Research On Motion Trajectory Control Of Concrete Pump Truck Boom Tip

In view of the existing concrete pump truck boom at the tip of trajectory and low control precision problem of the unreasonable energy distribution of boom system,this article mainly studied from the angle of the kinematics of realizing trajectory precision control and boom tip system energy distribution of trajectory planning algorithm,and based on the trajectory planning algorithm,the conflicts between the tip of the boom and obstacles,the unstable operation of the boom joints and the large vibration range of the boom system in the process of transition between the primary and secondary tasks are studied.The specific research contents of the paper includes the following parts:(1)A weighted closed-loop inverse kinematics trajectory planning algorithm based on gradient projection was used to solve the problems of low precision control of trajectory and unreasonable energy distribution of boom system.Taking the pump truck boom system as the research object,the forward kinematics equation of pump truck boom is established.Considering the traj ectory accuracy requirement of the boom tip,a closed-loop control system was introduced,and the real-time coordinate value of the boom tip was fed back to the inverse kinematics algorithm to correct the error of the boom tip.Considering the reasonable energy distribution of the boom system,the minimum weight of the change of the boom angle is used to distribute the joint angle twice under the constraint of the limit range of the boom joint angle,so as to minimize the energy of the boom system.Finally,the simulation results in Matlab show that the trajectory planning algorithm proposed in this paper can be used to accurately control the tip trajectory of the boom of the pump truck.(2)In order to solve the conflicts between the tip of the boom and the position of obstacles,the unstable operation of the boom and the large vibration range of the boom system in the process of transition between the primary and secondary tasks,the obstacle avoidance algorithm of the boom of the pump truck based on the danger field method was adopted.Will improve traditional danger field formula,the improved danger field value feedback to weighted closed loop inverse kinematics trajectory planning algorithm,realizing of pump truck boom of obstacle avoidance,compare the value of the danger field with the threshold value of the danger field,to realize freedom transition between the primary and secondary tasks,introducing the smooth transition factor to realize the pump truck boom trajectory planning and obstacle avoidance motion smooth transition between the primary and secondary tasks,Finally,simulation analysis is carried out in Matlab to verify the effectiveness of the algorithm.(3)A semi-physical simulation platform is built in Simulink,and CAN signals are collected into the control system.The trajectory planning algorithm is encapsulated in Matlab Function module,and the three-dimensional model of the boom is imported into Simulink to establish the real-time control system of the boom of the pump truck.The advantages and disadvantages of data collected and analyzed by Zhou Ligong USB-CAN and PCAN-USB analyzers are compared and analyzed,the semi-physical simulation platform of pump truck boom is built based on PCAN-USB data analyzer.(4)The trajectory planning algorithm is verified in the semi-physical simulation system by the collection of the CAN signals.The trajectory planning algorithm of pump truck boom is verified by experiments based on semi-physical simulation system.The correctness of the algorithm under horizontal left velocity and variable velocity conditions are verified through two groups of experiments respectively.