V. Balestro, Á. G. Horváth and H. Martini, Angle measures, general rotations, and roulettes in normed planes, Analysis and Mathematical Physics 7(4), pp. 549-575, 2017. (arXiv link) (journal link)
Comments: Fixing a Borel measure in the unit circle (or even in any star-like Jordan curve in the plane) one can define a group of “fixed angle rotations”. With this tool in hands, it is possible to define rigid motions of the plane. Finally, roulettes are defined and analogous to the Euler-Savary equations are obtained.