Knee orthosis demonstrator with implemented TSA. The demonstrator is able to move 110° over 4.6 s, to the standing position. [Mühlbauer P, Stewart K, Pott PP, Demonstrator of a low-cost active knee orthosis with twisted string actuation, ETG/GMM-Fachtagung Innovative Klein- und Mikroantriebstechnik, 10.-11.09.2019, Würzburg]
Photo: Swantje Janzen
Elderly people as well as individuals after e.g. a stroke need active support in order to be able to perform everyday movements (again). To this end, we are looking in particular at the knee and elbow joints and developing novel methods to support them with torque. This includes the actuator technology, which has to be as small, light, quiet and energy-efficient as possible, and the sensor technology, with the help of which we want to estimate the intention of the person using the device. Here we also use machine learning methods to fuse sensor data and gain additional information.
The general concept of the demonstrator actuated with a TSA: A coupling sleeve (2) connects the electric DC motor (1) with the strings (3). A cable (5) is connected to the linear guide (4) and the lower rail. At the knee joint, a cam disc (6) converts the tensile force caused by the twisted strings into a torque pulling the lower leg to the extension position. [Mühlbauer P, Stewart K, Pott PP, Demonstrator of a low-cost active knee orthosis with twisted string actuation, ETG/GMM-Fachtagung Innovative Klein- und Mikroantriebstechnik, 10.-11.09.2019, Würzburg]
Photo: Swantje Janzen