Research On Iterative Learning Control Of The Robotic Manipulators

With the development of computer technology,automatic production and robot technology have been further researched and promoted,and manipulator which has a high degree of automation is widely used in each link of production.The use of manipulator in production can not only reduce production cost but also increase efficiency and improve quality.So designing a suitable control system to control objects with characteristics of difficult modeling and highly nonlinear such as manipulator is very important.In order to study and design manipulator motion control system with low cost and high performance,this paper propose a motion control scheme combined PC with STM on the base of analysis and research of manipulator and its control theory.This control scheme has a hardware designation that takes STM32 micro controller as the core to control the manipulator.This paper is based on an amount of research about Pneumatic Manipulator which carried out by those experts both at home and abroad.And take the three degree of freedom Pneumatic Manipulator as the research object to analyze the speed control of manipulator servo system.We analyze the nonlinear of the system and its influence on the system characteristics from three aspects,i.e.,nonlinear flow of proportional servo valve in pneumatic servo system,cylinder friction characteristics,creeping characteristics.In addition,the related nonlinear compensation technique is proposed.A mathematical model for the speed control of the pneumatic manipulator servo system is established.Based on the model,the effect of system parameter variation on system performance is analyzed.And the dynamic performance of the control system is corrected.Since the manipulator in the actual operation possesses constant repetitive motion characteristics,and is nonlinear and time-varying system.By referring to papers,we know that iterative learning control is suitable for the controlled system with characteristics of repeated movements.And also has good control effect in Nonlinear,time-varying,uncertainty,interference and cross coupling system.This paper has proved the convergence of iterative learning control used in this system.Iterative learning control model is established in Simulink.Through Matlab and simulation language,the control and iterative learning control can be compared from simulation analysis.It can be verified that the improved PD type iterative learning control has better convergence compared with the control of D type ILC and improved D type ILC.And it also showed that improved PD type iterative learning control used in this system has better control effects.The thesis ended with a conlusion of the research work,and prospected the future research interests.