Development of a hybrid humanoid platform and incorporation of the passive actuators

This paper describes the design and development of a new hybrid humanoid platform conceived to use both active and passive actuators. Power efficiency and mechanical response capability of the robot were the main concerns driving this development. Maintaining the use of off-the-shelf RC servomotors, due to their limited cost and commercial availability, the platform was nonetheless custom-designed for lightness, mechanical stiffness and prone to vast sensorial enrichment for future advanced control. Low-cost actuators may degrade and perform poorly and erroneously in demanding conditions; therefore, one major inspiration for this work relies on the potential energy storage mechanism, using elastic elements to overcome the motors limitation, avoiding their operation near the limits, while saving energy and wearing, and also obtain faster responses of the overall platform in various motion schemes and gaits. A standard simulation environment allows the initial design and future tuning of the passive actuators for several joints in motion tasks. The early simulation results show that the elastic elements approach indeed eases the actuators tasks and is a must in the future development of the new platform now presented.