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Structure instability forecasting and analysis of giant rock pillars in steeply dipping thick coal seams

International Journal of Minerals,Metallurgy and Materials 2015年第12期22卷 1233-1244页

作者： Xing-ping Lai Huan Sun Peng-fei Shan Ming Cai jian-tao cao Feng Cui Energy School Xi’an University of Science and Technology Key Laboratory of Western Mines and Hazard Prevention (Ministry of Education of China) Bharti School of Engineering Laurentian University

Structure stability analysis of rock masses is essential for forecasting catastrophic structure failure in coal seam mining. Steeply dipping thick coal seams （SDTCS） are common in the Urumqi coalfield, and some dynamical hazards such as roof collapse and mining-induced seismicity occur frequently in the coal mines. The cause of these events is mainly structure instability in giant rock pillars sand- wiched between SDTCS. Developing methods to predict these events is important for safe mining in such a complex environment. This study focuses on understanding the structural mechanics model of a giant rock pillar and presents a viewpoint of the stability of a trend sphenoid fractured beam （TSFB）. Some stability index parameters such as failure surface dips were measured, and most dips were observed to be between 46° and 51°. We used a digital panoramic borehole monitoring system to measure the TSFB＇s height （△H）, which varied from 56.37 to 60.50 m. Next, FLAC^3D was used to model the distribution and evolution of vertical displacement in the giant rock pillars; the results confirmed the existence of a TSFB structure. Finally, we investigated the acoustic emission （AE） energy accumulation rate and observed that the rate commonly ranged from 20 to 40 kJ/min. The AE energy accumulation rate could be used to anticipate impeding seismic events related to structure failure. The results presented provide a useful approach for forecasting catastrophic events related to structure instability and for developing hazard prevention technology for mining in SDTCS.

关键词： coal mining structural instability rock pillars forecasting acoustic emission (AE) steeply dipping coal beds

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PARAMETRIC IDENTIFICATION OF PARALLEL MANIPULATOR WITH REDUNDANCY DRIVEN BY PNEUMATIC MUSCLES

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Chinese Journal of Mechanical Engineering 2008年第1期21卷 66-71页

作者： ZHU Xiaocong tao Guoliang cao jian State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

A new parameter estimation algorithm is proposed for parametric identification of a parallel manipulator driven by pneumatic muscles with redundancy. Due to the special physical properties of the parallel manipulator studied, the regression model for parametric identification is characterized by multieollinearity, which will result in unreliable and inaccurate parameter estimations with large eovarianee if the conventional parameter estimation algorithm based on single error minimizing criterion is used. To improve the quality of parameter estimation and achieve high precise posture trajectory tracking control of the parallel manipulator, a new parameter estimation algorithm based on composite error minimizing criterion is developed in need of theoretical contractive forces of pneumatic muscles. The experimental results indicate that the proposed algorithm integrated with adaptive robust control could provide reliable parametric identification and greatly enhance the control accuracy in the trajectory tracking control of the parallel manipulator, and that the variation of known theoretical contractive forces of pneumatic muscles has slight influence on the control performance.

关键词： Pneumatic muscle Parallel manipulator Redundancy Parameter estimation

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Pressure observer based adaptive robust trajectory tracking control of a parallel manipulator driven by pneumatic muscles

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第12期8卷 1928-1937页

作者： ZHU Xiao-cong tao Guo-liang cao jian The State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

This paper presents a pressure observer based adaptive robust controller (POARC) for posture trajectory tracking of a parallel manipulator driven by three pneumatic muscles without pressure sensors. Due to model errors of the static forces and friction forces of pneumatic muscles, simplified average flow rate characteristics of valves, unknown disturbances of entire system, and unmeasured pressures, there exist rather severe parametric uncertainties, nonlinear uncertainties and dynamic uncertainties in modeling of the parallel manipulator. A nonlinear pressure observer is constructed to estimate unknown pressures on the basis of a single-input-single-output (SISO) decoupling model that is simplified from the actual multiple-input-multiple-output (MIMO) coupling model of the parallel manipulator. Then, an adaptive robust controller integrated with the pressure observer is developed to accomplish high precision posture trajectory tracking of the parallel manipulator. The experimental results indicate that the system with the proposed POARC not only achieves good control accuracy and smooth movement but also maintains robustness to disturbances.

关键词： Pneumatic muscle Parallel manipulator Pressure observer Adaptive robust control Trajectory tracking

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Adaptive Robust Tracking Control of Pressure Trajectory Based on Kalman Filter

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Chinese Journal of Mechanical Engineering 2009年第3期22卷 433-439页

作者： cao jian ZHU Xiaocong tao Guoliang YAO Bin The State Key Lab of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China School of Mechanical Engineering Purdue University Lafayette IN 47907 USA

When adaptive robust control（ARC） strategy based on backstepping design is applied in pneumatic servo control, accurate pressure tracking in motion is especially necessary for both force and position trajectories tracking ofrodless pneumatic cylinders, and therefore an adaptive robust pressure controller is developed in this paper to improve the tracking accuracy of pressure trajectory in the chamber when the pneumatic cylinder is moving. In the proposed adaptive robust pressure controller, off-line fitting of the orifice area and on-line parameter estimation of the flow coefficient are utilized to have improved model compensation, and meanwhile robust feedback and Kalman filter are used to have strong robustness against uncertain nonlinearities, parameter fluctuations and noise. Research results demonstrate that the adaptive robust pressure controller could not only track various pressure trajectories accurately even when the pneumatic cylinder is moving, but also obtain very smooth control input, which indicates the effectiveness of adaptive model compensation. Especially when a step pressure trajectory is tracked under the condition of the movement of a rodless pneumatic cylinder, maximum tracking error of ARC is 4.46 kPa and average tracking error is 0.99 kPa, and steady-state error of ARC could achieve 0.84 kPa, which is very close to the measurement accuracy of pressure transducer.

关键词： pneumatic servo control adaptive robust control Kalman filter orifice area

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MODELING AND CONTROLLING OF PARALLEL MANIPULATOR JOINT DRIVEN BY PNEUMATIC MUSCLES

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Chinese Journal of Mechanical Engineering 2005年第4期18卷 537-541页

作者： tao Guoliang Zhu Xiaocong cao jian State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

A parallel manipulator joint driven by three pneumatic muscles and its posture control strategy are presented. Based on geometric constraints and dynamics, a system model is developed through which some influences on dynamic response and open-loop gain are analyzed including the supply pressure, the initial pressure and the volume of pneumatic muscle. A sliding-mode controller with a nonlinear switching function is applied to control posture, which adopts the combination of a main method that separates control of each muscle and an auxiliary method that postures error evaluation of multiple muscles, especially adopting the segmented and intelligent adjustments of sliding-mode parameters to fit different expected postures and initial states. Experimental results show that this control strategy not only amounts to the steady-state error of 0. 1° without overshoot, but also achieves good trajectory tracking.

关键词： Pneumatic muscle Parallel manipulator joint Sliding-mode controller Posture control

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Electrical Derivative Measurement of High-Power InGaAs LDs Under Scanning Current with Variable Step

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Chinese Journal of Electronics 2017年第3期26卷 508-513页

作者： tao Min GUAN jian GAO Fengli GAO Liangli cao Junsheng State Key Laboratory on Integrated Optoelectronics College of Electronic Science and Engineering Jilin University The 27th Research Institute China Electronics Technology Group Corporation Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences

For the large driving current of high-power semiconductor Laser diodes(LDs),a modified method to measure the electrical derivative of LDs under scanning driving current with variable step length is proposed,which is to achieve the fast and accurate measurement of optical and electrical characteristic parameters of LDs with a relatively small data *** experimental results show that,with fewer measurements,this method can effectively and accurately measure and extract the LDs corresponding parameters including threshold current(Ith),voltage-current characteristic(V-I),luminous power-current relation(P-I),electrical derivative curve(Id V/d I-I).The wavelet transformation singularity testing results of the threshold current also verify the accuracy,reliability,and advantage of this method.

关键词： Semiconductor laser diodes(LDs) Electrical derivative Scanning current Wavelet transform Singularity detection

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Roll gap prediction in acceleration and deceleration process of cold rolling based on a data-driven method

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Journal of Iron and Steel Research International 2023年第5期30卷 1013-1021页

作者： Yun-jian Hu Jie Sun Huai-tao Shi Qing-long Wang jian-zhao cao School of Mechanical Engineering Shenyang Jianzhu UniversityShenyang 110168LiaoningChina The State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina Department of Mechanical Engineering North China Electric Power UniversityBaoding 071003HebeiChina

Severe fluctuation of the effective roll gap in the acceleration and deceleration section of the cold rolling process is a significant factor causing thickness ***,the conventional roll gap compensation method and control strategy do not meet the stringent strip quality *** roll gap model in the acceleration and deceleration process is studied to increase the thickness control *** order to improve model accuracy,a roll gap prediction method based on data-driven is *** the complexities of the cold rolling process,the extreme gradient boosting(XGBoost)method is used to predict the roll gap model as the rolling speed ***,support vector regression and neural network-based methods are taken to evaluate and compare the prediction *** on the field data,the simulation experiments are carried *** demonstrated that the prediction performance of the proposed method outperformed the other two *** values of root mean square error,determination coefficient value,mean absolute percentage error and mean absolute error obtained from the XGBoost model were equal to 0.000346,0.952,7.02,and 0.00028,*** addition,the proposed method analyzed the contribution rates of the rolling affecting parameters on the roll *** data showed that in the controllable rolling parameters,the rolling speed is the most impacting factor that disturbs the roll gap model in the acceleration and deceleration process,which can provide a useful direction for actual roll gap adjustment.

关键词： Cold rolling Acceleration Deceleration Roll gap model Extreme gradient boosting Contribution rate Analysis

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Optimized shearing strategy for heavy plate based on contour recognition

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Journal of Iron and Steel Research International 2023年第9期30卷 1821-1833页

作者： jian-zhao cao Yu-xia Wang Shao-wen Huang Chang-tao Wang School of Computer Science and Engineering Shenyang Jianzhu UniversityShenyang 110168LiaoningChina Shandong Iron and Steel Co. Ltd.Jinan 271105ShandongChina School of Electrical and Control Engineering Shenyang Jianzhu UniversityShenyang 110168LiaoningChina

The shearing line is the key to improve the quality and efficiency of heavy plates.A model of contour recognition and intelligent shearing strategy for the heavy plate was ***,multi-array binocular vision linear cameras were used to complete the image ***,the total length of the steel plate after cooling was predicted by back propagation neural network algorithm according to the contour ***,using the scanning line and a new camber description method,the shearing strategy including head/tail irregular shape length and rough dividing strategy was *** practical application shows that the model and strategy can effectively solve the problems existing in the shearing process and can effectively improve the yield of steel *** maximum error of detection width,length,camber,and the length of the irregular deformation area at the head/tail of the plate are all less than 5 *** correlation coefficient of the length prediction model based on the back propagation neural network is very *** reverse ratio result of edge cutting failure using the proposed rough dividing strategy is 1/401=0.2%,which is 2%higher than that by human.

关键词： Heavy plate Contour detection Intelligent shearing strategy Length prediction Neural network model

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The Mechanism of Heating Rate on the Secondary Recrystallization Evolution in Grain Oriented Silicon Steel

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期 275-282页

作者：高倩 LI Jun WANG Xianhui cao Laifu GONG jian LI Bo Central Iron and Steel Research Institute Group Shougang Zhixin Electromagnetic Material R&D (Beijing) Co. Ltd. Beijing Shougang Co. Ltd.

Grain-oriented silicon steels were prepared at different heating rates during high temperature annealing, in which the evolution of magnetic properties, grain orientations and precipitates were studied. To illustrate the Zener factor, the diameter and number density of precipitates of interrupted testing samples were statistically calculated. The effect of precipitate ripening on the Goss texture and magnetic property was investigated. Data indicated that the trend of Zener factor was similar under different heating rates, first increasing and then decreasing, and that the precipitate maturing was greatly inhibited as the heating rate increased. Secondary recrystallization was developed at the temperature of 1 010 ℃ when a heating rate of 5 ℃/h was used, resulting in Goss, Brass and {110} oriented grains growing abnormally and a magnetic induction intensity of 1.90T. Furthermore, increasing the heating rate to 20 ℃/h would inhibit the development of undesirable oriented grains and obtain a sharp Goss texture. However, when the heating rate was extremely fast, such as 40 ℃/h, poor secondary recrystallization was developed with many island grains, corresponding to a decrease in magnetic induction intensity to 1.87 T. At a suitable heating rate of 20 ℃/h, the sharpest Goss texture and the highest magnetic induction of 1.94 T with an onset secondary recrystallization temperature of 1 020 ℃ were found among the experimental variables in this study. The heating rate affected the initial temperature of secondary recrystallization by controlling the maturation of precipitates, leading to the deviation and dispersion of Goss texture, thereby reducing the magnetic properties.

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Effect of Al on Expansion Behavior of Mg–Al Alloys During Solidification

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Acta Metallurgica Sinica(English Letters) 2019年第5期32卷 559-565页

作者： Yi Meng jian Sun Lei-Gang cao Yue Yang Hai-tao Zhang jian-Zhong Cui School of Mechanical and Materials Engineering North China University of Technology Key Laboratory of Electromagnetic Processing of Materials Ministry of Education Northeastern University

The cooling curves and the change of contraction/expansion during solidification and cooling were tested by using a selfmade device which could achieve the one-dimensional contraction instead of three-dimensional contraction of the ***, the effects of Al content(0, 1.1, 3, 5, 10, 12.9, 15, 17, 19, 22, 24 and 30 wt%) on the thermal contraction/expansion of the binary Mg-Al as-cast alloys during solidification were obtained. The results showed that expanding instead of contraction was present in Mg-Al alloys with the addition of 0-30 wt% Al during solidification. The values of expansion significantly increased at first and then decreased with the increase in Al content. And the maximum expansion ratio of 0.44%(maximum expansion value: 0.841 mm) was present in the Mg-15 wt% Al alloy. Contraction instead of expansion occurred once the temperature drops to the temperature corresponding to the expansion value in total, indicating the occurrence of a continuous expansion during the solidification process in mushy zone for the Mg alloys with Al addition of 5-30 wt%. The expansion value in total consisted of two parts: the expansions occurring in the liquid-phase zone and mushy zone. The expansion in liquid zone was present in every Mg-Al alloy, and it contributed to the most proportion of the total expansion value when the Al content in Mg-Al alloy was lower than 10 wt% or higher than 22 wt%. However, the total expansion value was mainly determined by the solidification behavior in mushy zone when the Al content was among 10-22 wt% in Mg-Al alloys.

关键词： Solidification Mg alloys Al content Expansion

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