Compliant Leg Mechanism of Coman

  • Nikos G. TsagarakisEmail author
  • Gustavo Medrano Cerda
  • Darwin G. Caldwell
Reference work entry


The incorporation of passive compliance in robotic systems has the potential to improve their performance during interactions and impacts, enhance their energy storage and efficiency, and facilitate greater general safety for the robots, humans, and environment. This chapter introduces the design and mechatronics of the leg mechanisms developed for COmpliant huMANoid COMAN. The COMAN leg is powered by passive compliance drives based on a series elastic actuation principle (SEA). Within the chapter, the design and implementation of the COMAN leg is discussed including the details of the SEA drive, the realization of the different leg joints, and the tuning of the joint distributed passive elasticity. The joint stiffness is a critical parameter in the compliant leg design as it defines the overall intrinsic adaptability of the leg, and strongly affects the control of its actuation system. The chapter presents a systematic method to optimally tune the joint elasticity of the multi-dof SEA leg based on resonance analysis and energy storage maximization criteria. The method is applied to the selection of the passive elasticity of COMAN legs. The chapter concludes with a discussion on future research directions and challenges in compliant actuation and robot design.


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Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  • Nikos G. Tsagarakis
    • 1
    Email author
  • Gustavo Medrano Cerda
    • 2
  • Darwin G. Caldwell
    • 2
  1. 1.Istituto Italiano di Tecnologia (IIT-Genova)Humanoids & Human Centred MechatronicsGenoaItaly
  2. 2.Istituto Italiano di Tecnologia (IIT-Genova)Advanced RoboticsGenovaItaly

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