Research On Motion Control Method Of Overlength Boom End Of Telescopic Handler

Telescopic handler is mainly used for goods transportation and stacking in construction site,farm and other scenes.The straight movement function at the end of the boom has become an urgent engineering application because of the particularity of its use scene and the continuous improvement of work efficiency and quality in practical application.This paper aims at simulation research and implementation of boom end motion control method.An improved control method and parameter optimization algorithm are proposed to maximize the control performance by analyzing the main factors which affecting the accuracy of motion control.Finally,the effectiveness of the control method is verified by experiments.The main job content of this paper is as follows specifically:(1)The dynamical model and hydraulic model of boom system of telescopic handler is constructed.With the comparison of simulation and test of 60 data curves under 12 operating modes,so the model is proved to be accurate.On this basis,a motion control model of the boom is built based on parallel control and PID controller.The linear motion function of the boom end is basically realized through multi-domain co-simulation.(2)Aiming at the delay of telescopic and variable amplitude action of boom system and the time-varying load of control system,an improvement scheme of master-slave control and fuzzy PID control is put forward.The maximum control errors under horizontal-extend and vertical-lift modes are improved by 26.7% and 78.6% respectively through co-simulation,which indicates that with the control method matched by master-slave control and fuzzy PID,the trajectory accuracy of boom end improved compared to the control method before improvement which matched by parallel control and conventional PID control,so verifies the feasibility of the improved method.(3)The initial values of the fuzzy PID are not always the optimal value that tuned by experiential compact method,so there is still room for improvement of control accuracy.To solve this problem,particle swarm optimization is used to optimize the initial value of fuzzy PID,and a group of better parameters are obtained for simulation of horizontal delivery and vertical lifting conditions.The arm length error is improved by 55.2% and 39.5% respectively,which effectively improves the arm end trajectory accuracy.(4)Based on the above research results,a control program is programmed into the motion controller of telescopic handler,and vehicle commissioning and experimental data acquisition are carried out.Among them,the maximum track error of 8m’s horizontal-extend is 14.8cm and that of 3.5m’s vertical-lift is 7.7cm.The motion control accuracy of boom end meets the requirements of practical engineering application throuth the company’s identification.So the feasibility and validity of the above control methods and the reference value of control parameters based on particle swarm optimization is vertified.