Error Compensation Method Of Measurement While Drilling Gyroscope

With the continuous exploration and exploitation of underground resources and the need for underground engineering drilling in recent years,measurement while drilling(MWD)has been widely used.Steering drilling technology is a high-tech in the field of drilling engineering.Its technological progress is closely related to the development of strap down inertial navigation system(SINS),which mainly uses gyroscopes,accelerometers and magnetometer micro-inertial devices(MEMS).Micro Inertial Measurement Unit(MIMU),through which the unit can collect the information of the three-axis acceleration and angular velocity of the drill bit,and obtain the inclination angle,tool face angle and azimuth angle of the drilling tool through calculation.The MEMS gyroscope has the advantages of low cost,low power consumption,small size,strong impact resistance and high reliability,and can be directly calculated to obtain three important information of the drilling tool.However,in the process of drilling,the gyroscope drifts,and the cumulative error of the drilling tool continues to increase in the long-term high temperature and strong vibration environment,resulting in a large amount of noise in the attitude information of the drilling tool.Therefore,in view of the research of a large number of documents at home and abroad,this article first analyzes the main error characteristics of the gyroscope while drilling,and directly processes the nonlinear gyroscope error characteristics through the algorithm;and then uses the neural network model to reduce vibration and noise for the interference of the gyroscope,the focus is on the error compensation method of the gyroscope while drilling under the inertial combination.The main research contents are as follows:(1)The working principle of the gyroscope is briefly introduced,and the error characteristics of the gyroscope are analyzed and the Allan variance error model is established,and the least square error identification is carried out.(2)In order to improve the measurement accuracy of the MEMS gyroscope in the process of measuring while drilling,a sparse redundancy algorithm is proposed to effectively extract the useful information of the gyroscope in order to solve the problem of noise in the modal function decomposed by EMD.(3)Aiming at the problem of a large amount of noise in the MEMS gyroscope signal under different vibration frequencies of the drill bit during the drilling process,an SNN algorithm with improved synaptic plasticity was proposed to effectively improve the antiinterference ability of the gyroscope signal.(4)Aiming at the problem of the drift of the gyroscope while drilling,a quaternion model of the acceleration quaternion estimation gyroscope error under the inertial combination is established,and an improved robust Kalman filter algorithm is proposed to estimate and compensate the model.There are 29 pictures,6 tables,and 68 references.