Trajectory tracking using motion primitives for the Purcell's swimmer

Locomotion at low Reynolds numbers is a topic of growing interest, spurred by its various engineering and medical applications. This paper presents a novel prototype and locomotion algorithm for the 3-link planar Purcell's swimmer. The kinematic model of the prototype swimmer is a driftless control-affine system based on Cox theory. Using the existing strong controllability and related results, the existence of motion primitives is initially shown. The Lie algebra of the control vector fields is then used to synthesize control profiles to generate motions along the basis of the Lie algebra of the structure group of the system. An open loop control system with vision-based positioning is successfully implemented which allows tracking any given continuous trajectory of the swimmer's base link's position and orientation. Alongside, the paper also provides theoretical explanation of the symmetry arguments presented in the existing literature to generate the control profiles of the swimmer.