Nami Kidane

CONTROLLER FOR A NONLINEAR SYSTEM WITH AN INPUT CONSTRAINT BY USING A CONTROL LYAPUNOV FUNCTION I

Abstract In this paper, we generalize the Malisoffs controller for a nonlinear system with an input constraint. Malisoff and Sontag proposed a universal control formula for a nonlinear system such that the k -norm of inputs is less than one. However, k is limited to 1 k ≤ 2. We improve the Malisoffs formula so that it can be applied in any case of k ≥ 1. We also confirm the effectiveness of the improved controller by computer simulation.

Observer based I/O-linearizing control of high index DAE systems

In this paper, we consider an I/O-linearization control problem for a nonlinear differential algebraic equation (DAE) system with high index. First, we show a way to transform a DAE system to an explicit ordinary differential equation (ODE) system that is restricted on a manifold. Second, a method is presented to achieve I/O linearization by a state feedback law. Finally, we propose an observer that globally stabilizes the controlled system.

Controller design method for a nonlinear system with an input constraint and its application to a robot arm

In this paper, we propose a controller for a nonlinear system with an input constraint depending on the state. The proposed controller is based on Kidanes controllers. Then, if system has one input, we can tune optimality and robustness easily. We apply the proposed controller to single-link robot arm in order to verify the effectiveness of the proposed controller

NONLINEAR CONTINUOUS-TIME REFERENCE GOVERNORS FOR CONSTRAINED NONLINEAR SYSTEMS

Abstract This paper proposes a reference management technique for closed-loop systems with input constraints. A management rule is given by a nonlinear continuous time differential system based on the input-to-state stability and the control Lyapunov approach. Moreover, we confirm the effectiveness of our proposed method by computer simulation.

Controller design for a nonlinear system with inputs restricted to a direct product of Minkowski balls

In this paper, we propose a continuous controller for a nonlinear system such that the inputs are restricted to a direct product of Minkowski balls. We also demonstrate the effectiveness of the controller by computer simulation.

Observer design for nonlinear systems described by differential-algebraic equations

Abstract We propose an observer design method for a differential-algebraic equation (DAE) systems with index one. In the observer, the algebraic equation constraint is fulfilled asymptotically. The error of the constraint converges to zero in finite time by means of functions that do not satisfy the local Lipschitz condition. The dynamics part of the observer is designed via the linear matrix inequality (LMI) technique. The observer is globally asymptotically stable under certain assumptions. Since the algebraic equations include input variable, the observer requires the derivative of input to plant. The derivative of the input is calculated from the controller states directly or estimated by the exact differentiator of Levant.

I/O-linearizing controller and observer for nonlinear DAE systems with high index

We consider I/O-linearization problems for differential algebraic equation (DAE) systems with high index using dynamic output feedback. First, a way to transform a DAE system to an explicit ordinary differential equation system is shown. Next, a design method is presented to achieve the I/O-linearization by a static feedback law. Finally, an observer is proposed to stabilize globally the controlled system.