Article
Computer Science, Information Systems
Bayandy Sarsembayev, Kanat Suleimenov, Ton Duc Do
Summary: This paper presents a disturbance observer-based control system design, using high order disturbance observer control to improve the speed tracking performance of PMSM drives. Experimental results validate the feasibility of the proposed control scheme in real-time scenarios.
Review
Engineering, Mechanical
Tong Li, Qingguo Li
Summary: This paper systematically reviews state-of-the-art robotic load carriage assistive devices, analyzing their mechanisms and performances. The efficacy of different designs and strategies is discussed from engineering and biomechanical perspectives, and challenges and insights for future studies are provided.
MECHANISM AND MACHINE THEORY
(2023)
Article
Automation & Control Systems
Yu Wang, Haoping Wang, Yang Tian
Summary: This article proposes a nonlinear disturbance observer based flexible-boundary prescribed performance controller (NDOPPC) for lower limb exoskeletons to achieve exceptional transient and steady-state tracking performance. The NDOPPC utilizes a nonlinear disturbance observer (NDO) to estimate and compensate for disturbances, and ensures trajectory tracking performance by constraining tracking errors within preset boundaries. The proposed NDOPPC, designed based on backstepping and stability analysis with Lyapunov theorem, demonstrates effectiveness and superiority compared to other controllers in comparative simulations.
INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE
(2021)
Article
Automation & Control Systems
Mohammad Mahdi Share Pasand, Ali Akbar Ahmadi
Summary: This paper investigates the performance of cubic observers in state estimation of linear systems. The proposed observer yields a smaller estimation error norm compared to a linear one. It is shown that cubic observers can be designed to perform similar to linear observers in the presence of disturbances and delays.
Article
Chemistry, Analytical
Zhipeng Wang, Chifu Yang, Zhen Ding, Tao Yang, Hao Guo, Feng Jiang, Bowen Tian
Summary: The advantages of Bowden cable-based exoskeletons lie in their lightweight and flexible nature, making them convenient for human assistance. However, their performance is restricted by the exoskeleton's structure and human-exoskeleton interaction. In this study, control methods including disturbance observer, human-exoskeleton interaction feedforward model, and angle prediction using encoder are proposed to compensate for disturbances and limitations, thus improving the accuracy of assistance.
Article
Engineering, Mechanical
Lin Liu, Steffen Leonhardt, Lukas Bergmann, Berno J. E. Misgeld
Summary: This paper presents an integration of reducing the output impedance and the vibration at the trajectory tracking into one variable stiffness actuator (VSA) system. The VSA operates within the cascade impedance control framework with the unknown input observer (UIO) in the inner torque control loop. By utilizing gain-scheduled UIO and the low and high physical stiffness of VSA, the paper achieves low-output impedance and steady trajectory tracking.
MECHANISM AND MACHINE THEORY
(2023)
Article
Automation & Control Systems
B. Adhira, G. Nagamani, G. Soundararajan
Summary: This paper addresses the problem of exponentially extended dissipative criteria for a class of delayed discrete-time neural networks (DNNs) with resilient observer-based controller design. By designing a memoryless full-order Luenberger state observer and resilient control, the exponentially extended dissipative criterion is obtained and the observer and resilient control gain matrices are determined by solving a set of linear matrix inequalities (LMIs).
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS
(2022)
Article
Automation & Control Systems
Yu Wang, Haoping Wang, Yang Tian
Summary: In this paper, an adaptive interaction torque-based assist-as-needed (AITAAN) control method for lower limb rehabilitation exoskeleton is proposed. The effectiveness and superiority of the AITAAN controller were verified through co-simulations by evaluating muscle torque using a nonlinear disturbance observer and achieving trajectory tracking using a flexible boundary prescribed performance controller.
Article
Energy & Fuels
Yanping Xu, Zhongqiao Yan, Yanping Zhang, Ruochen Song
Summary: This paper proposes a model predictive current control strategy based on sliding mode observer, which has better tracking ability for current and speed under disturbance. The effect of motor parameter mismatches on current predicted values is analyzed, and a sliding mode disturbance observer is designed to compensate for parameter mismatches and unmodeled dynamic disturbances. The speed loop PI controller is replaced by a deadbeat predictive controller, and a sliding mode load torque observer is constructed to improve the anti-load disturbance performance. Furthermore, a sliding mode reaching law based on sinusoidal saturation function is proposed to suppress chattering of sliding mode observer. Experimental results demonstrate that the proposed strategy achieves faster dynamic response and good tracking performance under disturbance.
IEEE TRANSACTIONS ON ENERGY CONVERSION
(2023)
Article
Automation & Control Systems
Prashant Kumar, Devara Vijaya Bhaskar, Utkal Ranjan Muduli, Abdul R. Beig, Ranjan Kumar Behera
Summary: This article investigates the modeling and control strategy of permanent magnet brushless direct current motor (PMBLDCM) considering iron loss. A disturbance observer based sensorless scheme is proposed, and a linear feedback control law is introduced to reduce copper loss. Model predictive control technique is used to select optimum switching vector, resulting in improved performance.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Automation & Control Systems
Kenan Yong, Mou Chen, Yang Shi, Qingxian Wu
Summary: This article investigates the tracking control problem for uncertain nonlinear systems with strong external disturbances and prescribed performance. A flexible performance-based control scheme is proposed, which introduces an external disturbance criterion and synthesizes a disturbance interval observer to ensure the prescribed performance.
IEEE TRANSACTIONS ON CYBERNETICS
(2022)
Article
Engineering, Biomedical
Mojtaba Rayati, Rezvan Nasiri, Majid Nili Ahmadabadi
Summary: By considering reflex excitation as a nonvoluntary mechanism, we improved the existing model for force distribution over the muscles. The improved model can explain the large difference between biological torque and experimentally optimized assistive torque profiles. We propose that reflexive excitation's nonvoluntary nature highly restricts biological torque compensation. Our improved model also has the potential to characterize co-activation behavior in antagonistic muscles.
IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING
(2023)
Article
Automation & Control Systems
Haichao Zhang, Zhaoyue Chen, Bing Xiao, Bo Li
Summary: This paper investigates the attitude tracking control problem of rigid spacecraft under external disturbance and prescribed performance constraints. Firstly, a fast fixed-time stability theorem is developed. Then, a continuous disturbance observer is designed to drive the estimation error into a small neighborhood containing zero within a fixed time. Moreover, the spacecraft's attitude tracking error is transformed into unconstrained dynamics. A disturbance observer-based prescribed performance tracking controller is designed to stabilize the unconstrained dynamics within a fixed time, ensuring that the attitude tracking errors meet the prescribed performance. Simulation examples of spacecraft are presented to validate the effectiveness of the proposed controller.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2023)
Article
Engineering, Multidisciplinary
Dongyang Shang, Xiaopeng Li, Meng Yin, Fanjie Li
Summary: In this study, an adaptive PI control strategy with a disturbance observer (DOB) was used to suppress the vibration of a manipulator by weakening angular velocity fluctuations. The dynamics equations of the manipulator servo system with bearing friction were established and a low-pass filter in the DOB was designed for robust stability. Experimental results showed that the adaptive control strategy effectively reduced angular velocity errors under varying conditions of the manipulator's telescopic arm.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Automation & Control Systems
Kyeong-Won Park, Jungsu Choi, Kyoungchul Kong
Summary: Lower-limb exoskeletons are promising applications of robotic rehabilitation. This study proposes a hybrid control method with a disturbance observer for robust robotic rehabilitation. Experimental results demonstrate the effectiveness of the proposed method on a practical user with motor impairment.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Automation & Control Systems
Nauman Masud, Christian Smith, Magnus Isaksson
Review
Computer Science, Interdisciplinary Applications
Rakesh Krishnan, Niclas Bjorsell, Elena M. Gutierrez-Farewik, Christian Smith
MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING
(2019)
Article
Chemistry, Analytical
Binbin Su, Christian Smith, Elena Gutierrez Farewik
Article
Automation & Control Systems
Nauman Masud, Dario Senkic, Christian Smith, Magnus Isaksson
Summary: This paper proposes a novel control strategy for low degree of freedom exoskeletons, combining passive arm-supports with active compliance to achieve safer and improved human-robotic interaction. Additionally, a four-degree of freedom exoskeleton test-rig design is presented. Simulation and experimentation show that the proposed strategy enhances physical human-robotic interaction for exoskeletons using limited-power actuators, with the disturbance observer-based dynamic load-torque compensator outperforming traditional compensators.
Article
Computer Science, Artificial Intelligence
Longbin Zhang, Yixing Liu, Ruoli Wang, Christian Smith, Elena M. Gutierrez-Farewik
Summary: This study presents a realistic human knee exoskeleton model based on a physical system and its application in musculoskeletal modeling software. Different assistive strategies applied during simulated gaits have varying effects on the user's physiological burden, highlighting the importance of considering joint direction and interaction forces when designing controllers for physical exoskeleton systems.
FRONTIERS IN NEUROROBOTICS
(2021)
Article
Automation & Control Systems
Longbin Zhang, Zhijun Li, Yingbai Hu, Christian Smith, Elena M. Gutierrez Farewik, Ruoli Wang
Summary: This article compared the performance of predicting ankle joint torques using EMG-driven neuromusculoskeletal (NMS) model and artificial neural network (ANN) model, finding that the NMS model generally outperformed the ANN model in predicting ankle joint torques with some exceptions. The study highlighted the importance of detailed comparative analysis in determining the most suitable model for exoskeleton control strategies.
IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING
(2021)
Proceedings Paper
Automation & Control Systems
Matteo Iovino, Jonathan Styrud, Pietro Falco, Christian Smith
Summary: The study proposes a method using genetic programming to learn the structure of a behavior tree for solving robotic tasks in unpredictable environments. After learning with a simple simulator, it is demonstrated that the learned behavior trees can solve the same tasks in a realistic simulator.
2021 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA 2021)
(2021)
Article
Computer Science, Information Systems
Yi-Xing Liu, Longbin Zhang, Ruoli Wang, Christian Smith, Elena M. Gutierrez-Farewik
Summary: The study focused on how weight distributions of knee exoskeleton components affect muscle activities, showing that different weight distributions lead to varied muscle activities. The design of exoskeletons should ideally take into consideration the user's activity goals and abilities, as there is no one-size-fits-all design for all movements.
Proceedings Paper
Computer Science, Artificial Intelligence
Silvia Cruciani, Kaiyu Hang, Christian Smith, Danica Kragic
2019 IEEE-RAS 19TH INTERNATIONAL CONFERENCE ON HUMANOID ROBOTS (HUMANOIDS)
(2019)
Proceedings Paper
Computer Science, Artificial Intelligence
Silvia Cruciani, Christian Smith, Danica Kragic, Kaiyu Hang
2018 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS)
(2018)
Proceedings Paper
Computer Science, Artificial Intelligence
Silvia Cruciani, Christian Smith
2018 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS)
(2018)
Proceedings Paper
Robotics
Rakesh Krishnan, Silvia Cruciani, Elena Gutierrez-Farewik, Niclas Bjorsell, Christian Smith
2018 IEEE-RAS 18TH INTERNATIONAL CONFERENCE ON HUMANOID ROBOTS (HUMANOIDS)
(2018)
Article
Automation & Control Systems
Ran Jiao, Wenjie Liu, Ramy Rashad, Jianfeng Li, Mingjie Dong, Stefano Stramigioli
Summary: A novel end-effector bilateral rehabilitation robotic system (EBReRS) is developed for upper limb rehabilitation of patients with hemiplegia, providing simulations of multiple bimanual coordinated training modes, showing potential for application in home rehabilitation.
Article
Automation & Control Systems
Qiaosheng Pan, Yifang Zhang, Xiaozhu Chen, Quan Wang, Qiangxian Huang
Summary: A resonant piezoelectric rotary motor using parallel moving gears mechanism has been proposed and tested, showing high power output and efficiency.
