非常应变模式数字相关方法的初值估计

Initial Estimates in Digital image Correlation Method by a New Displacement Mode

本文给出了基于高精度非常应变子区位移模式数字相关方法的 Newton-Raphson迭代法求解的新通用公式 .对相关迭代算法中的初值估计问题进行了研究 ,提出两种初值估计方法 :(1 )利用“实时相减”和“精密调节”相结合的方法而获得零初值 ;(2 )快速迭代初值估计方法 .从而有效地解决了 Newton- Raphson迭代算法中的初值估计问题 。

On the basis of a new displacement mode for Digital image Correlation Method, both the Jacobian Vector and the Hessian matrix of Newton Raphson iterative procedure are given. The initial estimates of displacement and displacement gradients for Newton Raphson iteration are studied. Two methods of initial estimates are proposed: (1) using real time image subtraction scheme and a micro motion compensation mechanism to take zero constantly as initial estimates; (2) using fast iteration to give the initial estimates of displacement. Some problems in the initial estimates and the convergence of Newton Raphson iteration are discussed.