Inspired by human motor control theory, stiffness control is highly effective in manipulation and human-interactive tasks. The implementation of stiffness control in robotic systems, however, has largely been limited to close-loop control, and suffers from multiple related issues such as limited frequency range, potential stability issue, and lack of contribution to energy efficiency. Variable-stiffness actuator represents a better solution, but the current designs are complex, heavy, and bulky. The approach in this paper seeks to address these issues by using pneumatic actuator as a variable series elasticity actuator, leveraging the compressibility of the working fluid. In this work, a pneumatic actuator is modelled as an elastic element with controllable stiffness and equilibrium point, both of which are functions of air masses in the two chambers. As such, for the implementation of stiffness control in a robotic system, the desired stiffness/equilibrium point can be converted to the desired chamber air masses, and a predictive pressure control approach is developed to control the timing of valve switching to obtain the desired air mass while minimizing control action. Experimental results showed that the new approach in this paper requires less expensive hardware (on-off valve instead of proportional valve), causes less control action in implementation, and provides good control performance by leveraging the inherent dynamics of the actuator.
Skip Nav Destination
ASME 2015 International Mechanical Engineering Congress and Exposition
November 13–19, 2015
Houston, Texas, USA
Conference Sponsors:
- ASME
ISBN:
978-0-7918-5740-3
PROCEEDINGS PAPER
Modeling and Control of the Series Elasticity in Pneumatic Actuators Available to Purchase
Hao Zheng,
Hao Zheng
University of Alabama, Tuscaloosa, AL
Search for other works by this author on:
Xiangrong Shen
Xiangrong Shen
University of Alabama, Tuscaloosa, AL
Search for other works by this author on:
Hao Zheng
University of Alabama, Tuscaloosa, AL
Xiangrong Shen
University of Alabama, Tuscaloosa, AL
Paper No:
IMECE2015-51054, V04BT04A024; 8 pages
Published Online:
March 7, 2016
Citation
Zheng, H, & Shen, X. "Modeling and Control of the Series Elasticity in Pneumatic Actuators." Proceedings of the ASME 2015 International Mechanical Engineering Congress and Exposition. Volume 4B: Dynamics, Vibration, and Control. Houston, Texas, USA. November 13–19, 2015. V04BT04A024. ASME. https://doi.org/10.1115/IMECE2015-51054
Download citation file:
22
Views
Related Proceedings Papers
Related Articles
An Energetic Control Methodology for Exploiting the Passive Dynamics of Pneumatically Actuated Hopping
J. Dyn. Sys., Meas., Control (July,2008)
Practical Design of a Sliding Mode Controller for Pneumatic Actuators
J. Dyn. Sys., Meas., Control (December,1997)
Pneumatic Variable Series Elastic Actuator
J. Dyn. Sys., Meas., Control (August,2016)
Related Chapters
Study of Annular Fluid and Pressure Control in Turbine Drilling of CCSD
Geological Engineering: Proceedings of the 1 st International Conference (ICGE 2007)
Engineering Design about Electro-Hydraulic Intelligent Control System of Multi Axle Vehicle Suspension
International Conference on Instrumentation, Measurement, Circuits and Systems (ICIMCS 2011)
High Speed Data Processing SOPC System Based on NIOS II Reconfigurable Soft IP Cores
International Conference on Computer Technology and Development, 3rd (ICCTD 2011)