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, which performs jitter distribution estimation by combining a sampling clock signal and an external clock input signal in a wireless transmission mode, and directly estimates a clock jitter amount by utilizing a signal-to-noise ratio of clock signal acquisition data. Interpolationcorrection is performed according to the jitter amount estimation result, so that the problem of data acquisition errors caused by serious jitter of an external clock input signal of the data acquisition system in a rotating environment is solved, the phase error of the external clock input signal is reduced, and the precision and accuracy of data acquisition are improved. Compared with the priorart, the method has the advantages of multi-channel acquisition, comprehensive jitter amount estimation and the like, can obviously reduce external clock jitter, and is also suitable for improving external clock input stable transmission of a 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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