Dsp-based Real-time Micro-shear Stress Sensor Array Signal Processing System

MEMS technology plays an important role in aerodynamics due to device dimensions on the μm-scale. One of the potential applications is the active control of the thin boundary layer flow to improve aircraft's performance. In the paper, a DSP subsystem is designed for MEMS active flow control, which is refered to control seperation flow by using micro sensor arrays and actuator array.Firstly, according to the special requirements for active flow control, the overall scheme of the system is established, the principle of separation detection using micro thermal sensor array and the principle of separation control using micro balloon actuator array are described.Secondly, the hardwre design for the system is designed in detail, including constant circuit bias circuit of micro thermal sensor array, filter attenuation circuit, analog signals acquisition circuit, DSP mini system, LCD display system and control circuit of micro balloon actuator array, and the logic design for CPLD is developed. In addition, some important problems about hardware design is presented.Finally, in order to reduce noise interference of DSP system, a real-time wavelet de-noising algorithm is designed. Meanwhile, based on the boundary layer theory and the change of surface shear stress distribution, a signal processing algorithm is proposed to determine the location of separation.The results of wind tunnel testing show that the above algorithm can be used to determine the location of the separation point, and DSP system can meet the requirement of real time measurement.