Toward Compliant, Fast, High-Precision, and Low-Cost Manipulator with Hydraulic Hybrid Servo Booster

Sang-Ho Hyon1

  • 1Ritsumeikan University



Regular Papers


09:55 - 11:10 | Tue 30 May | Room 4011 | TUA1

Actuators 1

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We propose a novel hydraulic hybrid servo drive for robotic applications. This method embeds a small servo-controlled pump into a hydraulic metering circuit. The circuit is compactly integrated into a servo-unit, then replicated for each joint, and connected to one common low-pressure line. Thanks to the boosting effect, one can simultaneously achieve high-load and high-precision servo control performance with low-cost components. The paper describes the principle of the new circuit and two realizations: one for a slider testbed with a single-rod cylinder, the other for a three-joint manipulator prototype. The slider experiments show that the proposed circuit can not only achieve the high piston velocity, but also exclusively generate large piston force with a small positional error up to the resolution of the servo-pump. Moreover, experiments on the manipulator demonstrate that the robot can compliantly respond to external perturbations, thanks to the high backdrivability of the servo-pump.

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  • Novel hydraulic hybrid servo drive is first applied to a robotic manipulator.
  • High-speed, large torque, high-precision control are possible at low cost.
  • Compliant motion is achieved with the intrinsic back-drivability of the small servo-pump.
  • Experimental results include a simple slider testbed and a planar three-axis manipulator (video attached).