Study on the control of automatic transmission proportional solenoid valve at different temperatures

The automatic transmission control unit drives the proportional solenoid valve through PWM. The valve often appears the control fault at an oil higher temperature. Analyze the effect of the proportional solenoid valve on the coil current about the different ATF (Automatic Transmission Fluid) temperatures, PWM duty ratio and frequency. Test the oil output pressure under different parameters. The results show that under the high ATF temperature conditions, depending on different duty cycles to select the frequency that can reach the oil output pressure close to normal operating temperature. It maintains a low electromagnetic valve power loss and a certain flutter. (paper)