Development of Flexible Electro-Hydraulic Spherical Actuator

Wataru Kobayashi, Hiroaki Tamaki, Tetsuya Akagi , Shujiro Dohta and So Shimooka

Voluntary rehabilitation at home helps to prevent the joint contracture after medical treatment. Our previous studies concerned a low-cost portable rehabilitation device using a flexible spherical pneumatic actuator as a passive exercise device. However, the device requires a bulky compressor to drive it. This study results in a compact fluidic driving system that is highly flexible. The system adopts a flexible electro-hydraulic cylinder driven by an electric motor and a hydraulic gear pump. An empirical equation for the suitable pump rotation for the desired displacement of the system has been determined. As a result, the multi-position control of the system within the tracking error of 4 mm has been realized by using the on/off control scheme based on the obtained equation. In addition, a flexible, spherical electro-hydraulic actuator using two proposed drive systems is developed and tested. Control of the attitude of the tested spherical actuator is successfully realized.

Journal of Robotics and Mechatronics

Vol.34

No.2

382

389

https://doi.org/10.20965/jrm.2022.p0382