Design of a Front-enveloping Powered Exoskeleton Considering Optimal Distribution of Actuating Torques and Center of Mass

Traditionally, powered exoskeletons have predominantly featured a back-enveloping design due to its simplicity in both implementation and user donning. However, this design results in a backward shift of the center of mass (CoM) in the sagittal plane. This paper identifies the limitations of existing design approaches and determines the optimal anterior-posterior (A/P) CoM position considering factors like actuating power, balance in the neutral posture, and user’s hand workspace. Our optimization analysis recommends placing the CoM in front of the user. We address historical constraints on front-enveloping designs and propose solutions. Furthermore, we validate the usability of our designed exoskeleton through testing with a complete paraplegic user.