Train brake cylinder pressure control method and system

Abstract

The invention provides a train brake cylinder pressure control method and system, and the method comprises the steps: collecting a Cv pressure value outputted by an electromagnetic valve under a control strategy of an emergency brake test before a train leaves a garage; calculating electromagnetic valve parameters according to the Cv pressure value; when the train runs on line, the C-Cv linear fitting function of the relay valve is updated according to the collected multiple groups of C-Cv pressure values; calculating a Cv pressure target value according to a preset C pressure target value and the C-Cv linear fitting function; and outputting a control signal according to the Cv pressure target value and the electromagnetic valve parameter, and controlling an electromagnetic valve to act so as to output the corresponding Cv pressure. By estimating the parameters of the electromagnetic valve and the relay valve and controlling the pressure of the brake cylinder according to the parameters, higher accuracy, higher control speed and fewer action times of the electromagnetic valve are achieved, and the service life of the valve is greatly prolonged.

Description

technical field [0001] The invention relates to urban rail transit vehicle technology, in particular to a train brake cylinder pressure control method and system applicable to train sets. Background technique [0002] At present, in the air braking of EMUs or urban rail transit trains in domestic operation, a pair of solenoid valves and a relay valve are generally used as the main actuators for the control of brake cylinder pressure. The electronic system controls the air charging / exhausting action of the electromagnetic valve, and the flow is amplified through the relay valve. After the pressure of the brake cylinder reaches the set value, the brake caliper is driven to form a certain friction force between the brake pad and the brake shoe, thereby Realize the air brake of the train. [0003] figure 1 It is the gas circuit connection diagram of the solenoid valve and the relay valve. As shown in the figure, the relay valve 3 uses the total air cylinder air at the R port ...

AI Technical Summary

Problems solved by technology

In the control of Cv pressure based on PWM, although the control accuracy can be guaranteed, the control error and the current Cv pressure range are used as input, so that when the Cv pressure is close to the target value, the control system outputs a PWM signal with a duty cycle of less than 100%. The changing value of the solenoid valve 1 and the solenoid valve 2 cause frequent actions

In addition, due to individual differences in mass-produced relay valves and different operating environments, there are differences between the linear fitting of C-Cv and the actual situation, resulting in a large discrepancy between the C pressure of the brake cylinder and the set value after the Cv pressure reaches the target value. big gap

[0004] figure 2 The traditional brake cylinder pressure control method shown does not consider the characteristic changes and the number of actions of the solenoid valve and the relay valve. Readjustment of the control parameters according to the pressure range, thus resulting in more workload and control of the brake cylinder pressure off target, which will negatively affect the braking performance of the train and the service life of the valves

For example, in the PWM-based control, according to the Cv error, when using PID and other methods to adjust the pressure, when the Cv pressure is close to the target value, the solenoid valve will frequently perform air charging / exhausting actions, which greatly reduces the service life of the solenoid valve ;In addition, due to the long-term use in different environments and working conditions and the aging of the valve, the key parameters in the control algorithm: such as the response time of the solenoid valve opening and closing, the maximum change value of single-cycle pressure under 100% duty cycle, and the relay The C-Cv characteristics of the valve will change under the working conditions of high and low speed, and pressure-boosting, so that the output C pressure deviates from its target value

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