1. A robot having a plurality of movable sections, the robot comprising: phase signal generating means for generating a phase signal relating to a periodic motion of at least part of the movable sections; control means for generating a control signal for the movable sections according to the phase signal; drive means for driving the movable sections according to the control signal; state quantity detecting means for detecting the state quantities of the movable sections driven by the drive means; and estimation means for estimating the phase or the angular frequency of the periodic motion of the movable sections according to the state quantities; the phase signal generating means being adapted to update the phase signal according to the phase or the angular frequency estimated by the estimation means.