Control of a self-bearing servomotor

Self-bearing motors (SBM), also known as bearingless motors are electric motors that use magnetic levitation and rotate a shaft. In this article we deal with an SBM known as tooth-less self-bearing servomotor (TSBS), in which Lorentz force is the basis for both levitation and rotation. The article identifies the performance drawbacks of TSBS such as low bearing capacity and the conflict between bearing force and torque generation. These drawbacks are controlled by including a control scheme in the TSBS model that balances the load between two radial axes. A saturation constraint on the control input is established, that drives the rotational subsystem which preserves the stability of overall system. Several experiments are being performed to realize and validate the control design of TSBS.