Redundant multi-INS positioning algorithm of shearer and analysis of its rationality

The combination of Inertial Navigation System (INS) and encoder integrated navigation is an efficient method to improve the accuracy of shearer positioning.The position coordinate of shearer in navigation reference frame is calculated through dead reckoning in which attitude angles are outputted by INS and instantaneous velocity of shearer is reckoned on the basis of encoder’s output.In order to improve the accuracy of the method more effectively and decrease the drifting of inertial devices, a positioning method based on redundant configuration among whole INS was proposed.The position information of the triple-INS was used as the state quantities, and the distances among each INS were used as the measurement quantities, then the shearer redundant INS positioning Extended Kalman Filter (EKF) mathematical model was established.According to the model, the shearer redundant INS positioning simulation method was proposed and the reasonability of the algorithm was analyzed through comparing the results of multiple inertial navigation redundant positioning and single INS positioning and redundant INS positioning under several simulation conditions.The comparison results illustrated that using multi-INS redundant positioning algorithm can restrain the drift of positioning with single INS for a long time and improve the accuracy of positioning, which is also effective for several running conditions of shearer and several installed distances among INS.However, the linearized error of EKF leads to some difference among results under different simulation condition.Because there are many factors impact the positioning accuracy of redundant INS, for example, variety of installation, number of INS, usage of different nonlinear filtering algorithms and so on, the influence of these factors on the shearer positioning accuracy needs a further study.