胶囊机器人万向旋转磁场负反馈驱动控制

摘要

三轴亥姆霍兹线圈可叠加空间万向旋转磁场，使胶囊机器人在弯曲环境内的驱动成为可能。驱动电流频率变大，线圈感抗变大，旋转磁场强度变小，方位精度变差。为此，研制以DSP芯片为核心的负反馈控制系统，提高了旋转磁场的准确性和稳定性。根据系统的等效电路，建立了微分方程，推导传递函数，求得特征方程根，证明了系统的稳定性。通过保证三组线圈的电感与电阻的比值相等，使三组线圈滞后角及时间常数相等，降低了系统故障率，提高了系统效率与安全性。%Triaxial Helmholtz coils can superimpose spatial universal rotating magnetic field, which is potential to drive the robot in curved environment. When the frequency of driving current increases, the inductance of coils increases, the magnetic field becomes smaller and accuracy of its orientation becomes lower, so we build the negative feedback controlling system based on the DSP chip, which enhances accuracy and stability of rotating magnetic field. According to equivalent circuit of the driving system, we obtain differential equation,transfer function and roots of characteristic equation,which demonstrates that the system is stable. The ratios of the inductance to the resistance of three coils are equal, thus the lag angles and time constants of three coils are equal to each other respectively,which makes sure that the failure rate of system is reduced,and the efficiency and safety are improved.