Static characteristic analysis and force optimization of a short-stroke planar motor

In the multi-degree-of-freedom high precision positioning systems, high positioning accuracy can be not achieved only with long-stroke motors. The proposed planar motor with a millimeter range of movement can be used as a precision compensation actuator for long-stroke motors due to its high positioning accuracy, high force resolution, high structural strength and low force ripples. This paper deals with the static characteristic analysis and force optimization of the 3-DOF short-stroke planar motor. First, the operation principle and structure of this planar motor are introduced. Second, the accurate air-gap flux density distribution is obtained analytically and the specific force expression is derived using numerical integration method. Third, the analytical static characteristics are verified by the experimental measurements. Finally, the trend of force, force density and acceleration versus the magnet height and the pole pitch are obtained, which provide the basis and criterion for motor design.