基于各向异性参数模型的六自由度电磁跟踪系统

为了解决六自由度电磁跟踪系统三轴增益不一致带来的参数计算精度降低问题,提出了各向异性参数的模型.由三轴线圈匝数、面积、激励电流幅值和频率、电路增益决定各向异性参数的数值.在磁偶极子近场模型基础上推导出了包含各向异性参数的电磁跟踪系统模型.结合基于最大单位指向矢的跟踪算法和特征向量法求解位置参数,提高了算法的稳定性,克服了原跟踪算法位置参数求解局部误差放大的问题.,由接收信号矩阵直接推导姿态变换矩阵的表达式,避免了误差积累.该模型符合系统的实际运行环境,降低了硬件设计难度.实验结果验证了模型的正确性,提高了系统定位的精度.

Six degree of freedom electromagnetic tracking system based on anisotropic parameters model

In order to solve the problem of precision degrading caused by the different gains of three axes in six degree of freedom (6DOF) electromagnetic tracking system, the model of anisotropic parameters was introduced. The anisotropic parameters could be obtained by the coil numbers, coil area, current magnitude and frequency, and circuit gain. Electromagnetic tracking model with anisotropic parameters was introduced based on magnetic dipole antennas near filed model. An improved arithmetic was proposed to calculate the position parameters, which was a combination of the maximal ponderance of unit pointing vector tracking arithmetic and the eigenvector arithmetic. The improved arithmetic solved the problem of magnifying calculation error in some angle area. The attitude transformation matrix can be calculated by received matrix, which avoids the error accumulation. The calculation method simplifies the complexity and promotes the stability. The model is more accordant to the nature of the system and simplifies the system hardware design. The experiment results prove the model is valid and can improve the precision of the system.