基于复杂可编程逻辑器件的流速快速测量系统

以旋浆作为传感器测量流速,关键是要获得旋浆的旋转周期T。对T值的几种测量方式和误差进行了分析比较。为克服测频方式在多通道、低流速时测量速度慢、误差大等缺点,并充分利用中断方式响应速度快等优点,提出了用中断方式实现计数标准时钟数以测量脉冲宽度的方法,从而实现低流速下的多点快速、准确测量,并详细阐述了系统依托复杂可编程逻辑器件实现中断测脉宽的具体方法。系统克服了传统方法的不足,能够满足多点流速的同步、快速、精确、自动测量。

High speed system to measure flow velocity based on CPLD

When propeller is used as sensor to measure flow velocity, the key point is how to acquire cycle T of propeller. Several methods to measure T and their errors are analyzed and compared. Usually, pulse frequency measure mode is used, but under the condition of multiple channel and low flow velocity,it has some disadvantages such as slowness and imprecision.To overcome these shortcomings and fully utilize high speed response of interrupt mode,a method to measure pulse width is put forward by counting standard clock number with interrupt mode,multiple points and low flow velocity can be measured rapidly,precisely. Detailed method is specified as how to realize it with the help of CPLD.The system overcomes traditional method's defects,it can measure multiple point flow velocity synchronously,rapidly,precisely and automatically.