Method and device for determining pressure of brake air cylinder of motor train unit

The invention provides a method and device for determining the pressure of a brake air cylinder of a motor train unit, and the method comprises the steps: obtaining the real-time data of a brake air cylinder pressure sensor, and determining the state result of the sensor according to the real-time data of the brake air cylinder pressure sensor; if the state result of the sensor is that pressure value estimation needs to be carried out, opening of an air charging valve and an exhaust valve in an electromagnetic valve is controlled according to preset valve starting time, and a real-time pre-control pressure rising value is obtained; and according to the corresponding relation between the pre-measured pre-control pressure rising value and the air cylinder pressure value, the brake air cylinder pressure estimation value is determined through the real-time pre-control pressure rising value. According to the invention, the hysteresis characteristic of the pressure change of the brake cylinder is utilized, and the