Institute for Systems Research Technical Reports
Permanent URI for this collectionhttp://hdl.handle.net/1903/4376
This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.
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Item Modeling of Impact on a Flexible Beam(1993) Wei, Q.F.; Krishnaprasad, Perinkulam S.; Dayawansa, Wijesuriya P.; ISRWe consider the problem of modeling dynamical effects of impact of an elastic body on a flexible beam. We derive a nonlinear integral equation by using the Hertz law of impact in conjunction with the beam equation. This equation does not admit a closed form solution. We demonstrate the existence of solutions, derive a reliable numerical method for computing solutions, and compare the numerical results with those obtained by others.Item Optimal Control of a Rigid Body with Two Oscillators(1993) Yang, R.; Krishnaprasad, Perinkulam S.; Dayawansa, Wijesuriya P.; ISRThis paper is concerned with the exploration of reduction and explicit solvability of optimal control problems on principal bundles with connections from a Hamiltonian point of view. The particular mechanical system we consider is a rigid body with two driven oscillators, for which the bundle structure is (SO (3) x 者, 者, SO (3)). The optimal control problem is posed by considering a special nonholonomic variational problem, in which the nonholonomic distribution is defined via a connection. The necessary conditions for the optimal control problem are determined intrinsically by a Hamiltonian formulation. The necessary conditions admit the structure group of the principal bundle as a symmetry group of the system. Thus the problem is amendable to Poisson reduction. Under suitable hypotheses and approximations, we find that the reduced system possesses additional symmetry which is isomorphic to S1. Applying Poisson reduction again, we obtain a further reduced system and corresponding first integral. These reductions imply explicit solvability for suitable values of parameters.Item Stabilization of Globally Noninteractive Nonlinear Systems via Dynamic State-Feedback(1991) Battilotti, S.; Dayawansa, Wijesuriya P.; ISRWe consider the problem of semiglobal asymptotic stabilization and noninteracting control via dynamic state-feedback for a class of nonlinear control systems. It is assumed that the plant has been already rendered noninteractive. A sufficient condition for the stabilization of the overall system, without destroying the noninteraction property, is given in terms of stabilizability of certain subsystems.Item Noninteracting Control with Stability for a Class of Nonlinear Systems(1991) Battilotti, S.; Dayawansa, Wijesuriya P.; ISRIn this paper we address the problem of noninteracting control with stability for the class of nonlinear square systems for which noninteraction can be achieved (without stability) by means of invertible static state-feedback. The use of both static state-feedback and dynamic state-feedback is investigated. We prove that in both cases the asymptotic stabilizability of certain subsystems is necessary to achieve noninteraction and stability. We use this and some recent results to state a complete set of necessary and sufficient conditions in order to solve the problem.Item Mechanical Systems with Partial Damping: Two Examples(1991) Wang, L.S.; Krishnaprasad, Perinkulam S.; Dayawansa, Wijesuriya P.; ISRWe discuss the problem of constructing steady state motions of mechanical systems with partial damping. A planar three bar linkage with viscous damping at one of the joints is considered as an example. We show that for a generic set of system parameters all steady state motions are confined to relative equilibria. We also consider the example of two rigid bodies with one-board rotors coupled via a ball-in-socket joint with viscous friction and show that in the steady state, the system is at a relative equilibrium.Item Asymptotic Stabilization of Low Dimensional Systems(1990) Dayawansa, Wijesuriya P.; Martin, C.F.; ISRThis paper studies the asymptotic stabilization of two and three dimensional nonlinear control systems. In the two dimensional case we review some of our recent work and in the three dimensional case we give some new sufficient conditions and necessary conditions.Item Asymptotic Stability of Nonlinear Systems with Holomorphic Structure(1990) Dayawansa, Wijesuriya P.; Martin, C.F.; ISRWe consider the local asymptotic stability of a system dx/dt = F(z), z = C sup n , F : C sup n - C sup n is holomorphic, t R, and show that if the system is locally asymptotically stable at some equilibrium point in the N sup th approximation for some N , then necessarily its linear part is asymptotically stable also.Item Global Tracking Problem for Minimum Phase Nonlinear Systems(1990) Dayawansa, Wijesuriya P.; Martin, C.F.; Knowles, G.; ISRWe consider the tracking problem for a globally minimum phase nonlinear system. It is assumed that the signal to be tracked is slowly varying and a priori bounds on its magnitude are known. We show that if the system has bounded derivatives and exponentially stable zero dynamics then the system admits an output feedback controller which solves the tracking problem.