In this paper the design of a biped robot actuated with Shape Memory Alloy (SMA) springs with minimum degrees of freedom is presented. SMA springs are a class of smart materials that are known for their high power to mass and volume ratios. It was shown that utilizing spring type of SMAs have many advantages as large deformation, smooth motion, silent and clean movement compared to ordinary typ...

Since the piezoelectrically actuated system has nonlinear and time-varying behavior, it is difficult to establish an accurate dynamic model for a model-based sensing and control design. Here, a model-free adaptive sliding controller is proposed to improve the small travel and hysteresis defects of piezoelectrically actuated systems. This sensing and control strategy employs the functional appro...

In this paper we present Recompose, a new system for manipulation of an actuated surface. By collectively utilizing the body as a tool for direct manipulation alongside gestural input for functional manipulation, we show how a user is afforded unprecedented control over an actuated surface. We describe a number of interaction techniques exploring the shared space of direct and gestural input, d...

A spatial parallel mechanism namely 3-RRS mechanism has been assigned to be attached to the seat of a standard electric wheelchair to prevent the turning over of the handicapped sitting on the wheelchair. The system of the wheelchair and the mechanism is a self-balancing robotic wheelchair and has coped with several road conditions. A stability control system calculates the proper moments on th...

Electrostatically actuated microbeams have been studied by many researchers in the last few years. The aim of this study is to present an improved numerical analysis of the dynamic instability of a cantilever microbeam immersed in an incompressible viscous fluid. The finite element method is used for solving the vibrational equation of the microbeam and the potential functions of the fluids in ...

1. Abstract Recently there is a growing need for micro water cooling systems with the development of small-sized fuel cells for mobile electric devices. In general, a water cooling system requires a valve for controlling flow rate of coolant in order to keep targeted devices at appropriate working temperature. Traditional type of a flow control valve is driven by an external power source and a ...

We describe a numerical method for computing optimal trajectories for fully actuated mechanical systems. This method uses the fact that fully actuated mechanical systems are diierentially at with conngura-tion variables as at outputs to parametrize the system trajectories by connguration space trajectories. Our approach has the advantage that the system ODEs are implicitly satissed and hence we...

The utilization of pneumatic muscles in the actuation of robotized systems is still in its early stages, hence the requirement of a study of such constructive solutions. Consequently the paper presents the constructive solution and performance of a robotized arm actuated by pneumatic muscles. This system is mounted on a wheelchair for persons with locomotive disabilities. The main reason underl...

This paper deals with the design of a control strategy that combines a nonlinear observer and a partial feedback linearization controller to stabilize the periodic orbits of an under-actuated three link biped robot. We show first that passive dynamics (non-actuated coordinates) can be linearized and decoupled from the rest of the system by applying a nonlinear feedback. Then, the proposed obser...

Tracking the unactuated configuration variable in an underactuated system, in a global sense, has not received much attention. Here we present a scheme to do so for a pendubot a two link robot actuated only at the first link. We propose a control law that asymptotically tracks any smooth reference trajectory of the unactuated second joint , from almost-any initial condition, termed as almost-gl...