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New Method for Type Synthesis of 2R1T Redundant Driven Parallel Mechanisms

Jixie Gongcheng Xuebao/Journal of Mechanical Engineering 2019年第23期55卷 25-37页

作者： Li, Yongquan Zhang, Yang Guo, Yu Li, Xuran Zhang, Lijie 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

In the fields of milling, riveting and welding, 2R1T DOF actuators are required, especially in high stiffness, large workspace, good driving stability and other occasions, redundant actuators are required to improve the performance of 2R1T parallel mechanism. Therefore, based on Grassmann linear geometry and atlas method, a new method for typy synthesis of 2R1T redundant actuated parallel mechanism is proposed. The degree-of-freedom curve of the moving platform is obtained according to the motion mode of the mechanism, and then the constraint curve of the moving platform is obtained according to the dual rule. The redundant constraint curve and its equivalent curve were obtained by adding redundant lines to the moving platform constraint curve. According to the allocation principle of branch chain constraint, it is divided into 7 schemes. The corresponding branch chain are constructed based on the constraint scheme by using the atlas method, and the preliminary type of the mechanism is synthesized according to the selection and allocation rule of the branch chain. Each scheme synthesizes 12, 67, 96, 0, 12, 48 and 16 new types respectively, and a total of 251 new types are synthesized, including some 2R1T redundant parallel mechanisms studied in literature. The instantaneous analysis of the synthesized mechanism is carried out by the atlas method, and it is found that the synthesized mechanism of scheme 1 and scheme 2 is instantaneous. An improved method of coaxial placement with a pair of parallel force constraints in this kind of mechanism is proposed to eliminate its instantaneity. The feasibility and rationality of the synthesis method are verified by instantaneous analysis. The method is also suitable for type synthesis of redundant 4, 5 and 6 DOF parallel mechanisms. © 2019 Journal of Mechanical Engineering.

关键词： Mechanisms

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Recurrence Plot Quantitative Analysis-Based Fault Recognition Method of Rolling Bearing

Recurrence Plot Quantitative Analysis-Based Fault Recognitio...

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Prognostics and System Health Management Conference (PHM-Qingdao)

作者： Wanlu Jiang Zhenbao Li Anqi Jiang Yafei Lei Haonan Wang Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao China Key Laboratory of Advanced Forging & Stamping Technology and Science (Yanshan University) Ministry of Education of China Qinhuangdao China

Aiming at the problem that rolling bearings are widely used but have high failure rate. A fault diagnosis method combined with local projective noise reduction method and recurrence plots quantification analysis for rolling bearings is presented. The fault vibration signals of rolling bearings are taken as the analysis objects. Firstly, the vibration signal is denoised by local projective noise reduction method. Then, the recurrence plots of denoised vibration signals are drawn. The system dynamic behavior reflected in the recurrence plots is extracted by recurrence quantification analysis. The determinism (DET) and entropy (ENTR) are selected to form the characteristic vectors. Finally, the characteristic vectors of the training samples are clustered by kernel fuzzy C-means (KFCM) clustering method. The minimum Euclidean distance principle is used to identify the test samples. Comparing the recurrence plot quantification analysis method with the quantitative feature method of phase space complex network. The results show that the recurrence plots quantification analysis-based fault diagnosis method of rolling bearings has a higher diagnosis rate.

关键词： Time series analysis Rolling bearings Complex networks Noise reduction Fault diagnosis Kernel Machinery

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Research on On-Board Geometric Information Measurement System of Road Restricting Based on the Binocular Stereo Vision Principle

Research on On-Board Geometric Information Measurement Syste...

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International Conference on Smart City and Systems Engineering (ICSCSE)

作者： Yuqin Zhao Jingchao Liu Runsheng Zhang Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of National Education Yanshan University Qinhuangdao Hebei China College of Vehicle and Energy Yanshan University Qinhuangdao Hebei China

ISBN: (纸本)9781509055319

This article developed an on-board road restrictions geometric information measurement system, it is based on the principle of binocular stereo vision. This thesis complete the stereo camera calibration, finished the establishment of stereo camera model. According to the characteristics of the bridges and tunnels' lower edge, this thesis proposes a bridge detection method based on vehicle vision. The results show that, the system has good real-time performance and high reliability, can effectively reduce the traffic accident like wedging or hitting bridges caused by over-height vehicles.

关键词： Image edge detection Bridges Cameras Vehicles Image segmentation Feature extraction

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Research on Algorithm of Braking Pressure Estimating for Anti-lock Braking System of Motorcycle

Research on Algorithm of Braking Pressure Estimating for Ant...

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2016 IEEE/CSAA International Conference on Aircraft Utility Systems(AUS)

作者： Jing YAO Yang ZHANG Juan WANG Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education of China Hebei Province Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University School of Mechanical Engineering Yanshan University

An effective pressure estimation algorithm of ABS for motorcycles was proposed in this paper to get the relatively accurate wheel cylinder ***,the performance characteristics of hydraulic control unit was studied and the vehicle model was established by using ***,the pressure estimation algorithms of master cylinder and wheel cylinder were *** estimated pressure is modified according to different vehicle braking ***,based on an actual motorcycle the wheel cylinder pressure was obtained under different pavements and braking initial speeds by ABS experimental platform to validate the effectiveness of wheel cylinder pressure estimation *** results show that the actual wheel cylinder pressure can be well tracked by the estimated wheel cylinder pressure with an allowable pressure error.

关键词： anti-lock braking system of motorcycle pressure estimation hydraulic control unit vehicle model

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The energy saving factor research of secondary regulation system of cement coating machine

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ICIC Express Letters, Part B: Applications 2015年第11期6卷 3077-3084页

作者： Kong, Xiangdong Luo, Hongliang Ai, Chao He, Long Dong, Yanwu Key Laboratory of Advanced Forging and Stamping Technology and Science Ministry of Education of China No. 438 Hebei Avenue Qinhuangdao China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University No. 438 Hebei Avenue Qinhuangdao China

The cement coating machine is widely used, but it wastes a lot of energy when braking. In order to overcome the weakness, secondary regulation system is put forward to recycle energy. Firstly the secondary regulation speed control system is proposed. Then the mathematical model of hydraulic secondary regulation system is established, and efficiency calculation method is derived. At last, through the simulation analysis and experimental verification, the feasibility of energy saving project is proved. With bigger slope and lower hydraulic pressure, the system can recycle more energy. © 2015 ICIC International.

关键词： Energy conservation

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Output Feedback Control of Hydraulic Driven Flexible Actuator with Imprecise Modeling

Output Feedback Control of Hydraulic Driven Flexible Actuato...

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第43届中国控制会议

作者： Huidong Hou Jinsong Zhao Yi Liu Xianwei Niu Yunpeng Zhang School of Mechanical Engineering Yanshan University State Key Laboratory of Crane Technology Yanshan University Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Key Laboratory of Advanced Forging and Stamping Technology and Science Ministry of Education

ISBN: (数字)9789887581581

ISBN: (纸本)9798350366907

In recent years,flexible soft robots have received increasing attention compared to rigid robots. The modeling of flexible actuators has always been difficult to solve. The control problem of hydraulic driven flexible actuators in this paper under the premise of imprecise modeling. In this paper,an innovative output feedback controller based on Unknown System Dynamics Estimator(USDE) is proposed to improve the position tracking accuracy of hydraulic driven flexible actuators with imprecise model. Firstly,the strict feedback high order electro-hydraulic servo system is transformed into a new standard form that incorporates servo valve dynamics. Therefore,controllers designed using traditional backstepping methods are rendered obsolete. Subsequently,a High-Gain Observer(HGO) is introduced for state reconstruction of the new system. To counteract the impact of lumped unknown system dynamics which include imprecise modeling dynamics of hydraulic driven flexible actuator,a USDE with straightforward parameter tuning and robust performance is introduced. Finally,both scalar containing error terms and USDE are integrated into the design of the output feedback controller. Experimental validation is conducted to demonstrate the effectiveness of the proposed method.

关键词： Electro-hydraulic servo system Flexible actuator Imprecise model estimation Output feedback control

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Reliability Prediction Method of Hydraulic System by Fuzzy Theory

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IFAC Proceedings Volumes 2013年第5期46卷 457-462页

作者： Dongning Chen Chengyu Yao Zhongkui Feng Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao China (Tel: ***) Key Laboratory of Advanced Forging & Stamping Technology and Science (Yanshan University) Ministry of Education of China Qinhuangdao China Key Laboratory of Industrial Computer Control Engineering of Hebei Province Yanshan University Qinhuangdao China

The hydraulic system's reliability is a key factor to ensure the reliable operation of equipment and it is very important to evaluate reliability of hydraulic system. The paper describes a reliability prediction method that may be used to evaluate the reliability of hydraulic systems for industrial applications. The proposed method takes advantage of fuzzy set theory. The aim of this method is to minimize the deficiencies of the traditional reliability prediction methods treating a failure rate as fixed value due to insufficiency practice data. Triangular fuzzy number and Gaussian fuzzy number are used in the application of this prediction method, where environmental factor, derating factor, and other factors are considered. Finally, an example of type crane's hydraulic system is given to verify the feasibility and practicability of the method.

关键词： Type crane Hydraulic system Reliability prediction Fuzzy theory Reliability logic diagram

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Reliability Optimization of Multi-state Hydraulic System Based on T-S Fault Tree and Extended PSO Algorithm

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IFAC Proceedings Volumes 2013年第5期46卷 463-468页

作者： Chengyu Yao Bin Wang Dongning Chen Key Laboratory of Industrial Computer Control Engineering of Hebei Province Yanshan University Qinhuangdao China (Tel: ***) Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao China Key Laboratory of Advanced Forging & Stamping Technology and Science (Yanshan University) Ministry of Education of China Qinhuangdao China

In order to overcome the difficulty of constructing the multi-state system's reliability optimization model, and the shortage of premature convergence of PSO (Particle Swarm Optimization) algorithm, a new reliability optimization method based on T-S fault tree and EPSO (Extended PSO) algorithm is proposed. According to the T-S fault tree and T-S rules of the events, the multi-state system reliability optimization model is constructed, at the same time, given constraint conditions on the system cost, weight and volume, and combined with the death penalty to construct the fitness function. Furthermore, EPSO algorithm based on the attraction and repulsion forces in the artificial physics is applied to the reliability optimization of multi-state hydraulic system. Comparing with PSO algorithm, the results of EPSO algorithm are in a better performance in obtaining global optimal solution.

关键词： Hydraulic system Reliability optimization Multi-state T-S fault tree EPSO algorithm

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Simulation and Experimental Research of Digital Valve Control Servo System Based on CMAC-PID Control Method

Simulation and Experimental Research of Digital Valve Contro...

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第六届工程机械与车辆工程新进展国际学术会议

作者： ZHAO Jin-song ZHAO Zi-ning WANG Zhi-peng ZHANG Chuan-bi YAO Jing 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 School of Mechanical Engineering Yanshan University

Digital valve control servo system is studied in this *** order to solve the system problems of poor control precision and slow response time,this paper proposes a CMAC-PID(Cerebellar model artic

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Fault diagnosis method for hydraulic pump based on order tracking

Fault diagnosis method for hydraulic pump based on order tra...

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International Conference on Fluid Power and Mechatronics (FPM)

作者： Wanlu Jiang Yong Zhu Meng Wang Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao China Key Laboratory of Advanced Forging & Stamping Technology and Science (Yanshan University) Ministry of Education of China Qinhuangdao China

ISBN: (纸本)9781479987719

Aiming at the problem of extracting fault features from hydraulic pump under variable rotating speed, a fault diagnosis method based on order tracking was proposed. Firstly, the original signal was decomposed by ensemble empirical mode decomposition into a series of intrinsic mode function (IMF) components. Afterwards, the fault sensitive IMF was selected by combining energy spectrum and spectral kurtosis. Secondly, the selected IMF was processed by Hilbert demodulation and down-sampling. Moreover, an appropriate frequency band was chosen and the signal was further processed by wavelet cluster-based bandpass filtering. Then, the fault sensitive envelope signal was obtained. Thirdly, the instantaneous frequency was extracted from the envelop signal by wavelet ridge tracking, and the time instant of phase discrimination was further calculated. Moreover, the even angle spaced resample was performed to the envelope signal. Then, the time domain non-stationary signal was transformed to the angular domain stationary signal. Finally, the stationary signal was analyzed by order tracking, and the fault diagnosis was executed according to the order spectrum. Furthermore, an application was performed to the vibration signals of hydraulic pump under variable rotating speed. The signals were respectively acquired in four typical states, which were normal, loose slipper, slipper wear and swash plate wear. Results indicate that the proposed method can effectively extract the fault features of hydraulic pump and further realize fault diagnosis.

关键词： Vibrations Fault diagnosis Feature extraction Time-domain analysis Pumps Valves Demodulation

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