Abstract
New control algorithm for reducing sound pressure level of fan noise is proposed. As the algorithm basically comes from learning control which is invented for controlling the repetitive motion of a robot, it is effective for reducing the periodic components of fan noise. The control system utilizing the algorithm contains only error microphones without reference signal, which means the computer program realizing the algorithm is much shorter than that for conventional control algorithms, filetered-X or filetered ε, for example. The control experiment was conducted to prove the high efficiency of the new control algorithm. The result of the control experiment proved the superiority of the learning control over the conventional algorithms.
