Design and Control of a Discrete Variable Stiffness Actuator With Instant Stiffness Switch for Safe Human-Robot Interaction

Mechanically stiffness-adjustable actuator using a leaf spring for safe physical human-robot interaction

A Stiffness Estimator for Agonistic-Antagonistic Variable-Stiffness-Actuator Devices

Safe Physical Human Robot Interaction, conservation of energy and adaptability are just the main robotic applications that prompted the development of a number of Variable Stiffness Actuators (VSA). Implemented in a variety of ways, they use various technologies, and feature the most diverse mechanical solutions, all of which share a fundamentally unavoidable nonlinear behavior. The control sch...

Stiffness control of a legged robot equipped with a serial manipulator in stance phase

The ability to perform different tasks by a serial manipulator mounted on legged robots, increases the capabilities of the robot. The position/force control problem of such a robot in the stance phase with point contacts on the ground is investigated here. A target plane with known stiffness is specified in the workspace. Active joints of the legs and serial manipulator are used to exert the de...

Variable Stiffness Actuators for Fast and Safe Motion Control

In this paper we propose Variable Stiffness actuation [1] as a viable mechanical/control co–design approach for guaranteeing control performance for robot arms that are inherently safe to humans in their environment. A new actuator under development in our Lab is then proposed, which incorporate the possibility to vary transmission stiffness during motion execution, thus allowing substantial mo...

AVASTT: A New Variable Stiffness Actuator with Torque Threshold

Variable Stiffness Actuators (VSAs) emerged as an alternative to conventional actuators in a variety of applications, such as walking robots and service robotics. New requirements, which were obviated in the design of rigid actuators, must be accounted for during the mechanical design of such new devices. Among them, we find the possibility of tunning the natural frequency of the mechanical sys...