Calibration of a parallel mechanism in a serial-parallel polishing machine tool based on genetic algorithm
Calibration of a parallel mechanism in a serial-parallel polishing machine tool based on genetic algorithm
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DOI：
10.1007/s00170-015-7150-y
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发表时间：
2015-05
期刊：
影响因子：
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通讯作者：
Cheng Fan;G. Zhao;Ji Zhao;Lei Zhang;Lining Sun
中科院分区：
文献类型：
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作者：
Cheng Fan;G. Zhao;Ji Zhao;Lei Zhang;Lining Sun
标定对提高并联机构的精度非常重要。提出了一种基于直接运动学模型和遗传算法的并联机构标定新方法。所提出的标定方法避免了在标定过程中测量运动平台的绝对位置/姿态。首先，建立了混合动力机床并联机构的理想运动学模型和带误差的运动学模型；由于缺乏直接运动学的解析解，采用牛顿迭代法求解。由于并联机构的标定可以看作是一个包含多个设计变量的离散优化问题，因此具体采用遗传算法对运动学模型中的参数进行辨识。最后进行了标定实验，验证了所提方法的有效性。实验结果表明，并联机构的定位误差从0.083 mm大幅度降低到0.018 mm。
The calibration is very important to improve the accuracy of the parallel mechanism. This paper proposed a new calibration approach for the parallel mechanism based on the direct kinematics model and the genetic algorithm. The proposed calibration approach avoids the measurement of the absolute position/posture of the moving platform in the calibration. Firstly, the ideal kinematics model, as well as the kinematics model with errors, of the parallel mechanism in the hybrid machine tool is established. Due to the absence of an analytical solution to the direct kinematics, the Newton iterative method is used to provide a solution. Since the calibration of the parallel mechanism can be regarded as a discrete optimization problem of multiple designed variables, the genetic algorithm is specifically used to identify the parameters in the kinematics model. Finally, the calibration experiment is carried out to verify the effectiveness of the proposed method. According to the experimental results, the positioning error of the parallel mechanism is largely reduced from 0.083 to 0.018 mm.