this paper considers the problem of stable limit cycles generating in a class of uncertain nonlinear systems which leads to stable oscillations in the system’s output.this is a wanted behavior in many practical engineering problems. for this purpose, first the equation of the desirable limit cycle is achieved according to shape, amplitude and frequency of the required output oscillations. then,...

in this paper the effects of non-linearity of suspension on dynamic behavior of a railway wheelset has been studied. this wheelset has four degrees of freedom that with two constraints it has reduced to two degrees of freedom. vermeulen-johnson theory has been used to calculate contact forces between wheel and rail. in this study the creep coefficients have considered constant. any linearizatio...

This paper presents a robust control strategy driving an actuated compass gait robot towards steady and periodic gaits. By robust we mean a large basin of attraction for the limit cycle. The originality lies in the generation of the swing leg reference angle and speed as a simple function of the supporting leg angle. Simulations and experimentation with a prototype showed that the system exhibi...

The robust control problem for nonlinear systems is discussed from the standpoint of the amplitude sensitivity of the nonlinear plant and nal control system. Failure to recognize and accommodate this factor may give rise to nonlinear control systems that behave diierently for small versus large input excitation, or perhaps exhibit limit cycles or instability. Sinusoidal-input describing functio...

This paper investigates the problem of analysis of a Takagi-Sugeno (T-S) fuzzy control system in the frequency domain. First, a linear plant with a T-S fuzzy controller is considered, and the complex dynamic behaviors of the system generated by the nonlinearity in the controller are analyzed. The global stability, instability and existence of limit cycles of the system are predicted with the ai...

The robust control problem for nonlinear systems is discussed from the standpoint of the amplitude sensitivity of the nonlinear plant and final control system. Failure to recognize and accommodate this factor may give rise to nonlinear control systems that behave differently for small versus large input excitation, or perhaps exhibit limit cycles or instability. Sinusoidal-input describing func...

The main contribution of this work is a general method for stabilization of periodic orbits for hybrid systems with impact effects. Our primary motivation is controller synthesis for walking robots, but the method can be also applied to problems such as flight control or automotive control. Limit cycles of hybrid systems are characterized by the fact that they span different dynamic regimes. Fo...

In this paper, a class of multi-input/multi-output aeroelastic systems with unstructured nonlinear uncertainty is considered. By using leadingand trailing-edge control surface actuations, a continuous robust controller is proposed to suppress the aeroelastic vibrations of a nonlinearwing-sectionmodelwith plunging andpitching degrees of freedom. Under amild restriction that the system uncertaint...