高可靠小车红外光循迹设计原则

Design principles of car infrared tracking with high reliability

小车采用传统光循迹电路有两点不足:一是容易受环境光线的影响而造成误判;二是光衍射现象又容易被相邻的光敏管接收也造成误判。针对这两点不足,提出设计原则是采用低占空比强红外光调制发射能克服环境光线的干扰;再对光接收信号进行交流放大后解调能进一步克服环境干扰;采用逐个循环发射、接收能克服光衍射对相邻光敏管的干扰。最后对改进型的方案予以设计,给出电路结构框图及部分电路图。

There are two disadvantages in traditional design of car optical tracking circuit, one is that the ambient light could result in mistake of judgment, and the other one is that light diffraction could be received by the light-sensitive diodes nearby and also result in mistake of judgment. To resolve these problems, a design principle is proposed that use strong infrared with low duty cycle instead of normal light to modulate could overcome the interference of ambient light, and then AC amplifier is used before demodulation, which could further overcome the interference. Sending and receiving the signals one by one is an effective measure to overcome the interference from diffraction to the light-sensitive diodes nearby. Finally, the improved version of scheme is designed, and the structured flowchart and electronic schematic is given.