The Research Of Trajectory Planning And Control System Of The Three-way Fork Of Intelligent Stacking Forklift

Safe and efficient transport has important significance for agricultural storage system.At present,low degree of agricultural loading and unloading,handling,palletizing mechanization,warehousing equipment automation and management information are existing in C hina’s agricultural logistics.Intelligent three-way stacking forklift can effectively solve these problems effectively.Foreign products about intelligent auto three-way stacking forklift is much better than ours.In order to exploit the control system and related control method of intelligent auto three-way stacking forklift with our own intellectual property rights,this paper constructed a t hree-way experimental platform.The kinematics modeling and simulation analysis were established in this paper,and a control system with algorithm was designed too.This article also carried out a research about trajectory planning verified by experiment.The main research work and the results are as follows:1)Based on sliding table and stepping motor this paper designed a three-way experimental platform,and used stepping motor to control ball screw as the main power of platform.According to the standard DH parameters the relation of link parameters and the link of Platform DH model are deep studied.O n the basis of the D-H model of the three-way platform,the positive and negative kinematics of the three-way platform is carried out.And the correctness of the positive inverse kinematics is proved by a simulation model.2)On the basis of reviewing a large amount of literature,the advantages and disadvantages of the existing trajectory planning method were summarized and compared with the actual requirements of the three-way palletized forklift.The trajectory planning of the three-way forklift was carried out by using the fifth-order polynomial interpolation method Based on the designed three-way experimental platform,the mathematic model of the fifth-order polynomial interpolation function trajectory planning was deduced.3)Using the Robotics Toolbox in MATLAB,a virtual prototype model of three-way tool was established.By setting the corresponding simulation conditions,kinematic simulation and barrier-free trajectory planning are carried out,by which the smooth angular displacement,velocity and acceleration of each joint curve were obtained.4)The control system of the three-way experimental platform was designed by using the incremental PID control algorithm.The stepping motor of each joint was selected by calculating the joint torque of the three-way experimental platform.According to the measurement stroke and the precision requirement,Suitable cable encoders and angle encoders were selected.Based on the designed trajectory planning method,the experiments of the three-way experimental platform were carried out.The results show that the mathematical model of the fifth-order polynomial interpolation has a good fit with the experimental values of the joint angular displacement,the angular velocity and the angular acceleration.,Meanwhile the correctness of the designed trajectory planning method is verified.This paper provides a reference for the control of the three-way forklift of the forklift,which lays the foundation for further research combined with the positioning and navigation technology.