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Thesis on combination stock forecasting model with wavelet denoising and optimized arima method

ICIC Express Letters 2014年第8期8卷 2315-2320页

作者： Shan, Rui Shi, Sutong Liu, Wen Zhao, Jingyi School of Science No. 438 Hebei Ave. Qinhuangdao 066004 China Key Laboratory of Advanced Forging and Stamping Technology and Science Ministry of Education of China No. 438 Hebei Ave. Qinhuangdao 066004 China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University No. 438 Hebei Ave. Qinhuangdao 066004 China

Stock market prediction is utility important in the economic system. With the rapid development of economy, stock data is becoming increasingly complex. This paper presents a new method using the principles of wavelet transform and wavelet denoising to de-noise the stock data, and then the improved Auto-Regressive Integrated Moving Average (ARIMA) model is used to predict the future trends of stock data. The presented model is compared with some other classical forecasting methods such as ARIMA model method, BP model method and the method proposed by Dai. The results tested with data indicate: this forecasting method introduced in this paper can realize multi-step prediction and the forecasting accuracy is higher than that of stock data which is predicted by the ARIMA model or the other forecasting model. © 2014 ICIC International.

关键词： Conjugate gradient method

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The feedback control and simulation of a new chaotic system

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ICIC Express Letters 2013年第11期7卷 2927-2932页

作者： Liu, Wen Cui, Yanling Zhao, Jingyi Zhang, Hui College of science Yanshan University No. 438 Hebei Ave Qinhuangdao 066004 China Key Laboratory of Advanced Forging and Stamping Technology and Science Ministry of Education of China Yanshan University No. 438 Hebei Ave Qinhuangdao 066004 China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University No. 438 Hebei Ave Qinhuangdao 066004 China

In this paper, a new 3D autonomous chaotic system is presented. The chaotic behavior of the system, the stability at the equilibriums and control problems are discussed. Based on Lyapunov stability theory, utilizing the feedback control method, the linear and nonlinear feedback controllers are designed. Under the effective controllers, the sufficient condition of the unstable equilibrium is obtained. The theoretical analysis and simulation results are given to show the effectiveness of the method. © 2013 ISSN 1881-803X.

关键词： Feedback control

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Positioning control of a one-DOF manipulator driven by pneumatic artificial muscles based on active disturbance rejection control

Positioning control of a one-DOF manipulator driven by pneum...

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第三十四届中国控制会议

作者： Ling Zhao Qi Li Hongjiu Yang Hongbo Li Hebei Province Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Key Laboratory of Advanced Forging & Stamping Technology and Science(Yanshan University) Ministry of Education of China College of Mechanical EngineeringYanshan University College of Mechanical Engineering Yanshan University Institute of Electrical Engineering Yanshan University Department of Computer Science and Technology Tsinghua University

The purpose of this paper is to study positioning control performance of the one-DOF manipulator driven by pneumatic artificial muscles using active disturbance rejection controller. Owing to the pneumatic artificial muscle's highly nonlinear and time-varying behavior, it is difficult to achieve good positioning performance. In this paper, the nonlinear and time-varying behavior of pneumatic artificial muscle is considered as disturbance to be estimated by extended state observer. Tracking differentiator is designed to get corresponding smooth signal and differential signal of reference input to avoid overshoot. A linear error feedback combining with estimated value compensation of disturbance is designed to ensure a good response of system. Moreover, stability analysis of the close-loop system is given by Lyapunov theory. Finally, simulation results verify the effectiveness of the proposed controller.

关键词： Active disturbance rejection control,positioning control,pneumatic artificial muscle,disturbance estimation

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A modified nls-dy conjugate gradient method

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ICIC Express Letters 2016年第12期10卷 2921-2925页

作者： Shan, Rui Qi, Changxia Zhao, Jingyi Xu, Yumin School of Science Yanshan University No. 438 Hebei Ave. Qinhuangdao066004 China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University No. 438 Hebei Ave. Qinhuangdao066004 China Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan University No. 438 Hebei Ave. Qinhuangdao066004 China

This paper proposes a modified NLS-DY conjugate gradient method with disturbance parameters. And under the strong Wolfe line search, the sufficient descent condition and the global convergence are established. At last, the results of numerical experiments demonstrate the effectiveness of the presented algorithm. © 2016 ICIC International.

关键词： Conjugate gradient method

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Type Synthesis of 3-Translational Redundant Actuated Parallel Mechanisms With Closed-Loop Branch Chains Based On Graphical Approach

Research Square

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Research Square 2021年

作者： Li, Yong-Quan Jiang, Hong-Sheng Zheng, Tian-Yu Xi, Ke-Long Jing, Han Zhang, Li-Jie Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education of China Yanshan University Qinhuangdao066004 China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao066004 China

The 3-translational parallel mechanism is widely used in industrial, medical, and military fields, among others. With the development of the national logistics industry, a pressing need for a kind of 3-translational parallel mechanism emerged. Such mechanisms have high stiffness and high bearing capacity and are used for cargo handling and sorting. A novel method based on the graphical approach was proposed for the synthesis of 3-translational redundancy actuated parallel mechanism with closed-loop branch chains. The new mechanism has four symmetrically arranged branch chains, which eases subsequent kinematics and dynamics analyses while providing good mechanical properties. Based on the graphical approach theory, according to the constraint number contained in the branch chain, two types of redundant driven branch chains with closed-loop structures were constructed. The first type includes rotation constraint in one direction, while the second type includes the rotation constraint in two directions. Based on various combinations of two branch chain types, their allocation schemes can be divided into two types. Moreover, said these two allocation schemes can be integrated into at least 500 and 400 types of 3-translational redundant actuated parallel mechanisms with closed-loop branch chains. Then, the degree of freedom properties of representative mechanisms were tested using the screw theory. A large number of novel mechanisms were integrated assessed using this method, and branch chains such mechanisms were symmetrically distributed. They have a strong bearing capacity, simple calculation, and control, and can be applied to the handling and sorting of goods, large-scale precision machine tools, and large construction machinery vibration isolation systems, among others. © 2021, CC BY.

关键词： Redundancy

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Effect of Process Parameters on the Formability, Microstructure and Mechanical Properties of Laser-Arc Hybrid Welding of Q355b Steel

SSRN

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SSRN 2022年

作者： Bi, Jiang Zhang, Liping Peng, Genchen Yuan, Xiaoming Li, Wen Zhang, Lijie Hebei Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao066004 China Jiangsu XCMG Construction Machinery Research Institution Ltd. Xuzhou221000 China Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education of China Yanshan University Qinhuangdao066004 China

Thick plate steel structure is widely used in construction machinery, pressure vessels, ships and other manufacturing fields. To obtain an acceptable welding quality and efficiency, the thick plate steel is always joined by laser-arc hybrid welding technology. In this paper, the Q355B steel with the thickness of 20 mm was taken as the research object, and the process of narrow groove laser-arc hybrid welding was studied. The results showed that the laser-arc hybrid welding method could realize one backing and two filling welding with the single groove angles of 8-12°. At different plate gaps of 0.5 mm, 1.0 mm and 1.5 mm, and the shape of weld seams were satisfied with no undercut, blowhole or other defects. The average tensile strength of welded joints was 486~493 MPa, and the fracture position was in the base metal area. Due to the high cooling rate, a large amount of lath martensite formed in heat affected zone (HAZ) and this zone exhibited higher hardness values. The impact roughness of the welded joint was almost 66-74 J with different groove angles. © 2022, The Authors. All rights reserved.

关键词： Microstructure

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The stability performances improvement through kinematic and dynamic modeling of the hopping robots

The stability performances improvement through kinematic and...

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UKACC International Conference on Control (CONTROL)

作者： Adrian Bruja Luige Vladareanu Gal Ionel Alexandru Hongbo Wang Hongnian Yu Jingjing Liu Institute of Solid Mechanics of Romanian Academy (IMSAR) Bucharest Romania School of Design Engineering and Computing Boumemouth University Poole Dorset UK Parallel Robot and Mechatronic System Laboratory of Hebei Province Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University Qinhuangdao China

The paper presents an innovative design for a wheeled hopping robot. Our main objective was to obtain a stable and efficient robot, which can jump over obstacles and has the ability to reach a certain ledge. The innovative design of our robot has the capability to jump to a certain distance even with a zero initial velocity provided by the wheels movement. Also, we took into consideration the wind speed which can prevent our robot to reach the desired destination, and compensated with an initial velocity on the direction of movement. For testing we designed a simulation which had as inputs different initial conditions to test and present the jumping capability of our robot in different jumping conditions. In the end we provide a jump area which the robot can reach for certain initial conditions, so we can later chose the optimal one for reaching the target position.

关键词： Mobile robots Springs Wheels Trajectory Collision avoidance Shafts

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Microstructure, Mechanical Properties and Multiphase Synergistic Strengthening Mechanisms of an Al14znmgzr Alloy Printed by Laser Powder Bed Fusion

SSRN

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SSRN 2024年

作者： Bi, Jiang Wang, Keqi Wu, Chen Chi, Jinze Liu, Bokun Zhang, Liping Chen, Xi Lu, Nannan Starostenkov, Mikhail Dmitrievich Dong, Guojiang Qin, Xikun Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education Yanshan University Qinhuangdao066004 China National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology Harbin150001 China Institute of Metal Research Chinese Academy of Sciences Shenyang110016 China General Physics Department Altai State Technical University Leninst. 46 Barnaul656099 Russia

In this work, a novel aluminum alloy with high Zn content was designed for laser powder bed fusion (LPBF) forming process. Aluminum alloy powder containing 14 wt.% Zn and 2 wt.% Zr was produced to conduct LPBF experiments with different process parameters. The analysis of the specimens revealed that the up facing surface exhibited an average microhardness peak value of 170.6 HV, achieving the ultimate tensile strength (UTS) of 573 MPa and the elongation of 11.6%. There was no significant change in grain size and a large amount of plate-like η' phase precipitated within the grains after aging treatment (120°C, 21h). The specimen reached the average microhardness peak of 181.7 HV and the UTS of 605 MPa. The principal strengthening mechanisms in the LPBF-formed samples were solid solution strengthening and grain refinement strengthening. After aging treatment, the precipitation of the second phase from solute atoms led to grain refinement strengthening and second-phase strengthening becoming the predominant factors to enhance the sample's strength. Al14ZnMgZr alloy have great application prospect in high strength and tough service environment. © 2024, The Authors. All rights reserved.

关键词： Aluminum alloys

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Forced responses of field modulated magnetic gear system

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ICIC Express Letters 2014年第7期8卷 2025-2030页

作者： Yuan, Xiaoming Zhang, Lijie Du, Bing Hao, Xiuhong Key Laboratory of Advanced Forging and Stamping Technology and Science Ministry of Education of China Yanshan University No. 438 Hebei Ave. Qinhuangdao 066004 China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University No. 438 Hebei Ave. Qinhuangdao 066004 China School of Mechanical Engineering Yanshan University No. 438 Hebei Ave. Qinhuangdao 066004 China

Considering the torque ripples on the rotors, the dynamic model and the dynamic differential equations of field modulated magnetic gear (FMMG) system are founded. When the excitation frequency is close to a certain natural frequency of FMMG system, the expressions of the forced responses are deduced and the laws of the resonance responses are discussed. Results show that the amplitude of only a certain degree of freedom is always much bigger than others, because the electromagnetic coupling stiffnesses are weaker than the supporting stiffnesses. Forced responses of FMMG system can provide the theoretical basis for the parameter optimization during designing. © 2014 ISSN 1881-803X.

关键词： Dynamic models

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Game Scene Construction for Lower Limb Rehabilitation Robot Based on Virtual Reality

Game Scene Construction for Lower Limb Rehabilitation Robot ...

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International Conference on Electromechanical Control technology and Transportation (ICECTT)

作者： Yongfei Feng Di Jin Qianjun Shao Jianye Niu Luige Vladareanu Hongbo Wang Faculty of Mechanical Engineering & Mechanics Ningbo University Ningbo China Hebei Key Laboratory of Robot Sensing and Human-Robot Interaction Hebei University of Technology Tianjin China Robotics and Mechatronic Department Institute of Solid Mechanics of the Romanian Academy Bucharest Romania Parallel Robot and Mechatronic System Laboratory of Hebei Province and Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University Qinhuangdao China

ISBN: (数字)9781728199283

ISBN: (纸本)9781728199290

At present, the number of patients with lower extremity dysfunction is increasing year by year. However, traditional rehabilitation training cannot meet the needs of patients for rehabilitation training. Rehabilitation robot is a good solution to train patients instead of the rehabilitation physician. Based on clinical practice experience, a lower limb rehabilitation training system based on virtual reality (VR) is designed, which combined the VR technology and rehabilitation evaluation program to improve the rehabilitation efficiency of patients. According to the functional requirements of the lower limb rehabilitation robot (LLR-RO), the construction of rehabilitation robot control system and sensor system is completed. Based on the Unity3D development environment, a VR scenes of space shooting is planned and created for rehabilitation training VR technology which enables patients to complete the training process while maintaining a pleasant mood. Through the software and hardware debugging, the feasibility, data transmission capability of VR-based remote rehabilitation training system and the synchronization performance of VR scenes and rehabilitation robots are verified. In the future, more virtual reality scenes will be studied to adapt to patients of different genders and ages.

关键词： Games Training Rehabilitation robotics Space vehicles Legged locomotion Aircraft Aerospace electronics

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