This paper presents analysis and design results for control systems subject to oscillatory inputs, i.e., inputs of large amplitude and high frequency. The key analysis results are a series expansion characterizing the averaged system and various Lie-algebraic conditions that guarantee the series can be summed. Various example systems provide insight into the results. With regards to design, we ...

Current prosthetic hands are basically simple grippers with one or two degrees of freedom, which barely restore the capability of the thumbindex pinch. Although most amputees consider this performance as acceptable 6r usual tasks, there is ample room for improvement by exploiting recent progresses in mechatronic design and technology. This paper focus on an innovative approach for the design an...

Analysis and control of underactuated mechanical systems in the nonzero velocity setting remains a challenging problem. In this paper, we demonstrate the utility of a recently developed alternative representation of the equations of motion for this large class of nonlinear control systems. The alternative representation gives rise to an intrinisic symmetric form. The generalized eigenvalues and...

In this paper, we consider the regulation control problem for an underactuated overhead crane system. Motivated by recent passivitybased controllers for underactuated systems, we design several controllers that asymptotically regulate the planar gantry position and the payload angle. Specifically, utilizing LaSalle’s invariant set theorem, we first illustrate how a simple proportional–derivativ...

To deal with complex nonlinear systems such as underactuated mechanisms, in this paper a global stable as well as optimal fuzzy controller is presented to achieve output tracking control of nonlinear systems by combining the linear optimal control theory and linear regulator theory with the Takagi-Sugeno fuzzy methodology. The stability of the entire closed-loop fuzzy system is ensured by the L...

ontrol of underactuated biped robots is one of the challenging problems in the robotics field. The main difficulties of this problem that make it hard to control are its highly nonlinear dynamics, open-loop instability and impact event at the end of each step. Partial feedback linearization is a method to control underactuated systems but it is not robust against uncertainties and disturbances....

This paper considers the stabilization problem of Inertia Wheel Pendulum, a widely studied benchmark nonlinear system. It is a classical example of a flat underactuated mechanical system, for which the design of control law becomes a challenging task owing to its underactuated nature. A novel nonlinear controller design, fusing the recently introduced Dynamic Surface Control and the Control Lya...

This paper investigates the possibility of converting grasped objects from precision grasps to power grasps using a variable transmission ratio for an underactuated finger. To this effect, a variable radius pulley was designed. A simulation study is presented to analyse grasping behaviour and a potential energy method is used to predict the equilibrium positions of finger and object. With this ...

ontrol of underactuated biped robots is one of the challenging problems in the robotics field. The main difficulties of this problem that make it hard to control are its highly nonlinear dynamics, open-loop instability and impact event at the end of each step. Partial feedback linearization is a method to control underactuated systems but it is not robust against uncertainties and disturbances....