A Review of Dynamic Control of the RigidFlexible Macro-Micro Manipulators

A review of the control strategy for rigid-flexible macro-micro manipulators is presented. This type of manipulators has great potential applications due to the advantages of high ratio of workspace and volume and fast response. Generally it consists of a cable-driven macro parallel mechanism and a rigid-driven micro mechanism serially mounted on the previous. Because of the flexibility and redundant actuation of the macro mechanism, the two submechanisms interact and cable tension solutions are non-unique. To control the macro-micro manipulators, it is significant to tackle the problems of dynamic modeling, decoupling and cable tension optimization. The methods for solving the dynamic problems are compared, and the targets, algorithms and evaluation indexes of the cable tension optimization are summarized. Based on the dynamic analysis and cable tension optimization, the control methods of the global mechanism and the performance of kinematic and dynamic controllers are reviewed. Further, the prospects of the methods for the three important issues, the dynamic decoupling, cable tension optimization and dynamic control, are pointed out.