球形微机器人控制及运动特性的研究

发布时间：2018-05-19 09:16

本文选题：胃肠道疾病 + 亥姆霍兹线圈　；参考：《天津理工大学》2017年硕士论文

【摘要】：目前,医用管道微机器人是一种理想的人体胃肠道疾病无创诊断和治疗的方案,根据临床实践的操作需求,本研究提出了一款由外部磁场驱动的新型医用球形微机器人样机,并且设计了相应的激励源系统,在新的流体实验平台上对医用球形微机器人的运动特性进行了评价与分析。系统通过上位机远程界面发送控制指令,经无线射频芯片通信实现对信号发生电路输出的正弦信号的频率或者幅值参数进行实时调节,同时将调节好的三路正弦信号通入到三轴亥姆霍兹线圈系统中去,在正弦信号的激励作用下,线圈系统在中心区域产生旋转磁场。利用外部旋转磁场与球形微机器人内嵌永磁体产生的内磁场之间耦合效应,实现球形微机器人的有效运动。本课题分别对三轴亥姆霍兹线圈模型、线圈激励源系统以及新型球形微机器人样机进行了设计与分析,并且通过一系列的流体实验评价球形微机器人的运动特性。首先,本课题设计并加工了三轴亥姆霍兹线圈模型,并且用有限元软件ANSYS分析了三轴亥姆霍兹线圈产生的外部旋转磁场的电磁特性,讨论了亥氏线圈产生外磁场用于驱动球形微机器人运动的理论基础。其次,结合控制系统对外部旋转磁场的特性需要以及三轴亥姆霍兹线圈的驱动原理,本课题为三轴亥氏线圈模型设计了相应的激励源系统,主要包括信号发生电路和上位机远程控制电路两个部分。同时本课题还对比了外部旋转磁场的理论值与实验测量值之间的误差,验证了驱动控制系统的有效性以及仿真结果的正确性。再次,本课题设计并制作了新型球形微机器人样机,分析了球形微机器人受到的磁场力、浮力以及阻力,推导了外部旋转磁场驱动球形微机器人运动的空间算法。结合三轴亥姆霍兹线圈的外磁场特性分析,本研究还对外磁场与球形微机器人内嵌永磁体产生的内磁场进行了耦合分析,进而得到了外部旋转磁场驱动球形微机器人有效运动的磁场力的理论值。最后,本研究通过一系列的评价实验,在新的流体实验平台上评价了新型球形微机器人的运动特性,主要分析了水流流速及方向、正弦信号的频率及幅值参数对球形微机器人运动的影响,并进行了球形微机器人的转弯实验。实验结果表明,新型的球形微机器人具有良好的动态特性,不仅可以实现在直线方向上的往返运动,而且其转弯特性更为优越。本研究提出的外部旋转磁场驱动的球形微机器人具有广阔的医学应用前景,能够满足临床化的需求。在未来,医用胃肠道诊疗微机器人研究的临床化、实用化,对延长人类寿命,提高人类生活质量具有重要的科学意义,胃肠道机器人也必将成为医学工程发展史上的里程碑式事件。
[Abstract]:At present, the medical pipeline microrobot is an ideal non-invasive diagnosis and treatment scheme for human gastrointestinal diseases. According to the operational requirements of clinical practice, a new type of medical spherical microrobot driven by external magnetic field is proposed in this paper. The corresponding excitation source system is designed and the kinematic characteristics of the medical spherical micro robot are evaluated and analyzed on a new fluid experimental platform. The system sends control instructions through the remote interface of the host computer, and realizes the real-time adjustment of the frequency or amplitude parameters of the sinusoidal signal output by the radio frequency chip communication. At the same time, the three-channel sinusoidal signal is transferred into the three-axis Helmholtz coil system. Under the excitation of the sinusoidal signal, the coil system produces a rotating magnetic field in the center region. Using the coupling effect between the external rotating magnetic field and the inner magnetic field produced by the permanent magnet embedded in the spherical micro-robot, the effective motion of the spherical micro-robot is realized. In this paper, the three axis Helmholtz coil model, the coil excitation source system and the prototype of a new spherical micro robot are designed and analyzed, and the motion characteristics of the spherical micro robot are evaluated by a series of fluid experiments. Firstly, the model of three-axis Helmholtz coil is designed and fabricated, and the electromagnetic characteristics of the external rotating magnetic field generated by the three-axis Helmholtz coil are analyzed by the finite element software ANSYS. The theoretical basis of the motion of spherical micro robot driven by the external magnetic field generated by the Helmholtz coil is discussed. Secondly, according to the characteristics of the control system for the external rotating magnetic field and the driving principle of the three-axis Helmholtz coil, the corresponding excitation source system is designed for the three-axis Helmholtz coil model. Mainly includes the signal generation circuit and the host computer remote control circuit two parts. At the same time, the error between the theoretical and experimental values of the external rotating magnetic field is compared, which verifies the validity of the drive control system and the correctness of the simulation results. Thirdly, a new spherical micro-robot prototype is designed and manufactured. The magnetic field force, buoyancy and resistance of the spherical micro-robot are analyzed, and the spatial algorithm of the spherical micro-robot driven by the external rotating magnetic field is deduced. Combined with the analysis of the external magnetic field characteristics of the three-axis Helmholtz coil, the external magnetic field is coupled with the internal magnetic field generated by the permanent magnet embedded in the spherical micro-robot. The theoretical value of the magnetic field force of the spherical micro robot driven by the external rotating magnetic field is obtained. Finally, through a series of evaluation experiments, the kinematic characteristics of a new type of spherical micro robot are evaluated on a new fluid experimental platform, and the flow velocity and direction are mainly analyzed. The effects of sinusoidal signal frequency and amplitude parameters on the motion of spherical micro robot are studied. The experimental results show that the new spherical micro robot has good dynamic characteristics, not only can realize the round-trip motion in the straight line, but also its turning characteristics are more superior. The spherical micro robot driven by external rotating magnetic field has a broad prospect of medical application and can meet the clinical needs. In the future, the clinical and practical research of medical gastrointestinal microrobot is of great scientific significance to prolong human life and improve the quality of human life. Gastrointestinal robot will also become a milestone event in the history of medical engineering.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP242

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