小型飞行器低速气压式空速计设计

Design of Low Pressure Airspeed Meter in Small UAV

针对小型飞行器相对空速测量问题,提出一种气压式空速计设计方案;首先分析计算200km/h以内、精度1m/s的空速计测量需求,提出选用SM5662-003-D3L作为气压敏感元件,分析其工作特性及测量精度;给出信号调理电路的总体设计架构,分别完成公用电源电路、仪表放大电路、三阶巴特沃斯低通滤波器电路、高精度有源限幅电路的构建和调试;设计完成等效气压传感器输出电路,检验了信号调理电路的工作性能,结果表明,空速计能准确感应相对空速,电路输出稳定。

In order to solve the relatixie airspeed measurement of small UAV, an design scheme of air pressure airspeed meter was pro posed in this paper. The measurement requirement that is the speed V;200 km/h and the maxim absolute error e≤1m/s of airspeed meter was calculated firstly, based on the calculation result, the SM5662 003--D3L, which running characteristic and the measurement precision was analyzed, was selected as the pressure sensor; The general design scheme of signal conditioning circuit was proposed, the public power supply circuit, the instrumentation OP circuit, the third order Butterworth LPF circuit, the high precision active amplitude limiter circuit was constructed and debugged. Finally, the working performance of signal conditioning circuit was verified using the equivalent baroceptor output circuit,, the test results shows that the relative airspeed can be influenced exactly and the circuit output is very stable.