The Research For The Trajectory Planning Of Aluminium Ingot Servo Stacker

As the important equipment in the aluminum ingot casting production line,aluminum ingot stacker has become one of the indispensable equipment used to product aluminum ingots.Path planning is an important module of the stacker control,which has a significant impact on the stacker motion characteristics and working efficiency. Therefore,the optimal trajectory was optimized in this thesis based on aluminum ingot stacker in 28t/h developed by Lanzhou University of technology.At first,the robot trajectory planning method is mainly using such methods as polynomial, parabolic,linear interpolation,cubic spline interpolation and arc interpolation to finish trajectory planning.They were compared and analyzed to find that cubic spline interpolation method not only preserves various advantages of low order interpolation polynomials,but also improves the smoothness of interpolation function.So cubic spline interpolation was chose to plan the trajectories of aluminum ingot stacker,which not only can guarantee the speed and acceleration at junctions,but also can make the path smooth,reduce the impact and vibration on the body of stacker in the movement,and greatly improve its life.Secondly,kinematic analysis of stacker structure was carried out to plan its trajectory.Cubic spline curve was used to plan running trajectory of stacker,to set up coordinates of crib layers,exhaustive method was used to obtain the grabbing position(Z=425mm) in the shortest path.Combined the definition of cubic spline formula with MATALB toolbox,the trajectory equations the from the first layer to the eleventh floor were solved out,and they were simulated using MATALB to get the trajectories in 11 th layer of aluminum ingots stacker.Finally,the shortest path was solved through path planning,the time was taken as the optimization objective to seek the optimal solution with adaptive genetic algorithm(the first layer and the eleventh layer stack trace as an example). A brief introduction of the principle and realization steps of genetic algorithm was described,and the objective function and fitness function was selected to get genetic operators according to the optimization objective.At last,the trajectory of cubic spline curve which meet the constraints was obtained through genetic algorithm based on MATALB process and industrial common trigonometric function of the velocity curve.The running time reduced to 14.3% after optimization and the trajectory optimization results were simulated.