Basic Research on Active Noise Control for Moving Error Points by Multi-channel Wave Synthesis Method

在强噪声环境中，人们迫切需要采用有源噪声控制技术来降低人耳处的噪声。在这项研究中，我们专注于波合成（WS）算法，这是有效的减少周期性噪声，如发动机噪音和风扇音，预计将是有用的移动接收点。得出以下结论。首先推导了一种新的多通道WS算法，并通过仿真验证了该算法的有效性。其次，单通道系统和双通道系统的制作使用DSP，和他们的降噪性能和收敛性能被发现是足够的，通过一些实验，使用电路。最后，在像办公室的真实的声场中进行了一些实验，并且发现系统通常是有用的，但是在一些声场条件下是不稳定的。分析了原因，并认为增加扬声器系统可以解决这个问题。

It is strongly required to reduce noise at moving persons’ ears in a noisy room by some active noise control techniques. In this research, we focused on the Wave Synthesis (WS) algorithm which is effective for reducing periodic noise such as engine noises and fan tones and is expected to be useful for moving receiving points. The following conclusions were obtained. First, a Multi-Channel WS algorithm was newly deduced and its usefulness was proved by some simulations. Secondary, the single-channel system and the dual channel system were manufactured using DSP, and their noise reducing performance and converging performance were found to be sufficient by some experiments using electrical circuits. Finally, some experiments were performed in real sound fields like an office and the systems were found to be generally useful but to be unstable in some sound field conditions. The reason was examined and an additional speaker systemwas considered to be recommendable to solve this problem.