Design and evaluation of an energy management system applied to a lower limb robotic exoskeleton

This paper presents the design, development and evaluation of an energy management system (EMS) for covering the energy demand from an autonomous lower limb exoskeleton (ALLEX) prototype. The ALLEX prototype is composed by four energy subsystems: actuators, sensing, communications, and control. The energy de-manded by ALLEX is estimated by considering metabolic requirements of neurological rehabilitation applied to the actuators subsystem, as well as average consumption of the sensing, communications, and control subsystems. The EMS proposed in this paper is composed by a lithium-ion battery bank, a battery management system (BMS), and prop-er instrumentation for measuring voltages, currents, and temperature from the battery pack. Experimental results show adequate coverage of the energy demand from ALLEX, both instantly and during continuous operation (1 hour approximately). Additionally, the efficiency of the EMS is assessed by testing the cells balancing and battery charg-ing/discharging processes, which showed equalized values of the energy cells as well as correct temperature operating values.