为了提高肠道机器人无线能量发射系统性能，对能量发射系统进行了理论建模及优化设计.基于UCC3895芯片移相控制的全桥串联谐振电路设计了适用于大尺寸发射线圈、大驱动电流条件的无线能量发射电路，以达到工作稳定及频率和功率可调节的目的；建立了发射线圈交流电阻、自感及寄生电容参数的数值计算模型；使用单股利兹线绕制直径为69cm的单层发射线圈，并根据线圈解析模型，通过线圈匝数的可行域分析确定了发射线圈结构参数.结果表明，在工作频率为218kHz时，所设计的能量发射系统的传输功率最大可达650mW，传输效率为 3.60%，能够满足肠道机器人的功率需求，从而提高了系统的适用性.
This paper proposed an analytical model and optimal design for wireless power transmitting system used for gastrointestinal robots. Based on the phase-shift PWM controller UCC3895, a wireless power transmitting circuit which is suitable for large-sized coils and large driving current conditions was designed. The system has the characteristics of stable operation, adjustable frequency and power. We optimized the number of turns of a single-layer transmitting coil with a diameter of 69cm according to the analytical model and the feasible region analysis of the coil. The results show that at the operating frequency of 218kHz, the power transmitting system can provide up to 650mW for endoscopic robots with a transmission efficiency of 3.60%.
［1］颜国正, 陈雯雯. 肠道内窥镜机器人研究进展［J］. 生物医学工程学杂志, 2015, 32 (1): 214-217.
YAN Guozheng, CHEN Wenwen. Latest development of intestinal capsule endoscopy robot［J］. Journal of Biomedical Engineering, 2015, 32(1): 214-217.
［2］International Commission on Non-Ionizing Radiation Protection. Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic fields (up to 300GHz)［J］. Health Physics, 2009, 97(3): 257-258.
［3］XIN W H, YAN G Z, WANG W X. Study of a wireless power transmission system for an active capsule endoscope［J］. International Journal of Medical Robotics Computer Assisted Surgery Mrcas, 2010, 6(1): 113-122.
［4］辛文辉, 颜国正, 王文兴, 等. 胶囊内窥镜能量发射装置的设计及实现［J］. 北京生物医学工程, 2009, 28(5): 494-498.
XIN Wenhui, YAN Guozheng, WANG Wenxing, et al. Design and implementation of power transmitting equipment using in power transmission for capsule endoscope［J］. Beijing Biomedical Engineering, 2009, 28(5): 494-498.
［5］杨凯, 颜国正, 高晋阳. 胶囊机器人无线能量传输系统设计［J］. 北京生物医学工程, 2016, 35(5): 510-515.
YANG Kai, YAN Guozheng, GAO Jinyang. Design of wireless power supply system for robotic capsule［J］. Beijing Biomedical Engineering, 2016, 35(5): 510-515.
［6］石煜, 颜国正, 朱柄全. 胶囊内窥镜便携式无线能量发射系统［J］. 光学精密工程, 2014, 22(1): 132-137.
SHI Yu, YAN Guozheng, ZHU Bingquan. Portable wireless power transmitting system for video capsule endoscopes［J］. Optics and Precision Engineering, 2014, 22(1): 132-137.
［7］KE Q, LUO W J, YAN G Z, et al. Analytical model and optimized design of power transmitting coil for inductive coupled endoscope robot［J］. IEEE Transactions on Bio-medical Engineering, 2015, 63(4): 694-706.
［8］YANG Y, XIE X, LI G L, et al. A combined transmitting coil design for high efficiency WPT of endoscopic capsule［C］∥IEEE International Symposium on Circuits and Systems. Lisbon, Portugal: IEEE, 2015: 97-100.
［9］SUN T J, XIE X, LI G L, et al. A two-hop wireless power transfer system with an efficiency-enhanced power receiver for motion-free capsule endoscopy inspection［J］. IEEE Transactions on Bio-medical Engineering, 2012, 59(11): 3247-3254.
［10］BASAR M R, AHMAD M Y, CHO J, et al. Stable and high-efficiency wireless power transfer system for robotic capsule using a modified helmholtz coil［J］. IEEE Transactions on Industrial Electronics, 2017, 64(2): 1113-1122
［11］LIN W, SHI Y, JIA Z W, et al. Design of a wireless anchoring and extending micro robot system for gastrointestinal tract［J］. Int J Med Robot, 2013, 9(2): 167-179.
［12］JIA Z W, YAN G Z, HUA L, et al. The optimization of wireless power transmission: design and realization［J］. International Journal of Medical Robotics Computer Assisted Surgery Mrcas, 2012, 8(3): 337-347.
［13］BASAR M R, AHMAD M Y, CHO J, et al. Application of wireless power transmission systems in wireless capsule endoscopy: an overview［J］. Sensors, 2013, 14(6): 10929-10951.
［14］贾智伟, 颜国正, 石煜, 等. 基于生物安全性的无线能量传输系统发射线圈优化设计［J］. 高技术通讯, 2012, 22(8): 857-862.
JIA Zhiwei, YAN Guozheng, SHI Yu, et al. Optimization design of transmitting coils in a wireless power transmission system based on the human tissue safety［J］. High Technology Letters, 2012, 22(8): 857-862.
［15］MA G, YAN G Z, HE X. Power transmission for gastrointestinal microsystems using inductive coupling［J］. Physiological Measurement, 2007, 28(3): 9-18.
［16］JIA Z W, YAN G Z, JIANG P P, et al. Efficiency optimization of wireless power transmission systems for active capsule endoscopes［J］. Physiological Measurement, 2011, 32(10): 1561-1573.
［17］PUERS R, CARTA R, THON J. Wireless power and data transmission strategies for next-generation capsule endoscopes［J］. Journal of Micromechanics and Microengineering, 2011, 21(5): 2703-2712.
［18］FERREIRA J A. Electromagnetic modelling of power electronic converters［M］. Dordrecht, Netherlands: Kluwer Academic Publishers, 1989.
［19］KAZIMIERCZUK M. High-frequency magnetic components［M］. 2nd ed. New Jersey, USA: Wiley Publishing, 2013.
［20］FERREIRA J A. Analytical computation of AC resistance of round and rectangular litz wire windings［J］. IEEE Proceedings B-Electric Power Applications, 1992, 139(1): 21-25.
［21］YANG Z, LIU W T, BASHAM E. Inductor modeling in wireless links for implantable electronics［J］. IEEE Transactions on Magnetics, 2007, 43(10): 3851-3860.
［22］ZIERHOFER C M, HOCHMAIR E S. Geometric approach for coupling enhancement of magnetically coupled coils［J］. IEEE Transactions on Biomedical Engineering, 1996, 43(7): 708-714.
［23］CHEN W W, YAN G Z, WANG Z W, et al. A wireless capsule robot with spiral legs for human intestine［J］. International Journal of Medical Robotics and Computer Assisted Surgery, 2014, 10(2): 147-161.
