abstract: this paper presents dynamic modelling and control of a linear prismatic series of elastic actuator. the capability of generating large torques is why this actuator is increasingly used in human-assistive robotic systems. due to having human in the loop, the actuator requires precise control. a fractional pid controller known for its improved performance is used for the control, due to...

: investigating the mechanical behaviour of a healthy human ankle shows that it can be simulated by a mechanism composed of simple elements such as spring, and actuator. hence, appropriate design of this mechanism can be resulted to an artificial ankle that can help amputees properly. researches show that whatever the biomechanical behaviour of artificial ankle is similar to that of natural ank...

The Series Elastic Actuator (SEA) has recently been developed by many research groups and applied in various fields. As SEA is the combination of motor, spring, gear and load, various types and configurations of mechanism have been developed as SEAs to satisfy many requirements necessary for the applications. This paper provides a theoretical framework to categorize and compare these various co...

Series elastic actuators have a spring intentionally placed at the actuator output. Measuring the spring strain gives an accurate measurement for closed-loop actuator force control. The low spring stiffness allows for high control gain while maintaining actuator stability. This gives series elastic actuators many desirable properties including high bandwidth at moderate force amplitudes, low ou...

The Series Elasic Actuator has been proposed as a method for providing safe force or torque based acutation for robots that interact with humans. In this paper we look at some outstanding issues in the implementaion and control of Series Elastic Actuators. The study addresses issues in making the Series Elastic Actuator respond effectively in the presence of physical difficulties such as sticti...

Series Elastic Actuators provide many benefits in force control of robots in unconstrained environments. These benefits include high force fidelity, extremely low impedance, low friction, and good force control bandwidth. Series Elastic Actuators employ a novel mechanical design architecture which goes against the common machine design principal of “stiffer is better”. A compliant element is pl...

Series Elastic Actuators provide many benefits in force control of robots in unconstrained environments. These benefits include high force fidelity, extremely low impedance, low friction, and good force control bandwidth. Series Elastic Actuators employ a novel mechanical design architecture which goes against the common machine design principal of “stiffer is better”. A compliant element is pl...

Compared to non-amputees, above knee amputees expend significantly more metabolic energy. This is a result of the passive nature of most knee prostheses, as the development of clinically successful powered knee prostheses has remained a challenge. The addition of powered elements, such as electric motors, allow prosthetic knees to more closely emulate natural knee biomechanics. However, the add...

This paper presents the development of a compact, modular rotary series elastic actuator (SEA) design that can be customized to meet the requirements of a wide range of applications. The concept incorporates flat brushless motors and planetary gearheads instead of expensive harmonic drives and a flat torsional spring design to create a lightweight, lowvolume, easily reconfigurable, and relative...

Series-elastic actuation offers several important benefits to dynamic robots, including high-bandwidth force control and improved safety. While this approach has become common among legged robots, the lack of commercial series-elastic actuators and the unique design requirements of these robots leaves custom-built actuators as the only option. These custom actuators are often designed for nomin...