Current Issue

  • Regular PapersMay 1, 2024

    Push-sum Distributed Dual Averaging Online Convex Optimization With Bandit Feedback

    Ju Yang, MengliWei, YanWang, and Zhongyuan Zhao*

    International Journal of Control, Automation, and Systems 2024; 22(5): 1461-1471

    https://doi.org/10.1007/s12555-023-0211-3

    Abstract

    Abstract : This paper investigates the distributed online convex optimization problem in multi-agent systems, where each node cannot directly access the gradient information of its own cost function. The communication topology is formed by the strongly connected time-varying directed graphs with the column stochastic weight matrices, where each node updates its own decisions by exchanging information with neighbouring nodes. It is not feasible to sample objective function values at several consecutive points simultaneously since the online setting is timevarying. To solve this problem over directed graphs, a push-sum one-point bandit distributed dual averaging (PSOBDDA) algorithm is proposed, where the one-point gradient estimator is employed to estimate the true gradient information, to guide the updating of the decision variables. Moreover, by selecting the appropriate exploration parameter δ and step sizes α(t), the algorithm is shown to achieve the sublinear regret bound with the convergencerate O(T56). Furthermore, the effect of one-point estimation parameters on the regret of the algorithm in online settings is explored. Finally, the performance of the algorithm is evaluated through simulation.

  • Regular PapersMay 1, 2024

    Abstract

    Abstract : This paper investigates secure semi-global bipartite consensus (SSGBC) of linear multi-agent systems (MASs) with input saturation under denial-of-service (DoS) attacks via dynamic event-triggered control (DETC). A distributed DETC protocol is proposed for avoiding redundant information transmission. Subsequently, by utilizing Lyapunov stability theory and a low-gain feedback based bipartite consensus algorithm, it is proved that SSGBC of linear MASs can be achieved under the proposed DETC protocol under the assumption that the frequency and the duration are limited. Moreover, Zeno behavior of each follower can be excluded. Finally, a simulation example is given to verify effectiveness of the proposed DETC protocol.

  • Regular PapersMay 1, 2024

    Abstract

    Abstract : This paper aims to optimize the performance of a scalar continuous-time linear time-invariant system, whose feedback information is transmitted through a rate-constrained communication network with random network delay. Due to the limitation of feedback network resources, the feedback information can not be available to the controller precisely and continuously. Moreover, the random transmission delay will reduce the amount of feedback information and degrade the performance of the concerned system. To resolve the above issues, we propose an event-triggered sampling strategy that can utilize the transmission resources more efficiently. Compared with the optimal time-driven sampling strategies and the optimal Lebesgue sampling strategies, our event-triggered sampling strategy can guarantee better performance under the same transmission constraints. The effectiveness of the proposed event-triggered sampling strategies is further illustrated via simulations.

  • Regular PapersMay 1, 2024

    Event-based Consensus of Double-integral Heterogeneous Hybrid Multiagent Systems With Communication Delays

    Yanhan Li, Hong Zhang, and Xuejun Ye*

    International Journal of Control, Automation, and Systems 2024; 22(5): 1499-1510

    https://doi.org/10.1007/s12555-022-0942-6

    Abstract

    Abstract : This paper investigates the issue of event-based consensus for double-integral heterogeneous hybrid multi-agent systems with communication delays under directed graphs. The system contains continuous-time and discrete-time subsystems, both of which are heterogeneous systems, including single-integral and double-integral agents. To achieve consensus among agents with different dynamics, two distributed event-based control algorithms are designed. Combined with the sampled-data approach, efficient event-triggered functions based on hybrid measurements are designed. Then, sufficient conditions of control parameters, sampling interval and coupling gains are proposed. By applying non-negative matrix theory, graph theory and other mathematical methods, consensus of fixed topology and switching topologies are proved with the assumption that the directed graph has a spanning tree. A simulation example finally confirms the effectiveness of the event-triggered protocols.

  • Regular PapersMay 1, 2024

    Quasi-time-dependent H∞ Control for Discrete-time Switched Systems With Time-varying Delay and Unstable Modes

    Xiaomin Liu, Baowei Wu*, Yue-E Wang, and Lili Liu

    International Journal of Control, Automation, and Systems 2024; 22(5): 1511-1525

    https://doi.org/10.1007/s12555-022-1085-5

    Abstract

    Abstract : The issues of stability, l2-gain analysis and H∞ control are addressed for a class of discrete-time switched systems subject to time-varying delay and unstable modes in this paper. To solve the problems, firstly, a hybrid mode-dependent average dwell time (HMDADT) switching strategy is designed by combining slow/fast switching strategy to cope with stable and unstable modes. And improved reciprocally convex combination inequality method is adopted to deal with time-varying delay. Then, by constructing a quasi-time-dependent (QTD) LyapunovKrasovskii functional (LKF) with triple sum, new sufficient criteria for global uniform asymptotic stability and l2-gain analysis of the constructed systems are presented. Moveover, based on the above results, a set of QTD H∞ controllers are designed to ensure that the corresponding closed-loop system is globally uniformly asymptotically stable (GUAS) with a prescribed weighted H∞ performance. The QTD controllers designed in this paper are less conservative than the time-independent ones. Finally, two examples are carried out to demonstrate the effectiveness and validity of the developed results.

  • Regular PapersMay 1, 2024

    Noise and Interference Suppression Control Method of DC-DC Buck Converters Based on Cascaded Filter LADRC

    Yufang Chang*, Feifei Zhou, Huaicheng Yan, Wencong Huang, and Guoao Luo

    International Journal of Control, Automation, and Systems 2024; 22(5): 1526-1536

    https://doi.org/10.1007/s12555-023-0003-9

    Abstract

    Abstract : Due to the high gain characteristics of the extended state observer (ESO), ADRC technology will be affected by high-frequency measurement noise in the buck circuit, the traditional method of using low-pass filters to filter the output signal will cause loss of amplitude and phase. A novel DC-DC buck noise and disturbance rejection control method based on a filter cascade-based linear active disturbance rejection control (F-CLADRC) is proposed to solve the above problems in this paper. Consequently, while suppressing noise, firstly, it can enhance LADRC’s ability to estimate and compensate for disturbances in real-time. Secondly, it can improve the system’s robustness and ensure the tracking accuracy. Thirdly, it can effectively compensate for the amplitude and phase loss caused by output filtering. A set of simulations conducted on the DC-DC buck converter system show that, the proposed method is more reasonable and effective compared with the conventional control methods.

  • Regular PapersMay 1, 2024

    The Relationship Between Augmented Lyapunov-Krasovskii Functionals and Estimated Inequalities

    Daixi Liao*, Shouming Zhong, Jun Cheng, Kaibo Shi, Shaohua Long, and Can Zhao

    International Journal of Control, Automation, and Systems 2024; 22(5): 1537-1544

    https://doi.org/10.1007/s12555-022-1233-y

    Abstract

    Abstract : Different estimated inequalities and augmented Lyapunov-Krasovskii functionals (LKFs) play important role in assessing the stability of time-delay systems. In this technical note, three categories of estimated inequalities are introduced, in which either all matrices, some matrices or no matrices are free. Then, the internal relationship among the three categories of estimated inequalities is fully revealed. Next, an optimal method is provided for selecting the estimated inequalities and constructing the Lyapunov-Krasovskii functionals. That is, the inequalities and the functionals should tailor for each other (see Table 2), which is proved theoretically. Finally, a numerical example is presented to verify the results.

  • Regular PapersMay 1, 2024

    On Scheduled Space-Time Convergence: Sliding Mode Control Through the Scheduled Time Function

    Weixiang Liu, Yutong Sun*, Haifeng Ma*, Zhenhua Xiong, Zhanqiang Liu, and Yangmin Li

    International Journal of Control, Automation, and Systems 2024; 22(5): 1545-1554

    https://doi.org/10.1007/s12555-022-0030-y

    Abstract

    Abstract : Previous researches on sliding mode control focus on the time or space domain, regardless of the combination of the two domains. This paper presents a new scheduled space-time barrier sliding mode control (SSTBSMC) scheme for disturbed systems. The SSTBSMC scheme is established based on the designed scheduled time function (STF). One uniqueness of the proposed scheme lies in that it ensures the scheduled space-time convergence, i.e., the sliding variable can converge into a scheduled space within a scheduled time. Besides, the scheduled space and time can be predetermined regardless of the initial condition and unified uncertainty. Moreover, the SSTBSMC scheme applies a more reasonable state-preserving upper bound assumption, removing the conservative assumption of constant upper bound on the unified uncertainty. In addition, the proposed scheme mitigates the overestimation of the control gain to attenuate chattering effect. The stability of the closed-loop disturbed system is verified by theoretical analysis. The effectiveness of the proposed scheme is confirmed through a series of simulations and experimental investigations.

  • Regular PapersMay 1, 2024

    Global Output Feedback Stabilization for Switched Nonlinear Systems Under Arbitrary Switching

    Shuyan Zhan, Xianglei Jia*, and Chengdi Xiang

    International Journal of Control, Automation, and Systems 2024; 22(5): 1555-1562

    https://doi.org/10.1007/s12555-022-0922-x

    Abstract

    Abstract : Global stabilization of a class of switched nonlinear systems with unknown arbitrarily switched output function is achieved via output feedback. A couple of improved high-gain observer and output feedback control law are proposed by using dual high-gain scaling technique. In the presence of non-differentiable output function, a common dynamic output feedback controller is established, where a generalized Lyapunov inequality is introduced with explicit calculation. By constructinga single Lyapunov function for all subsystems, it shows the closed-loop switched systems are globally asymptotically stable under arbitrary switching. Ultimately, two examples are given to illustrate the effectiveness of our control scheme.

  • Regular PapersMay 1, 2024

    Abstract

    Abstract : This paper addresses the control problem for a class of discrete event systems with disturbances, which is subject to mutual exclusion constraints (MECs). Our aim is to propose a new analytical method for designing control laws to guarantee a set of MECs in network timed event graphs (NTEGs) with uncontrollable input transitions. To develop this control law, linear min-plus equations are used to describe the behavior of the NTEGs and min-plus inequalities to translate the specifications to be satisfied. Sufficient conditions for the existence of causal control laws are established. These calculated laws are represented by control places that will supervise the NTEGs to ensure that constraints are respected. To demonstrate the effectiveness of the suggested approach, an illustrative application on an assembly system is carried out.

  • Regular PapersMay 1, 2024

    Stabilizing Switching Force Control for the Hunt-Crossley Model

    Yun-Jae Yang, Jeong-Un Nam, and Tae-Woong Yoon*

    International Journal of Control, Automation, and Systems 2024; 22(5): 1573-1584

    https://doi.org/10.1007/s12555-023-0426-3

    Abstract

    Abstract : This paper proposes a switching control scheme for the Hunt-Crossley model, which represents the behavior of contact between two surfaces in mechanical systems. The scheme comprises a PID force feedback controller and a position/velocity feedback controller. Its objective is to apply the desired amount of pressure while ensuring closed-loop stability. The PID force feedback controller operates in contact mode, while the position/velocity feedback controller operates in non-contact mode. For the PID control, a non-quadratic Lyapunov function is devised together with an invariant domain of attraction within the contact region, including the equilibrium steady state. For the non-contact region where the state trajectories stay only temporarily, the position/velocity feedback control is equipped with a disturbance compensation term on the basis of a Lyapunov min-max approach, which leads to a quadratic Lyapunov function. Notice the two different ways of achieving infinite gain operation for handling modeling errors and disturbances: infinite gain at DC, resulting from integral action in the contact mode, and infinite gain at equilibrium, resulting from the use of a signum function in the non-contact mode. The asymptotic stability of the overall switching control system is proven by demonstrating that the two Lyapunov functions defined in the contact and non-contact regions satisfy certain decreasing properties. Simulations confirm that the applied force closely tracks the desired value in the presence of a DC disturbance and model uncertainty.

  • Regular PapersMay 1, 2024

    Decentralized Position/torque Control of Modular Robot Manipulators via Interaction Torque Estimation-based Human Motion Intention Identification

    Yuexi Wang, Tianjiao An, Yiming Cui, Yuanchun Li, and Bo Dong*

    International Journal of Control, Automation, and Systems 2024; 22(5): 1585-1600

    https://doi.org/10.1007/s12555-023-0004-8

    Abstract

    Abstract : For the application background of physical human robot interaction (pHRI), a novel decentralized position/torque control scheme of modular robot manipulators (MRMs) is developed based on the human motion intention identification in this investigation. Different from traditional control schemes which are oriented to pHRI tasks depending on the biological signal or the multisensory, the developed decentralized position/torque control is realized by utilizing only position measurements of each joint module in this paper. A novel extend state observer (ESO)-based interaction torque estimation method is proposed to identify the human motion intention that can provide motion tracking information for robots in pHRI tasks by using only joint local dynamic information. In addition, the interaction torque estimation is utilized to design the decentralized position/torque control scheme which can implement high-performance of interaction torque tracking and position tracking. The trajectory tracking error and the interaction torque tracking error of the closed-loop MRM system are uniformly ultimately bounded (UUB) which is proved by Lyapunov theory. Finally, pHRI experiment is utilized to verify the effectiveness and advancement of the proposed method.

  • Regular PapersMay 1, 2024

    Observer-based Fixed-time Output Feedback Control for Flexible-joint Manipulators via Improved Command-filtered Backstepping

    Shengxuan Fan, Hengheng Liu, Senping Tian* and Panpan Gu

    International Journal of Control, Automation, and Systems 2024; 22(5): 1601-1612

    https://doi.org/10.1007/s12555-022-0941-7

    Abstract

    Abstract : In this paper, an observer-based fixed-time output feedback control method for flexible-joint manipulators is proposed. First, a novel extended-state observer is designed to estimate unmeasurable states and lumped disturbances exactly in a fixed time, and the chattering phenomenon caused by discontinuous terms is reduced to a considerable extent by adding the order of observer by one. Then, a novel fixed-time command filter is designed to eliminate the ‘explosion of complexity’ in backstepping without chattering phenomenon. Next, the control laws are designed to ensure the tracking errors converge to a small neighborhood of the origin in a fixed time. Finally, simulation examples are carried out to illustrate the effectiveness of the proposed method.

  • Regular PapersMay 1, 2024

    Quadrupedal Locomotion in an Energy-efficient Way Based on Reinforcement Learning

    Tiantian Hao*, De Xu, and Shaohua Yan

    International Journal of Control, Automation, and Systems 2024; 22(5): 1613-1623

    https://doi.org/10.1007/s12555-022-1218-x

    Abstract

    Abstract : Achieving energy-efficient motion is important for the application of quadruped robots in a wide range. In this paper, we propose a hierarchical control framework that combines reinforcement learning and virtual model control to achieve energy-efficient motion with a planned gait. A reinforcement learning network is designed to learn the policy that maps the state of the robot to the action. The action is the increment of stance ratio, one of the gait parameters. The learned policy network is used as a high-level gait parameter modulator to adjust the gait parameters according to the body’s velocity. The virtual model control method is used to compute the required force of robot’s body. Then this force is decomposed to the feet of the stance legs with quadratic programming optimization. In the lowest level, the proportional-derivative controllers are used to control the joints’ motion. Simulation and experiments are well conducted on the robot A1. The experimental results verify the effectiveness of the proposed method.

  • Regular PapersMay 1, 2024

    Adaptive Dynamic Formation Control of Robotic Vehicle Systems Based on Rigid Graph Theory

    Guanglei Zhao*, Lu Luo, and Changchun Hua

    International Journal of Control, Automation, and Systems 2024; 22(5): 1624-1635

    https://doi.org/10.1007/s12555-023-0189-x

    Abstract

    Abstract : In this paper, dynamic formation problem of three-dimensional (3D) robotic vehicle systems with nonholonomic constraint and dynamics model is investigated. The control objectives are to achieve formation acquisition (i.e., vehicles form a predefined geometric shape) and formation maneuvering (vehicles move as a whole following predefined velocity). For the first objective, the nonlinear model is transformed into a dynamic model similar as the Euler-Lagrangian system with uncertain parameters. Then, we propose a rigid graph based adaptive dynamic formation control law, which enables the robotic vehicle system to converge to the target formation. Meanwhile, collision avoidance between vehicles can be achieved because the rigid graph theory naturally ensures the distance constraint. Then, formation maneuvering problem is investigated, on the basis of formation acquisition, a predefined velocity signal is added to the proposed adaptive formation control law such that robotic vehicles move as a whole following the predefined velocity. Compared with the existing results, the proposed rigid graph based formation control method can effectively reduce the appearance of non-desired equilibrium points of traditional distance based methods, moreover, the distance between robot vehicles can be time-varying, and the formation shape or size can be time-varying. Simulation results confirm the effectiveness of the dynamic formation control law.

  • Regular PapersMay 1, 2024

    A Novel Impedance Control Based on Equivalent Stiffness for Hydraulic Single-leg Robot

    Pengyu Zhao*, Anhuan Xie, Shiqiang Zhu, Lingkai Chen, Lingyu Kong, and Dan Zhang

    International Journal of Control, Automation, and Systems 2024; 22(5): 1636-1653

    https://doi.org/10.1007/s12555-022-0264-8

    Abstract

    Abstract : This paper presents a proposed strategy for improving the position-tracking accuracy of force-based impedance control in hydraulic single-leg robots. Initially, the mechanical structure and drive system of the single-leg robot are introduced. Subsequently, a kinetic and dynamic model is developed to determine the desired position and force for each joint based on the given action. The proposed strategy, called equivalent stiffness impedance control, is then presented. It combines a penalty function and the stiffness of each joint near the desired position to calculate the equivalent stiffness. Simulations and experiments are conducted to evaluate the performance of the control strategy. The results demonstrate that the proposed strategy achieves fast response speed and high position tracking accuracy. Moreover, the mechanical characteristics near the desired position are comparable to traditional impedance control. This research provides valuable insights for impedance control in bionic-legged robots.

  • Regular PapersMay 1, 2024

    Data-based Vehicle Trajectory Prediction Model for Lane-change Maneuver

    Wansik Choi and Changsun Ahn*

    International Journal of Control, Automation, and Systems 2024; 22(5): 1654-1665

    https://doi.org/10.1007/s12555-023-0478-4

    Abstract

    Abstract : Several advanced driver assistance systems (ADASs) control a vehicle in the longitudinal direction. However, an ADAS that controls the vehicle in the lateral direction is uncommon since it requires the accurate lateral position prediction of the target vehicle because of the small safety margin in this direction. To reduce this problem, we suggest a data-based vehicle trajectory prediction model that mimics the human ability to predict the trajectory. The proposed model focuses on the lane-change maneuver because it is the most frequent and hard to predict from the road geometry, unlike other lateral maneuvers. The model is composed of four models to acquire interpretable outcomes. The first model predicts the longitudinal trajectory. The second and third models predict the lane-change maneuver and the time to lane change, and the last model predicts the lateral trajectory. These models are based on a recurrent neural network to consider the sequential characteristics of the input data. To train the proposed model, we generated a dataset that includes a vehicle’s lateral dynamics information using the NGSIM I-80 dataset. To validate the proposed model, a test set in the dataset is used. The proposed model shows better accuracy than baseline methods based on vehicle kinematics.

  • Regular PapersMay 1, 2024

    MPC-based Lateral Motion Control for Autonomous Vehicles Through Serially Cascaded Discretization Method Considering Path Preview

    Guozhu Zhu, Hao Jie, Zekai Zheng, and Weirong Hong*

    International Journal of Control, Automation, and Systems 2024; 22(5): 1666-1679

    https://doi.org/10.1007/s12555-023-0008-4

    Abstract

    Abstract : Autonomous vehicles have gained popularity over the past few years. In this paper, an MPC-based lateral motion controller for autonomous vehicles through serially cascade discretization method is developed. A single discretization method in the entire prediction horizon is usually adopted in MPC. This article seeks to cascade discretization methods of different levels of precision within a single prediction horizon to realize a tradeoff between path tracking accuracy and real-time performance. Leveraging the nature of MPC, a high-fidelity plant model obtained by orthogonal collocation discretization method in the first part of the prediction horizon continuously provides a high quality of control, while the rest of the horizon can be extended by Euler method at a low computational cost. For the specific high-speed driving condition, a prediction horizon expansion strategy considering path preview is combined with MPC to further improve the real-time performance on the premise of maintaining the path tracking performance. The proposed controller is validated in four cases on the MATLAB/Simulink and CarSim co-simulation platform. On average, the tracking error is reduced by 31.2% compared with the controller based on single Euler discretization and the online computing time is 27.3% less than the controller discretized by single orthogonal collocation method. The results show its effectiveness in improving path tracking accuracy and real-time performance. In addition, The viability of the proposed controller in the obstacle avoidance scenario is demonstrated.

  • Regular PapersMay 1, 2024

    Virtual-leader Split/Rejoin-based Flocking Control With Obstacle Avoidance for Multi-agents

    Jianhui Wu, Yuanfa Ji*, Xiyan Sun, and Weibin Liang

    International Journal of Control, Automation, and Systems 2024; 22(5): 1680-1690

    https://doi.org/10.1007/s12555-022-0950-6

    Abstract

    Abstract : In the research of flocking control algorithm with obstacle avoidance, the constraints of obstacle information, shape and boundary limit their practical applications. To relax these constraints, we assume that the agent can only perceive the position of static obstacle boundary points within its sensing radius, and propose a virtual-leader split/rejoin-based flocking control algorithm with obstacle avoidance. In this algorithm, the virtual-leader is divided into target virtual-leader and bypass virtual-leader, the bypass virtual-leader is designed to lead the agent to move along the boundary of static obstacles, and the target virtual-leader is designed to lead multi-agents split by static obstacles perturbation to re-aggregate and realize the group objective following. Additionally, the position cooperation term is designed to realize the separation and aggregation between agents and between the agent and static obstacle boundary points, and the velocity consensus term is designed to realize velocity matching. Then, the sufficient conditions that the agent does not collide are demonstrated. Finally, it is further verified by simulations that the proposed algorithm can relax the constraints of obstacle shape and boundary, and achieve better environmental adaptability.

  • Regular PapersMay 1, 2024

    Abstract

    Abstract : Lithium-ion batteries are currently used as a key energy source in various industrial facilities, electronics, and automotive industries. However, due to the frequent charging and discharging of batteries, overcharging and overdischarging can occur, leading to fire and safety accidents as well as additional financial damages due to equipment failure. Therefore, accurately estimating the battery state of charge (SOC) is very important. In this paper, the robustness of estimation models was analyzed in relation to data collected amidst sensor failures. This analysis was especially pertinent during the battery SOC estimation process, when voltage and current sensors were prone to failure. The impact of these sensor failures on the accuracy and reliability of the SOC estimation models was rigorously scrutinized. Normal data was trained as training data, and Gaussian distribution, Laplace and chi-square combined distribution, Add bias distribution were employed as the test data. Herein, multilayer neural network, long short-term memory, gated recurrent unit, gradient boosting machine (GBM) were used as neural networks, the failure signal processing performance of each estimation algorithm was compared and analyzed, and the failure diagnosis was performed using support vector machine and GBM.

  • Regular PapersMay 1, 2024

    Design and Simulation of Voltage Control System for Simscape Boost Converter Model With Disturbances

    Ibrahim Khalaf Mohammed

    International Journal of Control, Automation, and Systems 2024; 22(5): 1707-1716

    https://doi.org/10.1007/s12555-023-0311-0

    Abstract

    Abstract : In this paper, a voltage control system for an applicable Boost converter system under disturbances is presented. The voltage adjustment performance of the Boost converter is governed by a feedback PID controller system. The realism of the proposed power system is validated through using the Simscape environment, which is adopted to model and simulate the PID based Boost converter system. The presented Simscape system is more applicable in real-time than the Simulink model as the model of the Simscape components and devices is built based on practical considerations like tolerance and parasitic elements. PSO optimization algorithm is utilized to develop the performance of the PID controller through operating the converter system based on best values for PID gain parameters. The simulation design of the proposed power system is implemented in the Matlab tool and its results are presented and discussed to evaluate the performance of the presented feedback PID controller. To validate the robustness of the converter performance the voltage adjustment behavior of the PID controller is assessed based on disturbance of supply voltage, reference voltage and resistive load working conditions. Simulation results revealed the ability of the PID controller to reject the supply voltage disturbances and enable the Boost output to track the demand input trajectories effectively.

  • Regular PapersMay 1, 2024

    Study on Hybrid Vector and Sector Optimization of FCS-MPC for PWM Converter

    Shaomin Yan*, Chengmin Li, Yue Cui, Lingyi Yang, and Bin Cai

    International Journal of Control, Automation, and Systems 2024; 22(5): 1717-1727

    https://doi.org/10.1007/s12555-022-0411-2

    Abstract

    Abstract : Finite control set model predictive control (FCS-MPC) strategy for power converter system outputs single optimal vector by vector ergodic optimization algorithm, with flaws of low vector control accuracy, unfixed switching frequency and high computational burden for microprocessor. In this paper, a hybrid vector and sector model predictive control (HVS-MPC) strategy is proposed for medium and small power converter systems with high control frequency to improve system performance on three aspects. First, a sector optimization algorithm is adopted to reduce computational burden according to radiation range of basic vector and sector location of target vector. Second, a vector synthesis algorithm is adopted in linear modulation area to improve vector control accuracy with fixed switching frequency by vector operation time calculation and sequence setting. Third, in order to improve system performance in over modulation area without extra computational burden, the hybrid vector modulation algorithm is proposed based on target vector length and modulation area. Finally, the proposed strategy is verified through experiment and simulation.

  • Regular PapersMay 1, 2024

    Controller Design Based on a Synchronous Error Compensator for Wheeled Cross-coupled Systems

    Yeon-Beom Choi, Sang-Hoon Lee, and Doo-Hee Jung*

    International Journal of Control, Automation, and Systems 2024; 22(5): 1728-1738

    https://doi.org/10.1007/s12555-023-0687-x

    Abstract

    Abstract : This study proposes a method for operating wheeled cross-coupled systems. Wheeled cross-coupled systems are more sensitive to disturbances than other cross-coupled systems. When the slip phenomenon occurs in wheels, it causes synchronous errors between axles, resulting in differences in the controller outputs of the two axles. In the worst case, the two axles can end up competing. To solve this problem, this study introduces base controllers to each axle using a discrete-time variable structure control system with a decoupled disturbance compensator and an auxiliary controller, called a synchronous error compensator (SEC), to minimize synchronous errors arising from differences in the states of the two axles. Experiments are conducted on a verification system with a similar form of overhead hoist transfer (OHT) to demonstrate the effectiveness of the proposed method. Results reveal that the SEC generates control commands to make the control inputs (current command) and state variables (velocity feedback) of the two axles similar.

  • Regular PapersMay 1, 2024

    Analysis of Bandwidth Expansion and Interference Suppression of Digital Hydraulic Cylinder System

    Hui Yu*, Hui Wang, and Chenguang Guo

    International Journal of Control, Automation, and Systems 2024; 22(5): 1739-1750

    https://doi.org/10.1007/s12555-022-0589-3

    Abstract

    Abstract : This paper concentrates on digital hydraulic cylinder systems’ interference suppression and bandwidth expansion problems. The goals are to ensure the system’s stability and improve the rapid response-ability. First, a non-linear dynamics is used instead of linearization to formulate the plan. Then, considering the serious measurement noise of the load acceleration signal and the mismatching uncertainties of the electro-hydraulic servo system in practical applications, a new integral robust control strategy is proposed. Further, through the frequency-domain method, the selection laws of the feedback gains are determined. Finally, the control performance of the system is verified by simulation. The results show that the proposed controller can effectively control uncertainties and improve high-frequency tracking performance.

  • Regular PapersMay 1, 2024

    Abstract

    Abstract : This paper studies the fully cooperative game tracking control problem (FCGTCP) for a class of discretetime multi-player linear systems with unknown dynamics. The reference trajectory is generated by a command generator system. An augmented multi-player systems composed of the origin multi-player systems and the command generator system is constructed, and an exponential discounted cost function is introduced to derive an augmented fully cooperative game tracking algebraic Riccati equation (FCGTARE). When the system dynamics are known, a model-based policy iteration (PI) algorithm is proposed to solve the augmented FCGTARE. Furthermore, to relax the system dynamics, an online reinforcement Q-learning algorithm is designed to obtain the solution to the augmented FCGTARE. The convergence of designed online reinforcement Q-learning algorithm is proved. Finally, two simulation examples are given to verify the validity of the model-based PI algorithm and online reinforcement Q-learning algorithm.

IJCAS
May 2024

Vol. 22, No. 5, pp. 1461~1759

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