Many real-world systems are inherently nonlinear by nature, hence it is of great benefit to develop control techniques for general nonlinear systems. In this thesis, we will investigate two specific questions in the nonlinear context: synthesis and analysis of nonlinear control systems. For the task of synthesis, we shall mainly consider systems which can be modeled by physical laws. For this t...

The problem of stabilization and trajectory tracking of feedback linearizable systems in the presence of input saturation is considered in this paper. The need to perform output tracking for nonlinear systems dictates the choice of feedback linearization in our control design. Explicit characterization of the space of feasible trajectories that can be tracked using bounded inputs is provided.

In this paper we discuss di erent control design methods for nonlinear control systems. We focus our attention on passivity-based control and the feedback linearization approach for solving set-point and tracking control problems. We also consider the case of model and parameter uncertainties. We concentrate on Euler-Lagrange systems which is a fairly wide and illustrative class of nonlinear sy...

A feedback linearizing control strategy for discrete-time nonlinear systems subject to input constraints is proposed. The control system comprises: (i) a feedback linearizing controller; ( ii) a constraint mapping algorithm that transforms the actual input constraints into constraints on the feedback linearized system; and (iii) a linear model predictive controller that regulates the resulting ...

We consider the optimal control of feedback linearizable dynamic systems subject to mixed state and control constraints. The optimal controller is allowed to be discontinuous including bang-bang control. Although the nonlinear system is assumed to be feedback linearizable, in general, the optimal control does not linearize the dynamics. The continuous optimal control problem is discretized usin...

In this work we consider the concept of differential flatness defined by Fliess, Levine, Martin and Rouchon. The structural property of k-flatness (the case in which flat outputs depends up to the kth derivative of the inputs) is studied based on the properties of the dynamic extension algorithm and the Cartan-Kähler theorems on the existence of integral manifolds of exterior differential syste...

In this paper, we establish the local separation principle for the class of nonlinear systems which is approximately error linearizable and locally asymptotically stabilizable. For this class of nonlinear systems, it is first shown that there exists a local nonlinear observer whose estimation error converges to zero exponentially. In order to achieve local output feedback stabilization, the pro...

This paper shows that coprime right factorizations exist for the input to state mapping of a continuous time nonlinear system provided that the smooth feedback stabilization problem be solvable for this system. In particular, it follows that feedback linearizable systems admit such factorizations. In order to establish the result a Lyapunov-theoretic deenition is proposed for \bounded input bou...

This paper shows that coprime right factorizations exist for the input to state mapping of a continuous time nonlinear system provided that the smooth feedback stabilization problem be solvable for this system. In particular, it follows that feedback linearizable systems admit such factorizations. In order to establish the result a Lyapunov-theoretic definition is proposed for “bounded input bo...