Research On Dynamic Accurate Positioning Method Of Shearer

Self-navigation and positioning technology of shearer is one of the key technologies for longwall mining automation.It is important to automatically adjust the drum of the shearer and the automatic alignment of the scraper conveyor.The research on positioning technology with inertial navigation system and odometer had proved the feasibility of this method for autonomous navigation to longwall mining automation.But its positioning accuracy can not satisfy the demand for dynamic precision positioning of shearer.Therefore,it is necessary to study the error causes and elimination methods of positioning technology with inertial navigation system and odometer.This paper analyzed the deterministic deviation for the installation bias and the initial misalignment when the positioning device was initialized based on a large number of the positioning data.The deterministic deviation had an approximate linear effect on the positioning accuracy and must be eliminated to the biggest extent.The shearer positioning error model was established.The influence law of deterministic deviation on positioning accuracy and the deterministic deviation compensation method was obtained.Experiments showed that this method can effectively reduce the deterministic deviation.After the compensation,the maximum position error in north,east and down was reduced to 0.22 m,0.18 m and 0.12 m respectively,and Spherical Error Probable(SEP)was reduced to 0.11 m.The positioning error was affected by the drift of the attitude angle through shearer four cutting tests.The drift of the heading angle was larger than the drift of the pitch angle.This leaded to the positioning accuracy in north and east much lower than that in down.With simulation tests,it was found that the influence of the positioning accuracy is non-linear due to the accumulation of heading angle drift,the increasing rate of error was largened with time.According to the working characteristic of the shearer,a closing path optimal estimation model was built with the defined advancing distance of longwall face.With the optimal estimation model,the north error of the second,third and fourth cutting operations is reduced from 0.43 m,0.95 m and 1.03 m to 0.49 m,0.52 m and 0.76 m respectively.The east error is reduced from 0.37 m,1.46 m and 1.40 m to 0.29 m,0.65 m and 0.81 m respectively.SEP was reduced from 0.24 m,0.72 m and 0.67 m to 0.22 m,0.35 m and 0.39 m,respectively after optimal estimation.The positioning accuracy was improved by nearly 50% because of the good constraints effect on the north and east directionThis positioning method with the optimal estimation model could reduce the influence of the heading angle drift with the inertial navigation system and improve the positioning accuracy of the shearer.