On Chaos In Flexible Redundant Robotic Manipulators

Flexible redundant robots have various advantages, such as obstacle or singularity avoidance, torque minimization and high speed with light weight, and therefore have drawn attention of researchers in intelligent robot field. However, they also have limitations in practical implementations, as the system is highly coupling and nonlinear with complex kinematic and dynamic behaviours. So, it's meaningful to investigate the motion internality of flexible redundant robot to improve its working performance. In this dissertation, the application of chaos theory to flexible redundant robot is studied systematically for the first time, and the main points of the studies are as follows.Firstly, the basic issues on chaos theory, including chaotic recognition, prediction and control are introduced and discussed to lay an important foundation for latter study.Secondly, the kinematics of flexible redundant robot is modeled based on Jacobian matrix.Thirdly, the chaotic recognition methods for flexible redundant robot, such as phase plot, and Poincare mapping, are studied by the numerical simulation. The numerical results show that, the self-motions of a planar 3R and a spatial 4R flexible redundant robot under the pseudoinverse control with PD controller are chaotic respectively when the end-effector traces a closed-path repeatedly in the workspace.Fourthly, the chaotic prediction for flexible redundant robot is studied, and a chaotic prediction approach for flexible redundant robot based on Lyapunov Exponents is presented. By using this approach, the effects of structural parameters and initial configurations of a planar 3R flexible redundant robot on its motion state is analyzed.Lastly, the chaotic control for flexible redundant robot is studied, and the delayed feedback method to control a chaotic flexible redundant robot is developed. It was demonstrated that chaotic motions of a planar 3R and a spatial 4R flexible...