Gong-kuang zidonghua (Aug 2022)
Shearer positioning method based on non-holonomic constraints
Abstract
At present, the shearer positioning method is based on the combination of the inertial navigation system and odometer. The method directly uses the output of the odometer to correct the shearer forward speed calculated by the inertial navigation system. However, the capability of suppressing the error divergence of the inertial navigation system is very limited. The shearer in the process of movement meets the characteristics of the non-holonomic constraints. When the shearer does not jump and sideslip, the lateral velocity and vertical velocity at the connection between the traction gear and the crawler are zero. Based on this characteristic, a new shearer positioning method based on non-holonomic constraints is proposed on the basis of the combination of the inertial navigation system and odometer. The output of the inertial measurement unit arranged in the middle of the shearer's body is mechanically arranged, so as to obtain the attitude, speed and position information of the shearer. The output of the odometer installed on the traction gear of the shearer is used to calculate the instantaneous velocity of the shearer. The Kalman filtering state equation is established by using a mechanical arrangement result of the inertial navigation system and an error propagation model. The non-integrity constraint is introduced at the joint of a traction gear and a crawler of the shearer. The Kalman filtering observation equation is established by using the difference between the velocity projected at the joint by the inertial navigation system and the velocity output by the mileometer as an observation vector. The output of the inertial navigation system is modified by using the results of the Kalman filtering algorithm as error feedback. Then the optimal estimation of the attitude, speed and position of the shearer is obtained. The experimental results show that compared with the traditional combined positioning method of inertial navigation system and odometer, the positioning error does not diverge with time after the non-holonomic constraint is added. The positioning method has good tracking performance on the actual trajectory. The positioning errors of the shearer in the forward, lateral and vertical directions are reduced by 66%, 62% and 67% respectively.
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