On the design of lower extremity exoskeleton with single drive (LEESD)

The design of the LEESD, a new exoskeleton for old people and patients, is presented in this paper. With one active degree of freedom (DOF) and two passive degrees of freedom, the LEESD can realize human walking gait. The hip joints and knee joints of the LEESD are directly driven by four-bar linkages and all these four-bar linkages are driven by merely one brushless DC motor which rotates at a constant speed. Considering these features, LEESD is a simple, as well as affordable mechanism. The details of the LEESD have been rigorously discussed and calculated during the design process.