Measurement of roadheader position and posture based on orientation laser scanning

Smart mining is the development direction of coal industry transformation and upgrading in China,and the intelligent and unmanned coal mining is the only way for the development of coal industry.Roadheader is one of the key equipments for comprehensive mechanized roadway driving in mine,the measurement of its position and posture are the basis and premise to control the heading machine’s self-moving and intelligent cutting,and then to realize the directional heading of roadway.However,the existing method or system of roadheader position and posture measurement has some short comings.Aiming at measure the absolute position and posture of the machine body,a method based on orientation laser scanning for the position and posture measurement of the roadheader is proposed.The composition and working principle of this measurement method are expounded.The relationship between the laser emitter and the measured point on the laser target is analyzed.The mathematical model of the position and posture measurement system of the roadhead based on the laser coordinate space coordinate transformation is established.The position and posture information of the roadheader is analyzed,and the error factors affecting the accuracy of the position and posture measurement of the roadheader are analyzed.The variation rules of the measurement errors of the roadheader′s position and posture parameters are obtained under the condition of different measurement distance and laser emitter distance.The results show that the error decreases with the increase of the distance between laser emitters.When the number of measurements is 10 and the distance is 50 m,the X-axis accuracy is less than 1 cm,the Y-axis and Z-axis errors are large,the roll angle accuracy is less than 0.1°,the pitch angle accuracy is less than 0.4°,and the direction angle accuracy is less than 0.6°.It is found that the main error source of the measurement system is the coordinate extraction error of the laser spot center of the laser target,and the measurement error of the position and posture parameters can be reduced by increasing the distance between the laser emitters and reasonably planning the installation posture of the laser target.