Nonlinear H∞ control is considered for uncertain nonholonomic systems with external disturbances in their chained form kinematic models. State feedback controllers are explicitly constructed to guarantee an L2 gain performance from the disturbance to the system output. Without the presence of the disturbance, the system states are regulated to the origin. Recent results in robust and adaptive c...

This paper studies the problem of dynamic output feedback H∞ control for nonlinear systems, which are described by Takagi–Sugeno fuzzy parts with measurable premise variables and uncertainty parts. The uncertainties are parameter dependent, unknown, and time varying but bounded. A switching fuzzy dynamic output feedback control scheme is proposed, which depends on the measurable premise variabl...

The classical control theory is based on the design of linear controllers for systems described by linear models. However, there exist some situations where it is not recommended, or even impossible, to use a linear controller. One of those situations arises when the magnitude of the process gain experiences a dramatic variation within the operating range of interest. A classic example of a che...

The paper presents a quaternion feedback attitude control law for spacecraft attitude maneuver. A nonlinear feedback controller is designed to achieve L2 gain performance, i.e., the resulting closed-loop system is designed such that the L2 gain from the exogenous disturbance to the performance measure is less than a scalar. The solution of the nonlinear H∞ control problem is known to be related...

This paper presents new techniques for controlling the motion of an underactuated vehicle when disturbances are present and only imperfect state measurements are available for feedback. A state feedback controller is developed and then it is converted to an imperfect state measurement feedback controller. The state feedback tracking control law uses an H∞-optimal design and produces a locally e...

This paper presents a practical direct adaptive fuzzy H tracking control (AFHC) approach for a class of uncertain nonlinear systems with unknown control gain functions and external disturbances. A modified output tracking error is defined to eliminate high gain at the control input and to improve transient performance. An ideal control law is developed to eliminate the restriction that the cont...

This paper considers the problem of designing explicit measurement feedback H∞ control laws for a class of Euler-Lagrange systems. For these systems the joint positions are assumed as outputs of the system, while velocity measures are to be estimated from an observer+controller structure. The main contribution of this work lies in the explicit formulation of the dynamic structure of a joined ob...

In the present paper the problem of tracking of rigid body motion in SE(3) in the presence of torque disturbances is addressed. A penalty variable whose Euclidean norm is a measure of the tracking error is deened. Then nonlinear H 1 control theory is applied to design a control law such that the closed loop system has L 2-gain from the torque disturbances to this penalty variable for a xed posi...

This paper is concerned with the global H∞ control problem for a class of switched nonlinear systems in lower triangular form under arbitrary switchings. A common Lyapunov function and a common smooth state feedback controller are constructed by backstepping such that the closedloop system is globally asymptotically stable under arbitrary switchings without disturbance input and has the prescri...

The problem of constructing nonlinear adaptive H∞ control of robotic manipulators under costraints is considered in this paper. In the proposed control scheme, the trajectory converges to the desired constrained trajectory, and the constraint force also follows the desired constraint one. The resulting control strategy is derived as a solution of certain H∞ control problem, where estimation err...