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Interference Suppression and Jitter Elimination Ability-Based Adaption Tracking Guidance for Robotic Fishes

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IEEE/CAA Journal of Automatica Sinica 2025年第1期 126-137页

作者： Dongfang Li Jie Huang Rob Law Xin Xu Limin Zhu Edmond Q.Wu IEEE the School of Electrical engineering and Automation Fuzhou University the Key Laboratory of System control and Information Processing Ministry of Education the School of Electrical engineering and Automation Fuzhou University 5G+Industrial Internet Institute Fuzhou University the University of Macau the college of mechatronics and Automation National University of Defense Technology the School of Mechanical engineering Shanghai Jiao Tong University the Department of Computer Science and engineering Shanghai Jiao Tong University

This work presents an adaptive tracking guidance method for robotic fishes. The scheme enables robots to suppress external interference and eliminate motion jitter. An adaptive integral surge line-of-sight guidance rule is designed to eliminate dynamics interference and sideslip issues. Limited-time yaw and surge speed observers are reported to fit disturbance variables in the model. The approximation values can compensate for the system's control input and improve the robots' tracking ***, this work develops a terminal sliding mode controller and third-order differential processor to determine the rotational torque and reduce the robots' run jitter. Then, Lyapunov's theory proves the uniform ultimate boundedness of the proposed method. Simulation and physical experiments confirm that the technology improves the tracking error convergence speed and stability of robotic fishes.

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High-precision solution to the moving load problem using an improved spectral element method

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Acta Mechanica Sinica 2018年第1期34卷 68-81页

作者： Shu-Rui Wen Zhi-Jing Wu Nian-Li Lu college of Shipbuilding engineering Harbin Engineering University School of mechatronics engineering Harbin Institute of Technology college of Aerospace and Civil engineering Harbin Engineering University

In this paper, the spectral element method(SEM)is improved to solve the moving load problem. In this method, a structure with uniform geometry and material properties is considered as a spectral element, which means that the element number and the degree of freedom can be reduced significantly. Based on the variational method and the Laplace transform theory, the spectral stiffness matrix and the equivalent nodal force of the beam-column element are established. The static Green function is employed to deduce the improved function. The proposed method is applied to two typical engineering practices—the one-span bridge and the horizontal jib of the tower crane. The results have revealed the following. First, the new method can yield extremely high-precision results of the dynamic deflection, the bending moment and the shear force in the moving load *** most cases, the relative errors are smaller than 1%. Second, by comparing with the finite element method, one can obtain the highly accurate results using the improved SEM with smaller element numbers. Moreover, the method can be widely used for statically determinate as well as statically indeterminate structures. Third, the dynamic deflection of the twin-lift jib decreases with the increase in the moving load speed, whereas the curvature of the deflection ***, the dynamic deflection, the bending moment and the shear force of the jib will all increase as the magnitude of the moving load increases.

关键词： Moving load Spectral element method Improved function Dynamic response High precision

Homogenization heat treatment for an additively manufactured precipitation-hardening high-entropy alloy

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Rare Metals 2022年第8期41卷 2853-2863页

作者： Zhi-Yuan Liu Xin-Yi Zhao Yao-Wen Wu Qiang Chen Bao-Hua Yang Pei Wang Zhang-Wei Chen Can Yang Additive Manufacturing Institute College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen518060China Sino-German college of Intelligent Manufacturing Shenzhen Technology UniversityShenzhen518118China

A precipitation-hardening high-entropy alloy(HEA),(FeCoNi)_(86)Al_(7) Ti_(7),was successfully fabricated using selective laser melting(SLM).Severe segregation of Ti occurred at the boundaries of dislocation ***,homogenization heat treatment at 1150℃for 0.5 h was performed to alleviate the *** homogenization,almost no dislocation cells were left in the grains,and recrystallization occurred as the average grain size increased from 37 to 54μ*** with the initial as-built HEA,the ductility of the HEA increases significantly from 29%to 40%,and the strength decreases slightly from 710 to 606 *** further aging,pre-homogenization can decrease the precipitation of ordered L2_(1) *** void has a high propensity to initiate from the matrix/L2_(1) incoherent interface,pre-homogenization reduced the number of weak points,thus considerably improving the plastic deformation ability of the aged HEA by 36%.In addition,the strengthening mechanism has also been analyzed for the aged *** was revealed that the coherent L1_(2)precipitate contributed the most to the increased strength.

关键词： High-entropy alloy Selective laser melting Homogenization heat treatment Strengthening mechanism

Adaptive backstepping control for levitation system with load uncertainties and external disturbances

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Journal of Central South University 2014年第12期21卷 4478-4488页

作者：李金辉李杰余佩倡王连春 college of mechatronics engineering and Automation National University of Defense Technology

To explore the precise dynamic response of the levitation system with active controller, a maglev guide way-electromagnet-air spring-cabin coupled model is derived firstly. Based on the mathematical model, it shows that the inherent nonlinearity, inner coupling, misalignments between the sensors and actuators, load uncertainties and external disturbances are the main issues that should be solved in engineering. Under the assumptions that the loads and external disturbance are measurable, the backstepping module controller developed in this work can tackle the above problems effectively. In reality, the load is uncertain due to the additions of luggage and passengers, which will degrade the dynamic performance. A load estimation algorithm is introduced to track the actual load asymptotically and eliminate its influence by tuning the parameters of controller online. Furthermore,considering the external disturbances generated by crosswind, pulling motor and air springs, the extended state observer is employed to estimate and suppress the external disturbance. Finally, results of numerical simulations illustrating closed-loop performance are provided.

关键词： maglev backstepping control nonlinearity mass variation adaptiveness extended state observer

Self-excited vibration problems of maglev vehicle-bridge interaction system

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Journal of Central South University 2014年第11期21卷 4184-4192页

作者：李金辉李杰周丹峰余佩倡 college of mechatronics engineering and Automation National University of Defense Technology

The self-excited vibration problems of maglev vehicle-bridge interaction system were addressed, which greatly degrades the stability of the levitation control, decreases the ride comfort, and restricts the cost of the whole system. Firstly, the coupled model containing the quintessential parts was built, and the mechanism of self-excited vibration was explained in terms of energy transmission from levitation system to bridge. Then, the influences of the parameters of the widely used integral-type proportion and derivation(PD) controller and the delay of signals on the stability of the interaction system were analyzed. The result shows that the integral-type PD control is a nonoptimal approach to solve the self-excited vibration completely. Furthermore, the differential-type PD controller can guarantee the passivity of levitation system at full band. However, the differentiation of levitation gap should be filtered by a low-pass filter due to noise of gap differentiation. The analysis indicates that a well tuned low-pass filter can still keep the coupled system stable.

关键词： maglev vehicle-bridge interaction system self-excited vibration energy

A new digital algorithm for the velocity translation vector

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Science China(Information Sciences) 2013年第8期56卷 237-249页

作者： SONG Min WU WenQi college of mechatronics engineering and Automation National University of Defense Technology

The error of the conventional sculling correction algorithm under maneuvers is analyzed through Taylor series expansion;a generalized error equation is *** frequency-series sculling algorithms in the digital algorithm for the velocity translation vector will cause the accuracy of the digital algorithm under maneuvers to decrease by one order in iteration time *** New sculling algorithms are developed and evaluated,which are as accurate as frequency-series sculling algorithms under vibrations,and are at least one order more accurate than frequency-series algorithms under *** new digital algorithms are constructed with the presented sculling algorithms for the velocity translation vector,which avoids the loss in accuracy of velocity translation vector under *** agree well with the analytical results.

关键词： sculling correction velocity translation vector maneuvers vibrations digital algorithm error evaluation

Mathematical modeling and analysis of thermodynamic processes in a twin-rotor piston engine

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Journal of Central South University 2014年第11期21卷 4163-4171页

作者：邹腾安徐海军潘存云徐小军陈虎 college of mechatronics engineering and Automation National University of Defense Technology

In order to study the major performance indicators of the twin-rotor piston engine(TRPE), Matlab/simulink was used to simulate the mathematical models of its thermodynamic processes. With consideration of the characteristics of the working processes in the TRPE, corresponding differential equations were established and then simplified by period features of the TRPE. Finally, the major boundary conditions were figured out. The changing trends of mass, pressure and temperature of working fuel in the working chamber during a complete engine cycle were presented. The simulation results are consistent with the trends of an actual working cycle in the TRPE, which indicates that the method of simulation is feasible. As the pressure in the working chamber is calculated, all the performance parameters of the TRPE can be obtained. The major performance indicators, such as the indicated mean effective pressure, power to weight ratio and the volume power, are also acquired. Compared with three different types of conventional engines, the TRPE has a bigger utilization ratio of cylinder volume, a higher power to weight ratio and a more compact structure. This indicates that TRPE is superior to conventional engines.

关键词： twin-rotor piston engine mathematic model thermodynamic process simulation utilization ratio of cylinder volume

A unified approach of observability analysis for airborne SLAM

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Journal of Central South University 2013年第9期20卷 2432-2439页

作者：方强黄新生 college of mechatronics engineering and Automation National University of Defense Technology

An unmanned aerial vehicle （UAV） is arranged to explore an unknown environment and to map the features it finds when GPS is *** navigates using a statistical estimation technique known as simultaneous localization and mapping （SLAM） which allows for the simultaneous estimation of the location of the UAV as well as the location of the features it *** is a key aspect of the state estimation problem of ***,the dimension and variables of SLAM system might be changed with new *** solve this issue,a unified approach of observability analysis for SLAM system is provided,through reorganizing the system *** dimension and variables of SLAM system keep steady,then the PWCS theory can be used to analyze the local or total observability,and under special maneuver,some system states,such as the yaw angle,become *** results validate the proposed method.

关键词： unmanned aerial vehicle (UAV) simultaneous localization and mapping (SLAM) inertial navigation system (INS) observability extend Kalman filter (EKF)

Prestiction friction compensation in direct-drive mechatronics systems

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Journal of Central South University 2013年第11期20卷 3031-3041页

作者：黎志强周擎坤张智永张连超范大鹏 college of mechatronics engineering and Automation National University of Defense Technology

LuGre model has been widely used in friction modeling and ***,the new friction regime,named prestiction regime,cannot be accurately characterized by LuGre model in the latest *** the extensive experimental observations of friction behaviors in the prestiction,some variables were abstracted to depict the rules in the prestiction *** upon the knowledge of friction modeling,a novel friction model including the presliding regime,the gross sliding regime and the prestiction regime was then presented to overcome the shortcomings of the LuGre *** reason that LuGre model cannot estimate the prestiction friction was analyzed in *** analysis of the proposed model in modeling the prestiction friction was also addressed.A parameter identification method for the proposed model based on multilevel coordinate search algorithm was *** proposed friction compensation strategy was composed of a nonlinear friction observer and a feedforward *** friction observer was designed to estimate the friction force in the presliding and the gross sliding *** the friction force was estimated based on the model in the prestiction *** comparative trajectory tracking experiments were conducted on a simulator of inertially stabilization platforms among three control schemes:the single proportional–derivative(PD)control,the PD with LuGre model-based compensation and the PD with compensator based on the presented *** experimental results reveal that the control scheme based on the proposed model has the best tracking *** reduces the peak-to-peak value(PPV)of tracking error to 0.2 mrad,which is improved almost 50%compared with the PD with LuGre model-based *** to the single PD control,it reduces the PPV of error by 66.7%.

关键词： prestiction friction LuGre model multilevel coordinate search friction compensation inertially stabilization platforms