小型轻便式流速仪检定系统设计

Design of Small and Portable Verification System for Hydrometric Propeller

为满足FP系列流速仪的计量检定需求,提出了一种小型便携式流速仪检定系统的设计方案;根据匀速运动时间等约束条件确定了环形水槽的几何参数;采用FPGA和上位机作为数据处理和控制核心,实现了对伺服电机转速的精确控制;设计了光电编码器和无线摄像机与上位机之间的通信方式,实现了检定装置标准流速值和被检仪器示值的数据读取;对测试数据的处理方法和测控软件的结构框架进行了分析;同时,对实验装置的测量误差进行了分析;结果表明,标准流速值的扩展不确定度为1.28×10-3 m/s,检定装置符合量值传递要求,可作为FP系列流速仪计量检定的标准装置。

In order to meet the measurement requirement of the FP series hydrometric propellers, a design scheme of a portable test and verification system is presented in this paper. The geometric parameter of the annular flume is designed based on the constraint conditions such as uniform motion time. FPGA and upper monitor are used as the core of data processing and control which can control the rotation speed of servo motor accurately. The communication mode between photoelectric eneoder and wireless camera with upper monitor is de- signed. Consequently, the standard flow velocity value and the flow probe indication value can be read into the upper monitor. In addition, the processing methods of test data and the structure of control software are analyzed. Furthermore, the measurement error of the experi- mental device is studied. The results show that the expanded uncertainty of standard flow velocity is 1.28×10^-3m/s, which meets the design requirement of the calibrating device. In other words, the device can be used as the calibration standard device of FP series hydrometrie pro- pellers.