Cao Yanfei 曹燕飞

Done by Y. Cao, M. Cai, B. Sun, Z. Qi, J. Xue, Y. Jiang, B. Hao, J. Zhu, X. Liu, C. Yang, L. Zhang*.

@ MAE, CUHK, Hong Kong, 2023-2024

Magnetic continuum robots (MCRs) have become popular owing to their inherent advantages of easy miniaturization without requiring complicated transmission structures. The evolution of MCRs, from initial designs with one embedded magnet to current designs with specific magnetization profile configurations (MPCs), has significantly enhanced their dexterity. While much progress has been achieved, the quantitative indexbased evaluation of deformability for different MPCs, which can assist in designing MPCs with enhanced robot deformability, has not been addressed before. Here we use "deformability" to describe the capability for body deflection when an MCR forms different global shapes under an external magnetic field. Therefore, in this paper, we propose methodologies to design and control an MCR composed of modular axially magnetized segments. To guide robot MPC design, for the first time, we introduce a quantitative index-based evaluation strategy to analyze and optimize robot deformability. Additionally, a control framework with neural network-based controllers is developed to endow the robot with two control modes: the robot tip position and orientation (M₁) and the global shape (M₂). The excellent performance of the learnt controllers in terms of computation time and accuracy was validated via both simulation and experimental platforms. In the experimental results, the best closed-loop control performance metrics, indicated as the mean absolute errors, were 0.254 mm and 0.626&deg for mode M₁ and 1.564 mm and 0.086&deg for mode M₂.

This work has been published online in IEEE Transactions on Robotics. LINK(🔥Highlighted in 机器人大讲堂)

Done by Y. Cao, Z. Yang, B. Hao, X. Wang, M. Cai, Z. Qi, B. Sun, Q. Wang, L. Zhang*.

@ MAE, CUHK, Hong Kong, 2022-2023

Magnetic continuum robots (MCRs), which are free of complicated structural designs for transmission, can be miniaturized and are therefore widely used in the medical field. However, the deformation shapes of different segments, including deflection directions and curvatures, are difficult to control simultaneously under an external programmable magnetic field. This is because the latest MCRs have designs with an invariable magnetic moment combination or profile of one or more actuating units. Therefore, the limited dexterity of the deformation shape causes the existing MCRs to collide readily with their surroundings or makes them unable to approach difficult-to-reach regions. These prolonged collisions are unnecessary or even hazardous, especially for catheters or similar medical devices. In this study, a novel magnetic moment intraoperatively programmable continuum robot (MMPCR) is introduced. By applying the proposed magnetic moment programming method, the MMPCR can deform under three modalities, that is, J, C, and S shapes. Additionally, the deflection directions and curvatures of different segments in the MMPCR can be modulated as desired. Furthermore, the magnetic moment programming and MMPCR kinematics are modeled, numerically simulated, and experimentally validated. The experimental results exhibit a mean deflection angle error of 3.3&deg and correspond well with simulation results. Comparisons between navigation capacities of the MMPCR and MCR demonstrate that the MMPCR has a higher capacity for dexterous deformation.

This work has been published online in Soft Robotics. LINK

Done by Y. Cao, F. Ju, L. Zhang, D. Bai, F. Qi, B. Chen*.

@ CMEE, NUAA, Nanjing, 2018-2020

First Design

This article presents a novel variable-stiffness flexible manipulator for minimally invasive surgery. Each module of the proposed manipulator contains a variable-stiffness mechanism actuated by proactive deformation of shape memory alloy. Due to low driving current, apparent mechanical deformation, suitable phase transformation temperature and biocompatibility of shape memory alloy wire actuation, it is well suited for the manipulator applied in minimally invasive surgery, where variable stiffness is urgently required. In this article, the conceptual design, elastic modulus model, thermo-electric model, stiffness controlling method and finite element method simulation for a single module of the proposed variable-stiffness flexible manipulator are presented. Moreover, the memory shape setting experiment of shape memory alloy wire and fabrication of the single module are carried out. Finally, stiffness characterizations of the mechanism and the single module are studied separately, theoretically and experimentally.

This work has been published in Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine. LINK

Further Design

Due to its unique dexterity and safety, continuum manipulators have been widely used in small constrained environment. However, its flexibility also brings negative effects such as poor stiffness and low strength. This paper presents a novel variable-stiffness sheath for continuum manipulators applied in minimally invasive surgery. We present a variable-stiffness sheath based on shape memory alloy (SMA) for each module of the continuum manipulators. The stiffness of the sheath can be continuously adjusted depending on the voltage between both ends of the sheath, along with the phase transformation of SMA between austenite and martensite. The experimental results demonstrate that the stiffness of the sheath and single module are able to increase up to 223.1% and 139.2%, separately, which verify the correctness of the proposed variable stiffness method. The robot integrated with the variable-stiffness sheath is demonstrated to possess a fine capacity of variable stiffness.

The work was presented at 2018 International Academic Conference for Graduates, NUAA (IACGN, 2018), and was honored with Best Paper Award in 2018 IACGN. LINK1 Subsequently, it was further improved and finally published in the International Journal of Medical Robotics and Computer Assisted Surgery. LINK2

Software Engineer

@ Department of Information and Communication Technology, HUAWEI, Nanjing, 2019-2021

I joined HUAWEI as a software engineer when I achieved the M. Sc. degree in NUAA. The team I served for supports a bunch series of HUAWEI's core products, like high-end communication devices named "NetEngine 8000 Series Routers" and stuff. I was mainly in charge of module development and maintenance of FMEA, related to periodically monitoring hardware failure and reporting alarms during equipment running. This assured the stability and reliability of equipments without impairing performance.

Over the two years or so, I have delivered 15+ product iterations on developing new software requirements, during which I served as iteration owner. Meanwhile, I solved 500+ defect tracking sheets (DTS) and was honored with Gold Network Award for 3 times.