We compare four spacecraft attitude control laws that require no prior modeling of the spacecraft mass distribution. All four control laws are based on rotation matrices, which provide a singularityfree attitude representation and unwinding-free operation without discontinuous switching. We apply these control laws to motion-to-rest and motion-to-spin maneuvers. Simulation results are given to ...

The focus of this paper is on the design of time optimal control profiles for flexible structures subject to deflection constraints. The benchmark floating oscillator is used to illustrate the variation in the structure of the control profile as a function of permissible deflection. The transition from a 5 switch bang-bang to a 7 switch bang-bang to finally, a 7 switch profile which includes no...

This paper deals with the study of the optimal control problem for the objective F (x, u, v) = ∫ T 0 f(x(t), x(t− h), ζ(t), u(t), v(t), t)dt, with x ∈ X, u ∈ U, v ∈ V ; X, U and V being vector spaces, and ζ(t) = ∫ h 0 R(t, τ )x(t− τ ) dτ , subject to the differential equation d dtx(t) = m(x(t), x(t− h), ζ(t), u(t), v(t), t) (0 6 t 6 T ), and the constraints g1(u(t), t) ∈ S1, g2(v(t), t) ∈ S2; n...

In this article, we propose a new paradigm of control, called a maximum-hands-off control. A hands-off control is defined as a control that has a much shorter support than the horizon length. The maximum-hands-off control is the minimum-support (or sparsest) control among all admissible controls. We first prove that a solution to an L-optimal control problem gives a maximum-handsoff control, an...

The finite-horizon optimal control problem with input constraints consists in controlling the state of a dynamical system over a finite time interval (possibly unknown) minimizing a cost functional, while satisfying hard constraints on the input. For linear systems the solution of the problem often relies upon the use of bang-bang control signals. For nonlinear systems the “shape” of the optima...

We are concerned with the optimal decision to sell or buy a stock in a given period with reference to the ultimate average of the stock price. More precisely, we aim to determine an optimal selling (buying) time to maximize (minimize) the expectation of the ratio of the selling (buying) price to the ultimate average price over the period. This is an optimal stopping time problem which can be fo...

In this paper, an integration of Improve Particle Swarm Optimization (IPSO) in combination with Successive Quadratic programming (SQP) so called IPSO-SQP algorithm is proposed to solve time optimal bang-bang control problems. The procedure is found not sensitive to the initial guess of the solution. Due to random selection in the first stage of the search process, the chance of converging to th...

In this paper, the time-optimal control problem for infinite order hyperbolic systems in which time delays appear in the integral form both in state equations and in boundary conditions is considered. Optimal controls are characterized in terms of an adjoint system and shown to be unique and bang-bang. These results extend to certain cases of nonlinear control problems. The particular propertie...

Time optimal control problems for an internally controlled heat equation with pointwise control constraints are studied. By making use of Pontryagin’s maximum principle and a special kind of property for nontrivial solutions of the heat equation, we derive a bangbang property for time optimal control. Using the bang-bang property and establishing certain connections between timeand norm optimal...