In this paper, an adaptive proportional-derivative sliding mode control(APD-SMC) law, is proposed for 2D underactuated overhead crane systems. The proposed controller has the advantages of simple structure, easy to im...In this paper, an adaptive proportional-derivative sliding mode control(APD-SMC) law, is proposed for 2D underactuated overhead crane systems. The proposed controller has the advantages of simple structure, easy to implement of PD control, strong robustness of SMC with respect to external disturbances and uncertain system parameters, and adaptation for unknown system dynamics associated with the feedforward parts. In the proposed APD-SMC law, the PD control part is used to stabilize the controlled system, the SMC part is used to compensate the external disturbances and system uncertainties,and the adaptive control part is utilized to estimate the unknown system parameters. The coupling behavior between the trolley movement and the payload swing is enhanced and, therefore, the transient performance of the proposed controller is improved.The Lyapunov techniques and the La Salle's invariance theorem are employed in to support the theoretical derivations. Experimental results are provided to validate the superior performance of the proposed control law.展开更多
Offshore cranes are widely applied to transfer largescale cargoes and it is challenging to develop effective control for them with sea wave disturbances. However, most existing controllers can only yield ultimate unif...Offshore cranes are widely applied to transfer largescale cargoes and it is challenging to develop effective control for them with sea wave disturbances. However, most existing controllers can only yield ultimate uniform boundedness or asymptotical stability results for the system's equilibrium point, and the state variables' convergence time cannot be theoretically guaranteed. To address these problems, a nonlinear sliding mode-based controller is suggested to accurately drive the boom/rope to their desired positions. Simultaneously, payload swing can be eliminated rapidly with sea waves. As we know, this paper firstly presents a controller by introducing error-related bounded functions into a sliding surface, which can realize boom/rope positioning within a finite time, and both controller design and analysis based on the nonlinear dynamics are implemented without any linearization manipulations. Moreover, the stability analysis is theoretically ensured with the Lyapunov method. Finally, we employ some experiments to validate the effectiveness of the proposed controller.展开更多
This paper investigated the implementation of an adaptive predictive controller using nonlinear dynamic echo state neural （ESN） model for a rotary crane system by the visual servo method. The control sequences withi...This paper investigated the implementation of an adaptive predictive controller using nonlinear dynamic echo state neural （ESN） model for a rotary crane system by the visual servo method. The control sequences within the control horizon were described using cubic spline interpolation to enlarge the predictive horizon. Verification of the proposed scheme in the face of exogenous disturbances and modeling error with inaccurate string length was demonstrated by both simulations and experiments.展开更多
For a gantry crane system, this paper presents a comparison between four control algorithms. These algo-rithms are being compared on simplicity, stability and robustness. Goal for the controller is to move the load on...For a gantry crane system, this paper presents a comparison between four control algorithms. These algo-rithms are being compared on simplicity, stability and robustness. Goal for the controller is to move the load on a gantry crane to a new position with minimal overshoot of the load and maximal speed of the load. An-other goal is to provide an insight in the behaviour of the possible controllers. In this article a parallel P-controller, cascade P-controller, fuzzy controller and an internal model controller are used. To be able to validate and design the controllers a model is derived from the gantry crane. The controllers and the model are being implemented in Matlab Simulink. Finally the controllers are validated and tuned in Labview on a laboratory gantry scrane scale model. Main conclusion is that all presented controllers can be used as a con-troller for the gantry crane system but the fuzzy controller is showing the best performance.展开更多
This paper proposed an online monitoring and early-warning system of dynamic stress of crane metal structure, and designed this system’s hardware,including sensor unit,data gathering unit,and controlling & proces...This paper proposed an online monitoring and early-warning system of dynamic stress of crane metal structure, and designed this system’s hardware,including sensor unit,data gathering unit,and controlling & processing unit of this sys- tem,and discussed the waterproof protection for resistance strain wafer and scheme of data gathering and transmission of dynamic strain gauge,moreover developed system software of real-time and online monitoring dynamic stress,including data gathering by DLL and data display & processing based on Visual C++.The system applies the dynamic strain gauge to gather the data of the stress,and communicates between PLC control system of crane and upper industrial computer,so that realize the real-time online monitoring and early-warning for crane’s metal structure stress.The test results show this system carry on real time and online monitoring to dynamic stress of loud-bearing metal structure longly and stability,and can give an alarm and overload protection on time.So the system has good practice value.展开更多
Reliability and safety are major issues in tower crane applications. A new adaptive neurofuzzy system is developed in this work for real-time health condition monitoring of tower cranes, especially for hoist gearboxes...Reliability and safety are major issues in tower crane applications. A new adaptive neurofuzzy system is developed in this work for real-time health condition monitoring of tower cranes, especially for hoist gearboxes. Vibration signals are measured using a wireless smart sensor system. Fault detection is performed gear-by-gear in the gearbox. A new diagnostic classifier is proposed to integrate strengths of several signal processing techniques for fault detection. A hybrid machine learning method is proposed to facilitate implementation and improve training convergence. The effectiveness of the developed monitoring system is verified by experimental tests.展开更多
Research on a hybrid system of a crane is a focus which considers environmental protection and energy saving. A new environmental protection and energy saving hybrid system of tyre crane, which utilizes supercapacitor...Research on a hybrid system of a crane is a focus which considers environmental protection and energy saving. A new environmental protection and energy saving hybrid system of tyre crane, which utilizes supercapacitors as the energy store device, is presented. Analyzing the principle of supercapacitors, the model of the crane＇s hybrid system is set up in this paper, and the model of main blocks are established. Through simulation analyzing, the energy saving result of the new hybrid system is obtained, and the good application value of the new hybrid system is explained.展开更多
The safety brake system of metallurgy bridge crane is generally composed of two separated block brake, brake disc, and torsion shaft. The analysis of natural frequency and main vibration mode on this two-degree torsio...The safety brake system of metallurgy bridge crane is generally composed of two separated block brake, brake disc, and torsion shaft. The analysis of natural frequency and main vibration mode on this two-degree torsion vibration system is the basement to study the vibration model and vibration performance. In this work, we investigated natural frequency of the braking system of metallurgical crane with analytic method. This provides a systematic guidance towards a successful brake system design展开更多
A PI control strategy based on fuzzy set-point weighting following was proposed for the active damping control of a hydraulic crane boom system （HCBS）. Two valve-controlled PI controllers, which include a proportion...A PI control strategy based on fuzzy set-point weighting following was proposed for the active damping control of a hydraulic crane boom system （HCBS）. Two valve-controlled PI controllers, which include a proportional feedforward controller based on fuzzy set-point weighting following and a limited semi-integrator（LSI）, are designed respectively. LSI is used to limit output signal and to prevent wind up at the low frequency of the spectrum. By using a range camera and an electronic feedback control, the tip damping on the HCBS can be adjusted artificially. A collaborative control simulation technique of HOPSAN and MATLAB/SIMULINK is applied to the controller design. Simulation results show that the proposed PI control system has less overshoot as well as faster response. The tip damping on the HCBS during operation is improved.展开更多
The control of nuclear fuel manipulator crane （MC） drive system is essential for its running and other systems are designed surrounding the drive system.This paper gives a brief introduction to the composition and f...The control of nuclear fuel manipulator crane （MC） drive system is essential for its running and other systems are designed surrounding the drive system.This paper gives a brief introduction to the composition and function of MC,analyses its drive mode and control method and applies PLC to control its frequency transducer directly to help the motor work more stable.Based on the control requirements of bridge,trolley,Hoist,the control system of bridge applies a drive mode with 2-drag2 drive model on both sides and a multi-control method to realize simultaneous runningof two sides,1-drag-1 model on through-going axes and closed loop control method finish the precise location of trolley,and the using of 1-drag-1 model drive mode and closed loop control method solves the protect control difficulty of hoist which stops/starts repeatedly and changes speed.展开更多
A model for supercapacitor voltage equalization strategy is analyzed, and on this basis a supercapacitor voltage equalization method for Rubber Tyred Gantry Crane (RTG) energy saving system is proposed, namely active ...A model for supercapacitor voltage equalization strategy is analyzed, and on this basis a supercapacitor voltage equalization method for Rubber Tyred Gantry Crane (RTG) energy saving system is proposed, namely active voltage equalization method based on Buck-Boost converter. The equalizing speed of the proposed method is fast. Firstly, the working principle and process of the voltage equalization circuit is analyzed in detail. In addition, design of active voltage equalization circuit parameters and control strategy are given. Finally, simulation analysis of the series connection of supercapacitors module is performed. Results show that this method for equalizing voltage can avoid over-voltage of each cell and possess practicable and high value for supercapacitor RTG energy saving system.展开更多
This paper proposes the design scheme of Integration Management and Control System (IMCS) using the integration and optimization design theory of port cranes’ management and control system based on Enterprise Resourc...This paper proposes the design scheme of Integration Management and Control System (IMCS) using the integration and optimization design theory of port cranes’ management and control system based on Enterprise Resource Planning (ERP), Manufacturing Execution System (MES) and Process Control System (PCS). The functions, interface and software design of the three sub-modules of IMCS are presented. Outcomes of this research are being employed to practical port cranes’ operation and management, which eliminates the island phenomenon of cranes’ storage and application conditions between the management and control department. Hence, IMCS makes the integrated automatic port cranes system come true and it significantly improves the core competitiveness of the port.展开更多
The fuzzy comfortability of a wind-sensitive super-high tower crane is critical to guarantee occupant health and improve construction efficiency.Therefore,the wind-resistant fuzzy comfortability of a super-high tower ...The fuzzy comfortability of a wind-sensitive super-high tower crane is critical to guarantee occupant health and improve construction efficiency.Therefore,the wind-resistant fuzzy comfortability of a super-high tower crane in the Ma’anshan Yangtze River(MYR)Bridge site is analyzed in this paper.First,the membership function model that represents fuzzy comfortability is introduced in the probability density evolution method(PDEM).Second,based on Fechner’s law,the membership function curves are constructed according to three acceleration thresholds in ISO 2631.Then,the fuzzy comfortability for the super-high tower crane under stochastic wind loads is assessed on the basis of different cut-set levelsλ.Results show that the comfortability is over 0.9 under the required maximum operating wind velocity.The low sensitivity toλcan be observed in the reliability curves of ISOⅡandⅢmembership functions.The reliability of the ISOⅠmembership function is not sensitive toλwhenλ<0.7,whereas it becomes sensitive toλwhenλ>0.7.展开更多
The Caohai Wetland is an important habitat for many rare birds,such as black-necked cranes.This study focused on the species composition and diversity of plants in the seven main habitats of black-necked cranes in the...The Caohai Wetland is an important habitat for many rare birds,such as black-necked cranes.This study focused on the species composition and diversity of plants in the seven main habitats of black-necked cranes in the Caohai Wetland,and on the distribution characteristics of black-necked cranes in these habitats in the winter season from November in 2022 to March in 2023.A total of 138 species belonging to 111 genera,40 families,23 orders and 4 classes and 2 phyla were recorded during field investigations involving 31 investigated plots,which comprised 112 quadrats.Among the different investigated plots in the seven habitats of black-necked cranes,the Shannon-Wiener index values ranged from 0.1125 to 2.4800.Notably,plant species diversity decreased in almost all habitats from the terrestrial zone to the water-land transitional zone and from the water-land transitional zone to the shallow water zone.The water level,habitat area,microcirculation heterogeneity and grazing activities are critical factors related to plant species diversity.In this winter,about 2,469 black-necked cranes overwintered in the seven main habitats.Black-necked cranes inhabiting in Huyelin(HYL)and Wenjiatun(WJT)are of absolute advantage in terms of population among the seven major habitats.To better protect the habitat of black necked cranes,we need to control the spread of tall plants,scientifically regulate the plant community structure of the habitat in combining with black necked crane feeding habits,and to regulate the water level of Caohai Lake reasonably to ensure sufficient water-land transitional zone and shallow water zone for black-necked cranes to inhabit.展开更多
Food abundance and availability constitute fundamental determinants of foraging habitat quality for waterbirds, with high-quality foraging habitats playing a crucial role in supporting the survival and annual life cyc...Food abundance and availability constitute fundamental determinants of foraging habitat quality for waterbirds, with high-quality foraging habitats playing a crucial role in supporting the survival and annual life cycle of wintering populations. The ongoing degradation and loss of optimal habitats have forced wintering waterbirds to increasingly rely on alternative foraging sites and modify their behavioral adaptation strategies to cope with food scarcity. The Siberian Crane (Leucogeranus leucogeranus), a large-bodied endangered waterbird species characterized by specialized dietary preferences, demonstrates particular sensitivity to environmental alterations. Faced with diminishing suitable habitats and declining natural food resources, this species has progressively adapted to utilizing artificial habitats, including agricultural landscapes such as paddy fields and lotus ponds, as supplementary wintering foraging grounds to fulfill their energetic requirements. This study examines the hypothesis that Siberian Cranes adapt their foraging behavior through plastic behavioral strategies in artificial habitats under conditions of limited food availability, thereby enhancing population fitness. A comparative analysis of crane foraging behaviors was conducted between mudflats and lotus ponds throughout the 2023–2024 wintering period. This investigation focused on three critical environmental factors: food abundance, food burial depth, and sediment penetrability, examining their influence on foraging patterns across these distinct habitats. The results revealed significant inter-habitat differences: foraging success rates were substantially higher (p < 0.05) and food handling times markedly longer in lotus ponds compared to mudflats, whereas foraging effort and attempt frequency were significantly elevated in mudflat habitats. The superior food availability in lotus ponds facilitated enhanced foraging success rates, enabling cranes to accumulate essential energy reserves for winter survival. However, the deeper burial depth of lotus roots in these habitats required more intensive processing behaviors, including prolonged digging, breaking, and swallowing activities, which consequently increased handling time by approximately 40% and reduced foraging attempts by 25–30% compared to mudflat conditions. These behavioral trade-offs suggest that while lotus ponds provide adequate food resources, their structural characteristics may impose physiological constraints that limit their effectiveness as optimal foraging grounds for Siberian Cranes. These findings offer valuable insights into the behavioral plasticity of wintering Siberian Cranes response to spatial variations in food resource distribution, while contributing to our understanding of the ecological value of lotus roots as alternative winter food sources in artificial wetland ecosystems.展开更多
Poyang Lake,China's largest freshwater lake,is a critical wintering ground for most of the global Siberian Grane(Grus leucogeranus)population.However,increasingly prolonged dry seasons have degraded the natural we...Poyang Lake,China's largest freshwater lake,is a critical wintering ground for most of the global Siberian Grane(Grus leucogeranus)population.However,increasingly prolonged dry seasons have degraded the natural wetlands of Poyang Lake,forcing Siberian Cranes to shift to artificial habitats.From 2015 to 2023,field surveys revealed a substantial increase in the number of Siberian Cranes in artificial habitats,with peak counts reaching 3000individuals,accounting for up to 53%of the species'global population.Satellite telemetry of 13 individuals further confirmed the spatial use of these habitats,highlighting their consistent reliance on artificial sites over multiple years.Seven high-use hotspots were identified outside of Poyang Lake,including two artificial provisioning sites that supported dense foraging flocks for extended periods.Satellite telemetry confirmed this trend,with artificial habitats making up to 64.2%of the occurrence sites in some years.This reliance on artificial habitats was closely linked to the reduced tuber biomass in natural wetlands and low winter water levels in Poyang Lake,which collectively explained 83%of the variance in crane abundance in artificial habitats.Artificial habitat use peaked in December and January,indicating marked seasonal variation.Siberian Cranes also exhibited a pronounced circadian rhythm,foraging in artificial habitats during the day and returning to natural wetlands to roost at night.Despite the shift toward artificial habitats,natural wetlands remain critical for nighttime refuge.The continued dependence on artificial habitats raises concerns about disease transmission owing to dense congregations.Conservation strategies should prioritize both the careful management of artificial provisioning sites and the restoration of natural wetlands to improve food and habitat availability within natural ecosystems,ultimately enabling the return of Siberian Cranes to their traditional natural habitats.展开更多
Poyang Lake (PYL) and the Yellow River Delta (YRD) are two critical wintering areas for the Siberian Crane (Leucogeranus leucogeranus) along the East Asian–Australasian Flyway in China. Based on nearly two decades of...Poyang Lake (PYL) and the Yellow River Delta (YRD) are two critical wintering areas for the Siberian Crane (Leucogeranus leucogeranus) along the East Asian–Australasian Flyway in China. Based on nearly two decades of remote sensing and environmental data, this study used the MaxEnt model to assess wintering habitat suitability in Poyang Lake (PYL) and the Yellow River Delta (YRD). Landscape pattern and ecological network (EN) analyses were integrated to examine habitat changes and their impact on Siberian Crane distribution. In PYL, land use/land cover (LULC) change was driven primarily by water level fluctuations, leading to transitions among natural habitat types. In contrast, LULC change in YRD was dominated by anthropogenic activities, with widespread conversion of natural habitats into artificial habitats. In both regions, Siberian Cranes favored wetlands that are food-rich, flat, and minimally disturbed. In PYL, ecological sources were mainly found in sub-lakes of nature reserves and nearby moist areas, averaging 87.42 km^(2). In the YRD, sources were distributed across tidal flats, paddy land, and grasslands, with a larger mean area of 198.37 km^(2). Mann–Kendall tests showed significant trends in PYL, including increased patch density and decreased EN cumulative resilience. The maximum habitat suitability in the YRD significantly declined. Comparative analysis revealed that PYL had significantly higher habitat suitability and EN cumulative resilience, whereas the YRD had larger but more fragmented habitats. By introducing key stepping-stone nodes to optimize the ENs, the connectivity and resilience of PYL's EN were notably enhanced. Although improvements in the YRD were less marked, the optimization scheme still improved the security of the crane migration network. Based on the findings, it is recommended to implement refined water level management in PYL to maintain the stability of sub-lakes and adjacent wetlands, and to strengthen the protection of natural wetlands in the YRD by limiting the expansion of artificial land use, in order to mitigate habitat fragmentation.展开更多
Evaluating the habitat suitability of flagship species and its key influencing factors is vital for understanding potential conservation issues and developing coping strategies.We surveyed the wintering population siz...Evaluating the habitat suitability of flagship species and its key influencing factors is vital for understanding potential conservation issues and developing coping strategies.We surveyed the wintering population size and distribution of the Black-necked Crane(Grus nigricollis)in the Yarlung Zangbo River Basin(YZRB)from 10 to 29 January 2022,and predicted the current potentially suitable habitat distribution and its effective factors using the Max Ent model.A total of 9337 wintering Black-necked Cranes were recorded in the YZRB in 2022,76.58%of which were primarily found in Lhunzub,Samzhubze,Namling,and Lhaze.Compared to 2018,the crane population has exhibited a notable decline in Samzhubze and Taktse,likely due to farmland plowing,winter irrigation,changes in agricultural practices,road construction and hydraulic projects.The crane population within various counties exhibited a significant positive correlation with the suitable habitat area(r=0.70,P=0.002,n=17).We also found that the currently suitable habitat area covered 17,204 km~2,of which only 3244 km~2(18.86%)was effectively protected at the national level,which was predominantly distributed in farmland and rangeland habitats characterized by gentle slopes,altitudes not exceeding 4500 m,and proximity to human settlements along rivers,where suitable isothermal values(51)and less seasonal precipitation(20 mm)prevail.Our study will be helpful for formulating reasonable conservation strategies to protect the core population of this threatened highland flagship species.展开更多
The gantry crane system is a crucial equipment for loading and unloading containers at the shore site.The existing trend of crane technology is in the transition from in-site operators to remote operators outside the ...The gantry crane system is a crucial equipment for loading and unloading containers at the shore site.The existing trend of crane technology is in the transition from in-site operators to remote operators outside the cargo handling site,which will comply with all safety regulations,including conditional crane monitoring.However,remote control introduces certain drawbacks in machine maintenance,as no on-site operators can provide real-time feedback on abnormalities.Therefore,this study proposes a failure detection system that uses vibratory sensors installed on machines to monitor and provide early warnings for various failures.For faulty event identification,the Fast Fourier Transform is carried out for the raw vibratory signals,and several frequency bands are classified by using t-SNE to evaluate the significance among clusters.The adjustment of hyperparameters of the t-SNE will alter the quality of the classification of different events,and this process is conventionally operated in accordance with users’experience.In this study,we propose a novel rating approach to automatically tune the hyperparameters of t-SNE to evaluate the separation and cluster compactness of the t-SNE results.Then,the results of clusters served as input features for training the faulty event detection model,and the detection model shows more than 95%accuracy in identifying different abnormal conditions of the main hosting motor.展开更多
基金supported in part by the National High Technology Research and Development Program of China(863 Program)(2015AA042307)Shandong Provincial Scientific and Technological Development Foundation(2014GGX103038)+3 种基金Shandong Provincial Independent Innovation and Achievement Transformation Special Foundation(2015ZDXX0101E01)National Natural Science Fundation of China(NSFC)Joint Fund of Shandong Province(U1706228)the Fundamental Research Funds of Shandong University(2015JC027)
文摘In this paper, an adaptive proportional-derivative sliding mode control(APD-SMC) law, is proposed for 2D underactuated overhead crane systems. The proposed controller has the advantages of simple structure, easy to implement of PD control, strong robustness of SMC with respect to external disturbances and uncertain system parameters, and adaptation for unknown system dynamics associated with the feedforward parts. In the proposed APD-SMC law, the PD control part is used to stabilize the controlled system, the SMC part is used to compensate the external disturbances and system uncertainties,and the adaptive control part is utilized to estimate the unknown system parameters. The coupling behavior between the trolley movement and the payload swing is enhanced and, therefore, the transient performance of the proposed controller is improved.The Lyapunov techniques and the La Salle's invariance theorem are employed in to support the theoretical derivations. Experimental results are provided to validate the superior performance of the proposed control law.
基金supported by the National Key Research and Development Program of China(2018YFB1309000)the National Natural Science Foundation of China(61873134,U1706228)+1 种基金the Young Elite Scientists Sponsorship Program by Tianjin(TJSQNTJ-2017-02)the Tianjin Research Innovation Project for Postgraduate Students(2019YJSB070)。
文摘Offshore cranes are widely applied to transfer largescale cargoes and it is challenging to develop effective control for them with sea wave disturbances. However, most existing controllers can only yield ultimate uniform boundedness or asymptotical stability results for the system's equilibrium point, and the state variables' convergence time cannot be theoretically guaranteed. To address these problems, a nonlinear sliding mode-based controller is suggested to accurately drive the boom/rope to their desired positions. Simultaneously, payload swing can be eliminated rapidly with sea waves. As we know, this paper firstly presents a controller by introducing error-related bounded functions into a sliding surface, which can realize boom/rope positioning within a finite time, and both controller design and analysis based on the nonlinear dynamics are implemented without any linearization manipulations. Moreover, the stability analysis is theoretically ensured with the Lyapunov method. Finally, we employ some experiments to validate the effectiveness of the proposed controller.
基金supported by“MOST”for the support under Grants No.MOST 104-2632-B-468-001,No.MOST 103-2221-E-468-009-MY2,No.MOST 104-2221-E-182-008-MY2,No.MOST 105-2221-E-468-009,No.MOST 106-2221-E-468-023,No.MOST 106-2221-E-182-033Chang Gung Memorial Hospital under Grant No.CMRPD2C0053
文摘This paper investigated the implementation of an adaptive predictive controller using nonlinear dynamic echo state neural （ESN） model for a rotary crane system by the visual servo method. The control sequences within the control horizon were described using cubic spline interpolation to enlarge the predictive horizon. Verification of the proposed scheme in the face of exogenous disturbances and modeling error with inaccurate string length was demonstrated by both simulations and experiments.
文摘For a gantry crane system, this paper presents a comparison between four control algorithms. These algo-rithms are being compared on simplicity, stability and robustness. Goal for the controller is to move the load on a gantry crane to a new position with minimal overshoot of the load and maximal speed of the load. An-other goal is to provide an insight in the behaviour of the possible controllers. In this article a parallel P-controller, cascade P-controller, fuzzy controller and an internal model controller are used. To be able to validate and design the controllers a model is derived from the gantry crane. The controllers and the model are being implemented in Matlab Simulink. Finally the controllers are validated and tuned in Labview on a laboratory gantry scrane scale model. Main conclusion is that all presented controllers can be used as a con-troller for the gantry crane system but the fuzzy controller is showing the best performance.
基金Funded by the National Natural Science Fund grants 60574012
文摘This paper proposed an online monitoring and early-warning system of dynamic stress of crane metal structure, and designed this system’s hardware,including sensor unit,data gathering unit,and controlling & processing unit of this sys- tem,and discussed the waterproof protection for resistance strain wafer and scheme of data gathering and transmission of dynamic strain gauge,moreover developed system software of real-time and online monitoring dynamic stress,including data gathering by DLL and data display & processing based on Visual C++.The system applies the dynamic strain gauge to gather the data of the stress,and communicates between PLC control system of crane and upper industrial computer,so that realize the real-time online monitoring and early-warning for crane’s metal structure stress.The test results show this system carry on real time and online monitoring to dynamic stress of loud-bearing metal structure longly and stability,and can give an alarm and overload protection on time.So the system has good practice value.
文摘Reliability and safety are major issues in tower crane applications. A new adaptive neurofuzzy system is developed in this work for real-time health condition monitoring of tower cranes, especially for hoist gearboxes. Vibration signals are measured using a wireless smart sensor system. Fault detection is performed gear-by-gear in the gearbox. A new diagnostic classifier is proposed to integrate strengths of several signal processing techniques for fault detection. A hybrid machine learning method is proposed to facilitate implementation and improve training convergence. The effectiveness of the developed monitoring system is verified by experimental tests.
基金This paper is supported by the Youth Chenguang Project of Wuhan under Grant No.20045006071-29
文摘Research on a hybrid system of a crane is a focus which considers environmental protection and energy saving. A new environmental protection and energy saving hybrid system of tyre crane, which utilizes supercapacitors as the energy store device, is presented. Analyzing the principle of supercapacitors, the model of the crane＇s hybrid system is set up in this paper, and the model of main blocks are established. Through simulation analyzing, the energy saving result of the new hybrid system is obtained, and the good application value of the new hybrid system is explained.
文摘The safety brake system of metallurgy bridge crane is generally composed of two separated block brake, brake disc, and torsion shaft. The analysis of natural frequency and main vibration mode on this two-degree torsion vibration system is the basement to study the vibration model and vibration performance. In this work, we investigated natural frequency of the braking system of metallurgical crane with analytic method. This provides a systematic guidance towards a successful brake system design
基金This work was supported by the Natural Science Foundation of Hunan Province(No.04JJ6033) and Scientific Research Fund of Hunan ProvincialEducation Department(No. 03C066).
文摘A PI control strategy based on fuzzy set-point weighting following was proposed for the active damping control of a hydraulic crane boom system （HCBS）. Two valve-controlled PI controllers, which include a proportional feedforward controller based on fuzzy set-point weighting following and a limited semi-integrator（LSI）, are designed respectively. LSI is used to limit output signal and to prevent wind up at the low frequency of the spectrum. By using a range camera and an electronic feedback control, the tip damping on the HCBS can be adjusted artificially. A collaborative control simulation technique of HOPSAN and MATLAB/SIMULINK is applied to the controller design. Simulation results show that the proposed PI control system has less overshoot as well as faster response. The tip damping on the HCBS during operation is improved.
基金Supported by the National High Technology Research and Development Program of China(No.SQ2010AA0401265006)
文摘The control of nuclear fuel manipulator crane （MC） drive system is essential for its running and other systems are designed surrounding the drive system.This paper gives a brief introduction to the composition and function of MC,analyses its drive mode and control method and applies PLC to control its frequency transducer directly to help the motor work more stable.Based on the control requirements of bridge,trolley,Hoist,the control system of bridge applies a drive mode with 2-drag2 drive model on both sides and a multi-control method to realize simultaneous runningof two sides,1-drag-1 model on through-going axes and closed loop control method finish the precise location of trolley,and the using of 1-drag-1 model drive mode and closed loop control method solves the protect control difficulty of hoist which stops/starts repeatedly and changes speed.
文摘A model for supercapacitor voltage equalization strategy is analyzed, and on this basis a supercapacitor voltage equalization method for Rubber Tyred Gantry Crane (RTG) energy saving system is proposed, namely active voltage equalization method based on Buck-Boost converter. The equalizing speed of the proposed method is fast. Firstly, the working principle and process of the voltage equalization circuit is analyzed in detail. In addition, design of active voltage equalization circuit parameters and control strategy are given. Finally, simulation analysis of the series connection of supercapacitors module is performed. Results show that this method for equalizing voltage can avoid over-voltage of each cell and possess practicable and high value for supercapacitor RTG energy saving system.
文摘This paper proposes the design scheme of Integration Management and Control System (IMCS) using the integration and optimization design theory of port cranes’ management and control system based on Enterprise Resource Planning (ERP), Manufacturing Execution System (MES) and Process Control System (PCS). The functions, interface and software design of the three sub-modules of IMCS are presented. Outcomes of this research are being employed to practical port cranes’ operation and management, which eliminates the island phenomenon of cranes’ storage and application conditions between the management and control department. Hence, IMCS makes the integrated automatic port cranes system come true and it significantly improves the core competitiveness of the port.
基金The National Natural Science Foundation of China(No.52108274,52208481,52338011)State Scholarship Fund of China Scholarship Council(No.202306090285).
文摘The fuzzy comfortability of a wind-sensitive super-high tower crane is critical to guarantee occupant health and improve construction efficiency.Therefore,the wind-resistant fuzzy comfortability of a super-high tower crane in the Ma’anshan Yangtze River(MYR)Bridge site is analyzed in this paper.First,the membership function model that represents fuzzy comfortability is introduced in the probability density evolution method(PDEM).Second,based on Fechner’s law,the membership function curves are constructed according to three acceleration thresholds in ISO 2631.Then,the fuzzy comfortability for the super-high tower crane under stochastic wind loads is assessed on the basis of different cut-set levelsλ.Results show that the comfortability is over 0.9 under the required maximum operating wind velocity.The low sensitivity toλcan be observed in the reliability curves of ISOⅡandⅢmembership functions.The reliability of the ISOⅠmembership function is not sensitive toλwhenλ<0.7,whereas it becomes sensitive toλwhenλ>0.7.
基金supported by the Guizhou Provincial Science and Technology Projects(No.QKHZC[2023]YB215,QKHPT[2025]015).
文摘The Caohai Wetland is an important habitat for many rare birds,such as black-necked cranes.This study focused on the species composition and diversity of plants in the seven main habitats of black-necked cranes in the Caohai Wetland,and on the distribution characteristics of black-necked cranes in these habitats in the winter season from November in 2022 to March in 2023.A total of 138 species belonging to 111 genera,40 families,23 orders and 4 classes and 2 phyla were recorded during field investigations involving 31 investigated plots,which comprised 112 quadrats.Among the different investigated plots in the seven habitats of black-necked cranes,the Shannon-Wiener index values ranged from 0.1125 to 2.4800.Notably,plant species diversity decreased in almost all habitats from the terrestrial zone to the water-land transitional zone and from the water-land transitional zone to the shallow water zone.The water level,habitat area,microcirculation heterogeneity and grazing activities are critical factors related to plant species diversity.In this winter,about 2,469 black-necked cranes overwintered in the seven main habitats.Black-necked cranes inhabiting in Huyelin(HYL)and Wenjiatun(WJT)are of absolute advantage in terms of population among the seven major habitats.To better protect the habitat of black necked cranes,we need to control the spread of tall plants,scientifically regulate the plant community structure of the habitat in combining with black necked crane feeding habits,and to regulate the water level of Caohai Lake reasonably to ensure sufficient water-land transitional zone and shallow water zone for black-necked cranes to inhabit.
基金funded by the National Natural Science Foundation of China(No.32470553).
文摘Food abundance and availability constitute fundamental determinants of foraging habitat quality for waterbirds, with high-quality foraging habitats playing a crucial role in supporting the survival and annual life cycle of wintering populations. The ongoing degradation and loss of optimal habitats have forced wintering waterbirds to increasingly rely on alternative foraging sites and modify their behavioral adaptation strategies to cope with food scarcity. The Siberian Crane (Leucogeranus leucogeranus), a large-bodied endangered waterbird species characterized by specialized dietary preferences, demonstrates particular sensitivity to environmental alterations. Faced with diminishing suitable habitats and declining natural food resources, this species has progressively adapted to utilizing artificial habitats, including agricultural landscapes such as paddy fields and lotus ponds, as supplementary wintering foraging grounds to fulfill their energetic requirements. This study examines the hypothesis that Siberian Cranes adapt their foraging behavior through plastic behavioral strategies in artificial habitats under conditions of limited food availability, thereby enhancing population fitness. A comparative analysis of crane foraging behaviors was conducted between mudflats and lotus ponds throughout the 2023–2024 wintering period. This investigation focused on three critical environmental factors: food abundance, food burial depth, and sediment penetrability, examining their influence on foraging patterns across these distinct habitats. The results revealed significant inter-habitat differences: foraging success rates were substantially higher (p < 0.05) and food handling times markedly longer in lotus ponds compared to mudflats, whereas foraging effort and attempt frequency were significantly elevated in mudflat habitats. The superior food availability in lotus ponds facilitated enhanced foraging success rates, enabling cranes to accumulate essential energy reserves for winter survival. However, the deeper burial depth of lotus roots in these habitats required more intensive processing behaviors, including prolonged digging, breaking, and swallowing activities, which consequently increased handling time by approximately 40% and reduced foraging attempts by 25–30% compared to mudflat conditions. These behavioral trade-offs suggest that while lotus ponds provide adequate food resources, their structural characteristics may impose physiological constraints that limit their effectiveness as optimal foraging grounds for Siberian Cranes. These findings offer valuable insights into the behavioral plasticity of wintering Siberian Cranes response to spatial variations in food resource distribution, while contributing to our understanding of the ecological value of lotus roots as alternative winter food sources in artificial wetland ecosystems.
基金supported by the National Natural Science Foundation of China(No.32260275)Fundamental Research Funds of CAF(CAFYBB2024ZA033)。
文摘Poyang Lake,China's largest freshwater lake,is a critical wintering ground for most of the global Siberian Grane(Grus leucogeranus)population.However,increasingly prolonged dry seasons have degraded the natural wetlands of Poyang Lake,forcing Siberian Cranes to shift to artificial habitats.From 2015 to 2023,field surveys revealed a substantial increase in the number of Siberian Cranes in artificial habitats,with peak counts reaching 3000individuals,accounting for up to 53%of the species'global population.Satellite telemetry of 13 individuals further confirmed the spatial use of these habitats,highlighting their consistent reliance on artificial sites over multiple years.Seven high-use hotspots were identified outside of Poyang Lake,including two artificial provisioning sites that supported dense foraging flocks for extended periods.Satellite telemetry confirmed this trend,with artificial habitats making up to 64.2%of the occurrence sites in some years.This reliance on artificial habitats was closely linked to the reduced tuber biomass in natural wetlands and low winter water levels in Poyang Lake,which collectively explained 83%of the variance in crane abundance in artificial habitats.Artificial habitat use peaked in December and January,indicating marked seasonal variation.Siberian Cranes also exhibited a pronounced circadian rhythm,foraging in artificial habitats during the day and returning to natural wetlands to roost at night.Despite the shift toward artificial habitats,natural wetlands remain critical for nighttime refuge.The continued dependence on artificial habitats raises concerns about disease transmission owing to dense congregations.Conservation strategies should prioritize both the careful management of artificial provisioning sites and the restoration of natural wetlands to improve food and habitat availability within natural ecosystems,ultimately enabling the return of Siberian Cranes to their traditional natural habitats.
基金supported by the National Natural Science Foundation of China(Grant No.32360142).
文摘Poyang Lake (PYL) and the Yellow River Delta (YRD) are two critical wintering areas for the Siberian Crane (Leucogeranus leucogeranus) along the East Asian–Australasian Flyway in China. Based on nearly two decades of remote sensing and environmental data, this study used the MaxEnt model to assess wintering habitat suitability in Poyang Lake (PYL) and the Yellow River Delta (YRD). Landscape pattern and ecological network (EN) analyses were integrated to examine habitat changes and their impact on Siberian Crane distribution. In PYL, land use/land cover (LULC) change was driven primarily by water level fluctuations, leading to transitions among natural habitat types. In contrast, LULC change in YRD was dominated by anthropogenic activities, with widespread conversion of natural habitats into artificial habitats. In both regions, Siberian Cranes favored wetlands that are food-rich, flat, and minimally disturbed. In PYL, ecological sources were mainly found in sub-lakes of nature reserves and nearby moist areas, averaging 87.42 km^(2). In the YRD, sources were distributed across tidal flats, paddy land, and grasslands, with a larger mean area of 198.37 km^(2). Mann–Kendall tests showed significant trends in PYL, including increased patch density and decreased EN cumulative resilience. The maximum habitat suitability in the YRD significantly declined. Comparative analysis revealed that PYL had significantly higher habitat suitability and EN cumulative resilience, whereas the YRD had larger but more fragmented habitats. By introducing key stepping-stone nodes to optimize the ENs, the connectivity and resilience of PYL's EN were notably enhanced. Although improvements in the YRD were less marked, the optimization scheme still improved the security of the crane migration network. Based on the findings, it is recommended to implement refined water level management in PYL to maintain the stability of sub-lakes and adjacent wetlands, and to strengthen the protection of natural wetlands in the YRD by limiting the expansion of artificial land use, in order to mitigate habitat fragmentation.
基金supported by the National Natural Science Foundation of China(32070530)the National Key Research and Development Program of China(2019YFA0607103)+1 种基金the Qilian Mountain National Park Qinghai Province Management Bureauthe National Forestry and Grassland Administration of China。
文摘Evaluating the habitat suitability of flagship species and its key influencing factors is vital for understanding potential conservation issues and developing coping strategies.We surveyed the wintering population size and distribution of the Black-necked Crane(Grus nigricollis)in the Yarlung Zangbo River Basin(YZRB)from 10 to 29 January 2022,and predicted the current potentially suitable habitat distribution and its effective factors using the Max Ent model.A total of 9337 wintering Black-necked Cranes were recorded in the YZRB in 2022,76.58%of which were primarily found in Lhunzub,Samzhubze,Namling,and Lhaze.Compared to 2018,the crane population has exhibited a notable decline in Samzhubze and Taktse,likely due to farmland plowing,winter irrigation,changes in agricultural practices,road construction and hydraulic projects.The crane population within various counties exhibited a significant positive correlation with the suitable habitat area(r=0.70,P=0.002,n=17).We also found that the currently suitable habitat area covered 17,204 km~2,of which only 3244 km~2(18.86%)was effectively protected at the national level,which was predominantly distributed in farmland and rangeland habitats characterized by gentle slopes,altitudes not exceeding 4500 m,and proximity to human settlements along rivers,where suitable isothermal values(51)and less seasonal precipitation(20 mm)prevail.Our study will be helpful for formulating reasonable conservation strategies to protect the core population of this threatened highland flagship species.
基金funded by National Science and Technology Council,Taiwan,grant numbers 112-2622-E-992-022 and 112-2221-E-992-086.
文摘The gantry crane system is a crucial equipment for loading and unloading containers at the shore site.The existing trend of crane technology is in the transition from in-site operators to remote operators outside the cargo handling site,which will comply with all safety regulations,including conditional crane monitoring.However,remote control introduces certain drawbacks in machine maintenance,as no on-site operators can provide real-time feedback on abnormalities.Therefore,this study proposes a failure detection system that uses vibratory sensors installed on machines to monitor and provide early warnings for various failures.For faulty event identification,the Fast Fourier Transform is carried out for the raw vibratory signals,and several frequency bands are classified by using t-SNE to evaluate the significance among clusters.The adjustment of hyperparameters of the t-SNE will alter the quality of the classification of different events,and this process is conventionally operated in accordance with users’experience.In this study,we propose a novel rating approach to automatically tune the hyperparameters of t-SNE to evaluate the separation and cluster compactness of the t-SNE results.Then,the results of clusters served as input features for training the faulty event detection model,and the detection model shows more than 95%accuracy in identifying different abnormal conditions of the main hosting motor.
