State-feedback Controller (state-feedback + controller)

Distribution by Scientific Domains


Selected Abstracts


A novel discrete-time sliding mode technique and its application to a HDD dual-stage track-seek and track-following servo system

INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 4 2008
G. Herrmann
Abstract A novel approach for the design of a discrete-time sliding mode controller is presented showing that the dynamics of a sliding-mode state-feedback controller can be designed using a singular LQR approach. The weighting of the control signal is set to zero and dead-beat behaviour for the sliding mode reaching dynamics is achieved. The reaching dynamics are modified when the states are a significant distance away from the sliding surface to avoid any high magnitude control action due to the partial dead-beat approach. The control law also takes into account the constraints on the actuator amplitudes and a stability analysis is presented using a discrete-time version of the Popov criterion. The control approach is demonstrated in conjunction with a recently developed large-span track-seeking and track-following method for dual-stage actuator systems in a hard disk drive (HDD). It is shown how the discrete-time sliding mode control scheme can be incorporated into the observer-based control system for the secondary actuator. Superior performance for the track-seeking and track-settling process is demonstrated using an existing practical set-up of a dual-stage HDD servo system. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Delay-dependent robust control for singular discrete-time Markovian jump systems with time-varying delay

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 10 2010
Wuneng Zhou
Abstract The problem of delay-dependent robust stabilization for uncertain singular discrete-time systems with Markovian jumping parameters and time-varying delay is investigated. In terms of free-weighting-matrix approach and linear matrix inequalities, a delay-dependent condition is presented to ensure a singular discrete-time system to be regular, causal and stochastically stable based on which the stability analysis and robust stabilization problem are studied. An explicit expression for the desired state-feedback controller is also given. Some numerical examples are provided to demonstrate the effectiveness of the proposed approach. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Shortest path stochastic control for hybrid electric vehicles

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 14 2008
Edward Dean Tate Jr
Abstract When a hybrid electric vehicle (HEV) is certified for emissions and fuel economy, its power management system must be charge sustaining over the drive cycle, meaning that the battery state of charge (SOC) must be at least as high at the end of the test as it was at the beginning of the test. During the test cycle, the power management system is free to vary the battery SOC so as to minimize a weighted combination of fuel consumption and exhaust emissions. This paper argues that shortest path stochastic dynamic programming (SP-SDP) offers a more natural formulation of the optimal control problem associated with the design of the power management system because it allows deviations of battery SOC from a desired setpoint to be penalized only at key off. This method is illustrated on a parallel hybrid electric truck model that had previously been analyzed using infinite-horizon stochastic dynamic programming with discounted future cost. Both formulations of the optimization problem yield a time-invariant causal state-feedback controller that can be directly implemented on the vehicle. The advantages of the shortest path formulation include that a single tuning parameter is needed to trade off fuel economy and emissions versus battery SOC deviation, as compared with two parameters in the discounted, infinite-horizon case, and for the same level of complexity as a discounted future-cost controller, the shortest-path controller demonstrates better fuel and emission minimization while also achieving better SOC control when the vehicle is turned off. Linear programming is used to solve both stochastic dynamic programs. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Some nonlinear optimal control problems with closed-form solutions

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 14 2001
Michael Margaliot
Abstract Optimal controllers guarantee many desirable properties including stability and robustness of the closed-loop system. Unfortunately, the design of optimal controllers is generally very difficult because it requires solving an associated Hamilton,Jacobi,Bellman equation. In this paper we develop a new approach that allows the formulation of some nonlinear optimal control problems whose solution can be stated explicitly as a state-feedback controller. The approach is based on using Young's inequality to derive explicit conditions by which the solution of the associated Hamilton,Jacobi,Bellman equation is simplified. This allows us to formulate large families of nonlinear optimal control problems with closed-form solutions. We demonstrate this by developing optimal controllers for a Lotka,Volterra system. Copyright © 2001 John Wiley & Sons, Ltd. [source]


,, control of discrete-time Markov jump systems with bounded transition probabilities

OPTIMAL CONTROL APPLICATIONS AND METHODS, Issue 5 2009
E. K. Boukas
Abstract This paper deals with the class of discrete-time linear systems with random abrupt changes and unknown transition probabilities but varying between known bounds for each mode. The ,, control problem of this class of systems is revisited and new sufficient conditions are developed in the linear matrix inequality (LMI) setting to design the state-feedback controller that stochastically stabilizes the system under consideration and at the same time guarantees the disturbance rejection with a desired level , . Sufficient conditions for existence of the state-feedback controller are developed. It is shown that the addressed problem can be solved if the corresponding developed LMIs are feasible. Numerical examples are employed to show the usefulness of the proposed results. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Multi-objective state feedback control for linear delay systems

ASIAN JOURNAL OF CONTROL, Issue 4 2010
Wei Xie
Abstract This paper provides new linear matrix inequalities (LMI)-based formulae for mixed H2/H, state-feedback synthesis of linear continuous-time systems with state delays of any size. The proposed delay-independent LMI-based conditions enable us to parameterize a memoryless state-feedback controller without involving the Lyapunov variables in the formula. Compared with previous results based on a common Lyapunov variable, the proposed formula provides less conservative results. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]