双三步三角形相移编码结构光三维测量技术

Dual three-step triangular phase-shifting coding structured light three-dimensional measurement technology

为了减小编码结构光三维测量的误差,对三步三角形相移算法进行了分析。提出了一种可以有效减小强度比偏差的方法,构建了初始强度比相差T/6的两组三角形相移编码图案,两次使用传统三步三角形相移算法得到两幅折叠强度比图,再利用所提出的减小强度比偏差的方法,可以提高强度比的准确度。建立了编码结构光三维测量系统,结果表明该方法具有较好的减小强度比偏差的效果,比强度比先展开再补偿的方法更为简便有效,比传统三步三角形相移方法准确度明显提高,展开强度比的均方根误差值减小了87%。

In order to reduce the error of the coding structured light in three-dimensional measurement, detailed analysis on dual three-step triangular phase-shifting algorithm is performed. An effective method to reduce the intensity ratio deviation is proposed. Two sets of triangular phase-shifting coding pattern are built with the initial intensity ratio difference set as T/6. The traditional three-step triangular phase-shift- ing algorithm is used twice to obtain two wrapping intensity ratio maps. The proposed method of reducing the intensity ratio bias can be used to improve the accuracy of the intensity ratio. A coding structured light three-dimensional measurement system is estabhshed. The experiments show that the proposed meth- od has better compensation effect. It is more convenient and effective than the method of the compens of unwrapped intensity ratio maps. Compared with the traditional three-step triangular phase-shifting algo- rithm, the accuracy will improve significantly, and the wrapping intensity ratio root mean square error value will be reduced by 87%.