对称连杆曲线的FFT应用研究

Investigation on Application of FFT to Symmetric Coupler Curves

对机构学中对称连杆曲线的FFT分析和综合方法进行了研究。通过合理地选择坐标轴，使对称连杆曲线的离散数据满足共轭对称性。推导出共轭对称序列的快速付里叶变换FFT具有相位为零的特性；建立了单纯由幅度谱值构成的对称连杆曲线的特征参数。对给定需实现的对称运动轨迹，运用最小二乘法进行曲线特征参数的比较，实现连杆曲线及相应机构的综合，提高了效率和精度。

Makes research on the FFT analysis and synthesis method of the symmetric coupler curves in mechanism. By properly setting the coordinate axis,the discrete data of a symmetric coupler curve is made to satisfy the conjugate symmetry. It is derived that the phase of the FFT for a conjugate-symmetric sequence is zero. The characteristic values of a symmetric coupler curve are established to be consisting simply of the amplitudes. For a given desired symmetric kinetic path, the characteristic values of coupler curves are compared with the least square method,achieving the synthesis of the coupler curve and the corresponding linkage. The efficiency and the accuracy are improved.