A controller includes a combining module that generates a total control signal for the drive device of a disk drive by combining a feedback control signal and a feedforward control signal. A feedback control module generates the feedback control signal in response to at least one state of the drive device. A feedforward control module generates the feedforward control signal based on a smoothing function and a feedforward control function. The smoothing function is determined by evaluating a plurality of candidate smoothing functions by determining a smoothness factor associated with the control signal that results from each of the plurality of candidate smoothing functions, and selecting the smoothing function as one of the plurality of candidate smoothing functions, based on the smoothness factor.