Method and apparatus for controlling the frequency of vibration imparted to the ground by a compacting machine

摘要

Apparatus for controlling the frequency of vibrations imparted by the vibrating element of a compacting machine to the ground which comprises a vibration pick-up responsive to the amplitude of vibrations of a mass composed of the vibrating element and the ground being vibrated which produces a vibration signal; a position sensor sensing the angular position of an eccentrically loaded rotary shaft on which the vibrating element is mounted, which produces a position signal; and a phasemeter which receives the vibration and position signals and provides an output signal related to the phase difference therebetween. This phase difference may be displayed in which case the motor for the rotary shaft can be controlled manually in accordance therewith or it may be fed to an automatic control system in which it is compared with a set signal to produce an error signal for automatically regulating the speed of motor turning the rotary shaft. Preferably the vibration pick-up and position sensor are of identical constructions and processed by identical band pass filters.