Reduced Weight Hydraulic Actuation for Small Mobile Applications

Friday, October 28, 2011
Hall 1-2 (San Jose Convention Center)
Ismael Reveles , Aerospace Engineering, San Diego State University, San Diego, CA
Ephrahim Garcia, Ph.D , MAE, Cornell University, Ithaca
Hydraulic actuation is a dominant technology in large stationary and mobile machines, but small scale robotic systems have remained largely the domain of electromechanical servo systems. In this paper we explore the suitability of reduced weight hydraulic systems for use in small mobile applications. We propose servo-actuated control valves and hydraulic artificial muscles as solutions to major scaling difficulties with solenoid control systems and traditional cylinder actuators. A two degree of freedom leg and a small terrestrial robot demonstrate the effectiveness of these control and actuation strategies in enabling the mobile operation of complex, small scale machines. The merits of a hydraulic approach over traditional electromechanical servo systems for these two robots are considered with respect to energy efficiency, system weight, and design space constraints.