为了解决目前点衍射绝对位移测量系统中位移重构算法存在的收敛率低问题,并针对实际测量中时效性和高精度要求,提出了基于快速搜索粒子群算法的点衍射干涉绝对位移测量方法。点衍射干涉绝对位移测量系统根据点衍射干涉场相位差的分布重构出点衍射探头的三维绝对位移。所提出的快速搜索粒子群算法针对测量中大量像素点数据的高效处理需要,在三维绝对位移迭代重构过程中采取非线性增加样本点数量的搜索方法,进而在保证测量精度的同时极大提高了测量效率。分别进行了仿真分析、测量实验以及三坐标机测量比对以检验所提出测量方法的可行性与稳定性。结果表明,该方法可实现三维绝对位移的快速检测,其收敛率可达90%,且在200mm×200mm×300mm的测量区域中达到优于微米量级测量精度。所提出的三维绝对位移测量方法具有较高的测量效率和精度,且具备高抗噪能力和可靠性,对其在微加工技术和高精度测量中的应用具有重要意义。
To enhance the convergence ratio, timeliness and accuracy of current iterative algorithm in the measurement of three dimensional absolute displacements with point-diffraction interferometer (PDI), the method based on quick searching particle swarm optimization (QS-PSO) algorithm is proposed for the reconstruction of absolute displacements. The three dimensional absolute displacement of the probe is determined from the distribution of the phase difference in the interference field. To realize the efficient procession of a large number of sampling pixel points, the sampling points are nonlinearly increased in the process of iteration in the proposed QS-PSO method, by which both the high-efficiency and high-precision measurement are achieved. Both thecomputer simulation and experimental measurements are carried out to verify the feasibility of the measurement. According to the analyzing results, the convergence rate and measurement precision of the proposed measurement method can reach 90% and better than the order of microns within a 200 mm×200 mm×300 mm working volume, respectively. The proposed absolute displacement measurement method is of high efficiency, measurement precision, anti-noise ability and reliability, and also of great significance for the application of micro-processing and high precision measurement.