A Clock Jitter Estimation and Correction Method for Data Acquisition in Rotating Environment

Abstract

The invention discloses a clock jitter estimation and correction method for data acquisition in a rotating environment. The jitter distribution is estimated by combining the sampling clock signal and the external clock input signal in the wireless transmission mode, and the clock jitter amount is directly calculated by using the signal-to-noise ratio of the data collected by the clock signal. Estimate, and perform interpolation correction according to the jitter estimation results, solve the problem of data acquisition errors caused by severe jitter of the external clock input signal of the data acquisition system in a rotating environment, reduce the phase error of the external clock input signal, and improve the accuracy and accuracy of data acquisition . Compared with the existing technology, this method not only has the advantages of multi-channel acquisition and comprehensive jitter estimation, but also can significantly reduce the external clock jitter, and is also suitable for improving the stable transmission of the external clock input of the data acquisition system.

Description

technical field [0001] The invention relates to the technical field of analog signal acquisition, in particular to a clock jitter estimation and correction method for a data acquisition system in a wind tunnel helicopter rotor rotation environment. Background technique [0002] In the wind tunnel helicopter rotor rotation test, it is usually necessary to obtain sampling data at different rotation azimuths. Due to the control deviation of the rotational speed, the on-board clock cannot accurately obtain sampling data at equal angles. Therefore, the pulse signal of the rotary encoder needs to be used as The external clock sampling signal is sent to the acquisition device to realize external trigger sampling. Therefore, the accuracy of the external clock sampling signal is the key link to ensure the equal angle sampling within 360 degrees at the same starting phase. Many tests have found that there are obvious defects in the process of sending the external sampling clock signal...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problem of data acquisition error caused by the external clock signal cable winding and serious clock jitter of the traditional data acquisition system in the wind tunnel helicopter rotor rotation environment, and adopt wireless transmission technology for external clock sampling signal transmission, using two sets of phase The DA triangular wave reference source signal with a difference of 90 degrees is used for equal-amplitude time detection, clock jitter estimation, interpolation correction and feedback on the acquisition signal, further reducing the acquisition signal error caused by the jitter of the external clock sampling signal, and improving the accuracy and accuracy of the acquisition action. High-precision data collection has a significant effect

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