To address the problem of flexible drive control of gastrointestinal(GI)tract micro-capsule robot posture,a novel dual helix magnetorheological fluid(MRF)micro-robot(DHMRFMR)is proposed and developed in this paper.Bas...To address the problem of flexible drive control of gastrointestinal(GI)tract micro-capsule robot posture,a novel dual helix magnetorheological fluid(MRF)micro-robot(DHMRFMR)is proposed and developed in this paper.Based on the mechanical properties of magnetorheological fluid,the relationship model of magnetic field force is obtained,and the thrust model is established.Double micro DC deceleration motor is used to drive the two ends of the helical actuator to make the DHMRFMR forward and backward,by changing the external magnetic field rotation speed,direction and distance,adjust the attitude direction of the robot.Numerical simulation software ANSYS is used to analyze the motion law of external fluid of DHMRFMR,and the visualization of fluid velocity and pressure distribution is realized.The front-end helix actuator can change the flow path of the fluid,and the middle and tail of the DHMRFMR bear less pressure,which improves the stability and flexibility of the robot.The novel DHMRFMR is suitable for internal drive in bending environment,and has a good application prospect in biomedical engineering field in human intestinal unstructured environment.展开更多
This paper presents a study of a non-uniform pitch helical resonator (NPHR) structure and the coupling mechanisms to design dual-passband filters. The previous research analyzes NPHR as a type of step impedance resona...This paper presents a study of a non-uniform pitch helical resonator (NPHR) structure and the coupling mechanisms to design dual-passband filters. The previous research analyzes NPHR as a type of step impedance resonator (SIR), however, it does not give analytical equations or prediction for the dual-resonance characteristics of the NPHR structure discussed in this paper. Consequently, a circuit model is proposed to analyze the dual-resonance characteristics of NPHRs. Analytical equations are derived, showing that the frequency ratio of a dual-band NPHR can be determined by the ratio of turns. EM simulation and experimental results have shown good agreement with the circuit analysis. The derived analytical equations from circuit model can be used for fast design of NPHRs. A step-width aperture is proposed to independently control the coupling coefficients at the each band of NPHRs. A third order dual-passband filter has been designed and fabricated. The filter has 3.3% and 3% fractional bandwidths at 789 MHz and 2402 MHz, respectively. The designed prototype filter shows that NPHRs can be utilized to realize compact filters with dual-band characteristics. The filter design can be extended from engineering perspective for application in wireless communication systems.展开更多
基金supported by the Key Research Development and Promotion Special Project of Henan Province,under Grant 212102310119 and 212102210358Scientific Research Foundation for High-level Talents of Henan Institute of Technology,under Grant KQ1869+6 种基金Research and Practice Project of Higher Education Teaching Reform in Henan Province,under Grant 2021SJGLX289University-Industry Collaborative Education Program,under Grant 202101187010 and 202102120046Innovation and Entrepreneurship Training Program for College Students of Henan Province,under Grant 202211329011Educational and Teaching Reform Research and Practice Project of Henan Institute of Technology,under Grant 2021-YB023 and JJXY-2021005Innovative Education Curriculum Construction Project of Henan Institute of Technology,under Grant CX-2021-0052022 Xinxiang Federation of Social Sciences Research topic,under Grant SKL-2022-254 and SKL-2022-2282022 Annual Research Topic of Henan Federation of Social Sciences,under Grant SKL-2022-2692.
文摘To address the problem of flexible drive control of gastrointestinal(GI)tract micro-capsule robot posture,a novel dual helix magnetorheological fluid(MRF)micro-robot(DHMRFMR)is proposed and developed in this paper.Based on the mechanical properties of magnetorheological fluid,the relationship model of magnetic field force is obtained,and the thrust model is established.Double micro DC deceleration motor is used to drive the two ends of the helical actuator to make the DHMRFMR forward and backward,by changing the external magnetic field rotation speed,direction and distance,adjust the attitude direction of the robot.Numerical simulation software ANSYS is used to analyze the motion law of external fluid of DHMRFMR,and the visualization of fluid velocity and pressure distribution is realized.The front-end helix actuator can change the flow path of the fluid,and the middle and tail of the DHMRFMR bear less pressure,which improves the stability and flexibility of the robot.The novel DHMRFMR is suitable for internal drive in bending environment,and has a good application prospect in biomedical engineering field in human intestinal unstructured environment.
文摘This paper presents a study of a non-uniform pitch helical resonator (NPHR) structure and the coupling mechanisms to design dual-passband filters. The previous research analyzes NPHR as a type of step impedance resonator (SIR), however, it does not give analytical equations or prediction for the dual-resonance characteristics of the NPHR structure discussed in this paper. Consequently, a circuit model is proposed to analyze the dual-resonance characteristics of NPHRs. Analytical equations are derived, showing that the frequency ratio of a dual-band NPHR can be determined by the ratio of turns. EM simulation and experimental results have shown good agreement with the circuit analysis. The derived analytical equations from circuit model can be used for fast design of NPHRs. A step-width aperture is proposed to independently control the coupling coefficients at the each band of NPHRs. A third order dual-passband filter has been designed and fabricated. The filter has 3.3% and 3% fractional bandwidths at 789 MHz and 2402 MHz, respectively. The designed prototype filter shows that NPHRs can be utilized to realize compact filters with dual-band characteristics. The filter design can be extended from engineering perspective for application in wireless communication systems.
