Patent ID: 8729838

Claim:
A controller for an electric actuator, the controller comprising: a plurality of inputs for receiving signals representing monitoring currents supplied to the electric actuator, for receiving a position feedback signal that represents a monitored position of the electric actuator, and for receiving a speed feedback signal that represents a monitored speed of the electric actuator; an abc-to-dq transformation block that converts the monitored current from an abc reference frame to a dq reference frame to generate each of a q-axis and d-axis current feedback signals; a reference model for receiving a position command signal that dictates a desired position of the electric actuator and generates a position reference signal and a speed reference signal in response to the receiving of the position command signal; a position speed control block that compares the position reference signal to the position feedback signal and compares the speed reference signal to the speed feedback signal to generate a q-axis current reference signal; a feed forward block that generates a q-axis current feed forward signal based on the speed reference signal and the position reference signal, wherein the feed forward block includes a viscosity function applied to the speed reference signal to account for mechanical viscosity of the electric actuator and a spring function applied to the position reference to account for mechanical spring force of the electric actuator, and wherein the output of the viscosity function is summed with the output of the spring function to generate the q-axis current feed forward signal; a synchronous current regulator that compares the q-axis current feedback signal to the q-axis reference signal to generate a q-axis current error signal, wherein the q-axis current error signal is modified by the q-axis current feed forward signal, and in response to the q-axis error signal generates a q-axis voltage reference signal and a d-axis voltage reference signal; a dq-to-abc transformation block that converts the q-axis voltage reference signal and the d-axis voltage reference signal from the dq reference frame to voltage reference signals in the abc reference frame; and a pulse width modulation (PWM) control block that generates PWM signals based on the voltage reference signals provided by the dq-to-abc transformation block for provision to an inverter that supplies current to the electric actuator.