Research On Wellbore Safety Detection Based On Inertial And 3D Laser Technology

In China's energy structure,coal still plays a leading role,and this situation will continue in a short time.With the improvement of mining technology and the continuous demand of resources,the depth of coal mines has increased year by year,and many coal mines have entered the depth of 1000-1500m.As the "throat" part of the whole mine,the shaft undertakes the important work of production promotion,personnel access,ventilation and drainage,which is the top priority of safety production.With the increase of mining depth and service life,as well as the change of soil and water conditions on the surface of thick soil,ancillary equipment such as shaft wall,tank path and tank beam will be deformed,seriously affecting mine safety production.Safety detection methods for coal mine wellbore have been developed for many years,but the existing methods have the following disadvantages:low efficiency,manual dependence,insufficient technological content and insufficient accuracy.Compared with the traditional methods,this paper proposes a mine shaft safety detection method based on inertial navigation and three-dimensional laser scanning technology,which uses the three-axis attitude information of inertial navigation to obtain the carrier trajectory Point cloud section extraction for deformation analysis provides a new direction for wellbore safety detection,which has important theoretical and practical significance.The research work of this paper mainly includes the following aspects:(1)This paper studies the background and significance of mine shaft safety detection,widely understands the current situation of mine shaft safety detection at home and abroad,summarizes the advantages and disadvantages of different methods,defines the characteristics of shaft damage,analyzes the causes of shaft damage,and finally concludes that the additional stress along the shaft wall is the main cause of most shaft damage accidents.(2)In the data processing of inertial unit,the characteristics of two kinds of inertial navigation methods are summarized,the navigation principle of strapdown inertial navigation is studied,the attitude matrix is calculated by quaternion method,the formula is deduced,and the solution equation is given.In the design of the digital scorer,the rectangular method is used to deduce the transfer function of the integrator,and the polynomial model is established based on the principle of difference and least square to carry out the acceleration signal detrended processing.Through MATLAB programming simulation,the effect of the detrended is ideal.According to the non-stationary and weak nonlinear characteristics of gyro signal,ARMA model based on time series is proposed.Variance and signal-to-noise ratio are used as the evaluation indexes of denoising effect.Appropriate wavelet coefficients are selected,and a new threshold function between soft threshold and hard threshold is proposed.The denoising effect is verified by simulation experiments.(3)In the processing of point cloud data,a deformation analysis method based on the extraction of cross-section is proposed.RANSAC algorithm is introduced to fit the quadratic curve.The cross-section is extracted with the help of normal plane according to the mileage position.The long and short half axes are determined by solving the ellipse fitting parameters of cross-section,and the deformation analysis is carried out by comparing with the initial design value.Finally,by comparing with the existing detection data,we got a better result.