Signal demodulation of automatic block with audio frequency shift modulated track circuits was implemented with phase-locked loop (PLL) technique and a singe chip microcomputer.
利用锁相环(LL)窄带跟踪特性，与单片机结合，实现自动闭塞系统移频信号解调。
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Secondly, we use the mean shift algorithm to track the faces. We realize automatic face tracking of image sequence eventually.