Frequency-Domain Properties of Reset Systems With Application in Hard-Disk-Drive Systems

This paper investigates frequency-domain properties of reset systems with arbitrary reset matrices and their application in disturbance rejection. First, we investigate the sinusoid input response of a reset system. Then, through calculating the describing function, we reveal how the reset matrix affects the frequency-domain properties of the reset system. At last, we generalize the reset phase-lead controller to the nonzero reset matrix case. As an application, the proposed reset phase-lead controller is applied to compensate for the phase lag caused by a narrow band compensator for midfrequency disturbance in hard-disk-drive systems. Simulation results show that the proposed control scheme can enhance the midfrequency disturbance attenuation without degrading stability.