Research On Static North Seeking Scheme And Data Analysis Method For Fiber Optic Gyro Total Station

Fiber optic gyroscopes and inertial measurement products with fiber optic gyroscopes as the core have been widely used in various fields such as navigation,aviation,aerospace,weapons,and energy.With the advancement of technology,the improvement of optical device performance,and the gradual maturity of manufacturing processes,fiber optic gyroscope products have achieved rapid development in recent years,but their applications in the field of engineering measurement are still relatively few.Fiber optic gyroscope,with its advantages of all solid-state,strong impact resistance,durability,light weight,low power consumption and cost,overcomes the disadvantages of traditional mechanical gyroscope directional measurement technology such as high cost,inconvenient transportation,large external interference torque,and easy breakage of suspension belts.It has broad development space.In practical engineering measurement applications,the data processing requirements for fiber optic gyroscopes are different from those in the navigation field.When processing fiber optic gyroscopes data in the navigation field,real-time performance is more important,while this article focuses more on its stability and accuracy.The output signal of the existing research surface fiber optic gyroscope is masked by a large amount of noise,and it is difficult to achieve good observation accuracy without processing.In response to the above issues,this article has carried out the following work and research:(1)Propose a method for processing the output values of fiber optic gyroscopes-an adaptive filtering denoising algorithm based on variational modes.Firstly,perform data preprocessing operations to eliminate coarse differences;Secondly,the VMD method is used to decompose the output signal of the fiber optic gyroscope.Based on the sample entropy,the sample entropy values of each IMF component after decomposition are calculated.A signal greater than a certain threshold is defined as a high noise signal,and a signal less than a certain threshold is defined as a low noise signal;Then,choose an adaptive filtering algorithm to filter and process the part of the signal that needs to be processed;Finally,perform signal reconstruction and use the reconstructed signal to calculate the azimuth angle.At the same time,a GUI interface was designed based on the MATLAB platform to visualize the entire data processing process,facilitating rapid data processing and analysis.(2)Using a four position north finding scheme,data from six consecutive observation cycles were collected in a relatively stable observation environment.The bias stability,standard deviation,and a series of Allen variance coefficients of the observation data in each direction of these six cycles were calculated to test the effectiveness of the algorithm.On the other hand,the data processing effect of the method proposed in this paper is tested by comparing the changes in the mean square error of north finding before and after processing.The results show that the method can improve the north finding accuracy of FOG total station.(3)The fiber optic gyro total station is applied to the actual project,and the observation results are compared with the BTJ-5 gyro total station.The results show that the instrument can indeed complete the north finding and orientation survey of underground projects,but the accuracy has not reached the level equivalent to the mechanical gyro;After using the algorithm proposed in this paper to process the observed data,the measurement results of FOG total station have been improved to a certain extent,which proves the feasibility of this algorithm for FOG total station data processing.