Xinsheng Wang, Bin Jiang, Tong Yao, Huaqiang Zhang
{"title":"Fractional-order fixed-time sliding mode control of robotic manipulators with robust exact differentiator","authors":"Xinsheng Wang, Bin Jiang, Tong Yao, Huaqiang Zhang","doi":"10.1002/asjc.3484","DOIUrl":"10.1002/asjc.3484","url":null,"abstract":"<p>This paper introduces a robust position tracking control structure of exoskeleton robots (ERs). An open environment and body flexibility are the main challenges in ER control system design. First, a fractional-order nonsingular terminal sliding mode (FONTSM) controller is proposed for a robotic manipulator with uncertainty, where lumped unknown dynamics are computed by time-delay estimation (TDE). Secondly, a robust exact differentiator (RED) is employed as the output feedback observer for the velocity sensorless robotic system. Thirdly, the stability of the FONTSM control system is demonstrated. It is proved that the system error can move to the specified value along the sliding mode surface at a fixed time and can reach the sliding mode surface after a finite time. Finally, simulations on a 2-DOF robotic manipulator show the effectiveness of the fixed-time control strategies. When a combined trigonometric function disturbance is applied, the joint angle error is reduced to 1% by the model-free controller based on output feedback within approximately 1 s.</p>","PeriodicalId":55453,"journal":{"name":"Asian Journal of Control","volume":"27 2","pages":"1087-1098"},"PeriodicalIF":2.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142249515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quadrotor attitude control with a modified fixed-time synergetic controller: A geometric analysis and experimental validation","authors":"Saadi Achour, Khalil Mokhtari, Abdelaziz Rahmoune","doi":"10.1002/asjc.3498","DOIUrl":"10.1002/asjc.3498","url":null,"abstract":"<p>This article proposes a novel modified fixed-time synergetic control (MFTSC) approach to address the quadrotor control problem in the presence of external disturbances. In contrast to previous fixed-time synergetic control (FTSC) methods, the proposed approach employs an aggregate macrovariable expression with independent fractional powers. This expression expands the set of real numbers that the parameters of the fractional power can take, leading to a significantly higher rate of convergence toward optimal control parameters (more than 28-fold), as demonstrated through geometric analysis. The stability of the proposed control system is established, and numerical simulations and experimental validation are conducted using a quadrotor test bench to corroborate the theoretical results.</p>","PeriodicalId":55453,"journal":{"name":"Asian Journal of Control","volume":"27 2","pages":"1051-1067"},"PeriodicalIF":2.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142249517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Output feedback stabilization of logical dynamical systems with state‐dependent control constraints","authors":"Chaoqun Dai, Yuqian Guo","doi":"10.1002/asjc.3495","DOIUrl":"https://doi.org/10.1002/asjc.3495","url":null,"abstract":"Control constraints are common in real‐world applications. However, when the control constraint depends on the system state, designing a stabilizing output feedback that adheres to the constraint can be challenging if the state is unmeasurable. This study proposes a novel dual‐loop structural output feedback for logical dynamical systems (LDSs) with state‐dependent control constraints. The inner‐loop controller is a pre‐output feedback designed based on the state‐dependent constraint, which always selects a common admissible control for all possible states. A system with free control input is obtained by combining the pre‐output feedback with the LDS. The outer‐loop controller, an ordinary output feedback, is then designed for the combined system. It is proven that any admissible time‐invariant output feedback can be decomposed into a pre‐output feedback and an ordinary output feedback. Furthermore, a necessary and sufficient condition for stabilizability by admissible output feedback is obtained. Finally, an example is presented to demonstrate the effectiveness of the obtained results.","PeriodicalId":55453,"journal":{"name":"Asian Journal of Control","volume":"2 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142249518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Disturbance estimation backstepping flight control based on the discrete Fourier transform","authors":"Ruichen Ming, Xiaoxiong Liu, Yu Li, Weiguo Zhang","doi":"10.1002/asjc.3491","DOIUrl":"10.1002/asjc.3491","url":null,"abstract":"<p>This paper presents the design of an adaptive backstepping (BS) nonlinear controller for time-varying disturbances in flight control. The discrete Fourier transform (DFT) is used to design an adaptive law to suppress the influence of time-varying disturbances. The traditional adaptive BS method ignores the derivatives of disturbances in the deduction process and cannot address certain fast, time-varying disturbances well. Therefore, an improved adaptive BS method based on the DFT is proposed. Instead of estimating the disturbance directly, the proposed method obtains the time-domain expression of the disturbance indirectly by estimating the disturbance spectrum and performing inverse DFT. The proposed method effectively overcomes the inability of the traditional adaptive BS method to estimate fast, time-varying disturbances accurately. Finally, the proposed method is compared with traditional adaptive BS and radial basis function (RBF) neural network control methods. Simulation results confirm that the proposed method outperforms other methods under Gaussian disturbance and turbulence.</p>","PeriodicalId":55453,"journal":{"name":"Asian Journal of Control","volume":"27 2","pages":"1033-1050"},"PeriodicalIF":2.7,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Model-free adaptive load frequency control for power systems with wind penetration under deregulation environment","authors":"Yiming Zeng, Xuhui Bu, Yanling Yin","doi":"10.1002/asjc.3481","DOIUrl":"10.1002/asjc.3481","url":null,"abstract":"<p>With the gradual deregulation of the power system by the power department, the power system has developed into a large-scale and multiregional control system. Because of the power system internal complexity enhancing, the stable operation of power system becomes increasingly difficult. This paper analyzes the load frequency control problem of multiregional interconnected power system with wind energy. This study designs an improved model-free adaptive control algorithm based on I/O data. It avoids model establishment of the multiregional power system. It also effectively solves the problem of frequency stability control under the influence of load change, introducing the generation participation matrix to simulate bilateral contracts under the power market. The dynamic evolution relationship of the system with the generation participation matrix is established, taking a three-regional power system with wind energy as an example. Frequency fluctuations in all three regions are between \u0000<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>±</mo>\u0000 <mn>0.1</mn>\u0000 <mspace></mspace>\u0000 <mtext>Hz</mtext>\u0000 </mrow>\u0000 <annotation>$$ pm 0.1kern0.1em mathrm{Hz} $$</annotation>\u0000 </semantics></math>. Convergence times of frequency deviation are all within 30 s, much less than the response time of load frequency control. The simulation results further demonstrate the effectiveness of the proposed algorithm, comparing the control algorithm proposed in this paper with other algorithms, which proves that the proposed algorithm has good control performance.</p>","PeriodicalId":55453,"journal":{"name":"Asian Journal of Control","volume":"27 2","pages":"948-961"},"PeriodicalIF":2.7,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Distributed fault estimation observer design for nonlinear multi-agent systems with directed graphs","authors":"Yuhui Weng, Jianwei Liu, Huiwen Liu, Ruizhi Qin","doi":"10.1002/asjc.3485","DOIUrl":"10.1002/asjc.3485","url":null,"abstract":"<p>This paper addresses the issue of fault estimation in nonlinear multi-agent systems characterized by a leader–follower structure within directed graphs. The proposed approach begins by developing a distributed fault observer that utilizes relative output estimation error. Subsequently, a dynamic error system is constructed to convert the fault estimation problem into a stability problem for the dynamic error system. Finally, the conditions for achieving asymptotic boundedness of the dynamic error system are presented in the form of linear matrix inequalities. Simulation results substantiate the efficacy of the proposed method, revealing the ability of the distributed fault observer to accurately estimate faults occurring in multiple followers of the multi-agent system.</p>","PeriodicalId":55453,"journal":{"name":"Asian Journal of Control","volume":"27 2","pages":"901-911"},"PeriodicalIF":2.7,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Event‐triggered shared control for Euler–Lagrange systems with actuator fault and unknown control direction","authors":"Xiaoying Feng, Xiaoyu Zhang","doi":"10.1002/asjc.3496","DOIUrl":"https://doi.org/10.1002/asjc.3496","url":null,"abstract":"Security is of paramount importance in the operation of human‐controlled mechanical systems. In the unfortunate event of an accident, the operator may find themselves in a state of distress. This research focuses on the study of adaptive event‐triggered shared control techniques for uncertain Euler–Lagrange systems afflicted by actuator faults and the presence of unknown disturbances. Unlike existing results on shared control, the uncertain Euler–Lagrange system considered in this study contains both an unknown control direction and actuator faults, making it more practical. Furthermore, the controller we have designed demonstrates enhanced stability in the face of these challenges. To counteract the impact of unknown control direction, we introduce a state feedback controller employing Nussbaum functions. Additionally, the devised event‐triggered mechanism serves to reduce the system's network communication resource utilization. The implementation of our shared control strategy ensures asymptotic tracking of target trajectories by the system's outputs while maintaining consistent operation within a defined safe region. Finally, a simulated example is presented to validate the effectiveness of our proposed methodologies.","PeriodicalId":55453,"journal":{"name":"Asian Journal of Control","volume":"7 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jawhar Ghommam, Lamia Iftekhar, Mohammad H. Rahman, Maarouf Saad
{"title":"Cooperative learning-based practical formation-containment control with prescribed performance for heterogeneous clusters of UAV/USV","authors":"Jawhar Ghommam, Lamia Iftekhar, Mohammad H. Rahman, Maarouf Saad","doi":"10.1002/asjc.3480","DOIUrl":"10.1002/asjc.3480","url":null,"abstract":"<div>\u0000 \u0000 <p>In this paper, a new approach for formation-containment control with prescribed performances is introduced for heterogeneous autonomous vehicles involving a cluster of leader unmanned aerial vehicles (UAVs) and follower unmanned surface vessels (USVs). We introduce a two-layer distributed control system: The upper layer focuses on guiding the UAVs to form a scalable lattice while synchronizing their movement along a predefined path, and the second layer guides the USVs to enter the convex hull formed by the UAVs, ensuring collision-free operation with static/dynamic objects. To prevent collisions and ensure lattice formation, a set of well-defined bump functions are utilized in the design of the backstepping control algorithm. Managing virtual controls, we incorporate a nonlinear dynamic surface control (NDSC), while a universal barrier function enhances the convergence of formation tracking errors. Furthermore, each USV employs a cooperative adaptive learning neural network to handle uncertainties in heterogeneous vehicle models. Utilizing the Lyapunov theorem, the stability of the formation-containment of UAV/USV is achieved, and all signals in the formation-containment systems are semiglobal uniform ultimate bounded (SGUUB). A simulation example showcases the effectiveness of our proposed approach, highlighting contributions in collision avoidance, synchronization speed, and adaptive learning. Our work advances the heterogeneous formation-containment literature towards more realistic scenarios with safety-critical considerations amidst multiple layers of uncertainties and unknown parameters.</p>\u0000 </div>","PeriodicalId":55453,"journal":{"name":"Asian Journal of Control","volume":"27 2","pages":"921-947"},"PeriodicalIF":2.7,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Idael Oliva‐Leal, Jorge Said Cervantes‐Rojas, Rogelio Lozano, Iván González‐Hernández
{"title":"Optimized chattering‐attenuated sliding mode controller for a perturbed VTOL system","authors":"Idael Oliva‐Leal, Jorge Said Cervantes‐Rojas, Rogelio Lozano, Iván González‐Hernández","doi":"10.1002/asjc.3492","DOIUrl":"https://doi.org/10.1002/asjc.3492","url":null,"abstract":"This study presents a novel design of an optimized chattering‐attenuated quasi‐sliding mode controller for the stabilization of a vertical take‐off and landing aircraft affected by external disturbances. We propose a methodology based on a particle swarm optimization algorithm to provide an optimal boundary layer thickness of the quasi‐sliding mode controller (QSMC) structure based on a sigmoid‐type function approximation to reduce the chattering noise in the control signal while an adequate stabilization quality is guaranteed. This represents an alternative to the common strategies based on a trial and error tuning of such boundary layer thickness of sigmoid‐type approximations. Also, the Lyapunov formalism is applied to restrict the search space of the QSMC gain to guarantee stability conditions. Some simulation tests were carried out to demonstrate the enhanced chattering attenuation capability of the proposed solution against a standard sliding mode controller and the superior stabilization performance versus other robust controllers.","PeriodicalId":55453,"journal":{"name":"Asian Journal of Control","volume":"2 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lin He, Ziang Xu, Yujiang Wei, Mingwei Wang, Chunrong Huang, Qin Shi
{"title":"A tune sliding control algorithm for angle following of electric motor steer-by-wire system","authors":"Lin He, Ziang Xu, Yujiang Wei, Mingwei Wang, Chunrong Huang, Qin Shi","doi":"10.1002/asjc.3487","DOIUrl":"10.1002/asjc.3487","url":null,"abstract":"<p>The sliding mode control has to design a sliding manifold for manipulating the system motion in engineering practice, making system asymptotic stability paramount. This is particularly challenging for using variable sliding manifold parameters to formulate the sliding manifold for fast convergence and precise control. While much of the research on sliding mode control has focused on constant sliding manifold parameters, comparatively little is known about the variable approach of the sliding manifold parameters. Therefore, sliding manifold parameters are treated as variables and are computed by a parameter tuning algorithm. Regarding the parameter tuning algorithm, its input is the sliding mode control law with variable sliding manifold parameters, and its output is the computed sliding manifold parameters that will be transmitted back to the sliding mode control law. Through tuning the sliding manifold parameters by an optimal method of lowest cost with the measuring value and model computing value of system states based on the historical information, the difference between the nominal model and the real system will be removed. Here we discuss a series of studies on the algorithm of tune sliding control that, collectively, develop an application of how the tune sliding controller steers the front wheels of the full self-driving vehicle. The designed approach has been tested in a steering test vehicle to realize a good angle tracking performance of the electric motor steer-by-wire system.</p>","PeriodicalId":55453,"journal":{"name":"Asian Journal of Control","volume":"27 2","pages":"962-972"},"PeriodicalIF":2.7,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}