Adaptive Output Control Research Articles

Adaptive output control with compensation of biased harmonic disturbance

Methods for compensation of biased harmonic disturbances using measurements of the output variable of the plant are developed. An algorithm of adaptive control, which outperforms known analogues in simplicity of implementation and in a number of characteristics is proposed.

Adaptive output control of a class of uncertain chaotic systems

In this paper, a new observer-based backstepping output control scheme is proposed for stabilizing and controlling a class of uncertain chaotic systems. The controller is designed through the use of a robust observer and backstepping technique. We firstly show that many chaotic systems as paradigms in the research of chaos can be transformed into a class of nonlinear systems in the feedback form. Secondly, the synchronization problem is converted to the tracking problem from control theory, thereby leading to the use of state observer design techniques. A new observer is utilized to estimate the unmeasured states. Unlike some existing methods for chaos control, no priori knowledge on the system parameters is required and only the output signal is available for control purpose. The Lyapunov functions are quadratic in the state estimates, the observer errors and the parameter estimation error based on the backstepping technique. It is shown that not only global stability is guaranteed by the proposed controller, but also both transient and asymptotic tracking performances are quantified as explicit functions of the design parameters so that designers can tune the design parameters in an explicit way to obtain the desired closed-loop behavior.

Adaptive output control of linear time-varying systems1

The problem of output control of linear time-varying systems with unknown fast-changing bounded parameters is considered. It is assumed that the plant is affected by unknown bounded disturbance. The method assuring the solution of tracking problem with prescribed accuracy is represented.

Adaptive stochastic output feedback control of resistive wall modes in tokamaks

An adaptive optimal stochastic output feedback control is developed to stabilize the resistive wall mode (RWM) instability in tokamaks. The system dynamics is experimentally determined via the extended least square method with an exponential forgetting factor and covariance resetting. The optimal output feedback controller is redesigned online periodically based on the system identification. The output measurements and past control inputs are used to construct new control inputs. The adaptive output controller can stabilize the time dependent RWM in a slowly evolving tokamak discharge. This is accomplished within a time delay of roughly three times the inverse of the growth rate. The design procedure is simpler and the computation time is shorter than the state feedback method reported earlier in Sun, Sen, and Longman [Phys. Plasmas13, 012512 (2006)].

On robustness property of dynamical systems feedback connection with respect to multiplicative disturbances

Feedback connection of (strict) passive systems with multiplicative disturbance on the input of one of systems is considered. Series of conditions are proposed, which provide (strict) passivity property for overall system. These conditions enlarge result from Hill, and Moylan (1977), where passivity property of such connection was established. Applications of proposed results to backstepping control and adaptive output control are investigated.

Robust Adaptive Control of Atomic Force Microscopes

A robust adaptive output controller was designed to control dynamics of atomic force microscopes (AFM). The controller guarantees global boundedness and asymptotic regulation in the presence and absence of disturbances, respectively. Simulations show that a substantial reduction in contact force can be achieved with the adaptive controller in comparison with a well-tuned Integral controller.

Adaptive output feedback control of a scale helicopter restricted to a 2DOF platform

In this paper we present an application of adaptive output control using radial basis functions as the building block to the adaptive element. The application focuses the tracking stabilization of a scale helicopter restricted to a 2DOF platform. Actuator saturation is handled through the Pseudo-Control Hedging (PCH) method. The plant model representing this restricted situation has 3DOF and the control efficiency can be stated through simulations.

Fuzzy gain-scheduled adaptive cardiac output control system for the electromechanical TAH - computer simulation and in vitro studies

Fuzzy gain-scheduled adaptive cardiac output control system for the electromechanical TAH - computer simulation and in vitro studies

Research of Adaptive Output Control of High Power Electric Locomotive.

Research of Adaptive Output Control of High Power Electric Locomotive.

Model Reference Adaptive Control of Thyristor Driven DC Motor Systems Subject to Current Limit a Tions

Direct model reference output adaptive control procedures, which do not require the existence of model matching conditions, have been applied to the speed control of a thyristor driven DC motor system. Taking into account both current and current rate limitations, the adaptive algorithm was used to generate the set point for a dual mode thyristor current regulator which was also adjusted depending upon whether or not the thyristor circuit was in the continuous or discontinuous conduction mode. Tests with representative variations in inertia and torque load showed the adaptive algorithm to be more robust than a constant model following controller and a conventional PI speed control system.