Derivation of an analytical model for the force produced during the motion of a magnetically suspended object

Magnetically suspended microrobots show a great deal of potential for use in the fields of medicine and manufacturing. A system developed by one of the authors consists of a magnetic drive unit that produces a magnetic field that levitates a microrobot. One of the limitations of the system is that the force produced by the magnetic drive unit is difficult to predict unless a numerical simulation is used. A need has therefore been identified to produce an analytic model of the generated force in order to aid in the design and optimization of a position controller. Initial experiments use a two-dimensional numerical model to derive the force profile, with curve fitting used to derive the analytical model. One of the main drawbacks of this method is that the force contributions of each component of the drive unit are combined by superposition, which results in errors between the numerical model and the analytical model. The procedure has shown enough promise to try and extend the analysis to a three-dimensional model.