Vol. 21, No. 12, December 2023
Sameer Pokhrel and Sameh A. Eisa*International Journal of Control, Automation, and Systems 2023; 21(12): 3839-3849
Abstract : Extremum seeking control (ESC) is an adaptive control technique, introduced nearly a century ago, to drive a dynamic system to the extremum of an objective function that may not be known expression-wise. A rigorous stability analysis of the so-called classical ESC structure, using averaging and singular perturbation theory, has increased research topics and applications involving ESC. Another class of ESCs, control-affine in nature and analyzed using Lie bracket system-based approaches, has emerged, but with some limited theoretical advancements compared to classical ESC. Gradient estimation tools are not well-established for such control-affine ESC structures. Also, stability analysis can be challenging due to complex bounds and conditions. So, in this paper, we introduce a geometric-based extended Kalman filter (GEKF) for gradient and Lie bracket estimation in control-affine ESC systems. We also propose a time-dependent stability condition for control-affine ESC based on the Lie bracket system’s evolution with time. This enables real-time stability tracking. The potential and advantage of our results are demonstrated through numerical simulations of two ESC cases in the literature, including a multi-agent problem.
Zhongzheng Liu, Zhen Liu*, Baoping Jiang, and Cunchen GaoInternational Journal of Control, Automation, and Systems 2023; 21(12): 3850-3859
Abstract : In this paper, an innovative sliding mode framework is used to propose an observer-based adaptive control scheme for uncertain switched systems with unknown time-varying delay. First, a state observer with no input information is built incorporating a new sliding manifold (SM) to rebuild the unmeasured state variables, which does not rely on accurate information of the time-delay. By picking a suitable Lyapunov function, using the average dwell time (ADT) approach and linear matrix inequality (LMI) tool, a novel stability criterion for the resultant sliding motion is devised. In addition, to meet the defined SM’s arrival condition, a new adaptive variable structure controller is constructed. Finally, two illustrative examples are given to demonstrate the efficacy of the control method.
Le Liu*, Xin Wang, Yueheng Sun, and Yiming FangInternational Journal of Control, Automation, and Systems 2023; 21(12): 3860-3871
Abstract : To improve the performance of a class of nonlinear system with actuator fault and external disturbance, a fault-tolerant control method with finite-time prescribed performance is proposed based on the super-twisting disturbance observer in this paper. First, the actuator bias fault and external disturbance of the system are regarded as a lumped disturbance, and it is estimated by the designed super-twisting disturbance observer in finite time. Second, a finite-time prescribed performance fault-tolerant controller under full state constraints is designed by combining the backstepping method, the modified barrier Lyapunov function (MBLF) method and the improved prescribed performance function (IPPF) method. Moreover, the “explosion of complexity” problem in the controller design is solved by the command filters with error compensation. Theoretical analysis shows that the closed-loop system can converge to the neighborhood near the equilibrium point in finite time, and all states are always within the constraint boundaries. Finally, the effectiveness and feasibility of the proposed method are verified by the comparisons of simulations and experiments based on a permanent magnet synchronous motor (PMSM) position system.
Jiawen Li, Yi Zhang*, Yingying Nie, and Song YangInternational Journal of Control, Automation, and Systems 2023; 21(12): 3872-3882
Abstract : This paper studies the adaptive fault-tolerant control problem for biological systems with the invasion of alien species. Firstly, to overcome the difficulty of dealing with nonlinear terms in the system, the T-S fuzzy method is applied to obtain the T-S fuzzy biological systems. Then, an augmented matrix is developed for the T-S fuzzy system, and a sliding mode observer is constructed to estimate the state vector, sensor faults, sensor failure and external disturbances. In addition, an observer-based adaptive sliding-mode control law is designed to ensure the stability of the closed-loop biological system. Finally, a simulation example is presented to illustrate the effectiveness of the proposed method.
Zhaoping Du*, Zhilin Zou, Hui Ye, and Jianzhen LiInternational Journal of Control, Automation, and Systems 2023; 21(12): 3883-3895
Abstract : In this paper, the problems of modeling and sliding mode control for a class of nonlinear discrete networked cascade control systems (NCCSs) are studied. Firstly, a class of discrete networked cascade control systems with nonlinear disturbance is considered, the sliding mode control is introduced and the model of the system is established. Based on this model and the Lyapunov functional method, the state feedback primary controller and the sliding mode secondary controller for this system are co-designed. Finally, an example of a thermal power plant is given to illustrate the effectiveness of the proposed co-design method. The main advantages are that the sliding mode control is introduced into cascade control system (CCS) and the design method of sliding mode controller for this system is proposed for the first time. On the premise of ensuring the stability of the system, it can be driven to the sliding mode surface in a limited time, and remain on the sliding mode surface in all subsequent times. The method can achieve better results and be applied to the corresponding industrial system with networked cascade control structure.
Hongfei Zhu, Jinhai Liu*, Shuo Zhang, Zhigang Zhang, and Fuming QuInternational Journal of Control, Automation, and Systems 2023; 21(12): 3896-3908
Abstract : This paper develops a novel framework with hybrid-driven waiting mechanism (HDWM) of consensus control for multi-agent systems (MASs) in the presence of communication delays and denial-of-service (DoS) attacks. Different from the existing waiting mechanism, the proposed HDWM not only involves the event-driven mechanism, but also involves the time-driven mechanism. If DoS attacks causes partial information to be lost, the information in the buffer can still be transmitted to the controller to update the states of agent via the time-driven mechanism. Meanwhile, the communication delays and DoS attacks are considered in the proposed sampled-databased resilient controller. Under the proposed HDWM and resilient controller, the MASs can achieve consensus. Finally, the simulation example is conducted to verify the effectiveness of the proposed method.
Chathura Wanigasekara*, Liruo Zhang, Frank Sill Torres, and Akshya SwainInternational Journal of Control, Automation, and Systems 2023; 21(12): 3909-3921
Abstract : This paper proposes a H∞ consensus controller for linear multi-agent systems (MASs) with N number of agents using a sampled-data based event-triggered mechanism. This mechanism allows the event-trigger condition to be intermittently examined at constant sampling instances. The proposed controller utilises the state information from neighbouring agents. The sufficient conditions of stability of the multi-agent system and the conditions for the H∞ performance are derived using the Lyapunov approach. The performance of the proposed control strategy is illustrated via simulations using an example of maritime container terminal operation under stress. The obtained simulation results demonstrate the capability of the proposed H∞ sampled-data based event-triggered consensus controller to assure safe execution considering the operational limits of the modelled system.
Xiao-Feng Zhao, Tao Han*, Bo Xiao, Xi-Sheng Zhan, and Huaicheng YanInternational Journal of Control, Automation, and Systems 2023; 21(12): 3922-3931
Abstract : This paper investigates the finite-time and fixed-time bipartite consensus tracking (Fin- and Fix-TBCT) problems for second-order multi-agent systems (MASs) under a signed directed communication network, in which both cooperative and competition exist. To achieve bipartite consensus tracking (BCT) within finite time and fixed time, two novel distributed control protocols utilizing integral sliding-mode control concept are presented and discussed, respectively. By virtue of Lyapunov stability and homogeneity with dilation, several sufficient conditions for achieving Fin- and Fix-TBCT for second-order MASs are obtained. Eventually, numerical simulation results are provided to verify the validity of the obtained theoretical results.
Jung-Min Yang and Seong Woo Kwak*International Journal of Control, Automation, and Systems 2023; 21(12): 3932-3944
Abstract : This article studies an attack mitigation strategy for the corrective control system of input/state asynchronous sequential machines (ASMs). The corrective controller suffers from an attacker invoking false data injection attacks, as the result of which not only the controller but also the controlled machine undergoes unauthorized state transitions. To overcome such attacks, we propose self-repairing transitions and additional controller components to make the closed-loop system exhibit desired input/state behaviors as well as resilience against the adverse effect of the attack on the controller. The stable reachability of the controlled ASM required to design a proper corrective controller is derived. Hardware experiments on field-programmable gate array (FPGA) on a space-borne digital system are provided to demonstrate the applicability of the proposed methodology.
Arthit Hongsri, WajareeWeera, Prem Junsawang, and Thongchai Botmart*International Journal of Control, Automation, and Systems 2023; 21(12): 3945-3956
Abstract : This article focuses on the stability problem of sampled-data systems, which is addressed using a new integral inequality. A method for systematic analysis is presented, then applied to the electric power market. The sampling point from tk to tk+1 assume to be a sampling interval but bounded. In addition, we develop a novel closed-loop Lyapunov functional that considers intervals from the sampling point t to tk and from t to tk+1. This new functional is utilized to derive a stability criterion that is less conservative than previous works based on novel integral inequalities for sampled-data systems. Numerical examples are proposed to demonstrate the efficacy and decreased conservatism of the suggested approach. Additionally, the method addresses the stability issue in electric power markets and explores the importance of reducing conservatism.
Xin Dai*, Xingxing Hua, Shaoxin Sun, and Yue SunInternational Journal of Control, Automation, and Systems 2023; 21(12): 3957-3969
Abstract : This paper investigates the incipient fault diagnosis problem of the multiple-output wireless power transfer system (MWPTS). And the MWPTS described in this paper has nonlinearity and high-order characteristics. Firstly, based on the Kirchhoff theorem and the interconnect system modeling method, a more realistic dynamics model of MWPTS with incipient faults, parameter uncertainty, and time delay is established. The proposed modeling method dramatically reduces the order of MWPTS. Then, a novel observer-based control strategy is proposed to estimate incipient faults while keeping the system stable even if MWPTS are affected by time delay and parameter uncertainty. Finally, the simulation result verified the availability of the incipient fault-tolerant method.
Young Jin Moon, Myungsoo Choi*, Wang-Lok Lee, Jinhae Park, Minju Shin, Wonjun Cho, and Juwon SongInternational Journal of Control, Automation, and Systems 2023; 21(12): 3970-3982
Abstract : An analysis of industrial accidents revealed that workers in the manufacturing field suffered from various injuries resulting in a huge loss of workdays. In order for an exosuit to better support physical activities including strengthening the human body, we expect to develop it further that can prevent worker injuries and improve work efficiency at the same time in the field. This study aims to develop an algorithm to distinguish between the gait, lifting, and lowering motions using inertial measurement units (IMUs). We also plan to make a soft exosuit that can help lifting heavy objects using actuators enhancing muscular assistance in gait, lifting, and lowering motions. In the design of an exosuit, elastic bands are used to ensure wearer comfort and we try to make the weight of actuators as light as possible so as to more efficiently assist the human body. With the total weight 0.52 kg of the exosuit, the algorithm can detect the gait motion with a weighted F1 score of 0.8525 and the lifting and lowering motions with the 0.9494. Furthermore, in consideration of rectus femoris which is agonist muscle for walking, lifting, and lowering movements, it appears that the root mean square (RMS) values of the electromyograms (EMGs) for the left and right rectus femoris during the standing up activity are decreased by 24.22% and 20.86%, respectively, compared with the values measured without wearing the exosuit. Additionally, the assisting effect on other major muscles is also significant, demonstrating that the exosuit can assist in improving muscle strength.
Seokbin Hwang, Suk-joong Lee, and Sungmin Kim*International Journal of Control, Automation, and Systems 2023; 21(12): 3983-3993
Abstract : Inaccurate screw insertion has been a major concern in pedicle screw placement in spinal surgery because of the potential for postoperative complications. Efforts to improve screw insertion have led to the development of novel surgical navigation systems. However, current surgical navigation systems have several problems in that the attention of surgeons is frequently interrupted during surgery, and complications occur in their depth perception because of the limitations of 2D monitors. This study proposes a surgical navigation system to address these issues using mixed reality (MR)-based smart glasses. We developed a navigation system that provides 3D visualization of the surgical tool with respect to the patient’s anatomy. It utilizes preoperative surgical planning data to provide visual feedback and guidance. An orthopedic surgeon performed pedicle screw placement with the navigation system in two different environments, using Microsoft HoloLens (HoloLens) and a 2D monitor. The results were evaluated according to procedural time, translational error, angular error, and clinical accuracy. The mean procedural time was 111.3±52.7 s with the HoloLens and 192.1±104.0 s with the 2D monitor. The mean translational error was 2.14 ± 1.13 mm at the entry and 3.14 ± 0.90 mm at the target with HoloLens. With the 2D monitor, the mean translational error was 2.10 ± 0.97 mm and 3.41 ± 2.16 mm at the entry and the target, respectively. The mean angular error was 6.44±1.94 deg with HoloLens and 7.14±4.20 deg with the 2D monitor. All screws were inserted intrapedicularly in both environments. The navigation system enables free visualization, reflects the human eye’s perspective, and retains the advantages of MR-based smart glasses. A navigation system compatible with minimally invasive surgery should be developed in the future.
Shuaishuai Sui, Yiping Yao*, and Tong ZhaoInternational Journal of Control, Automation, and Systems 2023; 21(12): 3994-4005
Abstract : A multi-degree-of-freedom (multi-DOF) control method is proposed in this paper for the optoelectronic platform affected by internal and external disturbances. First, internal model control (IMC) is used to track the desired signal, and combined with radial basis function neural network (RBFNN)-based sliding mode control (SMC) to compensate for friction torque and weaken model uncertainty. Then, linear active disturbance rejection control (LADRC) is introduced to observe and compensate for sensor noise as well as external unknown disturbances, so that the optoelectronic platform can operate under complex working conditions. The input and disturbance sensitivity functions in a pure feedback control system cannot reach their minimum values in the same frequency band, so there is an inherent contradiction between their tracking and disturbance rejection performance. Combining IMC-SMC-RBFNN with LADRC as a multi-DOF controller can guarantee both tracking and disturbance rejection performance. Lyapunov theory and Barbalat lemma prove the asymptotic stability of the control system. Simulations show that the multi-DOF controller has a good control effect under the mixed disturbances such as parameter perturbation, friction torque and sensor noise, which has reference value for the development of practical optoelectronic platform systems.
Seul JungInternational Journal of Control, Automation, and Systems 2023; 21(12): 4006-4014
Abstract : This paper presents the analysis of bilinear force/position control (BFC) schemes for the guaranteed force tracking performance of a robot manipulator under unknown environment. Borrowing the concept of impedance force control and hybrid force control, BFC schemes are formulated by combining two force control algorithms. The proposed BFC scheme guarantees the desired force/position tracking performance for any environment with the help of a model-based control method by achieving independent axis control. Guaranteed force tracking control performances of three different bilinear functions are presented and analysed. Their performances are tested and compared without knowing any information on the environment such as position and stiffness a priori. Simulation studies of BFC tracking performances for a robot manipulator to follow the sinusoidal trajectory while regulating a desired force on the environment are performed to verify the practical force tracking control performance.
Seema Mallavalli* and Afef FekihInternational Journal of Control, Automation, and Systems 2023; 21(12): 4015-4031
Abstract : This paper develops a fault tolerant control (FTC) approach for quadrotor aerial vehicles under different types of actuator faults. An observer-based fault detection and diagnosis mechanism is devised to estimate the faults. A robust finite-time convergent controller which merges the features of Backstepping, and Integral Nonsingular Fast Terminal Sliding surface is proposed to ensure the finite time stability of the states in nominal conditions and their asymptotic stability in faulty conditions. A control redistribution method is formulated to maintain the quadrotor in flight, in the case of complete actuator failure and lock in place (LIP) faults. The proposed controller was assessed in the presence of loss of actuator effectiveness (LOE) faults, complete damage of one rotor and LIP faults. The obtained results confirmed the ability of the proposed approach to enable the quadrotor to track the commanded trajectory precisely under partial LOE faults and continue tracking with an expected performance degradation under the effect of complete motor failure and LIP faults.
Dong-Han Lee, Kyung-Soo Kwak, and Soo-Chul Lim*International Journal of Control, Automation, and Systems 2023; 21(12): 4032-4040
Abstract : In robot-assisted minimally invasive surgery, there is a risk of skin tissue damage or suture failure at the suture site owing to incomplete tension. To avoid these problems and improve the inaccuracy of tension prediction, this study proposes a suture-tension prediction method using spatio-temporal features that simultaneously utilizes visual information obtained from surgical suture images and robot state changes over time. The proposed method can assist in minimally invasive robotic surgical techniques by predicting suture-tension through a neural network with image and robot information as inputs, without additional equipment. The neural network structure of the proposed method was reconstructed using ShuffleNet V2plus and spatio-temporal long-short-term memory, which are suitable for tension prediction. To validate the constructed neural network, we performed suturing expferiments using biological tissue and created a training database. We trained the proposed model using the built database and found that the estimated suture-tension values were similar to the actual tension values. We also found that the estimated tension values performed better than those of the other neural network models.
Seokyong Song, Juhwan Kim, Taesik Kim, Young-woon Song, and Son-Cheol Yu*International Journal of Control, Automation, and Systems 2023; 21(12): 4041-4056
Abstract : Underwater inspection of marine structures is important to ensure the safety and integrity of infrastructure; however, stable exploration using conventional underwater robots is limited because of various factors such as biofouling and currents. This study focuses on inspecting the surface under a marine structure. To inspect the surfaces covered with biofouling, a biomimetic underwater robot for inspection of marine structures (BRIM) with swimming, walking, and obstacle-negotiation capabilities was developed. The design parameters for walking on uneven terrain were adjusted, and a gait was developed to push aside obstacles that obstruct the view. Simulations of the dynamic models were implemented and stability measures of walking with various attitudes were computed to verify the proposed method. The feasibility of the robot in real-life scenarios was verified by performing unit and feasibility tests inside a water tank, demonstrating the effectiveness of the proposed system.
Quoc Van TranInternational Journal of Control, Automation, and Systems 2023; 21(12): 4057-4066
Abstract : This paper proposes a fixed-time (FxT) frame (or pose) localization scheme for multi-agent systems based on the inter-agent relative poses specified by SE(3) transformation matrices. Under the localization law, the agents’ local coordinate frames are localized almost globally in fixed-time with regard to a common reference frame. Based on the FxT frame estimation, the SE(3) formation control for multi-agent systems with connected graphs can be simply cast as the stabilization in SE(3) for each individual agent. When the desired formation is specified by the desired inter-agent bearing vectors, FxT bearing-based formation control is presented with no need for the global reference frame common to the agents. Simulation results are provided to support the theoretical development.
Luca Cavanini, Riccardo Felicetti, Francesco Ferracuti*, and Andrea MonteriùInternational Journal of Control, Automation, and Systems 2023; 21(12): 4067-4079
Abstract : In this paper, we propose an efficient method for handling large datasets in linear parameter-varying (LPV) model identification. The method is based on least-squares support vector machine (LS-SVM) identification in the primal space. To make the identification computationally feasible, even for very large datasets, we propose estimating a finite-dimensional feature map. To achieve this, we propose a two-step method to reduce the computational effort. First, we define the training set as a fixed-size subsample of the entire dataset, considering collision entropy for subset selection. The second step involves approximating the feature map through the eigenvalue decomposition of the kernel matrices. This paper considers both autoregressive with exogenous input (ARX) and state-space (SS) model forms. By comparing the problem formulation in the primal and dual spaces in terms of accuracy and computational complexity, the main advantage of the proposed technique is the reduction in space and time complexity during the training stage, making it preferable for handling very large datasets. To validate our proposed primal approach, we apply it to estimate LPV models using provided inputs, outputs, and scheduling signals for two nonlinear benchmarks: the parallel Wiener-Hammerstein system and the Silverbox system. The performances of our proposed approach are compared with the dual LS-SVM approach and the kernel principal component regression.
Jun-Wei Zhu*, Bo Wang, and Xin WangInternational Journal of Control, Automation, and Systems 2023; 21(12): 4080-4087
Abstract : Traditional fault diagnosis methods relies on sufficient fault samples, but it is unrealistic since the fault is a low possibility event in real industrial scenes. To address the above issue, this paper proposed a fault diagnosis method for chemical processes with small samples. First, a data self-generating-based transfer learning (DSGTL) method is presented to expand the fault samples. The characteristic of fault data is learned by adversarial relation and transferred to the generated data. Moreover, a model-based transfer learning strategy is adopted to improve the robustness of the proposed method to the quality of generated data. Second, the sample reconstruction-based convolutional neural network (SR-CNN) is proposed which adaptively extracts features from both spatial domain and time domain and identifies the fault type of industrial process with small samples. Finally, the experimental result of the Tennessee Eastman (TE) process proves the validity and the feasibility of the proposed method.
Jonghyun Ko and Wonzoo Chung*International Journal of Control, Automation, and Systems 2023; 21(12): 4088-4097
Abstract : In this paper, we propose an auxiliary loss function called an eigen loss to reduce the overfitting of fewshot learning algorithms. The proposed loss function predicts the class of unlabeled query images by measuring the similarity between the query image and reconstructed image constructed from the eigenimages of the support data. The eigen loss is used in a linearly combined form with the existing loss function of few-shot learning models. Experimental results of the eigen loss applied to representative few-shot learning models on widely used datasets (i.e., MiniImageNet, CUB, and TieredImageNet) show that the proposed method yields notable improvements in terms of classification accuracy.
Hung Duy Nguyen and Kyoungseok Han*International Journal of Control, Automation, and Systems 2023; 21(12): 4098-4110
Abstract : Safe decision-making strategy of autonomous vehicles (AVs) plays a critical role in avoiding accidents. This study develops a safe reinforcement learning (safe-RL)-based driving policy for AVs on highways. The hierarchical framework is considered for the proposed safe-RL, where an upper layer executes a safe explorationexploitation by modifying the exploring process of the ε-greedy algorithm, and a lower layer utilizes a finite state machine (FSM) approach to establish the safe conditions for state transitions. The proposed safe-RL-based driving policy improves the vehicle’s safe driving ability using a Q-table that stores the values corresponding to each action state. Moreover, owing to the trade-off between the ε-greedy values and safe distance threshold, the simulation results demonstrate the superior performance of the proposed approach compared to other alternative RL approaches, such as the ε-greedy Q-learning (GQL) and decaying ε-greedy Q-learning (DGQL), in an uncertain traffic environment. This study’s contributions are twofold: it improves the autonomous vehicle’s exploration-exploitation and safe driving ability while utilizing the advantages of FSM when surrounding cars are inside safe-driving zones, and it analyzes the impact of safe-RL parameters in exploring the environment safely.
Che-Lun Su, Wen-Jer Chang*, and Cheung-Chieh KuInternational Journal of Control, Automation, and Systems 2023; 21(12): 4111-4122
Abstract : This study addresses the control problem of a nonlinear large-scale descriptor system (LSDS) through the use of a decentralized proportional-plus-derivative state feedback fuzzy (DPDF) control strategy. The TakagiSugeno (T-S) fuzzy modeling technique, which is widely used by researchers, is used to describe the nonlinear LSDS as a set of linear subsystems with interconnections. Based on the constructed T-S fuzzy LSDS, a DPDF feedback method is proposed to address the limitations of the descriptor matrix of the T-S fuzzy LSDS and to solve the regular and impulse-free problems of systems while providing a more convenient and effective approach for discussing system stability. Additionally, the Lyapunov theory is chosen to analyze the stability conditions. This study uses a quadratic Lyapunov function to provide sufficient criteria to ensure the decay rate performance of the LSDS, which can be transformed into linear matrix inequality (LMI) form. The proposed method is demonstrated through several examples to showcase its effectiveness.
Yixuan Yuan, Junsheng Zhao*, Zong-yao Sun, Yaqi Gu, and Xuejing ZhaoInternational Journal of Control, Automation, and Systems 2023; 21(12): 4123-4132
Abstract : In this article, we solve the fast finite-time stabilization as well as adaptive fuzzy control design issues for a class uncertain stochastic nonlinear systems. Firstly, a new fast finite-time control scheme is proposed in virtue of generalizing the fast finite-time adaptive control strategy for deterministic systems to the stochastic case. Next, a novel adaptive fuzzy control strategy is developed to simultaneously deal with the stochastic nonlinear systems with completely unknown nonlinearities as well as the disturbances term. Then, stability analysis have been given based on a Jensen’s inequality. Finally, two simulations examples is presented to illustrate the effectiveness of the proposed control scheme.
Hyo-Sung AhnInternational Journal of Control, Automation, and Systems 2023; 21(8): 2429-2429
Xin Gong, Lixiao Wang, Yuanyuan Mou, Haili Wang, Xiaoqian Wei, Wenfeng Zheng*, and Lirong Yin*International Journal of Control, Automation and Systems 2022; 20(3): 1002-1017