On Task-Specific Redundant Actuation of Spring-Assisted Modular and Reconfigurable Robot

Modular and reconfigurable robots (MRRs) are unique and highly versatile for their self-innovation potential. Multiple working mode (MWM) on-line control adds potential by enabling each spring-assisted MRR (SA-MRR) joint module to switch independently between primary (motor-only) mode, and secondary, redundant actuation (spring-assisted) mode. In this work we proposed the spring-assisted mode as an on-board, physical innovation aid for uncertain, task-critical manipulation acts in uncontrolled environments. The spring-assisted mode is characterized by synergy of the spring and motor energy, and strengthens the SA-MRR by complementing the net actuation effort to help overcome task failure, to improve competency at ordinary tasks, and to enhance SA-MRR suitability as a tool for new tasks. Spring modules are fully reconfigurable offline through component swapping, and human-robot collaboration safety is considered. Task-specific, physical innovation with the SA-MRR was investigated by applying the spring-assisted mode directly to strenuous task segments in simulation case studies, demonstrating effectiveness of the proposed MWM approach.