In this paper, a practical method to design a robust controller for a flexible joint robot (FJR) using quantitative feedback theory (QFT) is proposed. In order to control fast and slow dynamics of the FJR separately, composite control scheme is considered as the basis for the design. A simple PD controller is used to stabilize the fast dynamics, and a QFT controller is used in addition to an in...

We propose a new model for robot manipulators with rigid links and flexible joints. Our model is expressed in Cartesian dependent coordinates which represent the positions, orientations and velocities of the links and the rotors, as opposed to independent generalized coordinates in which classical “Lagrangian” models are defined. The model consists of a set of dynamics equations and holonomic c...

Flexibility at the joint of a manipulator is an intrinsic property. Even “rigid-joint” robots, in fact, possess a certain amount of flexibility. Previous experiments confirmed that joint flexibility should be explicitly included in the model when designing a high-performance controller for a manipulator because the flexibility, if not dealt with, can excite system natural frequencies and cause ...

Actuator failure and joint flexibility will dramatically impact space robot system control. In this paper, free-floating flexible-joint space-manipulator dynamic-modeling is studied a state-observer-based robust backstepping fault-tolerant control proposed for the actuator failure. Based on simplified model, system’s rigid-flexible coupled-dynamic equations are established according to momentum...

The paper addresses the problem of controlling the joints of an flexible joint robot with a state feedback controller and proposes a gradual way of extending such a controller towards feedback linearization. The global asymptotic stability for the state feedback controller with gravity compensation is proven. Experimental results on the DLR light-weight robots validate the method.

This paper addresses the adaptive tracking control of flexible joint manipulators based on a singular perturbation approach. Comparisons between adaptive and nonadaptive tracking controllers are given. Experimental results with the DLR’s light weight robot are given for the 2 DOF case.

It is shown that it is possible to greatly improve the performance of the predictive control strategy proposed by Jankowski and Van Brussel [9] by using preliminary linear feedback. This is illustrated using the example of a flexible-joint robot path following problem.

We analyze the stability of our novel 2-way fuzzy adaptive controller using describing function technique. We use additivity property of fuzzy systems to develop a systematic analytical approach for the design of a multi-input singleoutput fuzzy controller that we use for the control of a flexible-joint robot arm. Copyright c ©2005 IFAC