Paper: Model reference adaptive control algorithms for industrial robots

Design issues, dynamic modeling, trajectory planning, and feedback control problems are presented for robot manipulators having components with mechanical flexibility, either concentrated at the joints or distributed along the links The chapter is divided accordingly into two main parts Similarities or differences between the two types of flexibility are pointed out wherever appropriate

Robots with Flexible Elements

Reference is made to the problem of controlling the dynamic behavior of robots with rigid links but in presence of joint elasticity. It is shown that use of the more general class of dynamic nonlinear state-feedback allows solving both the feedback linearization and the input-output decoupling problems. A constructive procedure for the decoupling and linearizing feedback is given which is based on generalization system inversion and on the properties of the so-called zero-dynamics of the system. A case study of a planar two-link robot with elastic joints is included. The role of dynamic feedback for this class of robots is discussed. >

Dynamic control of robots with joint elasticity

This paper analyzes multi-sender cheap talk when the state space might be restricted, either because the policy space is restricted or the set of rationalizable policies of the receiver is not the whole space. We provide a necessary and sufficient condition for the existence of a fully-revealing perfect Bayesian equilibrium for any state space. We show that if biases are large enough and are not in similar directions, where the notion of similarity depends on the shape of the state space, then there is no fully-revealing perfect Bayesian equilibrium. The results suggest that boundedness, as opposed to dimensionality, of the state space plays an important role in determining the qualitative implications of a cheap talk model. We also investigate equilibria that satisfy a robustness property, diagonal continuity.

/pdf/multi-sender-cheap-talk-with-restricted-state-spaces-2epsrq28ee.pdf

Multi-sender cheap talk with restricted state spaces

It is known that control of a rigid robot arm can easily be achieved via static state-feedback compensation of the nonlinearities. However, in many practical situations, the elasticity in gear boxes is not negligible. If this is the case, the use of such a control technique is not possible anymore because neither is the system feedback equivalent to a controllable linear one, nor its input-output behavior can be decoupled via static state-feedback. The purpose of this paper is to show how dynamic state-feedback compensation may be used in order to obtain full state-space iinearity, and to present an application to the model of a three link robot arm with elastic joints.

D. Lentini

Papers

Dynamical control of industrial robots with elastic and dissipative joints