Development of a slotless tubular linear interior permanent magnet micromotor for robotic applications

Linear micromotors play a key role in microrobotic systems. They can greatly simplify the drive mechanisms, which is crucial for microsystems. By using permanent magnets, much higher force-to-volume ratio can be obtained than using electromagnets and better drive performance can be achieved. This paper describes the development of a tubular permanent magnet linear motor for the actuation of microrobots. Important design criteria are established by both analytical and numerical methods. The field distribution, the electromagnetic force, and the stator phase winding inductances are analyzed and predicted by the finite-element analysis taking into account the nonlinear properties and saturation effects of the material.