Yang Du, Wei Zhao, Shan-Liang Zhu, Wei-Jie Hao, Shi-Cheng Liu, Yu-Qun Han
{"title":"Event-Triggered Adaptive Asymptotic Tracking Control for Stochastic Non-Linear Systems With Unknown Hysteresis: A New Switching Threshold Approach","authors":"Yang Du, Wei Zhao, Shan-Liang Zhu, Wei-Jie Hao, Shi-Cheng Liu, Yu-Qun Han","doi":"10.1002/rnc.7799","DOIUrl":"https://doi.org/10.1002/rnc.7799","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper proposes a novel event-triggered adaptive asymptotic tracking control (ATC) method for stochastic non-linear systems with unknown hysteresis. Firstly, in order to reduce the depletion of network resources while optimizing the asymptotic tracking performance of the system, a switching threshold mechanism (STM)-based event-triggered control (ETC) strategy is adopted. Secondly, a first-order filter is utilized to address the problem of the contradiction between event-triggered mechanism (ETM) output and rate-dependent hysteresis actuator input. By incorporating an enhanced backstepping technique and a bounded estimation method, it is rigorously demonstrate that the system achieves zero tracking error, effectively compensates for unknown hysteresis, and ensures that all closed-loop signals remain bounded in probability. Meanwhile, the Zeno phenomenon is excluded. Finally, the effectiveness and superiority of the proposed control scheme are verified by the simulation results.</p>\u0000 </div>","PeriodicalId":50291,"journal":{"name":"International Journal of Robust and Nonlinear Control","volume":"35 6","pages":"2324-2341"},"PeriodicalIF":3.2,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143581633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Robust Approximate Constraint-Following Control Design Based on Udwadia–Kalaba Theory and Experimental Verification for Collaborative Robots With Inequality Constraints and Uncertainties","authors":"Xinbao Ma, Shengchao Zhen, Chaoqun Meng, Xiaoli Liu, Guanjun Meng, Ye-Hwa Chen","doi":"10.1002/rnc.7788","DOIUrl":"https://doi.org/10.1002/rnc.7788","url":null,"abstract":"<div>\u0000 \u0000 <p>A robust approximate constraint-following control (RACC) approach is proposed in this article for collaborative robots with inequality constraints. The trajectory-following control and boundary control of the robot are investigated. First, an explicit constraint equation for the collaborative robot system is established based on the Udwadia–Kalaba (U-K) theory. Second, due to the monotone unbounded property of the tangent function, a special function is constructed to transform the joint output angles of the constrained robot into unconstrained state variables, and a new form of the robot constraint equation is obtained. Through this transformation, the joint motion of the robot will always be confined to specified angles and follow the desired trajectory. The constraint equation ensures the safety of the robot at the algorithmic level and innovatively solves the control problem of the equality and inequality of the robot's motion. According to theoretical analysis, the control approach can deal with uncertainty and satisfy both uniform boundedness (UB) and uniform ultimate boundedness (UUB) requirements. Finally, based on the rapid controller prototype CSPACE and a two-degree-of-freedom collaborative robot platform, experimental verification is carried out. Numerical simulation and experimental results demonstrate that the proposed RACC approach with state transformation exhibits significant advantages in trajectory tracking performance and safety for collaborative robots.</p>\u0000 </div>","PeriodicalId":50291,"journal":{"name":"International Journal of Robust and Nonlinear Control","volume":"35 6","pages":"2199-2212"},"PeriodicalIF":3.2,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143581830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 Integral Reinforcement Learning Control Based on Recursive Terminal Sliding Mode","authors":"Chao Jia, Yashuai Li, Hongkun Wang, Zijian Song","doi":"10.1002/rnc.7800","DOIUrl":"https://doi.org/10.1002/rnc.7800","url":null,"abstract":"<div>\u0000 \u0000 <p>For a class of continuous-time non-linear systems with saturated input and unknown non-linear disturbance, a novel event-triggered integral reinforcement learning (IRL) control strategy based on recursive terminal sliding mode (RTSM) is proposed in this paper. Firstly, a novel performance index function is designed based on RTSM and a two-player zero-sum game, and the robust control problem with saturated input and unknown disturbance can be transformed into an optimal control problem. To avoid the requirement of drift dynamics, the IRL technique is introduced. Secondly, a critic neural network is used to approximate the optimal value function, which not only simplifies algorithm implementation structure, but also relaxes initial admissible control in the learning of neural network weights. Then, considering the event-triggered mechanism, the asymptotic stability of the closed-loop system and the uniformly ultimately boundedness of weight estimation errors are proved by utilizing the Lyapunov theory. Finally, simulation results illustrate the effectiveness of the proposed control method.</p>\u0000 </div>","PeriodicalId":50291,"journal":{"name":"International Journal of Robust and Nonlinear Control","volume":"35 6","pages":"2342-2353"},"PeriodicalIF":3.2,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143581696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qian Dong, Tianchi Tong, Wenying Yuan, Jinsheng Sun
{"title":"The Disturbed Fault Diagnosis for Discrete-Time Euler–Lagrange System With Multi-Sensors Based on \u0000 \u0000 \u0000 \u0000 \u0000 χ\u0000 \u0000 \u0000 2\u0000 \u0000 \u0000 \u0000 $$ {chi}^2 $$\u0000 -Detection","authors":"Qian Dong, Tianchi Tong, Wenying Yuan, Jinsheng Sun","doi":"10.1002/rnc.7797","DOIUrl":"https://doi.org/10.1002/rnc.7797","url":null,"abstract":"<div>\u0000 \u0000 <p>This article investigates the sensor fault diagnosis problem of the discrete-time Euler–Lagrange (EL) system with multi-sensors. Firstly, the discrete-time EL system is converted into a second-order non-linear discrete-time system using the famous Dragon Gekuta method. Secondly, the proposed strategy leverages the multi-sensors data fusion framework, employing multiple local unscented Kalman filters for state estimation. Moreover, the convergence of the local estimation is analyzed such that the local estimation errors are stable in faults-free case. Thirdly, considering the sensor fault in the presence of process and measurement noises, the residual signal based on the local estimation error is designed to detect and isolate faults. The fault detection and isolation logic is conducted using <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow>\u0000 <mi>χ</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ {chi}^2 $$</annotation>\u0000 </semantics></math> detection, where the threshold is determined through the cumulative distribution function of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow>\u0000 <mi>χ</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ {chi}^2 $$</annotation>\u0000 </semantics></math> distribution. Finally, a single-link robot is used to illustrate the effectiveness of the proposed fault diagnosis based on the multi-sensors data fusion.</p>\u0000 </div>","PeriodicalId":50291,"journal":{"name":"International Journal of Robust and Nonlinear Control","volume":"35 6","pages":"2300-2309"},"PeriodicalIF":3.2,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143581695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}