Research On Trajectory Planning And Adaptive Stable Control For Manipulator Systems

The manipulator is a mechanical device which simulates arms of human beings,and a main actuator in a robot.In recent years,the study of manipulator technology has been making great progress.It is increasingly applied in varied areas,such as industrial production,medical treatment and space exploration.The smoothness and continuity of a manipulator's trajectory can be achieved by a reasonable trajectory planning.At the same time,due to lots of uncertainties in the dynamic characteristics of a manipulator,the impact which a nonlinear and uncertain manipulator has on the system should be considered to make this system immune to the uncertainty of parameters and prevent the damage on the manipulator itself as well as the operation object.All in all,trajectory planning and adaptive control deserve to be further researched.The main content of this thesis is summed up as follows:First of all,this part introduces the research background,significance and development course of manipulators,and analyzes the research status about its trajectory planning and adaptive stability control.Then,the mathematical foundation of a manipulator model and the manipulator's state space model which contains uncertainty is illustrated in this part.Next,for the beginning and ending in both velocity and acceleration are not zero,caused by Newton interpolation,polynomial interpolation method is assimilated into this to get a better trajectory planning.By using MATLAB,the simulation results show that the beginning and ending in both velocity and acceleration stay smooth,which tells the new method ensures its movements' steadiness,compared with that of Newton interpolation.After that,in terms of the manipulator system model including three uncertain dynamics,the adaptive backstepping theory is adopted to estimate parameters and design the adaptive controller,thus avoiding the damage generated by unknown factors on the manipulator itself and the controlled object.This algorithm maintains the nonlinearity of the system,and promptly estimates its unknown parameters to make the system stable.In addition,in order to improve the effectiveness of parameter estimation,I&I is used for the manipulator system to design the adaptive controller and parameter estimator.Lyapunov function is unnecessary when the controller is designed in this method,which means differential operation is redundant,hence averting the 'computing expansion' of backstepping method effectively.Also the I&I adaptive control does not invoke certainty equivalence.The whole uncertain parameters estimations are the sum of two terms.One is obtained by an update law like backstepping method.The other is an adequately chosen the.nonlinear function.The role of this additional term makes the parameters estimations more flexible and effective.Finally,the main research work of the thesis is summarized,followed by the proposal of next work's main points and further research's direction.