Research On Control System Of Pneumatic Assist Equipment Based On Compliance Control

Power assist equipment and industrial robot are widely used in the industrial field.The traditional power assist equipment heavily rely on human participation and lack of automatic execution ability.Most industrial robots have limited load-carrying capacity,and most of the control methods are off-line programming.The autonomy and adaptability to the external environment are poor.The pneumatic power assist equipment combines the advantages of the two kinds of equipment above,and it is widely used in practical engineering,but the problems of autonomy and adaptability still need to be further studied.In order to improve the self-control ability of pneumatic power assist equipment and its adaptability to complex and changeable environment,and to enrich the control system theory research,expand the function and application of power assist equipment,this paper studies the real-time trajectory planning of pneumatic power assist equipment and the compliance control of installation process.In this paper,based on the structure of pneumatic power assist experimental equipment and using robotics theory,the forward kinematics of pneumatic power assist equipment is solved,and the mapping relationship from the joint space to the Cartesian space at the end of the equipment is obtained.The inverse transformation method is used to obtain the transformation relationship between the end of the power assist equipment and the joint space.The dynamic derivation of the first six degrees of freedom of the pneumatic power assist experimental equipment is carried out by using the Lagrange method,and the corresponding kinematics and dynamics simulation models are established.It provides a theoretical basis for real-time trajectory planning.In allusion to the single degree of freedom of the fine tuning mechanism,the parameters are equivalent to the rotating shaft of the motor,and the mathematical model of the single degree of freedom drive device of the fine tuning mechanism is established,so as to facilitate the modeling of the compliance control system.This paper analyzes the principle of trajectory planning,taking kinematics theory as the basic method of realization,considering synthetically the factors of power assist equipment dynamics,according to the planning principle,select the five order polynomial interpolation algorithm as the trajectory planning algorithm,considering the actual working conditions synthetically,three typical working paths are summarized,namely I,L and Z.By using the five order polynomial interpolation algorithm,the trajectory planning simulation of the typical path is carried out on the basis of the kinematics and dynamics simulation model,so that the motion law of each joint is obtained.The rationality of the trajectory planning algorithm and the correctness of the planning process are verified,and the driving torque of the arm and the forearm required for the force balance is obtained by the trajectory planning simulation.And a graphical model is established and simulated by using other simulation software.The correctness of the kinetic results is verified by comparing the two results.In allusion to the compliance control system of fine tuning mechanism,several typical compliance control methods are analyzed,and the impedance control method is suitable for this subject and selected to study compliance control.Take second-order oscillatory system as example,based on the simulation of impedance control applied on this subject,the disadvantages are found,and an improved strategy is proposed.And the corresponding simulation model of compliance control is established,and the effect of the control method on the compliance movement and contact force limitation is analyzed.Finally,the simulation model of single degree of freedom and global compliance control of the fine tuning mechanism are established to verify the effectiveness of the compliance control strategy of the fine tuning mechanism.In order to verify the practical application effect of the fine tuning mechanism compliance control strategy,an experimental platform for fine tuning mechanism compliance control was built,and the compliance effect verification experiments were carried out for several situations.The experimental results show that,the compliance control strategy studied in this paper can meet the requirements of fine adjustment compliance installation,achieve compliance control effect,and achieve the goal of contact force limitation.