This paper considers the optimal control of time varying continuous time Markov chains whose transition rates are themselves Markov processes. In one set of problems the solution of an ordinary differential equation is shown to determine the optimal performance and feedback controls, while some other cases are shown to lead to singular optimal control problems which are more difficult to solve....

Optimal control of dampers has been proposed to mitigate vibration effects in mechanical systems. In many cases, systems are subject to periodic forcing and the goal is to maximize the energy dissipated by the damper. In contrast to prior work utilizing instantaneous or infinite-time−horizon optimization, this paper employs periodic optimal control to maximize the energy dissipated per cycle. F...

In this paper we study a singular control problem for a system of PDEs describing a phasefield model of Penrose-Fife type. The main novelty of this contribution consists in the idea of forcing a sharp interface separation between the states of the system by using heat sources distributed in the domain and at the boundary. We approximate the singular cost functional with a regular one, which is ...

It is shown that the so-called \pure" mixed H 2 =H 1 optimization problem does not have a \good" solution. More precisely, a class of non-singular \pure" mixed H 2 =H 1 optimization problems (minimization of an L 2-norm subject to a Youla parameterization and an L 1 constraint) is considered. It is shown that, whenever the L 1 constraint is not redundant, the optimal controller has innnite orde...

In this paper we present magnetic control of a spacecraft using the Dichotomous Coordinate Descent (DCD) algorithm with box constraints. What is common for most work on magnetic spacecraft control is the technique for solving for the control variables of the magnetic torquers where a cross product is included which is well known to be singular. The DCD algorithm provides a new scheme which make...

The quadratic optimal control problem for linear time-delay singularly perturbed systems is investigated via successive approximation approach (SAA) in this paper. Based on singular perturbation theory, the system is decomposed into two subsystems of a slow-time scale and a fast-time scale. The slow-time scale time-delay optimal control problem is transformed first into a sequence of nonhomogen...

In the present paper, we expand information about the conditions for passing through Type 2 singular configurations of a parallel manipulator. It is shown that any parallel manipulator can cross the singular configurations via an optimal control permitting the favorable force distribution, i.e., the wrench applied on the end-effector by the legs and external efforts must be reciprocal to the tw...

This paper deals with the control reconfiguration problem of partial actuator failure in a Three-Tank Multi-Input Multi-Output (MIMO) system. In order to tolerate known actuator failure, a reconfiguration in control parameter/structure is made through output/state feedback. A new Proportional-Integral (PI) Reconfigurable Controller (RC) design is proposed for servo tracking problem using Singul...