Benefit of Optimal Actuator Selection – A Comparative Study

Abstract

Abstract Actuators are a vital component, and often the limiting factor in robotics and robotic-related applications like humanoids, exoskeletons, prosthetics and orthosis. Actuator selection is critical due to system design flow-on effects including weight, energy consumption and form factor. A designer’s challenge is often to optimize the actuator to minimize size or weight and meet the performance specifications usually with trade-offs. This paper investigates the design impacts of selecting more suited actuators on the system through a representative humanoid configuration performing a task. It also looks at variations based on the scale of the humanoid using human anthropometric data for variations in limb lengths. The torques and speeds required at each joint to complete the task is simulated and the system design is updated to keep a constant member stress across all designs. The total energy and weight are calculated and used to compare actuator selection impacts. By knowing the extent of the flow-on effects actuator selection has on a configuration, and how this effect scales, designers are able to determine what investment should be allocated to locating the ideal actuator for their task.