Method and device for measuring pulse frequency

Abstract

The invention discloses a method and a device for measuring pulse frequency. The method comprises: firstly an RC delay unit stores phase difference information, and charging or discharging operation is carried out by use of a measured signal level in case of change of the measured signal level, wherein, a capacitive voltage reflects the phase difference between a measured signal and a measuring clock; a rising edge phase difference detection unit converts the capacitive voltage on the RC delay unit into digital quantity in the case of rising edge of the measured signal; a falling edge phase difference detection unit converts the capacitive voltage on the RC delay unit into digital quantity in the case of falling edge of the measured signal; a data caching unit caches the converted data; a timing sequence control unit controls the timing sequence of the measurement process; and an embedded single-chip microprocessor carries out compensation on the measured signal by means of the measured phase difference information so as to finally achieve the purpose of measuring the pulse frequency. By adopting the technical scheme, the measurement indeterminacy and errors can be effectively lowered, and the frequency measurement accuracy can be improved; and the real-time property is good, the cost is lower, and the implementation is easy.

Description

technical field [0001] The invention relates to the technical field of industrial measurement and control, in particular to a pulse frequency measurement method and device. Background technique [0002] Pulse frequency measurement is an important field in industrial measurement and control. For example, in the test and control of wind power generators, there are many pulse signals that need to be measured, including the speed and pitch control of the core components of the wind turbine generator. Information such as the speed of the variable pitch motor is obtained by measuring the frequency signal of the photoelectric encoder coaxially linked with it. Therefore, the accuracy of pulse frequency measurement directly affects the control accuracy of wind turbines. [0003] Commonly used pulse frequency measurement methods include frequency measurement method, cycle measurement method and multi-cycle synchronization method. The frequency measurement method has a relatively lon...

AI Technical Summary

Problems solved by technology

The frequency measurement method has a relatively long measurement time and is mainly suitable for high-frequency measurement; the cycle measurement method is relatively fast and is mainly used for low-frequency measurement, but it has an inherent error of one measurement clock cycle, which affects the test accuracy; multi-cycle synchronization The test accuracy of the method is relatively high, but the real-time performance of the test decreases accordingly.

In recent years, with the help of the continuous development of embedded technology, new methods such as analog interpolation method, vernier method and phase compensation method have continuously improved the test accuracy, but the test principles of many new methods are not easy to implement and the cost is high

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