Article
Automation & Control Systems
Xinjia Huang, Jiang Zou, Guoying Gu
Summary: In this article, a new variable curvature kinematic modeling approach was proposed for soft continuum robots, achieving accurate motion simulation and feedforward control. Experimental results validated the effectiveness of the model and control strategies, providing a tool for designing and analyzing soft continuum robots with desired workspace.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2021)
Article
Automation & Control Systems
Steeve Mbakop, Gilles Tagne, Sergey Drakunov, Rochdi Merzouki
Summary: Mobile soft continuum manipulator (MSCM) is widely used in various applications of everyday life. However, its shape control in unstructured environments remains a challenge. This paper proposes a kinematic-model-based shape control method for MSCM's autonomous navigation in the presence of obstacles. The shape is modeled using a parametric spatial Pythagorean hodograph (PH) curve, and the artificial potential field algorithm is used for shape adaptation. Experimental results demonstrate the advantages of using a simplified kinematic model based on PH curve for controlling the MSCM's shape in dynamic motion.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Automation & Control Systems
Yi Shen, Linan Deng, Ye Yuan, Fumin Zhang, Han Ding
Summary: This article introduces a new soft manipulator inspired by the hydrostatic skeleton of soft creatures, mimicking the bending motion of worms through a crossed-fiber arrangement and hybrid material structure that creates muscular antagonism. The proposed controller, based on a sparse Bayesian-learning kinematic model, demonstrates superior accuracy and reduced vibration compared to other controllers during experiments.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2022)
Article
Robotics
Xinjia Huang, Xiangyang Zhu, Guoying Gu
Summary: This article presents a general framework for the design, kinematic modeling, model-based characterization, and control of soft parallel robots. The developed continuum-based model accurately describes the configuration and deformation of the robot. The model is validated through experiments on the robot's workspace and stiffness, and a model-based trajectory tracking controller is established.
IEEE TRANSACTIONS ON ROBOTICS
(2022)
Article
Robotics
Elijah Almanzor, Fan Ye, Jialei Shi, Thomas George Thuruthel, Helge A. Wurdemann, Fumiya Iida
Summary: This study presents a novel image-based deep learning approach for closed-loop kinematic shape control of soft continuum robots. The method combines a local inverse kinematics formulation in the image space with deep convolutional neural networks for accurate and robust shape control. It offers an intuitive and user-friendly way to control the robot's 3-D shape and configuration through teleoperation using only 2-D hand-drawn images.
IEEE TRANSACTIONS ON ROBOTICS
(2023)
Article
Engineering, Multidisciplinary
Lu Jiajia, Du Fuxin, Li Yibin, Lei Yanqiang, Zhang Tao, Zhang Gang
Summary: This paper analyzes the inverse kinematics problem of inextensible continuum robots from a new perspective, by replacing the generatrix of the robot's workspace with the Kepler oval. The complicated inverse kinematics problem is simplified into solving the oval equations, leading to the design of an inverse kinematics algorithm. The proposed algorithm demonstrates excellent performance in accuracy and computational efficiency through validation simulations.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Robotics
Di Wu, Guowei Hou, Wenjie Qiu, Bin Xie
Summary: This study proposed a new method combining parameterization and T-IK to solve the inverse kinematics problem for redundant manipulators, showing improved global and local search abilities. Applied to an 8-DOF robot, it outperformed other algorithms on various trajectory tests, except in running time compared to MOEA/D.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2021)
Article
Engineering, Multidisciplinary
Fuxin Du, Gang Zhang, Yanjie Xu, Yanqiang Lei, Rui Song, Yibin Li
Summary: This paper proposes an efficient dexterity evaluation algorithm based on inverse kinematics (DEAIK) for continuum robots. The relationship between length distributions and dexterity distribution is obtained through simulation experiments, and the length distribution of a two-segment continuum robot is optimized using the fruit fly algorithm. Theoretical analysis and numerical simulations show that the dexterity of the structure-optimized continuum robot is better than that of the traditional continuum robot. The DEAIK algorithm is 3.68 times faster than the algorithm based on forward kinematics, and the IK algorithm in this paper is 3,203 times faster than the IK algorithm based on the Levenberg-Marquardt algorithm in the same accuracy.
Article
Robotics
Federico Renda, Costanza Armanini, Anup Mathew, Frederic Boyer
Summary: The inverse kinematic control of soft robots is an open challenge, and we propose a geometrically-exact approach for soft manipulators with threadlike actuators' routing, demonstrating its feasibility in simulation.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2022)
Article
Computer Science, Information Systems
Mrunal Kanti Mishra, Arun Kumar Samantaray, Goutam Chakraborty
Summary: This article proposes a real-time kinematic trajectory control method for pneumatically actuated multi-segment bionic continuum manipulators. The method combines a neural network and analytical model with a cascaded controller to overcome the challenges in controlling these manipulators. The proposed procedure is validated on a two-segment continuum manipulator and shown to reduce the manipulator tip trajectory error compared to existing methods.
Article
Automation & Control Systems
Guoxin Fang, Yingjun Tian, Zhi-Xin Yang, Jo M. P. Geraedts, Charlie C. L. Wang
Summary: This article presents an efficient learning method to solve the highly nonlinear inverse kinematic problem of soft robots. By using neural networks to learn the mapping function and Jacobian matrix of the forward kinematics, the IK problem can be solved through Jacobian-based iteration. A sim-to-real training transfer strategy is employed to make this approach more practical.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2022)
Article
Robotics
Amirhossein Kazemipour, Maram Khatib, Khaled Al Khudir, Claudio Gaz, Alessandro De Luca
Summary: We present a generalized algorithm for task control of redundant robots that handles hard constraints in both joint and Cartesian space. The algorithm treats these constraints equally and allows for online variations. Simulation and experimental results demonstrate the effectiveness of the approach.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2022)
Article
Robotics
Georg Boettcher, Sven Lilge, Jessica Burgner-Kahrs
Summary: A novel spatial parallel continuum robot composed of three tendon-actuated continuum robots coupled at a common end-effector platform by spherical joints is proposed. The robot utilizes a modular design approach to allow reconfiguration for specific constraints and environments. Experimental results show improved repeatability in position and orientation for the parallel continuum robot, with increases of 67% and 167% compared to individual continuum segments.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2021)
Article
Automation & Control Systems
Qingxiang Zhao, Jiewen Lai, Kaicheng Huang, Xiaobing Hu, Henry K. Chu
Summary: This article presents the development of a soft robotic system with embedded sensors to reconstruct the shape of the robot under various external disturbances. A shape reconstruction method and a local inverse kinematics model are proposed to effectively control the robot.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2022)
Article
Automation & Control Systems
Qingxiang Zhao, Jiewen Lai, Kaicheng Huang, Xiaobing Hu, Henry K. Chu
Summary: This article introduces a soft robotic system with embedded sensors to reconstruct the shape of the robot under external disturbances. A control system based on strain gauges and Neural Networks was developed to accurately control the robot with or without external payloads. Simulation and experiments confirmed the effectiveness of the proposed control system.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2022)
Article
Automation & Control Systems
Bohao Zhu, James Lam, Xiaoqi Song, Hong Lin, Jason Ying Kuen Chan, Ka-Wai Kwok
Summary: This paper focuses on the stability analysis and stabilization of periodic piecewise positive systems. A time-scheduled copositive Lyapunov function is constructed to establish an equivalent stability condition for periodic piecewise positive systems. The spectral radius characterization of the state transition matrix is proposed based on the asymptotic stability condition, and the relation between the spectral radius and the convergent rate of the system is revealed. An iterative algorithm is developed to stabilize the system by reducing the spectral radius of the state transition matrix. Numerical examples are provided to illustrate the results.
ASIAN JOURNAL OF CONTROL
(2023)
Article
Engineering, Multidisciplinary
Jiaren Xiao, Quanyu Dai, Xiaochen Xie, Qi Dou, Ka-Wai Kwok, James Lam
Summary: In this study, we propose a domain adaptive graph infomax method that computes node representations through neighborhood aggregation and maximizes mutual information between node representations and global summaries to encode global structural information. Conditional adversarial networks are used to reduce the domain discrepancy by aligning the multimodal distributions of node representations. Experimental results on real-world datasets validate the performance of our method in comparison with state-of-the-art baselines.
IEEE TRANSACTIONS ON NETWORK SCIENCE AND ENGINEERING
(2023)
Article
Robotics
Xiaomei Wang, Jing Dai, Hon-Sing Tong, Kui Wang, Ge Fang, Xiaochen Xie, Yun-Hui Liu, Kwok Wai Samuel Au, Ka-Wai Kwok
Summary: Image processing enhances the practical value of the eye-in-hand camera for quantitative measurement. This article proposes a fusion of visual information and sparse strain data collected from fiber Bragg gratings to improve continuum robot pose estimation. The integration of the proposed F-emp pose estimation method reduces sensing limitations caused by visual obstacles and lighting variations. A hybrid controller combining kinematics and data-driven algorithms achieves fast convergence and high accuracy using the fused pose feedback. The online-learning error compensator significantly improves target tracking performance.
IEEE TRANSACTIONS ON ROBOTICS
(2023)
Article
Computer Science, Artificial Intelligence
Jiaren Xiao, Quanyu Dai, Xiaochen Xie, James Lam, Ka-Wai Kwok
Summary: The high cost of data labeling results in node label shortage. To address this, a graph-based semi-supervised learning method is proposed, which leverages unlabeled nodes to train together with scarce labeled nodes. An attention-based aggregator is designed to generate node representations by aggregating information from neighboring nodes, and adversarial training is employed to improve robustness and generalization.
KNOWLEDGE-BASED SYSTEMS
(2023)
Article
Robotics
Yanzhou Wang, Ka-Wai Kwok, Kevin Cleary, Russell H. Taylor, Iulian Iordachita
Summary: In this study, an in situ needle manipulation technique used for spinal injections is modeled and its effect on needle shape and position is studied. A mechanics-based model is proposed and solved using finite element method. A test setup is presented to mimic the needle manipulation motion. Tissue phantoms made from plastisol and porcine skeletal muscle samples are used to evaluate the model accuracy. The effect of different compression models and model parameters on accuracy is studied, and the impact of needle-tissue interaction on the needle remote center of motion is examined. With the correct combination of compression model and parameters, the model simulation can predict needle tip position with submillimeter accuracy.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2023)
Article
Mathematics, Applied
Jason J. R. Liu, James Lam, Xiaomei Wang, Ka-Wai Kwok
Summary: This paper addresses the challenging problem of designing proportional-derivative (PD) controllers for positive linear systems in the discrete-time domain. The specific focus is on designing a PD controller for a system with constant time delay that ensures both closed-loop stability and positivity preservation. The synthesis process considers the additive gain variation of the controller. The paper presents systematic formulation and tractable algorithms for finding the PD controller gains for positive stabilization, and validates the performance through numerical examples. (c) 2023 Elsevier Inc. All rights reserved.
APPLIED MATHEMATICS AND COMPUTATION
(2023)
Article
Robotics
Kui Wang, Xiaomei Wang, Justin Di-Lang Ho, Ge Fang, Bohao Zhu, Rongying Xie, Yun-Hui Liu, Kwok Wai Samuel Au, Jason Ying-Kuen Chan, Ka-Wai Kwok
Summary: This article presents a simple, compact two-segment soft robot for flexible laser ablation, capable of omnidirectional bending and precise, fast steering of laser collimator. The proposed soft robot modeling and control scheme based on Koopman operators is validated through experiments, demonstrating its accuracy in laser path following across various contours/patterns.
IEEE TRANSACTIONS ON ROBOTICS
(2023)
Article
Computer Science, Artificial Intelligence
Jason J. R. Liu, James Lam, Ka-Wai Kwok
Summary: This article investigates the positive consensus problem of a special kind of interconnected positive systems over directed graphs. Based on the results in spectral graph theory, fractional-order systems (FOSs) theory, and positive systems theory, several necessary and/or sufficient conditions on the positive consensus of fractional-order multiagent systems (PCFMAS) are derived. A comprehensive comparison study shows that the proposed approaches have advantages over the existing ones.
IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS
(2023)
Article
Automation & Control Systems
Bohao Zhu, James Lam, Xiujuan Lu, Ka-Wai Kwok
Summary: This letter investigates stability issues related to linear discrete-time cone-preserving systems with time-varying delays. The study examines the monotonicity of discrete-time systems with cone invariance and provides equivalent asymptotic stability conditions for discrete-time cone-preserving systems with time-varying delays based on the monotonicity of cone-preserving systems and the comparison principle. The results indicate that time delays do not affect asymptotic stability and also analyze the alpha-exponential stability to characterize the decay rate of the system. A numerical example is presented to illustrate the theoretical findings. These results contribute to the understanding of stability analysis of cone-preserving systems with time-varying delays.
IEEE CONTROL SYSTEMS LETTERS
(2023)
Article
Automation & Control Systems
Yifeng Hao, Xiaomei Wang, Xiaoqi Song, Yingqi Li, Henry Fu, Alex Pui-Wai Lee, Kenneth Man-Chee Cheung, James Lam, Ka-Wai Kwok
Summary: Compact, low-inertia, and soft compliant robotic joint mechanisms are needed for safe interactions in human-robot collaborative tasks. Tensegrity joint, constrained by tension, provides mechanical stability without static/sliding friction. However, it is susceptible to actuation errors and requires complex kinematics modeling and sophisticated control. A low-inertia tensegrity joint covered with a FBG-embedded silicone sheath is proposed to enhance joint motion stability and enable self-contained sensing feedback.
ADVANCED INTELLIGENT SYSTEMS
(2023)
Article
Automation & Control Systems
Chi-Hin Mak, Yingqi Li, Kui Wang, Mengjie Wu, Justin Di-Lang Ho, Qi Dou, Kam-Yim Sze, Kaspar Althoefer, Ka-Wai Kwok
Summary: Optical waveguides offer flexible, quick, and compact options for soft sensing and electronic skins. By measuring and converting light intensities inside the waveguide, useful feedback such as strain or shape sensing can be obtained. Compared to other methods, optical waveguides offer greater scalability with fewer sensing nodes and less wiring.
ADVANCED INTELLIGENT SYSTEMS
(2023)
Proceedings Paper
Medicine, Research & Experimental
Yanzhou Wang, Yangsheng Xu, Ka-Wai Kwok, Iulian Iordachita
Summary: This paper investigates the possibility of using robotic manipulations to correct the needle tip position in robot-assisted, MRI-guided spinal injections, where real time MRI images cannot be effectively used to guide the needle. The open-loop control of the needle tip is derived from finite element simulation, and the proposed method is tested with ex vivo animal muscle tissues and validated using cone beam computed tomography. Preliminary results show promise for in situ needle tip correction to improve needle insertion accuracy when real-time feedback is not readily available.
2023 INTERNATIONAL SYMPOSIUM ON MEDICAL ROBOTICS, ISMR
(2023)
Article
Automation & Control Systems
Jing Dai, Xiaomei Wang, Yingqi Li, Zhiyu Liu, Yui-Lun Ng, Jiaren Xiao, Joe King Man Fan, James Lam, Qi Dou, Varut Vardhanabhuti, Ka-Wai Kwok
Summary: In this study, a coarse mask-guided deep domain adaptation network (CMD(2)A-Net) is proposed for automated prostate lesion detection and classification. The experiments demonstrate that CMD(2)A-Net performs well on multiple datasets and achieves better results in benign and malignant lesion classification compared to existing models.
ADVANCED INTELLIGENT SYSTEMS
(2023)
Article
Computer Science, Artificial Intelligence
Jason J. R. Liu, Ka-Wai Kwok, James Lam
Summary: In this paper, we study the decentralized H2 state-feedback control problem for networked discrete-time systems with positivity constraint. We propose necessary and sufficient synthesis conditions for networked positive systems, unlike most previous works that only provide sufficient conditions for a single positive system. We develop a primal-dual iterative algorithm based on these conditions to solve the problem and avoid converging to a local minimum. Two illustrative examples are used to verify our proposed results.
IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS
(2023)
