Disturbance Attenuation Control Research Articles

Finite‐time disturbance attenuation control problem for singularly perturbed discrete‐time systems

Finite‐time disturbance attenuation control problem for singularly perturbed discrete‐time systems

Finite‐time disturbance attenuation control problem for singularly perturbed discrete‐time systems

Finite‐time disturbance attenuation control problem for singularly perturbed discrete‐time systems

Design of Controllers for Quadratic Stability and Disturbance Attenuation of Uncertain Systems

In this paper, we discuss the design of controllers that provide quadratic stability and a desirable disturbance attenuation level (through an appropriately small L2 gain) for systems with time varying, real and structured uncertainty. It is shown that for a class of systems, the problem of designing dynamic output feedback can be separated into two stages, each an easily solvable convex problem. This information could be used in system design and configuration. Two examples are presented to illustrate the proposed approach.

Active force control of a flexible manipulator by distal feedback

The dynamics of flexible manipulators are considered and a method is presented for achieving their fast coordinated control. The method uses active force control for deformation and disturbance attenuation and PD control for trajectory tracking. The control of flexible manipulator arms poses difficult design problems. The flexibility itself introduces a theoretical infinity of modes each of which must be controlled. The degree of natural damping may be low and it may not be possible to introduce, early, a controlled measure of damping. There may also be present some unknown (and unmeasurable) external disturbance forcing. Here, the powerful methods of active force control which have proved so effective in the control of rigid arms in the face of disturbances, are extended to flexible arms. It is shown that by the use of distal feedback, i.e. feedback from the end of each link farthest from the driven joint, it is possible to obtain effective controller action. Results are shown for a two link arm.

Strictly proper projective controllers for disturbance attenuation

A design methodology is presented which applies projective controls to the disturbance attenuation problem for large flexible structures. Through this method, low-order strictly proper controllers are designed which improve the disturbance attenuation properties of the system. A new parameterization of the closed-loop system in terms of free parameters in the projective controller leads to an auxiliary minimization problem which determines the parameters of the controller. A flexible structure example demonstrates the use of this methodology.