Modeling and Control of a novel Variable Stiffness three DoF Wrist

by   Giuseppe Milazzo, et al.

This paper presents a novel design for a Variable Stiffness 3 DoF actuated wrist to improve task adaptability and safety during interactions with people and objects. The proposed design employs a hybrid serial-parallel configuration to achieve a 3 DoF wrist joint which can actively and continuously vary its overall stiffness thanks to the redundant elastic actuation system, using only four motors. Its stiffness control principle is similar to human muscular impedance regulation, with the shape of the stiffness ellipsoid mostly depending on posture, while the elastic cocontraction modulates its overall size. The employed mechanical configuration achieves a compact and lightweight device that, thanks to its anthropomorphous characteristics, could be suitable for prostheses and humanoid robots. After introducing the design concept of the device, this work provides methods to estimate the posture of the wrist by using joint angle measurements and to modulate its stiffness. Thereafter, this paper describes the first physical implementation of the presented design, detailing the mechanical prototype and electronic hardware, the control architecture, and the associated firmware. The reported experimental results show the potential of the proposed device while highlighting some limitations. To conclude, we show the motion and stiffness behavior of the device with some qualitative experiments.


page 1

page 3

page 6

page 8

page 9

page 11


Preliminary design of a device to assist handwriting in children with movement disorders

This paper presents the development of a new passive assistive handwriti...

Modular Self-Lock Origami: design, modeling, and simulation to improve the performance of a rotational joint

Origami structures have been widely explored in robotics due to their ma...

Comfort-Centered Design of a Lightweight and Backdrivable Knee Exoskeleton

This paper presents design principles for comfort-centered wearable robo...

A Robot Leg with Compact Variable Stiffness Joint based on Leaf-Spring Mechanism

The legged robots with variable stiffness actuators (VSAs) can achieve e...

SiMPLeR: A Series-Elastic Manipulator with Passive Variable Stiffness for Legged Robots

We propose a mechanically simple and cheap design for a series elastic a...

An anthropomorphic continuum robotic neck actuated by SMA spring-based multipennate muscle architecture

This work presents a novel Shape Memory Alloy spring actuated continuum ...

Please sign up or login with your details

Forgot password? Click here to reset