Affiliation:
1. Department of Mechanical Engineering, University College, London
Abstract
The UCL arm prosthesis is briefly described and its general performance capabilities outlined. Evaluation tests were conducted to assess the dynamic response of the hydraulic servo actuator systems. These included measurements of saturation velocity and stall load of the main arm articulations. Detailed observations were made of the shoulder elevation function, the heaviest loaded actuator, to provide data on the transient response of this servosystem. An analysis is described of a general hydraulic actuator used as an angular position controller, and this is simplified and used as the basis of a digital simulation of the shoulder motion. Results of running the digital simulation show a very good correlation with the experimentally derived data. The paper concludes by re-emphasizing the considerable advantages to be gained by using hydraulic actuation, illustrated by these test results.