一种二维编码标尺的数字水准仪系统原理设计与试验进展

The Principle Design and Testing Progress of a Digital Level System Based on Two-Dimension Encoding Staff

数字水准仪是一种集光学、电子技术、编码技术、图像处理及计算机技术于一体的水准测量系统。它凭借快速度、高精度、易于操作等特点,已广泛应用于高精度水准测量、工业测量等多种领域。当前的各类数字水准仪产品是基于一维条码技术设计的编码标尺,水准仪的设计是围绕相应标尺编码方法的读数系统展开。经过十多年的开发,国外几大测绘仪器生产厂商已将条码标尺的编码方法实行专利保护;国内起步较晚,已难以找到合适的编码方法。文中提出了一种新的基于二维平面的编码设计方案。该方案将标尺面分为数字标注、二维码粗测和圆心精测3个区域;而水准仪部分采用面阵CCD采集标尺图像,运用快速数字图像处理算法进行读数定位。理论分析和实验样机测试表明,这种设计可以生产精度高、性能优异的数字水准仪。

The digital level was a kind of leveling system including optics, electronic technology, encoding technology, image processing and computer technology. It had been widely used in leveling and industrial measurement because of its fast speed, high precision and convenient operation. All kinds of level staffs were designed based on one-dimensional bar code. And the designs on digital levels were developed around the appropriate encoding method of the staffs. After several years of development, the encoding methods had been patent protected by several foreign surveying and mapping equipment manufactories. The later internal starting made that finding more suitable encoding method is hard. Thus a new coding design based on 2D plane was put forward. This design classified a level staff into 3 modules including number symbol, two-dimension code and circles. The digital level utilized array CCD to get staff images and fast digital image processing algorithms to locate the height of the sight line. The theoretical analysis and model machine tests showed that this design could produce the digital level of high precision and excellent capability.