In pursuit of safer design for tightly coupled man-machine mechatronic systems

Abstract

Mechatronics has made possible more sophisticated and intelligent systems and significantly changed the way humans relate and interact with machines. A development worthy of special attention is the powered exoskeleton initiative. Powered exoskeletons are viewed as a means of enhancing human power and endurance capability in the absence of heavy lifting equipment. An example would be the early stages of civilian disaster response. In the past, powered exoskeletons were envisaged as vehicles with joystick and pushbutton controls, where the human commands the system. Current approach has moved towards more ‘transparent’ or intuitive controls where the system has to perceive the operators needs and to act accordingly. In the event of system failure, the powered exoskeleton can pose significant danger to the human operator encased in the system. The need for failsafe design is paramount. This paper highlights this approach in the identification of a safe design for a human powered exoskeleton system for human endurance enhancement. It describes a direct measurement and computational approach towards identifying the necessary torque, power and joint motion limits as a means of ensuring a safe design.