基于FPGA的高精度采集系统的优化设计

Optimization design of high precision acquisition system based on FPGA

在航空航天领域,研究飞行器的气动模型和飞行风洞,需要对飞行器的不同部位进行压力数据采集。由于飞行器舱内噪声环境复杂,各通道间容易出现信号串扰,因此文中针对高精度的测量要求,设计一种以FPGA为核心控制器的压力数据采集系统。该采集系统以模块化作为设计框架,以多通道采集和单通道调理作为设计方法;为减小干扰噪声的影响,在硬件方面设计高精度的调理电路和A/D转换电路,软件设计上采用过采样、去极值取均值算法和FIR数字滤波IP核。仿真结果表明:所设计的嵌入式算法可以减小噪声的影响;且文中系统采集精度优于0.2%F.S.,具有较高的信噪比。

In the field of aeronautics and astronautics,pressure data collection is required for different parts of the aircraft to research the aerodynamic model of the aircraft and the flight wind tunnel. Due to the complex noise environment in the cabin of the aircraft,signal crosstalk is easy to occur between channels. A pressure data acquisition system with FPGA(field programmable gate array) as the core controller is designed to meet the high accuracy measurement requirements. In this acquisition system,the modularization is taken as the design framework,and multi-channel acquisition and single channel conditioning are taken as the design method. In the hardware part,a high-precision conditioning circuit and A/D conversion circuit are designed to reduce the impact of interference noise. The oversampling,de extreme value averaging algorithm and FIR digital filter IP core are used in the software design. The simulation results show that the designed embedded algorithm can reduce the influence of noise,the acquisition accuracy of the system is higher than 0.2% F.S.,and has higher signal-to-noise ratio.