Sensor-less temperature estimation of control coil for automotive electro-hydraulic control unit

In the automotive electro-hydraulic control unit, the linear control of the control valve lead to the temperature rise of the control coil and to influence control performance of the control valve. In order to ensure the temperature endurance of the control coil and the control performance of the control valve we are proposed a method of the sensor-less temperature estimation of the control coil. This method firstly to establish the temperature rise model of control coil by energy conservation law; secondly to identify the model parameters by the actual measurement value of the control coil temperature; finally the temperature endurance of the control coil and control performance of the control valve are verified by the simulation model of electro-hydraulic control unit and the measurement values of the real-vehicle. The results show this method can effectively estimate the temperature rise of the control coil, this not only simplifies the hardware architecture of the electro-hydraulic control unit, but also to ensure the temperature endurance of the control coil and the control performance of the control valve.