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Zhang J.,Nanjing University of Science and Technology | Bo Y.-M.,Nanjing University of Science and Technology | Tao D.-J.,Nanjing University of Science and Technology | Ye C.-B.,Chongqing Wangjiang Industrial Co.
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010 | Year: 2010

Considering a class of networked control systems with time-varying delays, the fault detection is carried out with the presence of output delays and packet dropout in sensor data. By increasing sampling frequency in controller and equally dividing the sampling period of the sensor, the time delays could be approximate to an integral multiple of the sampling period of the controller. On this basis and the conditions of data arrival of controller, the error equation of the fault observer was constructed based on a discrete asynchronous dynamical system. And a linear matrix inequality gave the stability condition of this observer. When the system was normal, if the given inequality condition was satisfied, the observer system was stable. When a fault was present, the observer residue could change rapidly and detected the occurrence of the fault. Finally, an illustrative example was given to demonstrate the effectiveness of the proposed method. © 2010 IEEE. Source


Zhang S.,Chongqing University | Song C.,Chongqing University | Zhai H.,Chongqing University | Bai H.,Chongqing Wangjiang Industrial Co. | Zhu C.,Chongqing University
Chongqing Daxue Xuebao/Journal of Chongqing University | Year: 2015

Since the wind turbines are installed on the flexible support tower, the drive train of the wind turbines runs under severe work conditions with varying wind directions and loads. So its failure rate is high and it is the bottle neck of the wind power development. This work presents a study which takes the coupling effect of oscillating of tower barrel and the twisting vibration of driven train into account. Using the lumped parameter method, a coupled dynamic model for the megawatt wind turbine drive train is built by considering the flexible tower barrel support effects. Then, the dynamic characteristics of the megawatt wind turbine drive train are analyzed. The Campbell chart is used in this research to analyze the potential resonance points. And the potential resonance frequencies between the cutting in and cutting out rotational speed of the drive train are obtained. Finally, Simpack is used to analyze the dynamic characteristics of drive train and verify the correctness of the proposed method. ©, 2015, Chongqing Medical University. All right reserved. Source


Zhang J.,Nanjing University of Science and Technology | Bo Y.-M.,Nanjing University of Science and Technology | Ye C.-B.,Chongqing Wangjiang Industrial Co.
Key Engineering Materials | Year: 2011

Considering a class of networked control systems built around wireless sensor networks (WSN), the control method is carried out when the output delays are present. Firstly, by studying the characteristics of data transmission with wireless sensor networks, the original system state vector was augmented, and the augmented state feedback control system was obtained. Secondly, the equation of the closed-loop control system was equal to the discrete switched system related to the hop count of the wireless transmission. Finally, a simulation example was given to demonstrate the effectiveness of the proposed method. © (2011) Trans Tech Publications. Source


Jian Y.,Chongqing University | Li Q.,Chongqing University | Cheng H.,Chongqing University | Lai B.,Chongqing Wangjiang Industrial Co.
Advanced Materials Research | Year: 2012

Kinematic accuracy is a key reason which influence workpiece's geometric error precision on traditional working process of precisely CNC(Computerized Numerical Control)P3G(polygon profile with 3 lobes) grinding machine. A systematic geometric error model has been presented for CNC P3G grinding machine, proposed multi-body system theory integrate with the structure of CNC P3G grinding machine tools, researched on the machine's space geometric errors. By means of separate geometric errors from the machine tools, build geometric mathematical error model. Then, identify 21 error parameters through method of 9 lines, analysis and calculate the total space geometric errors of the workpiece and wheel. Finally, formed a parameter-list and applied software error compensational technique, achieved real-time control to the motions of workpiece and wheel. Experimental results shown that the geometrical error modeling technique is accurate and efficient, and the precision of CNC P3G grinding machine is highly raised 70%. © (2012) Trans Tech Publications, Switzerland. Source


Song Y.,Chongqing Wangjiang Industrial Co. | Li G.,Chongqing Wangjiang Industrial Co. | Li G.,Chongqing University | Chen X.,Chongqing Wangjiang Industrial Co. | And 2 more authors.
Chongqing Daxue Xuebao/Journal of Chongqing University | Year: 2015

Gear micropitting phenomenon is common in megawatt-class wind turbine gearbox because of the hard operating environment and complicated load case. More and more attention has been paid to it during recent years. Main factors influencing gear micropitting, such as surface roughness, modification coefficient, oil temperature, are discussed in this paper according to ISO/TR 15144-1:2010. Reasonable values for the factors are suggested and software for calculating micropitting is developed. Based on observation and discussion, measures for reducing gear micropitting risk in wind turbine gearbox design are proposed. ©, 2015, Chongqing Medical University. All right reserved. Source

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