Actuator Optimization for a Back-Support Exoskeleton: The Influence of the Objective Function

Exoskeletons have been interest of researchers and developers spanning a wide range of applications. Active and passive or quasi-passive exoskeletons are being developed. For this latter category, the actuator parameter tuning is generally based on optimization studies. This paper studies how the definition of the objective function affects the passive or quasi-passive exoskeleton actuators configuration and parameters. It also provides indications on how focusing solely on energy optimization might result in an assistance that could alter the user behaviour. Therefore, usability of the exoskeleton and user comfort could be negatively affected. Finally, as a result of the optimization output analysis, we discuss about the advantages of designing a quasi-passive exoskeleton.