Research On The Trajectory Planning Of Overhead Crane

In recent years,the extensive application of automation and intelligent technology in the field of industrial robots has brought efficient work efficiency and great economic benefits to enterprises.Large-scale construction machinery is also developing rapidly in this direction.As an indispensable part of intelligent operation of overhead cranes,trajectory planning has attracted the attention of researchers.However,there are few researches on trajectory planning of overhead cranes,and at present there is still no universal trajectory generation methods.Therefore,based on characteristics of overhead crane and the shortcomings of the existing research literature,the following control methods are put forward:First of all,in order to improve the work efficiency of the 2D overhead crane system,a time optimal trajectory planning scheme is proposed.firstly,some basic transformations on the system kinematics was implemented.Then,some physical and security constraints of the crane were taken into consideration to set up optimization problems.After that,the pseudospectral method was utilized to convert the constrained optimization problem into a nonlinear programming problem,which can be solved moreconveniently,The simulation results shows the feasibility of the algorithm.Secondly,most of the methods in the existing literature do not constrain the system's impact function(the jerk curve),and the trajectory does not have a clear analytical expression.In this paper,a trajectory planning method based on differential flatness theory is proposed.A trajectory with good control effect was generated under various constraint conditions,and its trajectory has a definite analytical expression.This method improves the smoothness of trajectories and facilitates tracking control in practical applications.The simulation results shows the effectiveness of the proposed method.Finally,for overhead cranes,most existing methods treat the payload swing as that of a simple pendulum.However,when the hook mass is not negligible compared with the payload mass or the payload size is large,the payload will rotate around the hook,which will increase the difficulty of control.Therefore,in order to solve this problem,In this paper,the differential flat method was used in trajectory planning,which can make the problem easy to analyze and the calculation is simple.A trajectory is generated with the precise positioning of the trolley and the load swing suppression capability.And the simulation shows the effectiveness of this method.