A Miniature Short Stroke Linear Actuator—Design and Analysis

We report a newly developed miniature short stroke tubular linear permanent-magnet actuator for robotic applications. Compared to a rotary-to-linear mechanism, the linear actuator has the advantages of efficiency, thrust control, and compact size in generating linear motion. We optimized the electromagnetic force of the actuator analytically by selecting appropriate dimensions and then predicted the force produced by the winding currents by the finite-element method under the brushless dc excitation scheme. We analyzed the actuation performance by dynamic modeling of the actuator. We constructed and tested a prototype on a specially designed test bench to verify the design. Finally, we analyzed and measured the end effect on the magnetic force due to the limited length of the stator core and translator.