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
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
Acoustics
Ali Ghasemi, Mohammad M. Azimi
Summary: This paper investigates the composite control of position and orientation of the quadrotor for tracking purposes. A composite adaptive fuzzy PID-Like controller is proposed to ensure the stabilization and tracking goals of the quadrotor in the presence of uncertainties and disturbances. The experimental results demonstrate that the proposed method leads to resilient stabilization and tracking compared to conventional methods.
JOURNAL OF VIBRATION AND CONTROL
(2023)
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.
Article
Computer Science, Information Systems
Tairen Sun, Long Cheng, Zengguang Hou, Min Tan
Summary: This paper introduces a tracking controller based on a sliding-mode disturbance observer (SMDOB) for a class of nonlinear systems with modeling uncertainties and external disturbances. The proposed controller guarantees semi-global asymptotic stability without the need for boundedness assumption of time derivatives of modeling uncertainties, and can be implemented with low complexity using only three parameters. Application to robot manipulators demonstrates the effectiveness of the SMDOB-based tracking control strategy.
SCIENCE CHINA-INFORMATION SCIENCES
(2021)
Article
Automation & Control Systems
Zhijia Zhao, Zhijie Liu
Summary: This paper presents a new finite-time convergence disturbance rejection control scheme for a flexible Timoshenko manipulator, utilizing three disturbance observers and boundary controllers to ensure system stability and finite-time convergence of disturbance estimation errors. Numerical simulations validate the efficacy of the scheme with appropriate parameter selection.
IEEE-CAA JOURNAL OF AUTOMATICA SINICA
(2021)
Article
Automation & Control Systems
Shifeng Huang, Jihong Chen, Jianwei Zhang, Zhihong Zhu, Huicheng Zhou, Fan Li, Xing Zhou
Summary: This article introduces an extended dynamic parameter set (EDS) and a novel parameters identification technique (RSIH). The research results show that the model based on EDS can adapt to different installation angles, and RSIH technique outperforms other commonly used identification techniques in terms of identification precision and robustness.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2022)
Article
Automation & Control Systems
Suneel Kumar Kommuri, Seungyong Han, Sangmoon Lee
Summary: This article investigates the estimation of external torque when a robot manipulator interacts with the external environment. A sliding-mode observer and a Luenberger observer are designed to effectively estimate the external torque caused by nonlinear friction and stabilize the dynamics of momenta error. Simulation and experimental results demonstrate the effectiveness of the proposed scheme.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(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
Automation & Control Systems
Guotai Zhang, Gang Shen, Yu Tang, Xiang Li
Summary: This paper proposes a practical control method for the 2-degrees of freedom position tracking problem of a robotized hydraulic-driven roadheader with high nonlinearities and strong uncertainties. The method achieves satisfactory performance against multi-source disturbances using a combination of backstepping sliding cascade control, adaptive compensator, and disturbance observers. The method does not require a precise model and ensures fast convergence and small tracking error. Based on stability analysis and experimental verification, the effectiveness and superiority of the method are confirmed.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING
(2023)
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
Mathematics, Applied
Jun Nie, Lichao Hao, Xiao Lu, Haixia Wang, Chunyang Sheng
Summary: The global fixed-time sliding mode control strategy is proposed for achieving global fixed-time trajectory tracking for manipulators in the presence of system model uncertainty, external disturbances, and actuator saturation. The strategy utilizes an adaptive fixed-time sliding mode disturbance observer to mitigate the effects of disturbances, a fixed-time sliding surface and nonsingular fixed-time sliding mode control to ensure global convergence, and a fixed time saturation compensator to counteract actuator saturation. The approach is theoretically analyzed using fixed-time stability theory and Lyapunov method and validated through simulation experiments.
Article
Automation & Control Systems
Dongyang Shang, Xiaopeng Li, Meng Yin, Fanjie Li
Summary: In this paper, a fuzzy adaptive PI control strategy containing disturbance observers (DOB) is proposed to suppress the vibration of a dual-flexible manipulator with an axially translating arm. The control strategy effectively reduces the output speed error and eliminates the influence of friction torque, thereby improving the movement accuracy of the end-effector.
INTERNATIONAL JOURNAL OF CONTROL AUTOMATION AND SYSTEMS
(2022)
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
Acoustics
Zeeshan Anjum, Hui Zhou, Saim Ahmed, Yu Guo
Summary: A new fixed-time sliding mode control approach is proposed for trajectory tracking control of robotic manipulator systems, providing fixed-time convergence, robust stabilization, and high precision. A novel fixed-time non-singular fast terminal sliding mode surface (FNFTSMS) with fixed-time convergence is introduced. An adaptive disturbance observer is used to enhance control performance and compensate for unpredictably occurring disturbances. The effectiveness and efficacy of the proposed control method are demonstrated through numerical simulations.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Review
Computer Science, Interdisciplinary Applications
Rakesh Krishnan, Niclas Bjorsell, Elena M. Gutierrez-Farewik, Christian Smith
MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING
(2019)
Article
Automation & Control Systems
Nauman Masud, Per Mattsson, Christian Smith, Magnus Isaksson
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.