Design and control of a 3DOFs parallel actuated mechanism for biped application (Q2583749)

At the IEEE International Conference on Robotics and Automation, Washington D.C., 2002, the project ROBIAN was introduced to increase the understanding of the human being locomotion system and for the design and development of a biped prototype. It was demonstrated that four degrees of freedom (4DOF) are necessary and sufficient to reproduce the dynamic effect exerted by the upper limb of this system. In the primary stages of the design, a serial 3DOF mechanisms for the hip joint received considerable attention. In this paper, a more robust parallel mechanism is presented, allowing the femur to move within a much larger range in one direction compared to the two others. A simplified structure is also adapted for the 2DOF's ankle joint. A geometric method is proposed for the study of the forward kinematics, an analytic form is derived for the inverse kinematics. The singularities of the different possible configurations of the mechanisms and their workspace limitations are determined, and optimisations are processed to fit the ROBIAN applications. A prototype is developed, and the experimental tests support the design decisions.