The reduction effect of construction machinery noise by feedforward type active noise control

We developed an active noise control (ANC) system which could be operated stably to the noise of moving (working) machineries. To the ANC system, we applied the feedforward control method with reference signal and without C. The control method estimated a predominant frequency in time domain and calibrated the phase delay. We checked the ANC by numerical simulation and laboratory experiment. The results are as follows. 1.By the numerical simulations, we confirmed the proposed method performed more stably and had the shorter convergence time of calibration, than the methods of general feedforward control and general feedback control. 2. Through laboratory experiments, we confirmed the ANC system with the proposed control method reduced the noise of construction machinery by about 10 dB.