Research On The Trajectory Control Of Bucket Of Three-arm Excavator

As a small number of excavators,the proportion of three arm excavator is very small in the actual production and application,but it is still worthy of in-depth study for its characteristics of adapting to a variety of harsh construction environment.In this paper,a three-arm excavator is designed.Taking the three-arm excavator as the research object,the automatic control theory technology is applied to the three-arm excavator,and the electrohydraulic servo control system is studied to realize the tracking control of the three-arm excavator’s motion tracking.In this paper,the three-arm excavator is designed firstly.Taking 15 T excavator as the prototype,the structure design of the working device of the three-arm excavator is completed,and the three-dimensional model of the three-arm excavator is built by using virtual prototyping technology.At the same time,in order to realize the automation of the three-arm excavator’control,the original traditional handle operated hydraulic system is transformed into an electro-hydraulic servo control system.Secondly,on the basis of the virtual prototype of the three-arm excavator,the kinematics and dynamics analysis and simulation can be carried out to obtain the relationship between the specific position of the bucket tip and the joint angle,the relationship between the length of the hydraulic cylinder and the joint angle,and the relationship between the forces on the joints.At the same time,the simulation results are compared with those of the 15 T excavator,which is more significant,it shows the superiority of the three-arm excavator in the working range of excavation.Finally,in order to realize the trajectory control of the three-arm excavator and ensure the accuracy and stability of the trajectory tracking,the traditional PID controller,sliding mode controller,feedback linearization sliding mode controller and nonsingular terminal sliding mode controller are designed respectively,and the effect of the four controllers on the trajectory tracking control of the three-arm excavator is analyzed and compared.The simulation results show that the tracking error of PID control and conventional sliding mode control is too large,and the feedback linearization sliding mode control and the nonsingular terminal sliding mode control in this paper improve the tracking effect of the control system.