Implementation of a Variable Stiffness Joint Based on the Twisted String Actuators
نویسندگان
چکیده
In this paper, the modeling and the control of a variable stiffness joint actuated by a couple of twisted string actuators in antagonistic configuration is reported. The twisted string actuation system is particularly suitable for very compact and light-weight robotic devices, like artificial hands and arms, and renders a very low apparent inertia at the load side, allowing the implementation of powerful tendon-based driving systems, using as actuators small-size DC motors characterized by high speed, low torque and very limited inertia. The basic properties of the twisted string actuation system are presented, and the way how they are exploited for the implementation of a variable stiffness joint is discussed. A control algorithm based on the feedback linearization of the device is used for tracking the desired position and stiffness profile. Preliminary experimental results are reported to validate the proposed control approach.
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