing train parameters for rainy or snowy weather. However, this invention only adjusts train acceleration and braking rate, without adjusting the parameters of the train operation protection safety braking model. When actual track conditions do not meet the GEBR value used in the model, it cannot achieve safe braking distance after emergency braking and safe separation from the preceding train. Furthermore, the need to statistically analyze a large number of slippage incidents before determining rainy or snowy weather causes a lag in setting rainy / snowy modes, preventing timely dynamic adjustments to train operation control.

[0004] Chinese patent CN112141172B describes a method, system, and controller for setting rain and snow modes. This invention sets rain and snow mode commands for track sections, and the corresponding area controller controls the train operation parameters within its jurisdiction after receiving the command. However, this invention fails to explain how the train's onboard controller achieves safe separation protection under poor operating conditions after receiving the rain and snow mode setting.

[0005] Chinese patent CN113147843B describes a train automatic control method based on environmental perception and signaling systems. A meteorological station is deployed at the center of the track section between every two stations to acquire meteorological data, which is then transmitted to a data processing server via a network. Track slippage analysis is performed to obtain the track slippage index, which is then sent to the ATS subsystem. The ATS subsystem determines the appropriate acceleration, braking rate level, and operating level, and sends the level command to the train's onboard subsystem. This invention can provide accurate and timely monitoring input for changes in weather conditions, but it does not explain how the train achieves safe separation protection.

[0006] Chinese patent CN113212497B introduces a method for accurately monitoring the emergency braking rate of operating trains. By determining the position and time changes during the emergency braking process of the train, the actual braking force under the on-site conditions can be dynamically calculated to obtain more accurate emergency braking rate parameters.

[0007] Chinese patent CN113734233B describes a train control method and system for non-stop switching between rain and snow modes. This method involves continuously monitoring the train's status while it operates under preset traction and braking forces, applying a first braking force, and acquiring the train's speed after braking in real time. If the post-braking speed is less than a preset speed limit threshold, an emergency braking trigger speed is determined based on train information and rain / snow information. If the emergency braking trigger speed is greater than or equal to the preset speed limit threshold, the train switches to rain / snow mode and operates at a preset speed. This invention uses dynamic braking monitoring to determine whether the train enters rain / snow mode, but it fails to explain how the train achieves safe separation protection in rain / snow mode. Summary of the Invention

[0008] The purpose of this invention is to provide a control method for dynamically adjusting train intervals in rainy and snowy weather, to solve the safety risks caused by using fixed GEBR values ​​for train interval protection control under poor rainy and snowy weather conditions, and to improve the operational safety of the train operation control system under slippery track conditions.

[0009] The technical solution to achieve the above objectives is:

[0010] Control methods for dynamically adjusting train intervals during rain and snow include:

[0011] Step S1: The ATS (Automatic Train Monitoring System) receives environmental change information from multiple input sources, integrates the information, and displays environmental change information for a specific line area and range.

[0012] Step S2: The ATS system makes a comprehensive judgment based on the environmental change information of the specific line area and range, sets the corresponding GEBR value, and sends it to the on-board controller and the trackside area controller.

[0013] Step S3: The onboard controller recalculates the safety braking model and adjusts the operation control curve and stopping point for trains entering a specific line area and range, based on the received GEBR values.

[0014] Step S4: The trackside area controller provides the updated stop point protection distance length to the trains operating within its jurisdiction that have already had their GEBR values ​​updated.

[0015] Preferably, in step S1, the environmental change information package includes information on meteorology, trackside environment, onboard environment, and braking change monitoring.

[0016] Multiple input methods include:

[0017] Input is based on manual assessment of rain and snow weather by the control center;

[0018] Information is provided to the control center via an environmental sensing system installed along the track.

[0019] After the environmental perception system installed on the train detects rain and snow, it directly provides status information to the onboard controller, which then provides the information to the control center for input.

[0020] The onboard controller provides information to the control center based on the actual emergency braking rate detected during emergency braking of currently operating trains.

[0021] Preferably, in step S2,

[0022] The control center manually judges the rain and snow weather, selects and sends the appropriate GEBR value to the vehicle controller and the trackside area controller through the human-machine interface of the ATS system.

[0023] After providing information to the control center through the environmental perception system set up on the trackside, the appropriate GEBR value is selected and sent to the on-board controller and the trackside area controller through the human-machine interface of the ATS system.

[0024] After the environmental perception system installed on the train detects rain and snow, it directly provides status information to the onboard controller. After the onboard controller provides the information to the control center, the appropriate GEBR value is selected and sent to the onboard controller and the trackside area controller through the human-machine interface of the ATS system.

[0025] Based on the actual emergency braking rate detected during emergency braking of currently operating trains, the onboard controller provides information to the control center, which compares it with the nominal GEBR and calculates the corresponding GEBR value. The appropriate GEBR value is then selected and sent to the onboard controller and the trackside area controller through the ATS system's human-machine interface.

[0026] Preferably, in step S3, the vehicle controller performs a security check on the received GEBR numerical information to determine that the input source is legal and safe, and that the value is within a reasonable range.

[0027] Preferably, in step S3, the on-board controller confirms the received GEBR value. When the train enters a specific line area and range, it immediately recalculates the safety braking model according to the new GEBR value to obtain the updated required safety protection distance, and automatically adjusts the updated operation control curve and stopping point.

[0028] Preferably, in step S3, the on-board controller receives the updated GEBR value during train operation. During the update calculation, the on-board controller will tolerate a more restrictive safety braking model and switch from the current speed curve to a new, more stringent speed curve without causing emergency braking.

[0029] In ATO driving mode, the train can be automatically decelerated; in manual ATP driving mode, the onboard display unit is updated to instruct the driver to reduce speed and transition to a new safe braking curve.

[0030] Preferably, in step S4, if the station parking protection distance is insufficient, the station parking protection distance provided by the trackside area controller is extended accordingly to ensure that the train can stop at the station.

[0031] Preferably, the GEBR value selection provided by the ATS system includes multiple options, with a typical mains rail GEBR value of 0.9 m / s in engineering applications. 2 The GEBR value for wet rails is 0.8 m / s. 2 At 0.1 m / s 2 The difference can be set and adjusted.

[0032] The beneficial effects of this invention are:

[0033] This invention provides suitable GEBR values ​​for onboard controllers of trains operating in specific line areas and ranges through diverse environmental data acquisition or input methods. After the onboard controller verifies the input and adopts the new GEBR values, it recalculates the train's safe braking model curve, updates the safe protection distance, and controls the operating interval. This not only prevents train slippage but also ensures a safe braking distance, mitigating the risk of train tracking. It rapidly adapts to safe operation under extreme rain and snow conditions, providing a more reliable way to reduce the risks of train safety protection and tracking interval issues, and improving the robustness and operational safety of the train operation control system under adverse weather conditions.

[0034] Furthermore, the comprehensive assessment of diverse rain and snow environments facilitates flexible selection of GEBR (Geometric Protection Buffer). Providing dynamic GEBR value settings allows for dynamic configuration and adjustment of train operation safety protection based on changes in the track environment. Flexible application of GEBR adjustments ensures the accuracy and applicability of safety protection distance updates. The trackside area controller provides updated stopping point protection distances to trains operating within its jurisdiction that are performing GEBR updates, ensuring normal station operation and stopping. Attached Figure Description

[0035] Figure 1 This is a flowchart of the control method for dynamically adjusting train intervals in rainy or snowy weather according to the present invention;

[0036] Figure 2 This is a schematic diagram illustrating the GEBR numerical configuration options provided by the ATS system in this invention;

[0037] Figure 3 This is a schematic diagram of the vehicle controller updating the safety braking model according to GEBR in this invention;

[0038] Figure 4 This is a schematic diagram of the trackside area controller updating and adjusting the station parking protection distance in this invention. Detailed Implementation

[0039] The invention will now be further described with reference to the accompanying drawings.

[0040] Please see Figure 1 The control method for dynamically adjusting train intervals in rainy or snowy weather according to the present invention includes the following steps:

[0041] Step S1: The ATS system receives environmental change information from multiple input sources, integrates the information, and displays environmental change information for a specific line area and range. Specifically, the environmental change information package includes: meteorological, trackside environmental, onboard environmental, and braking change monitoring information. That is, it receives one or more of the following: meteorological information, trackside environmental perception information, onboard environmental perception information, and actual emergency braking rate information of operating trains. After comprehensive judgment, it displays the environmental changes for a specific line area and range.

[0042] Multiple input methods include:

[0043] Source 1: The control center manually judges the rain and snow weather, selects and sends the appropriate GEBR value to the vehicle controller and the trackside area controller through the human-machine interface of the ATS system.

[0044] Source 2: Through the environmental sensing system set up by the trackside (refer to patent CN113147843B), such as trackside rain gauges, air humidity, rainfall, etc., information is provided to the control center, and then the appropriate GEBR value is selected and sent to the vehicle controller and the trackside area controller through the human-machine interface of the ATS system.

[0045] Source 3: After sensing rain and snow through the environmental perception system installed on the train, the system directly provides status information to the onboard controller. After the onboard controller provides the information to the control center, the appropriate GEBR value is selected and sent to the onboard controller and the trackside area controller through the human-machine interface of the ATS system.

[0046] Source 4: Based on the actual emergency braking rate detected during emergency braking of currently operating trains (refer to patent CN113212497B), the on-board controller provides information to the control center, compares it with the nominal GEBR, calculates the corresponding GEBR value, and selects and sends the appropriate GEBR value to the on-board controller and trackside area controller in the ATS system human-machine interface.

[0047] In step S2, the ATS system makes a comprehensive judgment based on the environmental change information of a specific line area and range, sets the corresponding GEBR value, and sends it to the on-board controller and the trackside area controller.

[0048] Regardless of whether the GEBR value is obtained from one or more of the above sources, after the control center confirms the change in the GEBR value of a specific line area or range, the appropriate GEBR value is selected and confirmed for the specific line area or range through the ATS system human-machine interface and sent to the on-board controller and the trackside area controller.

[0049] The ATS human-machine interface offers multiple GEBR values ​​within a reasonable range for selection. These selectable values ​​are typically progressively smaller than the default fixed GEBR value. Providing a variety of GEBR values ​​ensures that the updated safety protection distance can flexibly adapt to changes in environmental conditions and enables dynamic configuration of the vehicle controller using the GEBR input value for safety protection distance calculation.

[0050] Under normal circumstances, when rain or snow occurs, a lower GEBR value is required than under normal conditions to provide a greater protection distance for the train. In normal weather conditions, the onboard controller supports both the GEBR value for dry rails in tunnel conditions and the GEBR value for wet rails in elevated or open ground conditions. The onboard controller's automatic protection software automatically calculates a safe braking model based on the GEBR of the corresponding track range according to the train's location, providing tracking interval protection for the train. In rain or snow, when the initial wet rail GEBR value of the system on elevated or open ground sections cannot meet the protection requirements, the GEBR value can be updated to obtain better safe braking distance protection, ensuring driving safety and avoiding the risk of excessively short train tracking intervals or rear-end collisions. Furthermore, although tunnel conditions are generally not easily affected by rain or snow, special environments may result in extremely wet tracks, oil contamination of the rail surface and wheels, etc., which may compromise the protective effect of the initial GEBR setting. Therefore, the ATS system in this invention provides an option to update the GEBR value configuration for both dry and wet rails.

[0051] The ATS system offers multiple GEBR value options, allowing for flexible selection based on changing environmental conditions. In typical engineering applications, the GEBR value for dry rails is 0.9 m / s², and for wet rails it is 0.8 m / s². Adjustments are generally made in increments of 0.1 m / s², supporting flexible selection in actual operation. To ensure practicality, the system should be able to guarantee a safe braking distance even under very poor track slippery conditions, after selecting the minimum GEBR value. In typical engineering applications, the minimum GEBR value is assumed to be 0.3 m / s². Specifically, after selecting a specific control area and track area on the ATS line interface, a suitable GEBR value can be set as needed. Typical GEBR value configuration options provided by the ATS system include... Figure 2 As shown.

[0052] Based on the changes in environmental conditions in step S1, when environmental conditions continue to change or recover, it can be determined to update the GEBR value settings again to achieve flexible adjustment of the GEBR value for specific line areas and ranges.

[0053] In step S3, the onboard controller performs a security check on the received GEBR numerical information to determine that the input source is legal and safe, and that the value is within a reasonable range. After confirming the received GEBR value, the onboard controller immediately recalculates the safety braking model according to the new GEBR value once the train enters a specific track area and range, obtaining an updated required safety protection distance, and automatically adjusts the updated operation control curve and stopping point.

[0054] The onboard controller is responsible for calculating the train's safe protection distance. According to the IEEE 1474.1 standard's safe braking model, the GEBR value is a key parameter in the braking protection process, determining the length of the protection distance during braking. A smaller GEBR value results in a longer protection distance and a larger interval, leading to safer operation. However, in rainy or snowy weather conditions, the track adhesion coefficient decreases, increasing the train's braking distance. This necessitates the system providing a longer safe protection distance to ensure the train can stop safely within the protection distance. In this case, a smaller GEBR value needs to be set for the onboard controller to update the safe braking model, adapting to the new track conditions and ensuring train safety. The impact of different GEBR value configurations on the safe braking model calculation and safe tracking interval is as follows: Figure 3 As shown.

[0055] During operation, the train will receive updated GEBR values. To avoid unnecessary emergency braking when updating the safety protection distance, the onboard controller will tolerate a more restrictive safety braking model during the update calculation, switching from the current speed curve to the new, more stringent speed curve without causing emergency braking. To enable the use of the more restrictive GEBR values ​​as quickly as possible, the train can be automatically decelerated in ATO driving mode; in manual ATP driving mode, the driver is instructed to reduce speed by updating the onboard display unit to transition to the new safety braking curve.

[0056] Step S4: The trackside area controller provides updated stop point protection distances to trains operating within its jurisdiction that have already had their GEBR values ​​updated. If the station stop point protection distance is insufficient, the trackside area controller extends the station stop protection distance accordingly to ensure the train can stop at the station. Typically, when a smaller GEBR value is set, the original station stop point protection distance will be relatively insufficient. The trackside area controller adjusts the station stop protection distance based on the received updated GEBR value changes, using a longer stop protection distance to ensure the train can stop normally at the station. Figure 4 As shown.

[0057] Compared to existing CBTC signaling systems or fully automated operation systems that handle rain and snow modes using a fixed GEBR value for train interval protection, this mechanism typically reduces operating efficiency by limiting speed and / or decreasing acceleration and braking rate in severe weather. However, it doesn't fundamentally solve the train interval protection problem from a safety perspective. This invention dynamically adjusts the GEBR of trains operating in specific areas to quickly adapt to safe operation under extreme rain and snow conditions. It provides a more reliable way to reduce train safety and tracking interval safety risks, improving the robustness and operational safety of the train operation control system under severe weather conditions. Existing patents do not dynamically adjust the calculation and update of the train safety braking model and the safety protection distance under rain and snow modes.

[0058] The above embodiments are for illustrative purposes only and are not intended to limit the invention. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions should also fall within the scope of the invention and should be defined by the claims.

Claims

1. A control method for dynamically adjusting train intervals in rainy or snowy weather, characterized in that, include: Step S1: The ATS system receives environmental change information from multiple input sources, integrates the information, and displays environmental change information for a specific line area and range. Step S2: The ATS system makes a comprehensive judgment based on the environmental change information of the specific line area and range, sets the corresponding GEBR value, and sends it to the on-board controller and the trackside area controller. Step S3: The onboard controller recalculates the safety braking model and adjusts the operation control curve and stopping point for trains entering a specific line area and range, based on the received GEBR values. Step S4: The trackside area controller provides the updated stop point protection distance length to the trains operating within its jurisdiction that have already had their GEBR values ​​updated. In step S2, After providing information to the control center through the environmental perception system set up on the trackside, the appropriate GEBR value is selected and sent to the on-board controller and the trackside area controller through the human-machine interface of the ATS system. After the environmental perception system installed on the train detects rain and snow, it directly provides status information to the onboard controller. The onboard controller then provides the information to the control center, where the appropriate GEBR value is selected and sent to the onboard controller and the trackside area controller via the ATS system's human-machine interface.

2. The control method for dynamically adjusting train intervals in rainy or snowy weather according to claim 1, characterized in that, In step S1, the environmental change information includes: meteorological, trackside environment, onboard environment, and braking change monitoring information; Multiple input methods include: Input is based on manual assessment of rain and snow weather by the control center; Information is provided to the control center via an environmental sensing system installed along the track. After the environmental perception system installed on the train detects rain and snow, it directly provides status information to the onboard controller, which then provides the information to the control center for input. The onboard controller provides information to the control center based on the actual emergency braking rate detected during emergency braking of currently operating trains.

3. The control method for dynamically adjusting train intervals in rainy or snowy weather according to claim 2, characterized in that, In step S2, The control center manually judges the rain and snow weather, selects and sends the appropriate GEBR value to the vehicle controller and the trackside area controller through the human-machine interface of the ATS system. Based on the actual emergency braking rate detected during emergency braking of currently operating trains, the onboard controller provides information to the control center, which compares it with the nominal GEBR and calculates the corresponding GEBR value. The appropriate GEBR value is then selected and sent to the onboard controller and the trackside area controller through the ATS system's human-machine interface.

4. The control method for dynamically adjusting train intervals in rainy or snowy weather according to claim 1, characterized in that, In step S3, the vehicle controller performs a security check on the received GEBR numerical information to determine that the input source is legal and safe, and that the value is within a reasonable range.

5. The control method for dynamically adjusting train intervals in rainy or snowy weather according to claim 1, characterized in that, In step S3, the on-board controller confirms the received GEBR value. When the train enters a specific line area and range, it immediately recalculates the safety braking model according to the new GEBR value to obtain the updated required safety protection distance, and automatically adjusts the updated operation control curve and stopping point.

6. The control method of claim 1, wherein In step S3, the onboard controller receives the updated GEBR value during train operation. During the update calculation, the onboard controller will tolerate a more restrictive safety braking model and switch from the current speed curve to the new, more stringent speed curve without causing emergency braking. In ATO driving mode, the train can be automatically decelerated; in manual ATP driving mode, the onboard display unit is updated to instruct the driver to reduce speed and transition to a new safe braking curve.

7. The control method of claim 1, wherein In step S4, if the protection distance of the station parking point is insufficient, the station parking protection distance provided by the trackside area controller is extended accordingly to ensure that the train can stop at the station.

8. The control method of claim 3, wherein The ATS system offers several options for selecting the GEBR value, with a typical mainline GEBR value of 0.9 m / s for engineering applications. 2 The wet track GEBR value is 0.8 m / s 2 At 0.1 m / s 2 The difference can be set and adjusted.

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