For optimal control problems involving isoperimetric constraints, by using a two-norm approach, a new sufficiency theorem for a proper strong minimum is obtained. It is applicable to processes that satisfy the Legendre-Clebsch necessary condition but its strict version is not imposed, that is, the processes may be singular. The conditions are expressed explicitly in terms of the second variatio...

In this paper we provide a complete theoretical analysis of a two-dimensional degenerate non convex singular stochastic control problem. The optimisation is motivated by a storage-consumption model in an electricity market, and features a stochastic real-valued spot price modelled by Brownian motion. We find analytical expressions for the value function, the optimal control and the boundaries o...

An open question contributed by Yu. Orlov to a recently published volume ”Unsolved Problems in Mathematical Systems and Control Theory”, V.D. Blondel & A. Megretski (eds), Princeton Univ. Press, 2004, concerns regularization of optimal control-affine problems. These noncoercive problems in general admit ’cheap (generalized) controls’ as minimizers; it has been questioned whether and under what ...

In this paper we provide a complete theoretical analysis of a two-dimensional degenerate non convex singular stochastic control problem. The optimisation is motivated by a storage-consumption model in an electricity market, and features a stochastic real-valued spot price modelled by Brownian motion. We find analytical expressions for the value function, the optimal control and the boundaries o...

This paper presents a new technique for generating linear fractional transformation based uncertainty models for use in the robustness analysis of flight control systems using the structured singular value . The proposed approach does not require closedform linear expressions for the aircraft dynamics – only a non-linear software model of the closed loop aircraft, which can be efficiently trimm...

The problems of delay-dependent robust stability and stabilization for continuously singular timedelay systems with norm-bounded uncertainties are investigated in this paper. Based on a Lyapunov functional, which includes some non-positive items, the modified delay-dependent LMIs-based conditions are established for the singular time-delay systems to be regular, impulse free, and stable. Then, ...

This paper applies the block control method to form a decomposed control law suitabal for multivariable linear time-delay systems. A block controllable form is introduced and a non-singular transformation that reduces the system to this form, is proposed. A block deadtime compensation algorithm wich gives a sliding manifold, is derived. An example of the application of the proposed control stra...

This paper provides necessary and sufficient conditions for several forms of controlled system reliability. For comparison purposes, past results on the reliability analysis of controlled systems are reviewed and several of the past results are shown to be either conservative or have exponential complexity. For systems with real and complex uncertainties, conditions for robust reliable stabilit...

In the present paper we address a nonlinear singular H1 sub-optimal control problem for a rigid spacecraft with actuator dynamics. Using recent results from nonlinear H1 control theory , we nd an explicit feedback solution involving the Euler parameters. Our solution is based on a solution to a corresponding nonlinear regular H1 suboptimal control problem for a rigid spacecraft with three contr...

A b g r a a A simultaneous H2/H® control problem is considered. This problem seeks to minimize the H 2 norm of a closed-loop transfer matrix while simultaneously satisfying a prescribed H~ norm bound on some other closed-loop transfer matrix by utilizing dynamic state feedback controllers. Such a problem was formulated earlier by Rotea and Khargonekar (Automatica, 27, 307-316, 1991) who conside...