Field oriented motor controller for electrically powered active suspension for a vehicle

Claim 1

A field oriented controller for generating phase currents for driving a multiple phase electric motor in response to a commanded force signal, said controller generating phase currents to substantially conform the force developed by the motor to the force indicated by said commanded force signal and comprising: current signalling means for determining the currents flowing in the individual phases of said motor; motor monitoring means for determining the mechanical rotary position θ M of an armature of said motor; processor means for determining the electrical rotary position θ E of the armature of said motor from its mechanical rotary position θ M and for transforming the phase currents determined by said current signalling means into a quadrature axis equivalent current, I Q , and a direct axis equivalent current, I D ; comparator means for comparing said commanded force signal with a motor force signal representative of the actual force generated by said motor to generate a force error signal; first converter means for converting said direct axis equivalent current I D into a desired direct axis equivalent current I D * ; and second converter means for converting said force error signal into a desired quadrature axis equivalent current I Q * , said processor means further providing for calculating the phase currents, I A * , I B * , I C * , for driving said motor, as a function of θ E , I D * and I Q * .