针对Newton-Raphson算法求解轴偏置虎克铰型并联六自由度Hexapod平台位置反解时高精度计算会降低平台响应速度的问题，提出了一种新的基于Brent算法的位置反解求解方法。首先，根据平台几何特性和轴偏置虎克铰结构运动特性，建立了基于空间圆辅助模型的运动学模型；接着，提出了基于空间圆距离求解方法的位置反解算法，并针对丝杠螺母副产生的衍生运动，提出了补偿方案；然后，介绍了Brent求根算法，并将Brent算法应用于位置反解算法；最后，通过实验验证了衍生运动误差补偿方案的必要性，同时与采用Newton-Raphson算法的位置反解进行了对比，并测试了该算法控制下的Hexapod平台的响应速度和精度。实验结果表明：在保证平台重复精度低于10 μm和5″的工作需求下，基于Brent算法的位置反解与Newton-Raphson算法相比，综合响应速度提高了约0.5 s。因此，基于Brent算法的位置反解求解方法相对改善了Hexapod平台的响应速度。
Hexapod平台 响应 轴偏置虎克铰 位置反解 Brent算法 Hexapod platform response axis offset Hooke joint inverse displacement Brent’s method
Author Affiliations
Abstract
Engineering Research Center of Communication Devices and Technology, Ministry of Education, Tianjin Key Laboratory of Film Electronics and Communication Devices, Department of Computer and Communication Engineering, Tianjin University of Technology, Tianjin 300384, China
A tunable modulation format converter based on spectral line-by-line pulse shaper is proposed to realize different format conversions. The pulse shaper works as a format converter by setting its frequency response equivalent to the transform function between two formats. The working principles show that the format converter is suitable for different formats by adjusting its frequency response. Examples of format conversion from return to zero differential phase-shift keying (RZ-DPSK) to on-off keying (OOK) with different data packets and from return to zero (RZ) to non-return to zero (NRZ) are given. The results show that the format converter is not only suitable for different formats but also for random data packets.
光电子快报（英文版）
2014, 10(3): 228
