| Belt conveyor is the key transport equipment in coal mine industry,and its work efficiency determines the production efficiency of coal mine.Idlers are the main bearing parts of belt conveyor.Since the failure of belt conveyor caused by idlers accounts for 60% of the total accidents,timely replacement of damaged idlers is an important guarantee to avoid accidents.Current belt conveyor idler replacement methods require direct manual participation,if improper operation will threaten personal safety.Aiming at the above problems and the strategic requirements of "Made in China 2025",this paper designed a manipulator that can replace manual roller replacement,established a kinematic model,carried out path planning and trajectory planning,and proved the correctness of the design through dynamic simulation,and obtained the factors affecting the grasping accuracy.The main work of this paper is as follows:(1)According to the working conditions and the structure of belt conveyor,the structure design and hydraulic driving system design of roller replacement manipulator and auxiliary parts are carried out.The working moment of the manipulator joint is calculated,the driving element is selected,and the specific working process is described.It is proved that the design scheme of roller replacement manipulator meets the working requirements and is feasible.(2)The kinematic model of the roller replacement manipulator was established by the D-H parameter method,and the forward kinematic solution of the manipulator and the dimensionality reduction inverse kinematic connection under working conditions were obtained and verified.The working range of the manipulator was solved by Monte Carlo method.It is proved that the structure design of the manipulator is correct,the kinematic solution is correct,and the obtained workspace of the manipulator meets the demand,which provides a theoretical basis for the trajectory planning of the manipulator.(3)This paper describes the collision detection method of the manipulator.Informed RRT*algorithm is used to plan the working path of the manipulator,and cubic B-spline function is used to smooth the working path of the manipulator,and the trajectory planning of the manipulator is carried out by using cubic polynomial interpolation.The working path of the roller replacement manipulator is obtained,and it does not interfere with the belt conveyor.The trajectory planning results of each joint of the manipulator are obtained,and the curve is smooth without large inflection point,which lays a foundation for the dynamic simulation.(4)Adams is used to analyze the rigid body dynamics of the manipulator,which proves that the path planning and trajectory planning results are correct.After the flexible treatment of the main load components,the rigid-flexible coupling dynamics simulation of the manipulator is carried out,and the variation of the working path under different conditions is obtained and analyzed.The results show that the driving function of the manipulator,the pose of the manipulator and the end load are all the influencing factors that affect the working accuracy of the manipulator,and the adjustment parameters are obtained to provide support for the manipulator to grasp the idler accurately.There are 88 figures,17 tables and 80 references in this paper. |
PDF Full Text Request