This paper reports on the design of a biorobotic actuator intended for use in a powered, below-knee prosthesis. Design requirements for the artificial muscle and tendon are based on the properties of the natural limb. As biological properties often exhibit significant variability, data from a variety of vertebrate species are extracted from published reports in the biological literature and use...

In the real application of active control systems to mitigate the response of structures subjected to sever external excitations such as earthquake and wind induced vibrations, since the capacity of actuators is limited then the actuators saturate. Hence, in designing controllers for linear and nonlinear structures under sever earthquakes, the actuator saturation should be considered as a const...

We investigated small-scale hydraulic power actuation systems using a system level analysis, where smallscale refers to systems generating 10 to 100 Watts output power, to determine whether the high power density advantage of hydraulics holds at small sizes. Hydraulic actuator system power density was analyzed with simple physics models and compared to an equivalent electromechanical system com...

Studies have shown that feedback linearization can provide an effective controller for many types of nonlinear systems. It is known, however, that these controllers are not robust, in particular to model uncertainties as the feedback linearization process involves canceling of nonlinearities in the dynamics using an exact model which is seldom available. Although there are several strategies to...

Robustness and fault-tolerance are desirable properties for hydraulic working machines and field robots. In applications where service personnel do not have easy access to the machine, it is important that the machine can continue its operation despite single machinery faults. Digital hydraulics enables a design which is inherently fault-tolerant by having each hydraulic actuator controlled by ...

For maintenance microrobots for small diameter pipes in power plants and so on, a novel microgripper using divided-electrode type flexible electro-rheological valves (DE-FERVs) was proposed and developed. Each bendable finger consisted of the DE-FERV and a hydraulic rubber actuator and was several millimeters long. The DE-FERV had an axially divided parallel plate electrode pairs in a flexible ...

This thesis documents my personal contribution to the development of a hydraulic-based actuation system for a solar trough collector. The goal of this project was to design the actuation system using hydraulic actuators for a four meter solar collector prototype in Pittsfield, New Hampshire. After considering several hydraulic system architectures and conducting in-depth analysis into two of th...

Abstract: In order to coordinate the damping performance and energy regenerative performance of energy regenerative suspension, this paper proposes a structure of vehicle semi-active energy regenerative suspension with electro-hydraulic actuator (EHA). In light of the proposed concept, a specific energy regenerative scheme is designed and the mechanical properties test is carried out. Based on ...