Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (70)

Search Parameters:
Keywords = fast reaching control law

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
18 pages, 9954 KiB  
Article
Adaptive Continuous Non-Singular Terminal Sliding Mode Control for High-Pressure Common Rail Systems: Design and Experimental Validation
by Jie Zhang, Yinhui Yu, Sumin Wu, Wenjiang Zhu and Wenqian Liu
Processes 2025, 13(8), 2410; https://doi.org/10.3390/pr13082410 - 29 Jul 2025
Viewed by 235
Abstract
The High-Pressure Common Rail System (HPCRS) is designed based on fundamental hydrodynamic principles, after which this paper formally defines the key control challenges. The proposed continuous sliding mode control strategy is developed based on a non-singular terminal sliding mode framework, integrated with an [...] Read more.
The High-Pressure Common Rail System (HPCRS) is designed based on fundamental hydrodynamic principles, after which this paper formally defines the key control challenges. The proposed continuous sliding mode control strategy is developed based on a non-singular terminal sliding mode framework, integrated with an improved power reaching law. This design effectively eliminates chattering and achieves fast dynamic response with enhanced tracking precision. Subsequently, a bidirectional adaptive mechanism is integrated into the proposed control scheme to eliminate the necessity for a priori knowledge of unknown disturbances within the HPCRS. This mechanism enables real-time evaluation of the system’s state relative to a predefined detection region. To validate the effectiveness of the proposed strategy, experimental studies are conducted under three distinct operating conditions. The experimental results indicate that, compared with conventional rail pressure controllers, the proposed method achieves superior tracking accuracy, faster dynamic response, and improved disturbance rejection. Full article
(This article belongs to the Special Issue Design and Analysis of Adaptive Identification and Control)
Show Figures

Figure 1

18 pages, 3139 KiB  
Article
Sliding Mode Thrust Control Strategy for Electromagnetic Energy-Feeding Shock Absorbers Based on an Improved Gray Wolf Optimizer
by Wenqiang Zhang, Jiayu Lu, Wenqing Ge, Xiaoxuan Xie, Cao Tan and Huichao Zhang
World Electr. Veh. J. 2025, 16(7), 366; https://doi.org/10.3390/wevj16070366 - 2 Jul 2025
Viewed by 200
Abstract
Owing to its high energy efficiency, regenerative capability, and fast dynamic response, the Electromagnetic Energy-Feeding Shock Absorber has found widespread application in automotive suspension control systems. To further improve thrust control precision, this study presents a sliding mode thrust controller designed using an [...] Read more.
Owing to its high energy efficiency, regenerative capability, and fast dynamic response, the Electromagnetic Energy-Feeding Shock Absorber has found widespread application in automotive suspension control systems. To further improve thrust control precision, this study presents a sliding mode thrust controller designed using an improved Gray Wolf Optimization algorithm. Firstly, an improved exponential reaching law is adopted, where a saturation function replaces the traditional sign function to enhance system tracking accuracy and stability. Meanwhile, a position update strategy from the particle swarm optimization (PSO) algorithm is integrated into the gray wolf optimizer (GWO) to improve the global search ability and the balance of local exploitation. Secondly, the improved GWO is combined with sliding mode control to achieve online optimization of controller parameters, ensuring system robustness while suppressing chattering. Finally, comparative analyses and simulation validations are conducted to verify the effectiveness of the proposed controller. Simulation results show that, under step input conditions, the improved GWO reduces the rise time from 0.0034 s to 0.002 s and the steady-state error from 0.4 N to 0.12 N. Under sinusoidal input, the average error is reduced from 0.26 N to 0.12 N. Under noise disturbance, the average deviation is reduced from 2.77 N to 2.14 N. These results demonstrate that the improved GWO not only provides excellent trajectory tracking and control accuracy but also exhibits strong robustness under varying operating conditions and random white noise disturbances. Full article
Show Figures

Figure 1

18 pages, 1451 KiB  
Article
Sustainable Trajectory Tracking Control for Underactuated Ships Using Non-Singular Fast Terminal Sliding Mode Control
by Minjie Zheng, Qianqiang Chen, Yulai Su and Guoquan Chen
Sustainability 2025, 17(13), 5866; https://doi.org/10.3390/su17135866 - 26 Jun 2025
Viewed by 279
Abstract
Accurate and robust trajectory tracking is essential for ensuring the safety and efficiency of underactuated ships operating in complex marine environments. However, conventional sliding mode control (SMC) methods often suffer from issues such as chattering and slow convergence, limiting their practical application. To [...] Read more.
Accurate and robust trajectory tracking is essential for ensuring the safety and efficiency of underactuated ships operating in complex marine environments. However, conventional sliding mode control (SMC) methods often suffer from issues such as chattering and slow convergence, limiting their practical application. To address these challenges, this paper proposes a novel non-singular fast terminal sliding mode control (NFTSMC) strategy for sustainable trajectory tracking of underactuated ships. The proposed approach first designs a virtual control law based on surge and sway position errors, and then develops a non-singular fast terminal sliding mode control law using an exponential reaching strategy, guaranteeing finite-time convergence and eliminating singularities. The Lyapunov-based stability analysis proves the boundedness and convergence of tracking errors under external disturbances. The simulation results demonstrate that the proposed non-singular fast terminal sliding mode control outperforms traditional sliding mode control in terms of convergence speed, tracking accuracy, and control smoothness, especially under wind, wave, and current disturbances. Full article
Show Figures

Figure 1

24 pages, 1293 KiB  
Article
Singular Perturbation Decoupling and Composite Control Scheme for Hydraulically Driven Flexible Robotic Arms
by Jianliang Xu, Zhen Sui and Xiaohua Wei
Processes 2025, 13(6), 1805; https://doi.org/10.3390/pr13061805 - 6 Jun 2025
Viewed by 464
Abstract
Hydraulically driven flexible robotic arms (HDFRAs) play an indispensable role in industrial precision operations such as aerospace assembly and nuclear waste handling, owing to their high power density and adaptability to complex environments. However, inherent mechanical flexibility-induced vibrations, hydraulic nonlinear dynamics, and electromechanical [...] Read more.
Hydraulically driven flexible robotic arms (HDFRAs) play an indispensable role in industrial precision operations such as aerospace assembly and nuclear waste handling, owing to their high power density and adaptability to complex environments. However, inherent mechanical flexibility-induced vibrations, hydraulic nonlinear dynamics, and electromechanical coupling effects lead to multi-timescale control challenges, severely limiting high-precision trajectory tracking performance. The present study introduces a novel hierarchical control framework employing dual-timescale perturbation analysis, which effectively addresses the constraints inherent in conventional single-timescale control approaches. First, the system is decoupled into three subsystems via dual perturbation parameters: a second-order rigid-body motion subsystem (SRS), a second-order flexible vibration subsystem (SFS), and a first-order hydraulic dynamic subsystem (FHS). For SRS/SFS, an adaptive fast terminal sliding mode active disturbance rejection controller (AFTSM-ADRC) is designed, featuring a dual-bandwidth extended state observer (BESO) to estimate parameter perturbations and unmodeled dynamics in real time. A novel reaching law with power-rate hybrid characteristics is developed to suppress sliding mode chattering while ensuring rapid convergence. For FHS, a sliding mode observer-integrated sliding mode coordinated controller (SMO-ISMCC) is proposed, achieving high-precision suppression of hydraulic pressure fluctuations through feedforward compensation of disturbance estimation and feedback integration of tracking errors. The globally asymptotically stable property of the composite system has been formally verified through systematic Lyapunov-based analysis. Through comprehensive simulations, the developed methodology demonstrates significant improvements over conventional ADRC and PID controllers, including (1) joint tracking precision reaching 104 rad level under nominal conditions and (2) over 40% attenuation of current oscillations when subjected to stochastic disturbances. These results validate its superiority in dynamic decoupling and strong disturbance rejection. Full article
(This article belongs to the Special Issue Modelling and Optimizing Process in Industry 4.0)
Show Figures

Figure 1

17 pages, 4761 KiB  
Article
Non-Singular Fast Terminal Composite Sliding Mode Control of Marine Permanent Magnet Synchronous Propulsion Motors
by Zhaoting Liu, Xi Wang, Peng Zhou, Liantong An, Zhengwei Zhao, Baozhu Jia and Yuanyuan Xu
Machines 2025, 13(6), 470; https://doi.org/10.3390/machines13060470 - 29 May 2025
Viewed by 420
Abstract
Regarding the high susceptibility problem of the Permanent Magnet Synchronous Motor (PMSM) to various uncertain factors, including load variations, parameter perturbations, and external interferences in the ship’s electric propulsion system, this paper presents a non-singular fast terminal composite sliding mode control (NFTCSMC) strategy [...] Read more.
Regarding the high susceptibility problem of the Permanent Magnet Synchronous Motor (PMSM) to various uncertain factors, including load variations, parameter perturbations, and external interferences in the ship’s electric propulsion system, this paper presents a non-singular fast terminal composite sliding mode control (NFTCSMC) strategy based on the improved exponential reaching law. This strategy integrates the system’s state variables and the power function of the sliding mode surface into the traditional exponential reaching law, not only enhancing the sliding mode reaching rate but also effectively mitigating system chattering. Additionally, a sliding mode disturbance observer is developed to compensate for both internal and external disturbances in real time, further enhancing the system’s robustness. Finally, the proposed control strategy is experimentally validated using the rapid control prototyping (RCP) technology applied on a semi-physical experimental platform for ship electric propulsion. Experimental results indicate that, compared to traditional proportional–integral (PI), sliding mode control (SMC), and fast terminal sliding mode control (FTSMC) strategies, the NFTCSMC strategy enhances the propulsion and anti-interference capabilities of the propulsion motor, thereby improving the dynamic performance of the ship’s electric propulsion system. Full article
(This article belongs to the Section Automation and Control Systems)
Show Figures

Figure 1

15 pages, 11519 KiB  
Article
PID Sliding Mode Control of PMSM Based on Improved Terminal Sliding Mode Reaching Law
by Guodong Qin, Min Wang, Guizhou Cao, Qi Wang and Yuefeng Liao
Energies 2025, 18(10), 2661; https://doi.org/10.3390/en18102661 - 21 May 2025
Cited by 1 | Viewed by 346
Abstract
In order to enhance the dynamic performance and anti-disturbance ability of speed control for a permanent magnet synchronous motor (PMSM), a sliding mode control method based on a PID sliding surface and an improved terminal sliding mode reaching law (ITSMRL) is proposed. Firstly, [...] Read more.
In order to enhance the dynamic performance and anti-disturbance ability of speed control for a permanent magnet synchronous motor (PMSM), a sliding mode control method based on a PID sliding surface and an improved terminal sliding mode reaching law (ITSMRL) is proposed. Firstly, an ITSMRL is proposed to increase the reaching speed and reduce chattering; moreover, it has been verified that the reaching law (RL) can achieve a sliding mode surface in finite time. Then, based on the dynamic model of PMSMs with uncertainties, an extended state observer (ESO) is used to estimate the lumped disturbance, and it is proven that the estimated error is bounded. Finally, on the basis of the observed feedforward disturbance, to enhance the disturbance rejection ability of PMSMs, a controller that combines the PID sliding mode surface and the ITSMRL is proposed. Moreover, the stability of the closed-loop system is proven. The composite method has the characteristics of a fast reaching speed, small chattering and strong robustness, and is verified by experiments. Full article
(This article belongs to the Special Issue Linear/Planar Motors and Other Special Motors)
Show Figures

Figure 1

23 pages, 3350 KiB  
Article
Three-Dimensional Adaptive Variable-Power Sliding-Mode Multi-Vehicle Cooperative Guidance Law
by Jian Li, Tan Lu, Peng Liu, Hang Yu, Changsheng Li, He Zhang and Xiaohao Yu
Aerospace 2025, 12(5), 370; https://doi.org/10.3390/aerospace12050370 - 24 Apr 2025
Viewed by 334
Abstract
To address the problem of cooperative multi-vehicle operations targeting critical objectives in three-dimensional space, this paper proposes a variable-power adaptive fast sliding-mode guidance law. First, a dynamic vehicle–target model is established in three-dimensional space by using the projection of the horizontal vehicle–target plane [...] Read more.
To address the problem of cooperative multi-vehicle operations targeting critical objectives in three-dimensional space, this paper proposes a variable-power adaptive fast sliding-mode guidance law. First, a dynamic vehicle–target model is established in three-dimensional space by using the projection of the horizontal vehicle–target plane to determine the reference plane. The guidance law design is projected onto the reference plane based on the average consensus convergence control method. This not only drives the estimated deviations to zero to achieve time consistency but also ensures that the estimated time-to-go converges to the actual time-to-go. Additionally, an adaptive input compensation component is designed in the vertical line-of-sight (LOS) direction, driving the aspect angle to converge to zero before the final point is reached. Furthermore, in the vertical reference plane direction, an adaptive variable-power sliding-mode control method is designed based on the traditional sliding-mode control scheme, in which the corresponding power exponent is selected according to the variation exhibited by the sliding-mode values. On the one hand, higher power levels can result in faster convergence; on the other hand, lower power levels can be associated with better stability. Compared with the traditional sliding-mode control technique, the proposed method achieves guaranteed stable convergence at the end of the control process, with a 49% improvement in convergence efficiency. Finally, simulations verify the designed three-dimensional guidance law, demonstrating that it features fast convergence, high stability, and high precision. Full article
(This article belongs to the Section Aeronautics)
Show Figures

Figure 1

18 pages, 2478 KiB  
Article
Improved Non-Singular Fast Terminal Sliding Mode Control with Hysteresis Compensation for Piezo-Driven Fast Steering Mirrors
by Enfu Zhong, Shuai Wang, Chuanlong Zhai and Wenjie Li
Actuators 2025, 14(4), 170; https://doi.org/10.3390/act14040170 - 31 Mar 2025
Cited by 2 | Viewed by 495
Abstract
Piezo-driven fast steering mirrors (PFSMs) are widely employed in high-precision beam steering and accurate tracking applications. However, the inherent hysteresis nonlinearity of piezoelectric actuators significantly degrades tracking accuracy. To address the challenges posed by dynamic hysteresis nonlinearity, this study proposes an improved non-singular [...] Read more.
Piezo-driven fast steering mirrors (PFSMs) are widely employed in high-precision beam steering and accurate tracking applications. However, the inherent hysteresis nonlinearity of piezoelectric actuators significantly degrades tracking accuracy. To address the challenges posed by dynamic hysteresis nonlinearity, this study proposes an improved non-singular fast terminal sliding mode control strategy. The proposed method integrates a non-singular fast terminal sliding surface and introduces an adaptive function in the reaching law to enhance response speed and improve control robustness. Additionally, the strategy incorporates an extended state observer (ESO) and an inverse model-based feedforward compensation mechanism. Specifically, the feedforward compensation based on the inverse model aims to offset hysteresis effects, while the ESO provides a real-time estimation of the total system disturbance to mitigate the impact of external disturbances and unmodeled hysteresis. Experimental results demonstrate that the proposed method effectively compensates for the hysteresis nonlinearity of PFSMs, improves disturbance rejection performance, and enhances position control accuracy. Full article
(This article belongs to the Special Issue New Control Schemes for Actuators—2nd Edition)
Show Figures

Figure 1

18 pages, 4733 KiB  
Article
Cascaded Extended State Observer-Based Composite Sliding-Mode Controller for a PMSM Speed-Loop Anti-Interference Control Strategy
by Yifan Xu, Bin Zhang, Yuxin Kang and He Wang
Sensors 2025, 25(4), 1133; https://doi.org/10.3390/s25041133 - 13 Feb 2025
Viewed by 862
Abstract
To enhance the speed-control performance of a permanent magnet synchronous motor (PMSM) drive system, an improved sliding-mode anti-interference control strategy is presented. Firstly, to tackle the speed fluctuation issue caused by cogging torque (a periodic disturbance) and time-varying disturbances at low set speeds [...] Read more.
To enhance the speed-control performance of a permanent magnet synchronous motor (PMSM) drive system, an improved sliding-mode anti-interference control strategy is presented. Firstly, to tackle the speed fluctuation issue caused by cogging torque (a periodic disturbance) and time-varying disturbances at low set speeds in PMSM, an improved sliding-mode control (ISMC) is proposed. It consists of a continuous adaptive fast terminal sliding-mode surface (CAFTSMS) and a new reaching law (NRL). The CAFTSMS boosts the system’s immunity to interference, while the NRL, improved via an adaptive function, enhances the fast transient response and notably reduces speed fluctuations. Secondly, a quasi-proportional resonant (QPR) controller is introduced. It suppresses specific-order system harmonics, significantly reducing the harmonic amplitude and strengthening the system’s ability to handle periodic disturbances. Finally, a cascaded extended state observer (CESO) with a special cascade structure is proposed to solve the observation-delay problem in the traditional cascade structure. Experimental results show that the proposed sliding-mode anti-disturbance control strategy performs excellently in overcoming disturbances. Full article
(This article belongs to the Section Intelligent Sensors)
Show Figures

Figure 1

23 pages, 5111 KiB  
Article
A Novel Adaptive Non-Singular Fast Terminal Sliding Mode Control for Direct Yaw Moment Control in 4WID Electric Vehicles
by Jung Eun Lee and Byeong Woo Kim
Sensors 2025, 25(3), 941; https://doi.org/10.3390/s25030941 - 4 Feb 2025
Cited by 1 | Viewed by 1316
Abstract
This study proposes an adaptive non-singular fast terminal sliding mode control (NFTSMC)-based direct yaw moment control (DYC) strategy to enhance driving stability in four-wheel independent drive (4WID) electric vehicles. Unlike conventional SMC, the proposed method dynamically adapts to system uncertainties and reduces chattering, [...] Read more.
This study proposes an adaptive non-singular fast terminal sliding mode control (NFTSMC)-based direct yaw moment control (DYC) strategy to enhance driving stability in four-wheel independent drive (4WID) electric vehicles. Unlike conventional SMC, the proposed method dynamically adapts to system uncertainties and reduces chattering, a critical issue in control applications. The approach begins with the development of an NFTSMC method, analyzing its performance to identify areas for improvement. To enhance robustness and responsiveness, a novel adaptive NFTSMC method is introduced. This method integrates a non-singular fast terminal sliding mode surface with a novel adaptive fast-reaching control law that combines an adaptive switching mechanism and a fast-reaching law. The designed adaptive switching law adjusts the sliding gain in real time based on system conditions, reducing chattering without needing an upper bound on uncertainties as required by traditional NFTSMC methods. Concurrently, the fast-reaching law ensures rapid convergence from any initial condition and accurate tracking performance. Simulation results across various steering maneuvers, including step, sinusoidal, and fish-hook inputs, demonstrate that the proposed method significantly improves tracking accuracy and driving stability over traditional SMC and NFTSMC methods. Marked reductions in RMS and peak yaw rate errors, and effective chattering mitigation, highlight advancements in vehicle safety and stability. Full article
(This article belongs to the Section Sensors and Robotics)
Show Figures

Figure 1

22 pages, 9285 KiB  
Article
A Control Method for Thermal Structural Tests of Hypersonic Missile Aerodynamic Heating
by Chao Lu, Guangming Zhang and Xiaodong Lv
Mathematics 2025, 13(3), 380; https://doi.org/10.3390/math13030380 - 24 Jan 2025
Viewed by 998
Abstract
This paper presents an intelligent proportional-derivative adaptive global nonsingular fast-terminal sliding-mode control (IPDAGNFTSMC) for tracking temperature trajectories of a hypersonic missile in thermal structural tests. Firstly, the numerical analyses on a hypersonic missile’s aerodynamic heating are based on three different external flow fields [...] Read more.
This paper presents an intelligent proportional-derivative adaptive global nonsingular fast-terminal sliding-mode control (IPDAGNFTSMC) for tracking temperature trajectories of a hypersonic missile in thermal structural tests. Firstly, the numerical analyses on a hypersonic missile’s aerodynamic heating are based on three different external flow fields via the finite element calculation, which provides the data basis for the thermal structural test of hypersonic vehicles; secondly, due to temperature trajectory differences of a hypersonic missile and the thermal inertia and nonlinear characteristics of quartz lamps in thermal structural test, IPDAGNFTSMC is proposed, consisting of three components: (i) the mathematical model of the thermal structural test is established and further replaced via an intelligent proportional-derivative with a nonlinear extended state observer (NESO) for online unknown disturbances observation; (ii) compared with the traditional sliding-mode control method, the AGNFTSMC method eliminates the reaching phase and the initial control state is trapped on the sliding-mode surface. Therefore, it can alleviate chattering phenomenon, accelerate the convergence rate of the sliding mode, and ensure that there is no singular problem in the entire control process; (iii) the adaptive law is designed to effectively solve problems of convergence stagnation and chattering phenomenon. The Lyapunov stability theory is used to prove the stability of the proposed IPDAGNFTSMC-NESO. Finally, the advantages of the designed control method are verified by experimental simulation and comparison. Full article
Show Figures

Figure 1

17 pages, 1234 KiB  
Article
Fractional-Order Sliding Mode with Active Disturbance Rejection Control for UAVs
by Zhikun Zhang and Hui Zhang
Appl. Sci. 2025, 15(2), 556; https://doi.org/10.3390/app15020556 - 8 Jan 2025
Cited by 3 | Viewed by 1129
Abstract
This paper investigates the attitude control problem of unmanned aerial vehicles (UAVs), especially in the presence of uncertainties and external disturbances. To address this challenge, a fractional-order reaching law sliding mode with active disturbance rejection controller (FOSM-ADRC) is proposed. The controller combines a [...] Read more.
This paper investigates the attitude control problem of unmanned aerial vehicles (UAVs), especially in the presence of uncertainties and external disturbances. To address this challenge, a fractional-order reaching law sliding mode with active disturbance rejection controller (FOSM-ADRC) is proposed. The controller combines a fractional-order calculus operator and active disturbance rejection controller (ADRC) techniques to enhance the dynamic performance and robustness of the system. Through the inner and outer loop design, the jitter of the sliding mode controller (SMC) is effectively suppressed, and fast response and strong anti-jamming ability are achieved, which, in turn, improves the control accuracy. Firstly, the dynamic model of the UAV is established, and its nonlinear dynamic characteristics are analyzed in detail. On this basis, a fractional-order reaching law sliding mode controller (FO-SMC) is designed as the outer loop to achieve fast response. ADRC is employed in the inner loop to compensate for the internal and external disturbances of the system. The results show that the FOSM-ADRC can effectively suppress the jitter phenomenon and maintain good control performance. Full article
Show Figures

Figure 1

25 pages, 7487 KiB  
Article
A Novel Time Delay Nonsingular Fast Terminal Sliding Mode Control for Robot Manipulators with Input Saturation
by Thanh Nguyen Truong, Anh Tuan Vo and Hee-Jun Kang
Mathematics 2025, 13(1), 119; https://doi.org/10.3390/math13010119 - 31 Dec 2024
Cited by 5 | Viewed by 1244
Abstract
Manipulator systems are increasingly deployed across various industries to perform complex, repetitive, and hazardous tasks, necessitating high-precision control for optimal performance. However, the design of effective control algorithms is challenged by nonlinearities, uncertain dynamics, disturbances, and varying real-world conditions. To address these issues, [...] Read more.
Manipulator systems are increasingly deployed across various industries to perform complex, repetitive, and hazardous tasks, necessitating high-precision control for optimal performance. However, the design of effective control algorithms is challenged by nonlinearities, uncertain dynamics, disturbances, and varying real-world conditions. To address these issues, this paper proposes an advanced orbit-tracking control approach for manipulators, leveraging advancements in Time-Delay Estimation (TDE) and Fixed-Time Sliding Mode Control techniques. The TDE approximates the robot’s unknown dynamics and uncertainties, while a novel nonsingular fast terminal sliding mode (NFTSM) surface and novel fixed-time reaching control law (FTRCL) are introduced to ensure faster convergence within a fixed time and improved accuracy without a singularity issue. Additionally, an innovative auxiliary system is designed to address input saturation effects, ensuring that system states converge to zero within a fixed time even when saturation occurs. The Lyapunov-based theory is employed to prove the fixed-time convergence of the overall system. The effectiveness of the proposed controller is validated through simulations on a 3-DOF SAMSUNG FARA AT2 robot manipulator. Comparative analyses against NTSMC, NFTSMC, and GNTSMC methods demonstrate superior performance, characterized by faster convergence, reduced chattering, higher tracking accuracy, and a model-free design. These results underscore the potential of the proposed control strategy to significantly enhance the robustness, precision, and applicability of robotic systems in industrial environments. Full article
(This article belongs to the Special Issue Advancements in Nonlinear Control Strategies)
Show Figures

Figure 1

24 pages, 5970 KiB  
Article
Adaptive Fault-Tolerant Control of Mobile Robots with Fractional-Order Exponential Super-Twisting Sliding Mode
by Hao Wu, Shuting Wang, Yuanlong Xie and Hu Li
Fractal Fract. 2024, 8(10), 612; https://doi.org/10.3390/fractalfract8100612 - 19 Oct 2024
Viewed by 1196
Abstract
Industrial mobile robots easily experience actuator loss of some effectiveness and additive bias faults due to the working scenarios, resulting in unexpected performance degradation. This article proposes a novel adaptive fault-tolerant control (FTC) strategy for nonholonomic mobile robot systems subject to simultaneous actuator [...] Read more.
Industrial mobile robots easily experience actuator loss of some effectiveness and additive bias faults due to the working scenarios, resulting in unexpected performance degradation. This article proposes a novel adaptive fault-tolerant control (FTC) strategy for nonholonomic mobile robot systems subject to simultaneous actuator lock-in-place (LIP) and partial loss-of-effectiveness (LOE) faults. First, a nominal fractional-order sliding mode controller based on the designed exponential super-twisting reaching law is investigated to reduce the reaching phase time and eliminate the chattering. To address the time-varying LIP faults and uncertainties, a novel barrier function (BF)-based gain is explored to assist the super-twisting law. An estimator is designed to estimate the lower bound of the time-varying partial LOE fault coefficients, thus without requiring the boundary information of faults that is commonly requested in traditional FTC schemes. Combined with the nominal controller clubbed with BF and estimator-based LOE fault compensation term, the fault-tolerant controller is finally constructed. The proposed FTC scheme achieves fast convergence and the sliding variables can be confined in a predetermined neighborhood of the sliding manifold under actuator faults. The results show that the proposed controller has superior tracking performance under faulty conditions compared with other state-of-the-art adaptive FTC approaches. Full article
(This article belongs to the Section Engineering)
Show Figures

Figure 1

18 pages, 3225 KiB  
Article
Research on Global Nonsingular Fast Terminal Sliding Mode Control Strategy of Ball Screw Feed System Based on Improved Double Power Reaching Law
by Qin Wu, Shunqian Zhou and Xinglian Wang
Actuators 2024, 13(10), 423; https://doi.org/10.3390/act13100423 - 18 Oct 2024
Viewed by 920
Abstract
Aiming at the problems of low trajectory tracking accuracy, serious chattering and poor robust performance of ball screw feed systems in traditional sliding mode control (SMC), in this paper, a global nonsingular fast terminal sliding mode control (GNFTSMC) strategy based on improved double [...] Read more.
Aiming at the problems of low trajectory tracking accuracy, serious chattering and poor robust performance of ball screw feed systems in traditional sliding mode control (SMC), in this paper, a global nonsingular fast terminal sliding mode control (GNFTSMC) strategy based on improved double power reaching law (DPRL) and extended state observer (ESO) is proposed. Firstly, the system state variable is introduced into the power term of DPRL, so that the improved DPRL has the characteristics of variable speed reaching, which solves the contradiction between the reaching rate and the sliding mode chattering. Secondly, ESO is designed to observe the state of the system and match the external disturbance to improve the anti-interference performance of the system. Finally, GNFTSMC is designed for the ball screw feed system, and the global sliding mode factor is introduced to improve the trajectory tracking accuracy of the system. The results show that the proposed control strategy can effectively improve the tracking accuracy and anti-interference performance of the system. Full article
(This article belongs to the Section Control Systems)
Show Figures

Figure 1

Back to TopTop