Digital brake control system for passenger trains with friction surface icing detection function

Abstract

FIELD: railway.SUBSTANCE: invention relates to the diagnostics of railway rolling stock and is intended to monitor the brakes of each car in a passenger train and to promptly detect icing of their friction elements contacting with each other. Each passenger car is equipped with a brake cylinder pressure sensor, a brake line pressure sensor (standard, purchased), an icing sensor (also selected from standard existing solutions widely used in aviation) and a microprocessor diagnostic unit that receives information from the sensors, processes, records (stores) and transmits information about the condition of the brakes to the locomotive diagnostic unit. The locomotive diagnostic unit is installed on a passenger locomotive and receives and processes information from all car units, and then displays this information to the driver (via the control system or directly to the monitor).EFFECT: increase in traffic safety, efficiency of diagnostics and testing of brakes in passenger trains during their formation, preparation for travel, technical maintenance and repair.1 cl

Description

[0001] The invention relates to diagnostics of railway rolling stock and is intended for monitoring the brakes of each car in a passenger train and timely detection of icing of their friction elements in contact with each other.

[0002] Currently operating passenger rolling stock consists of various models of cars, manufactured at different times and with varying technical standards. Modern passenger cars are sophisticated vehicles equipped with digital devices for monitoring and controlling the car's life support systems, as well as smart gadgets for enhancing passenger comfort. However, a single train may contain modern passenger cars alongside cars built in previous years, equipped only with analog controls for the life support systems via electrical circuit switching.

[0003] In any case, all control systems, regardless of their technical level and equipment, are aimed at monitoring the car's life support systems and do not interact with the braking systems. At the same time, the locomotive crew, which controls the brakes of the entire passenger train, has very limited capabilities for monitoring their condition.

[0004] Passenger rolling stock uses pneumatic, electropneumatic, and manual parking brakes. When the train is moving, the engineer (or locomotive crew) controls the electropneumatic brakes (if they are operational) or the pneumatic brakes. There is virtually no monitoring of the pneumatic brakes while the train is moving. The operation of the pneumatic brakes is checked at the station during testing. While the train is moving, the engineer can only judge the operation of the pneumatic brakes by the pressure in the train's brake line and the rate of pressure change.

[0005] In a two-wire electropneumatic brake system, the control wire performs the monitoring function. This is achieved by applying a 50 V DC current from the locomotive between the operating wire and the rail to activate the electropneumatic brakes and switch them to braking or overrun mode. The integrity of the electropneumatic brake circuit is monitored by applying a 50 V AC current at 625 Hz between the operating and control wires.

[0006] Thus, the engineer (or locomotive crew) can only monitor the integrity of the electropneumatic brake circuit by monitoring the "O," "T," and "P" lamps on the control panel. If the "O" lamp lights when the electropneumatic brake is released, the electrical circuit is complete and has no breaks. If the "T" lamp lights when the electropneumatic brake is applied, the electrical circuit is complete and +50 V DC is supplied to the working wire and -50 V DC to the rail. If the "P" lamp lights when the brake is applied, the electrical circuit is complete and -50 V DC is supplied to the working wire and +50 V DC to the rail. In all other cases, if none of the lamps light, or several are lit simultaneously, this indicates a fault in the electrical circuit.

[0007] There is currently no direct control of the train's brakes. When giving a command to apply, apply, or release the brakes, the driver has no idea when all the brakes have been applied or released, whether all the brakes on the train have been applied, or whether there is a brake system malfunction on any of the cars. Furthermore, the driver (or locomotive crew) has no information about the condition of the brake system's friction surfaces, which are supposed to generate braking force through friction. If, despite the presence of safety systems, ice forms on the interacting friction surfaces (the surface becomes covered with a thin layer of ice), then even during emergency braking, the braking effect will be virtually nonexistent, as the friction coefficient will be near zero.

[0008] Currently, the only way to ensure braking effectiveness and stop a train in a timely manner is to perform so-called "warm-up" braking. The essence of "warm-up" braking is simple: when the brakes become icy, the brakes are applied until the ice is removed from the friction zone (with disc brakes, the linings press against the discs and their icy surfaces contact them, gradually thinning and melting the ice) and the braking effect is achieved. After this, normal braking resumes (with shoe brakes, the shoes are pressed against the wheels).

[0009] This method has a significant drawback. During warm-up braking, the friction surfaces heat up, causing snow to melt and freeze into a layer of ice when it hits the heated brake surfaces again. Therefore, warm-up braking must be performed strictly before service braking. However, performing warm-up braking every time before service braking is impractical, as in most cases there is no icing effect, and additional braking leads to train delays, reduced section and route speeds, and increased energy consumption.

[0010] To eliminate the above mentioned shortcomings, a digital brake control system for passenger trains with a function for detecting icing of friction surfaces is proposed.

[0011] The proposed system does not interfere with the control of existing brakes and does not require any design modifications to existing passenger brakes. The essence of the control system is as follows:

[0012] Each passenger car is equipped with a brake cylinder pressure sensor, a brake line pressure sensor (standard, purchased), an icing sensor (also selected from standard existing solutions widely used in aviation) and a microprocessor diagnostic unit that receives information from the sensors, processes, records (stores) and transmits information about the condition of the brakes to the locomotive diagnostic unit.

[0013] The locomotive diagnostic unit is installed on a passenger locomotive and receives and processes information from all car units, and then displays this information to the driver (via the control system or directly to the monitor).

[0014] Data transmission along the entire length of the train to the locomotive is carried out via a wire, using the rails and wires of the electropneumatic brake, which is currently installed in every passenger car. Unlike the 50 V DC current of the EPC, which flows between the operating wire and the rail during operation, an alternating current of 50 V at 625 Hz flows between the control wire and the rail (exclusively for circuit integrity monitoring). From a cybersecurity perspective, data transmission via the rail, control wire, and operating wire appears more effective. To ensure safe and reliable data transmission along the power circuits of the electropneumatic brake, appropriate transmission characteristics for data packets are selected to prevent interference with the operation of the EPC.Since the 625 Hz frequency used to monitor the integrity of the circuit does not affect the operation of the EPT, then the transmission of information with a higher frequency of alternating current will also not affect the operation of the EPT.

[0015] The implementation of this diagnostic system will allow the driver of a passenger train to monitor in real time the condition of the brakes of each car in the train, their efficiency and possible malfunctions, and not just the integrity of the EPT circuit.

[0016] For example, while the train is moving, each car's microprocessor unit processes information from pressure sensors and sends it via the electropneumatic brake circuits to the locomotive. The locomotive unit receives brake status information from each car and analyzes it. If a malfunction causes pressure in a brake cylinder or a drop in brake line pressure in any car, the driver will immediately be notified of the malfunction in that specific car. When the brake command is given, the driver will be able to monitor in real time on the monitor whether all brakes have applied and the pressure in the brake cylinders for each car. When the brakes are released, the driver will also be able to accurately determine the exact moment the brakes are released, allowing the train to engage traction and continue moving.

[0017] Timely warning of possible icing of brakes will help avoid serious traffic safety violations associated with loss of brake efficiency (including emergency stop-and-go braking) and subsequent driving through a red light.

[0018] The proposed monitoring system will not only improve travel safety but also enhance the efficiency of brake diagnostics and testing on passenger trains during formation, preparation for travel, maintenance, and repair. For example, the presence of a TM pressure sensor on each car will enable the detection of ice jams, narrowings, brake line leaks, and other malfunctions, which currently account for up to 40% of all passenger brake failures.

[0019] The implementation of a digital brake monitoring system on passenger trains will reduce failures and delays in passenger train operation. If the control wire of an electropneumatic brake breaks, the digital monitoring system can diagnose and transmit information to the locomotive that only the control wire has failed, while the operating wire and the electropneumatic brake as a whole are still functional.

[0020] In addition to improving safety and reliability, the effect will be reduced costs and shortened maintenance and repair time. The digital monitoring system will allow passenger car brake testing without the need for separate diagnostic devices (such as the SITOV-P and UPTV in depots and car sections during repairs, and the UZOT-P in yards and station tracks during maintenance). Brake testing for each car and for the entire train (including the anti-skid system) will be possible without leaving the car. Simply connect the car's brake line to a compressed air source and activate the test mode from the car's microprocessor unit.

[0021] It's worth noting that the proposed system doesn't require a lot of expensive equipment: three sensors and a microprocessor-based control unit are installed on each car. The brake system actuators remain unchanged on the car.

Claims

A digital brake monitoring system for a passenger train with a function for detecting icing of friction surfaces, characterized in that it consists of a locomotive monitoring unit installed on the locomotive and connected to the control system and electrical circuits of the electropneumatic brake; a car microprocessor unit installed on each passenger car and connected on one side to the electrical circuits of the electropneumatic brake, and on the other side to the sensors; brake line pressure sensors, a brake cylinder and an icing sensor, also installed on the passenger car and connected on one side to the car microprocessor unit, and on the other side to the braking system of the car; rails and wires of the electropneumatic brake are used to transmit information along the entire length of the train to the locomotive; the locomotive monitoring unit is designed with the ability to transmit information on the state of the brakes to the driver.