Two configurations of series elastic actuators for linearly actuated humanoid robots with large range of motion

2014 ◽  
Author(s):  
Coleman S. Knabe ◽  
Viktor Orekhov ◽  
Michael A. Hopkins ◽  
Brian Y. Lattimer ◽  
Dennis W. Hong
Keyword(s):  
Range Of Motion ◽  
Large Range ◽  
Humanoid Robots ◽  
Series Elastic Actuators ◽  
Series Elastic

Design of a Human-Like Range of Motion Hip Joint for Humanoid Robots

2014 ◽  
Author(s):  
Bryce Lee ◽  
Coleman Knabe ◽  
Viktor Orekhov ◽  
Dennis Hong
Keyword(s):  
Range Of Motion ◽  
Hip Joint ◽  
Disaster Response ◽  
Degrees Of Freedom ◽  
Humanoid Robot ◽  
Large Range ◽  
Humanoid Robots ◽  
Linkage Mechanism ◽  
Joint Torques ◽  
Similar Range

For a humanoid robot to have the versatility of humans, it needs to have similar motion capabilities. This paper presents the design of the hip joint of the Tactical Hazardous Operations Robot (THOR), which was created to perform disaster response duties in human-structured environments. The lower body of THOR was designed to have a similar range of motion to the average human. To accommodate the large range of motion requirements of the hip, it was divided into a parallel-actuated universal joint and a linkage-driven pin joint. The yaw and roll degrees of freedom are driven cooperatively by a pair of parallel series elastic linear actuators to provide high joint torques and low leg inertia. In yaw, the left hip can produce a peak of 115.02 [Nm] of torque with a range of motion of −20° to 45°. In roll, it can produce a peak of 174.72 [Nm] of torque with a range of motion of −30° to 45°. The pitch degree of freedom uses a Hoeken’s linkage mechanism to produce 100 [Nm] of torque with a range of motion of −120° to 30°.

scholarly journals Design, control, and testing of a thumb exoskeleton with series elastic actuation

2017 ◽  
Vol 36 (3) ◽  
pp. 355-375 ◽  
Author(s):  
Priyanshu Agarwal ◽  
Youngmok Yun ◽  
Jonas Fox ◽  
Kaci Madden ◽  
Ashish D Deshpande
Keyword(s):  
Range Of Motion ◽  
Degrees Of Freedom ◽  
Large Range ◽  
Kinematic Model ◽  
Torque Control ◽  
Thumb Motion ◽  
Performance Results ◽  
High Degree ◽  
Kinematic Mechanism ◽  
Series Elastic

We present an exoskeleton capable of assisting the human thumb through a large range of motion. Our novel thumb exoskeleton has the following unique features: (i) an underlying kinematic mechanism that is optimized to achieve a large range of motion, (ii) a design that actuates four degrees of freedom of the thumb, and (iii) a series elastic actuation based on a Bowden cable, allowing for bidirectional torque control of each thumb joint individually. We present a kinematic model of the coupled thumb exoskeleton system and use it to maximize the range of motion of the thumb. Finally, we carry out tests with the designed device on four subjects to evaluate its workspace and kinematic transparency using a motion capture system and torque control performance. Results show that the device allows for a large workspace with the thumb, is kinematically transparent to natural thumb motion to a high degree, and is capable of accurate torque control.

A Bowden Cable-Based Series Elastic Actuation Module for Assessing the Human Wrist

2018 ◽  
Author(s):  
Andrew Erwin ◽  
Nick Moser ◽  
Craig G. McDonald ◽  
Marcia K. O’Malley
Keyword(s):  
Range Of Motion ◽  
Biomechanical Properties ◽  
Torque Control ◽  
Wrist Flexion ◽  
Biomechanical Assessment ◽  
Flexion Extension ◽  
Control Evaluation ◽  
Actuation Scheme ◽  
Series Elastic Actuators ◽  
Series Elastic

Currently, wrist passive stiffness and active range of motion, two clinically relevant properties, are assessed using devices designed for rehabilitation. As a result, these devices do not have sufficient torque output and range of motion for complete wrist biomechanical assessment. To address these limitations, we are developing an actuation module specifically for assessing wrist biomechanical properties. Our device employs a serial kinematic exoskeletal architecture to directly interact with and measure wrist flexion/extension and radial/ulnar deviation. A Bowden cable-based actuation scheme, locating the motors off-board, was adopted for increased device range of motion and torque output compared with previous wrist exoskeletons. Additionally, the device was designed to incorporate a rotational elastic element at each joint, creating series elastic actuators, for accurate torque control and direct torque measurement. In this work, we present the design and demonstration of a 1-DOF module of the device, which can interact with a user’s wrist in flexion/extension, providing an important first step towards the control, evaluation, and application of the 2-DOF device.

Hopping frequency influences elastic energy reuse with joint series elastic actuators

2021 ◽  
Vol 119 ◽  
pp. 110319
Author(s):  
A. Mohammadi Nejad Rashty ◽  
M. Grimmer ◽  
A. Seyfarth
Keyword(s):  
Elastic Energy ◽  
Series Elastic Actuators ◽  
Series Elastic

A convex optimization framework for robust-feasible series elastic actuators

Mechatronics ◽  
2021 ◽  
Vol 79 ◽  
pp. 102635
Author(s):  
Edgar A. Bolívar-Nieto ◽  
Tyler Summers ◽  
Robert D. Gregg ◽  
Siavash Rezazadeh
Keyword(s):  
Convex Optimization ◽  
Optimization Framework ◽  
Series Elastic Actuators ◽  
Series Elastic

Flexible-Joint Humanoid Balancing Augmentation via Full-State Feedback Variable Impedance Control

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Emmanouil Spyrakos-Papastavridis ◽  
Jian S. Dai
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Impedance Control ◽  
Humanoid Robots ◽  
Flexible Joint ◽  
Model Free ◽  
Floating Base ◽  
Full State ◽  
Full State Feedback ◽  
Series Elastic Actuators

Abstract This paper attempts to address the quandary of flexible-joint humanoid balancing performance augmentation, via the introduction of the Full-State Feedback Variable Impedance Control (FSFVIC), and Model-Free Compliant Floating-base VIC (MCFVIC) schemes. In comparison to rigid-joint humanoid robots, efficient balancing control of compliant bipeds, powered by Series Elastic Actuators (or harmonic drives), requires the design of more sophisticated controllers encapsulating both the motor and underactuated link dynamics. It has been demonstrated that Variable Impedance Control (VIC) can improve robotic interaction performance, albeit by introducing energy-injecting elements that may jeopardize closed-loop stability. To this end, the novel FSFVIC and MCFVIC schemes are proposed, which amalgamate both collocated and non-collocated feedback gains, with power-shaping signals that are capable of preserving the system's stability/passivity during VIC. The FSFVIC and MCFVIC stably modulate the system's collocated state gains to augment balancing performance, in addition to the non-collocated state gains that dictate the position control accuracy. Utilization of arbitrarily low-impedance gains is permitted by both the FSFVIC and MCFVIC schemes propounded herein. An array of experiments involving the COmpliant huMANoid reveals that significant balancing performance amelioration is achievable through online modulation of the full-state feedback gains (VIC), as compared to utilization of invariant impedance control.

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