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A Closed-Loop Dynamic Controller for Active Vibration Isolation Working on A Parallel Wheel-Legged Robot

Chinese Journal of Mechanical Engineering 2023年第3期36卷 147-160页

作者： Fei Guo Shoukun wang Daohe Liu junzheng wang School of Automation Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Human Factors Engineering China Astronaut Research and Training CenterBeijing 100094China China State Shipbuilding Corporation Systems Engineering Research Institute Beijing 100048China

Serving the Stewart mechanism as a wheel-legged structure,the most outstanding superiority of the proposed wheel-legged hybrid robot(WLHR)is the active vibration isolation function during rolling on rugged terrain.However,it is difficult to obtain its precise dynamic model,because of the nonlinearity and uncertainty of the heavy robot.This paper presents a dynamic control framework with a decentralized structure for single wheel-leg,position tracking based on model predictive control(MPC)and adaptive impedance module from inside to outside.Through the Newton-Euler dynamic model of the Stewart mechanism,the controller first creates a predictive model by combining Newton-Raphson iteration of forward kinematic and inverse kinematic calculation of Stewart.The actuating force naturally enables each strut to stretch and retract,thereby realizing six degrees-of-freedom(6-DOFs)position-tracking for Stewart wheel-leg.The adaptive impedance control in the outermost loop adjusts environmental impedance parameters by current position and force feedback of wheel-leg along Z-axis.This adjustment allows the robot to adequately control the desired support force tracking,isolating the robot body from vibration that is generated from unknown terrain.The availability of the proposed control methodology on a physical prototype is demonstrated by tracking a Bezier curve and active vibration isolation while the robot is rolling on decelerate strips.By comparing the proportional and integral(PI)and constant impedance controllers,better performance of the proposed algorithm was operated and evaluated through displacement and force sensors internally-installed in each cylinder,as well as an inertial measurement unit(IMU)mounted on the robot body.The proposed algorithm structure significantly enhances the control accuracy and vibration isolation capacity of parallel wheel-legged robot.

关键词： Wheel-legged hybrid robot Adaptive impedance control Model predictive control Stewart mechanism Vibration isolation Parallel robot

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Lightweight Network Ensemble Architecture for Environmental Perception on the Autonomous System

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工程与科学中的计算机建模（英文） 2023年第1期134卷 135-156页

作者： Yingpeng Dai junzheng wang Jing Li Lingfeng Meng Songfeng wang School of Automation Beijing Institute of TechnologyBeijing100081China Institute of Tobacco Research of CAAS Qingdao266000China

It is important for the autonomous system to understand environmental information.For the autonomous system,it is desirable to have a strong generalization ability to deal with different complex environmental information,as well as have high accuracy and quick inference speed.Network ensemble architecture is a good choice to improve network performance.However,it is unsuitable for real-time applications on the autonomous system.To tackle this problem,a new neural network ensemble named partial-shared ensemble network(PSENet)is *** changes network ensemble architecture from parallel architecture to scatter architecture and merges multiple component networks together to accelerate the inference speed.To make component networks independent of each other,a training method is designed to train the network ensemble architecture.Experiments on Camvid and CIFAR-10 reveal that PSENet achieves quick inference speed while maintaining the ability of ensemble learning.In the real world,PSENet is deployed on the unmanned system and deals with vision tasks such as semantic segmentation and environmental prediction in different fields.

关键词： Neural network ensemble real-time application classification semantic segmentation

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Fault Diagnosis Method Based on Xgboost and LR Fusion Model under Data Imbalance

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Journal of Beijing Institute of Technology 2022年第4期31卷 401-412页

作者： Liling Ma Tianyi wang Xiaoran Liu junzheng wang Wei Shen School of Automation Beijing Institute of TechnologyBeijing 100081China

Diagnosis methods based on machine learning and deep learning are widely used in the field of motor fault diagnosis.However,due to the fact that the data imbalance caused by the high cost of obtaining fault data will lead to insufficient generalization performance of the diagnosis method.In response to this problem,a motor fault monitoring system is proposed,which includes a fault diagnosis method(Xgb_LR)based on the optimized gradient boosting decision tree(Xgboost)and logistic regression(LR)fusion model and a data augmentation method named data simulation neighborhood interpolation(DSNI).The Xgb_LR method combines the advantages of the two models and has positive adaptability to imbalanced data.Simultaneously,the DSNI method can be used as an auxiliary method of the diagnosis method to reduce the impact of data imbalance by expanding the original data(signal).Simulation experiments verify the effectiveness of the proposed methods.

关键词： imbalanced data fault diagnosis data augmentation method

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Event-Triggered Moving Horizon Pose Estimation for Spacecraft Systems

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Journal of Beijing Institute of Technology 2022年第4期31卷 382-390页

作者： Shuangxi Li Hengguang Zou Dawei Shi junzheng wang School of Automation Beijing Institute of TechnologyBeijing 100081China China Academy of Space Technology Beijing 100094China

An event-triggered moving horizon estimation strategy is proposed for spacecraft pose estimation.The error dual quaternion is used to describe the system state and construct the spacecraft attitude-orbit coupled model.In order to reduce the energy consumption on spacecraft,an event-triggered moving horizon estimator(MHE)is designed for real-time pose estimation with limited communication resources.The model mismatch caused by event-triggered is finally solved by solving the cost function of the min-max optimization problem.The system simulation model is built in Matlab/Simulink,and the spacecraft pose estimation simulation is carried out.The numerical results demonstrate that the designed estimator could ensure the estimation effect and save spacecraft communication and computing resources effectively.

关键词： state estimation pose estimation event-triggered moving horizon estimation

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Morphology and Field Emission of ZnO Nanomaterials at Different Positions

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Journal of Applied Mathematics and Physics 2022年第4期10卷 1028-1035页

作者： junzheng wang Lijun wang College of Science University of Shanghai for Science and Technology Shanghai China

By simply adjusting the temperature and the number of materials, rod-like ZnO with different morphology, such as ZnO nanoneedles, were synthesized by a flexible thermal evaporation method. The ZnO nanorod array has the lowest turn-on field, the highest current density, and the highest emission efficiency due to its good contact with the substrate and relatively weak field shielding effect. Experiments show that the morphology and orientation of one-dimensional ZnO nanomaterials have a great influence on its conduction field and emission current density, and the nanoarrays also contribute to electron emission. The research results have a certain reference value for the application of ZnO nanorod arrays as cathode materials for field emission devices.

关键词： Field Emission ZnO Films Vacuum Electron Beam Vapor Deposition

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High-adaption locomotion with stable robot body for planetary exploration robot carrying potential instruments on unstructured terrain

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Chinese Journal of Aeronautics 2021年第5期34卷 652-665页

作者： Kang XU Shoukun wang junzheng wang Xiuwen wang Zhihua CHEN Jinge SI School of Automation Beijing Institute of Technology.Beijing 100081China Key Laboratory of Intelligent Control and Decision of Complex System Beijing Institute of TechnologyBeijing 100081China Key Laboratory Ministry of Industry and Information Technology Beijing Institute of TechnologyBeijing 100081China

There is a strong demand for Planetary Exploration Mobile robots(PEMRs)that have the capability of the traversability,stability,efficiency and high load while tackling the specialized tasks on planet surface.In this paper,an electric parallel wheel-legged hexapod robot which has high-adaption locomotion on the unstructured terrain is presented.Also,the hybrid control framework,which enables robot to stably carry the heavy loads as well as to traverse the uneven terrain by utilizing both legged and wheeled locomotion,is also proposed.Based on this framework,robot controls the multiple DOF leg for performing high-adaption locomotion to negotiate obstacles via Gait Generator(GG).Additionally,by using Whole-Body Control(WBC)of framework,robot has the capability of flexibly accommodating the uneven terrain by Attitude Control(AC)kinematically adjusting the length of legs like an active suspension system,and by Force/torque Balance Control(FBC)equally distributing the Ground Reaction Force(GRF)to maintain a stable body.The simulation and experiment are employed to validate the proposed framework with the physical system in the planetary analog environments.Particularly,to smoothly demonstrate the performance of robot transporting heavy loads,the experiment of carrying 3-person load of about 240 kg is deployed.

关键词： Attitude control Gait generation High-adaption locomotion Obstacle avoidance Planetary exploration robot

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Event-triggered attitude tracking for rigid spacecraft

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Science China(Information Sciences) 2019年第12期62卷 178-193页

作者： Deheng CAI Hengguang ZOU junzheng wang Yuan HUANG Dawei SHI State Key Laboratory of Intelligent Control and Decision of Complex Systems School of AutomationBeijing Institute of Technology China Academy of Space Technology

This study aims to investigate the problem of attitude control for a spacecraft with inertial uncertainties, external disturbances, and communication restrictions. An event-triggered active disturbance rejection control approach is proposed for attitude tracking of the spacecraft. An event-triggered mechanism is introduced together with an extended state observer to jointly monitor the system states and total disturbances. The observation error is proved to be uniformly bounded. Based on the proposed control scheme,the integrated tracking system is shown to be asymptotically stable, implying successful attitude tracking of the spacecraft for the desired motion. Numerical results illustrate the effectiveness of the control strategy in achieving satisfactory tracking performance with a reduced data-transmission cost.

关键词： spacecraft attitude tracking active disturbance rejection control event-triggered control extended state observer

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Force Control of Electro-Hydraulic Servo System Based on Load Velocity Compensation

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Journal of Beijing Institute of Technology 2018年第3期27卷 326-333页

作者： Shoukun wang Hu Liu junzheng wang Deyang Zhang Key Laboratory of Intelligent Control and Decision of Complex Systems School of AutomationBeijing Institute of Technology

In an electro-hydraulic servo control system,the force servo system is an important component.However,due to the nonlinear characteristic of hydraulic systems,traditional control methods cannot achieve satisfactory control performances.To deal with this issue,a load velocity compensation algorithm based on the structural invariant principle is proposed in this paper.First,the theoretical analysis of the hydraulic and cylindrical force control system is presented,and the mathematical model of the force control system is established.Then the open-loop frequency response characteristics of the system are analyzed,in which the Bode diagram shows that the bandwidth of the system is obviously expanded after adopting the load velocity compensation algorithm.Finally,apractical hydraulic and cylindrical force servo system is introduced to validate the feasibility of the proposed controller,the experimental results demonstrate that the proposed method can improve the performance of force control and eliminate the influence of load stiffness on the dynamic characteristics of the system through a set of comparative experiments with different elastic loads.

关键词： electro-hydraulic servo control system force servo control load velocity compensation elastic load

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二氧化硅纳米片的合成与应用研究进展

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化学工业与工程 2024年第4期41卷 1-12页

作者：吴才军王军政天津大学化工学院

二氧化硅纳米片作为一种二维材料，兼备介孔特性，在生物医药、催化吸附和分离纯化等领域有着广泛的应用。由于二氧化硅缺乏层状前驱体，同时二维结构本身具有较高的表面能，导致合成出的纳米片有形状不规则、步骤繁琐和介孔孔径较小等... 详细信息

二氧化硅纳米片作为一种二维材料，兼备介孔特性，在生物医药、催化吸附和分离纯化等领域有着广泛的应用。由于二氧化硅缺乏层状前驱体，同时二维结构本身具有较高的表面能，导致合成出的纳米片有形状不规则、步骤繁琐和介孔孔径较小等系列问题。针对上述问题，从国内外二氧化硅合成的相关研究出发，阐述了不同合成方法的原理、总结出各自的优势及不足。此外，还介绍了二氧化硅纳米片在环境、生物和能源领域的应用，并对未来的应用研究方向进行了展望，可以为二氧化硅纳米片的进一步研究提供参考。

关键词：二氧化硅纳米片介孔二维材料

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Simplified Method for Joint Calibration of 3D Ladar and Monocular Camera

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Journal of Beijing Institute of Technology 2018年第3期27卷 319-325页

作者： Jing Li Liuzhi Yu junzheng wang Key Laboratory of Intelligent Control and Decision of Complex Systems School of AutomationBeijing Institute of Technology

To address the problem of data fusion between monocular camera image with 3 D data from laser detection and ranging(LADAR)sensor,this paper proposes a novel simplified scheme based on the planar feature method,which can meet the accuracy requirements of the joint calibration with fewer checkerboard calibration plate(CP)positions than traditional methods.First,a mathematical model of the joint calibration is established to obtain the calibration parameters.Secondly,the selection of positions and orientations of the CP are introduced and the corresponding influence to the calibration is analyzed.Then,the calibration result is optimized by using a nonlinear Levenberg-Marquardt(LM)optimization approach,and the distance residual method is utilized to estimate the accuracy.Finally,experimental results conclude that the minimum number of positions required to meet the joint calibration accuracy in the proposed method is 5,which is less than 12 in traditional methods.

关键词： 3D LADAR monocular camera joint calibration plane calibration method distance residual

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