A direct digital control ( ddc ) system was adopted , which can grab the dynamic image of fruits in real time , and send the results of image processing to the parallel port of computer , then control several step motors " status at the same time 本研究采用计算机直接数字控制方式,对动态水果图像进行实时采集,并通过计算机的打印端口输出图像处理结果,实现同时对多个执行器的动作状态进行控制。