A Miniature Short Stroke Actuator and its Position Control for a Haptic Key

This paper addresses the design and optimization of a small-sized linear electrodynamic actuator. This actuator is aimed to be inserted under a computer key in order to produce a force feedback to the user. Replacing the current rubber dome supporting the keys will help increasing the user's comfort and reduce musculoskeletal disorders. The actuator geometry is optimized in order to provide the maximal force. The optimization is done via finite element modeling computations (FEM) coupled with statistical methods called “design of experiments”. Few FEM simulations, well-chosen on the experimental domain boundaries, allow for the modeling, with a polynomial, of the actuator behavior in the entire domain. Once the geometry is optimized, a prototype is built for validation. Beside this, microcontroller- assisted control methods are proposed using Hall sensors for position feedback. Finally, measurements on the prototype are provided.