Leader-following Consensus of First-order Multi-agent Systems with Dynamic Hybrid Quantizer

Huaitao Shi,Maxiao Hou,Yuhou Wu,Jin Guo,Dakuo Feng 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.11

In this paper, we propose a dynamic hybrid quantizer to reduce the burden of communication networks and on this basis, the leader-following consensus problem of first-order multi-agent systems is solved. This dynamic hybrid quantizer not only overcome the two disadvantages of the static quantizer: fixed quantization interval and infinite quantization level, but also reduce quantization error compared with dynamic uniform quantizer. Therefore, it can make the acceptable quantization errors for better system performance. Finally, the effectiveness of our approach is illustrated by theoretical derivation and numerical examples.

Enhanced-coupling-based Tracking Control of Double Pendulum Gantry Cranes

Huaitao Shi,Fuxing Yao,Zhe Yuan,Yunjian Hu,Ke Zhang,Ling Fu 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.7

Gantry cranes are mostly regarded as single pendulum models to research. However, gantry cranes will produce a double pendulum effect during the actual operation when the hook mass or cable length between the load and hook cannot be ignored. Aiming at the problems of working inefficiency, poor positioning accuracy and violent hook/load swing during the lifting process of gantry cranes, an enhanced-coupling-based tracking control method is proposed. By referring to a smooth tracking trajectory, the proposed method ensures that the trolley runs steadily. And by combining with the passivity analysis of the gantry crane system, a coupling signal, which enhances the relationship between system variables, is constructed. The system stability is proved strictly by Barbarat theorem and Lyapunov method. Experiments and simulations are performed to demonstrate the feasibility of the proposed method. The final results reflect that the proposed method, which can not only ensure the precise positioning of the trolley, but also restrain and eliminate the system swings promptly, has excellent control performance. When the system parameters are changed or external disturbances are added, the proposed method can also obtain outstanding control performance and has excellent robustness. Not only does the proposed method provide an antiswing strategy for double pendulum underactuated gantry cranes, but also it provides a possibility for the research and development of the automatic driving of gantry cranes, which has great practical significance and application prospects.

Incipient Fault Detection of Full Ceramic Ball Bearing Based on Modified Observer

Huaitao Shi,Maxiao Hou,Yuhou Wu,Baicheng Li 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.3

As a key part of the energy transmission chain, full ceramic ball bearing elements are considered as important components in ultraprecise rotating machines, which is required as a special attention in order to avoid expensive production shutdown due to the appearance of massive failures. Therefore, it is necessary to detect the appearance of incipient faults for full ceramic ball bearing elements by implementing an appropriate model. In this paper, an observer-based incipient fault detection method for full ceramic ball bearings is proposed. Firstly, the mechanism model of full ceramic ball bearing with incipient faults is established, and it is converted into a discrete-time model based on the zero-order hold equivalent method. Secondly, a modified observer is proposed as a residual generator, which has more design degrees of the freedom than the Luenberger observer. Thirdly, the l1/H∞ performance is introduced to enhance the disturbance robustness and incipient fault sensitivity. In addition, the design of an adaptive threshold can effectively avoid fault false alarms. Finally, the effectiveness of the proposed method is verified by numerical simulation.

Nonlinear Anti-swing Control of Underactuated Tower Crane Based on Improved Energy Function

Huaitao Shi,Jianqi Huang,Xiaotian Bai,Xiang Huang,Jie Sun 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.12

The control system of tower crane exhibits strong nonlinearity in the process of control execution, which is prone to the problems of inaccurate positioning control of the payload and difficult anti-swing control. Aiming at the problems, this paper proposes a control law based on improved energy coupling analysis for suppressing the payload swing in the tower cranes. A three-dimensional dynamic model of tower crane system with considering friction is established, and an improved energy coupling signal is designed. The coupling relationship of trolley movement and payload swing, jib rotation and payload swing are considered, then a nonlinear anti-swing controller is established in order to reduce the swing. The closed-loop stability of the system with the controller is verified by the Lyapunov method and LaSalle invariance principle, simulations and experimental analyses are performed to verify the controller performance. The control performance of the controller is compared with other classic and typical current control methods, and the proposed controller outperformed other controllers. The anti-swing controller proposed in this paper has accurate positioning, and can achieve precise control when the payload is transported, reaching the set target position in a little time and eliminating residual swing angle. Meanwhile the proposed controller has a good control robustness, which can restore stability in around a very short time when the rope length and payload mass of the system’s inherent property are changed and external interference is added. In addition, when different target position parameters are uncertain, the proposed control law has good robust performance.

Robust Decentralized Output Regulation of Heterogeneous Uncertain Linear Systems with Multiple Leaders via Distributed Adaptive Protocols

Ranran Li,Huaitao Shi 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.5

In the current paper we consider the robust decentralized output regulation of heterogeneous uncertainlinear systems with multiple leaders. A novel class of distributed observers is proposed. The states of the distributedobservers synchronize to the states of their leaders, respectively. In contrast to the existing results, we consider amore general class of systems and furthermore we utilize the adaptive protocols to estimate the coupling weightsbetween neighboring agents online. Therefore the observers and internal model based control laws can be designedin a purely distributed way, i.e., without knowledge of the associated matrix of the network topology. Finally weapply the proposed methods to solve the synchronization problem of a group of RLC networks and the simulationresults show the effectiveness of the methods.

A Variable Working Condition Rolling Bearing Fault Diagnosis Method Based on Improved Triplet Loss Algorithm

Ke Zhang,Jingyu Wang,Huaitao Shi,Xiaochen Zhang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.4

In the case of large differences in working conditions and large noise effects, how to maintain the similarity of the same fault type is a major difficulty in the rolling bearing fault diagnosis. In addition, variable working conditions will cause the signal take place the local modulation, which makes the signal more susceptible to noise. Most of classification algorithms are difficult to eliminate the influence of variable working conditions on diagnostic results. To solve the problem, a fault diagnosis method is proposed which takes into account the change of speed and load in this paper. The method first applies the synchronous compression wavelet transformation to pre-process the data to reduce the effect of noise on feature extraction. Then, the Triplet loss function is improved and combined with the Hard Samples Mining theory to proposes a new loss function called Quadru-Hard loss to solve the problem of difficult classification under variable working conditions. Based on the experimental analysis of two sets of bearing fault data under variable speeds and variable loads, the results show that the method has a highly accuracy in fault diagnosis under two variable conditions.

Neural Network Based Visual Servo Control Under the Condition of Heavy Loading

Shenghao Tong,Ke Zhang,Huaitao Shi,Jinbao Zhao,Jie Sun 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.9

This paper proposes an image-based visual servo (IBVS) control system for hoist positioning under the condition of heavy loading. Various advanced visual servo methods for positioning have been proposed. However, the visual servo scheme under heavy load condition remains the following problems: 1) The deformation and oscillation of the end-effector under the condition of heavy loading will lead to coordinate deviation of end-effector and visual frame, which makes the system unstable and brings more errors. 2) The vibration velocity and offset caused by deformation and oscillation are difficult to measure and model. To address these concerns, we first model the system error based on visual error and differentiate it. We obtain that the basic vector of the system error derivative contains the vector of vibration velocity, then we use the basic vector of derivative of the system error to build up the relationship between system error and vibration velocity. Moreover, we construct a double parallel feed forward neural network to estimate the basic vectors which contain vibration velocity and offset, and compensate for them. Also, we give the proof of the boundedness of the parameters based on Lyapunov theory. Simulation results depict the superior performance of the proposed method against the other advanced visual servo methods under the condition of heavy loading. Furthermore, experiments are conducted on the hoisting platform in our laboratory, which verifies the effectiveness of the proposed method.

The Damage Criterion Affecting Life Prediction of Fiber-Reinforced Al–Li Alloy Laminates Under Spectrum Loading

Meng Weiying,Li Yupeng,Zhang Xiaochen,Shi Huaitao,Zhang Yu,Lv Xiao 한국항공우주학회 2020 International Journal of Aeronautical and Space Sc Vol.21 No.4

Fiber metal laminates, as the new generation of aircraft structural materials, are widely concerned by material researcher. This paper presents a study on the life prediction problems of fiber-reinforced Al–Li alloy laminates under spectrum loading by applying the cumulative damage and residual strength models. Firstly, fatigue life performance of the laminate materials is tested under different loading cases. Then, the most advanced damage accumulation and residual strength models are summarized, which is applied to composite laminates. Some models are directly abandoned because the data needed for fitting model cannot be obtained by this experiment or the model formulation is prevented directly to the application for the spectrum blocks with free loading. Meanwhile, a cumulative damage model considering residual strength is modified accordingly based on the characteristics of life prediction under spectrum loading. To study the impacts of these models on the fatigue life prediction for fiber reinforced Al–Li alloy laminate under spectrum loading, the predicted accuracy of these models will be compared by applying them to life prediction problems of 2/1 laminate and 3/2 laminate. Results show that compared with other models, modified model improves the prediction accuracy especially for 3/2 laminate.