Design And Implementation Of Reconfigurable Data Acquisition System For Smart Skin

The smart skin that integrates various types of sensors,drive elements,data acquisition system and control system,It can perceive various parameters of the aircraft in real time and realize “fly by feel” through feedback control.The type and number of sensors integrated in smart skin are different under different working conditions.The smart skin data acquisition system needs to sample variety of sensor signals,and should be able to flexibly configure the functions and channels of the data acquisition system according to actual working conditions.At present,conventional data acquisition systems can’t meet the application requirements of flexible configuration of the number and type of smart skin sensors.In this paper,a smart skin reconfigurable data acquisition system was designed.The data acquisition system is composed of a reconfigurable motherboard and several signal acquisition boards.Multiple acquisition boards can be combined arbitrary and connected to the reconfigurable motherboard.With the help of FPGA hardware programmable ability,the number of functions and channels of the acquisition system can be reconfigured.The hardware of the smart skin reconfigurable acquisition system was developed.By analyzing the working principles of the capacitive sensor,piezoelectric sensor,resistance sensor and hot film sensor in the smart skin application,the four types of sensor signal sampling schemes were designed in detail.Four kinds of signal acquisition boards and reconfigurable motherboard wree designed from the perspective of hardware compatibility.The FPGA hardware logic was built.The sampling controller cores based on AD7606 and PCAP01 were designed to control the hardware acquisition board for sensor signal acquisition;The trigger controller core was designed to provide accurate trigger signals for 4 acquisition boards;The multi-channel FIR filters were designed to filter the collected data in real time;The AXI DMA was built to transfer data with ARM.The ARM embedded software system and the virtual instrument were designed.The embedded software system was built to control hardware for sampling,and transfer data with FPGA through DMA,and use UDP protocol to communicate with PC.A virtual instrument interface based on Lab VIEW was designed to realize the control of the acquisition system and complete the visualization and storage of the sampled data.The acquisition system performance was tested and applied to wind tunnel experiment.The measurement accuracy,stability,FIR filter performance,data transmission reliability and reconfigurable ability of the acquisition system were tested through the intelligent skin sensing system,and the acquisition system was applied to the NACA0012 airfoil low-speed wind tunnel experiment.This proved this data acquisition system can meet the application requirements of flexible configuration of the number and type of smart skin sensors,and can work stably under real working conditions.