Generating realistic trajectories for robotic hippotherapy from 3D captured horseback motion

Riding a horse is a complex movement that is cognitively and physically demanding. It is established as a rehabilitation method for improving postural stability and locomotion performance, also known as hippotherapy. To facilitate the application in clinical environments, robotic hippotherapy systems have recently been developed. A therapy outcome equivalent to classical hippotherapy requires the robotic horse trajectories to be as close to reality as possible. In order to generate realistic trajectories executable by robotic systems, this work focuses on the synthesis of horseback motions based on 3D motion capture data. Representing the saddle of a therapy system, the horseback is treated as a rigid body. A marker selection approach is introduced to extract the data most significantly describing the rigid body motion of the horseback. The position and orientation components of the movement are determined by a least squares point matching algorithm and are approximated by Fourier series in order to generate smooth, cyclic and realistic trajectories effectively executable by robotic systems.