The structure of ejector used in automotive power steering oil discharge equipment is designed in accordance with the theory of gas-liquid ejector.The two important parameters of the ejector are elected respectively to five values and then 25 ejector models are obtained by the permutations and combinations.The ejector’s CFD model is created by Fluent module of Ansys,then it is divided into a grid and analyzed. Analyse its pressure distribution and velocity vector, which provides the optimal size for the manufacture of the ejectors and a theoretical basis for experiment.

A novel design of data acquisition system based on CPLD and DSP coordination control is presented. Verilog HDL is adopted in this system to realize the function of Schmitt trigger on CPLD. Combining with the method of zero-crossing detection, the RMS of signal voltage, current and frequency are effectively calculated. Experimental results indicate that the given method has improved the detection efficiency and computational accuracy.

The discreteness of device parameters exists in the analog signal processing using conventional phase measurement methods, and the error caused by threshold voltage of comparator is difficult to estimate and eliminate. Due to this shortcoming, a method based on TMS320F28335 eCAP module for measuring the phase difference is presented. Firstly, the AC signal is amplified and filtered to eliminate the error introduced by electromagnetic interference, and then the digital signal through the Schmitt Trigger designed by CPLD is converted to wave signal with the same frequency of the signal, by capturing the edge-triggered, enters the capture interruption subroutine to calculate the number of the sampling points of one period, finally the phase difference is calculated according to correlation method. Hardware circuit and software flow chart are given. The experimental results verify the method has higher reliability and precision than conventional methods.