Design And Implementation Of The Control System For Planar Cable-Driven Parallel Robot

Cable-Driven Parallel Robot(CDPR)is a parallel robot of new type and for special purpose.For compared with traditional robot,CDPR has many advantages: fast speed,small inertia,large workspace and so on.So,it has been paid close attention to by many scholars at home and abroad.However,control problem is one of the hot spots and difficulties,which has important theoretical and practical research value.Based on the existing achievements,this thesis focuses on the control problem of Planar Cable-Driven Parallel Robot(PCDPR).The prototype of PCDPR motion control system is built and it tests the feafibility of the control system scheme.The main work of this thesis is as follows:1.The kinematics and dynamics model of Planar Cable-Driven Parallel Robot which is driven by four cables and has two degrees of freedom is built.And kinematics and dynamics are analyzed.When synthesizing end effector model,driving unit model,cable model and statics model,the system dynamics model is built.And it provides theoretical support for further research on dynamic control problem.2.The shortcomings of conventional control algorithms such as PID control are described.The Sliding Mode Control algorithm is designed in consideration of the nonlinearity,uncertainty and outside disturbance of the control object.And through simulation,the results show that the motion trajectory is more accurate.3.Considering the proportion of state variables and control variables,a Linear Quadratic Control controller is designed,and the stability of the control algorithm is analyzed,so that there is a good trade-off between the control input and the control error.Considering the energy consumption and precision has corresponding engineering reference value for the control of PCDPR.4.The hardware and software of the control system are designed and implemented.Firstly,the overall architecture of the control system is proposed,and then the hardware of the system,the software of upper computer and lower computer are introduced.Then the motion controller GTS-400-PG and Microsoft Foundation Classes(MFC)based on C++ programming language are selected and the monitoring interface of motion control is developed.Finally,the experimental prototype of the PCDPR system is built.Based on the kinematics model,the motion control experiment is preliminarily carried out and the maximum error of accuracy is about 3 mm.For the research of Cable-Driven Parallel Robot,previous scholars research mainly on kinematics,dynamics,workspace and the optimization of redundant cable force.This thesis focuses on the design of control algorithms.And the the accuracy and rationality of the kinematics model are verified by experiments.On the one hand,it makes up for the lack of research on control problem,on the other hand,it lays a foundation for further in-depth theoretical research and engineering application.