In a controlled indoor environment,line tracking has become the most practical and reliable navigation strategy for autonomous mobile robots.A line tracking robot is a self-mobile machine that can recognize and track ...In a controlled indoor environment,line tracking has become the most practical and reliable navigation strategy for autonomous mobile robots.A line tracking robot is a self-mobile machine that can recognize and track a painted line on thefloor.In general,the path is set and can be visible,such as a black line on a white surface with high contrasting colors.The robot’s path is marked by a distinct line or track,which the robot follows to move.Several scientific contributions from the disciplines of vision and control have been made to mobile robot vision-based navigation.Localization,automated map generation,autonomous navigation and path tracking is all becoming more frequent in vision applications.A visual navigation line tracking robot should detect the line with a camera using an image processing technique.The paper focuses on combining computer vision techniques with a proportional-integral-derivative(PID)control-ler for automatic steering and speed control.A prototype line tracking robot is used to evaluate the proposed control strategy.展开更多
[Objective] The aim was to test the controlling effect of cleaning steriliza- tion system, material conveying system, and fermentation jar cooling system with equip- ments of fruit wine production line introduced in t...[Objective] The aim was to test the controlling effect of cleaning steriliza- tion system, material conveying system, and fermentation jar cooling system with equip- ments of fruit wine production line introduced in this study and its auto-control sys- tem field assembled and debugged. [Method] Based on controlling equipment and setting parameters on the configuration interface, the operation state of the control equipments could be real-time monitored and controlled with the help of configura- tion software. [Result] The result showed that the equipment system could reduce the temperature into 12 ℃ with the error of +0.5 ℃within 110 minutes when the fermentation temperature is set at 12 ℃ in real production. [Conclusion] The auto- control system of fruit wine production line was easy to be assembled and de- bugged to meet demands of different fruit wine productions.展开更多
Different choices of control variables in variational assimilation can bring about different influences on the analyzed atmospheric state. Based on the WRF model's three-dimensional variational assimilation system, t...Different choices of control variables in variational assimilation can bring about different influences on the analyzed atmospheric state. Based on the WRF model's three-dimensional variational assimilation system, this study compares the be- havior of two momentum control variable options-streamfunction velocity potential (ψ-χ) and horizontal wind components (U-V)-in radar wind data assimilation for a squall line case that occurred in Jiangsu Province on 24 August 2014. The wind increment from the single observation test shows that the ψ-χ control variable scheme produces negative increments in the neighborhood around the observation point because streamfunction and velocity potential preserve integrals of velocity. On the contrary, the U-V control variable scheme objectively reflects the information of the observation itself. Furthermore, radial velocity data from 17 Doppler radars in eastern China are assimilated. As compared to the impact of conventional observation, the assimilation of radar radial velocity based on the U-V control variable scheme significantly improves the mesoscale dynamic field in the initial condition. The enhanced low-level jet stream, water vapor convergence and low-level wind shear result in better squall line forecasting. However, the ψ-χ control variable scheme generates a discontinuous wind field and unrealistic convergence/divergence in the analyzed field, which lead to a degraded precipitation forecast.展开更多
In order to ensure that the off-line arm of a two-arm-wheel combined inspection robot can reliably grasp the line in case of autonomous obstacle crossing,a control method is proposed for line grasping based on hand-ey...In order to ensure that the off-line arm of a two-arm-wheel combined inspection robot can reliably grasp the line in case of autonomous obstacle crossing,a control method is proposed for line grasping based on hand-eye visual servo.On the basis of the transmission line's geometrical characteristics and the camera's imaging principle,a line recognition and extraction method based on structure constraint is designed.The line's intercept and inclination are defined in an imaging space to represent the robot's change of pose and a law governing the pose decoupling servo control is developed.Under the integrated consideration of the influence of light intensity and background change,noise(from the camera itself and electromagnetic field)as well as the robot's kinetic inertia on the robot's imaging quality in the course of motion and the grasping control precision,a servo controller for grasping the line of the robot's off-line arm is designed with the method of fuzzy control.An experiment is conducted on a 1:1 simulation line using an inspection robot and the robot is put into on-line operation on a real overhead transmission line,where the robot can grasp the line within 18 s in the case of autonomous obstacle-crossing.The robot's autonomous line-grasping function is realized without manual intervention and the robot can grasp the line in a precise,reliable and efficient manner,thus the need of actual operation can be satisfied.展开更多
This paper presents an adaptive gain-scheduled backstepping control(AGSBC) scheme for the balance control of an underactuated mechanical power-line inspection(PLI) robotic system with two degrees of freedom and a sing...This paper presents an adaptive gain-scheduled backstepping control(AGSBC) scheme for the balance control of an underactuated mechanical power-line inspection(PLI) robotic system with two degrees of freedom and a single control input.First, a nonlinear dynamic model of the balance adjustment process of the PLI robot is constructed, and then the model is linearized at a nominal equilibrium point to overcome the computational infeasibility of the conventional backstepping technique. Second, to solve generalized stabilization control issue for underactuated systems with multiple equilibrium points,an equilibrium manifold linearized model is developed using a scheduling variable, and then a gain-scheduled backstepping control(GSBC) scheme for expanding the operational area of the controlled system is constructed. Finally, an adaptive mechanism is proposed to counteract the impact of external disturbances. The robust stability of the closed-loop system is ensured by Lyapunov theorem. Simulation results demonstrate the effectiveness and high performance of the proposed scheme compared with other control schemes.展开更多
Half-wavelength transmission can transmit large-scale renewable energy over very long distances.This paper proposes an improved steady-state voltage-control method for half-wavelength transmission systems considering ...Half-wavelength transmission can transmit large-scale renewable energy over very long distances.This paper proposes an improved steady-state voltage-control method for half-wavelength transmission systems considering largescale wind-power transmission.First,the unique voltage characteristics of half-wavelength lines are deduced based on the distributed parameter model.In the secondary voltage-control level,reactive power-transmission limits of half-wavelength lines are introduced as another control objective except for tracing the pilot bus voltage reference.Considering the uncertainty and fluctuation of wind power,the overvoltage risk-assessment method of half-wavelength lines is presented to determine specific voltage-control strategies.Simulation results demonstrate that the proposed voltage-control method delivers superior tracking performance according to a voltage reference value and prevents the overvoltage risk of halfwavelength lines effectively in different wind-power penetrations.展开更多
Methods of the comprehensive evaluation have been studied for many years. However, the change speed of evaluated objects was rarely considered by the existing evaluation methods. An evaluation matrix is proposed to re...Methods of the comprehensive evaluation have been studied for many years. However, the change speed of evaluated objects was rarely considered by the existing evaluation methods. An evaluation matrix is proposed to remedy this deficiency. Firstly, the change speed state (CSS) of the evaluated objects is analyzed based on double inspiriting control lines (DICLs), and a matrix of the CSS is constructed. Then, 72 elements in the matrix are analyzed, and formulas describing each CSS are given. The efficiency of the proposed evaluation matrix is proved when the CSS merges with the change speed trend (CST) in the dynamic comprehensive evaluation. Finally, a computing example shows that the proposed evaluation matrix is feasible in the dynamic comprehensive evaluation with the speed feature.展开更多
This paper focuses on the investigation of the attachment line instability for Hybrid Laminar Flow Control(HLFC),one of the most promising drag reduction technologies for modern transport aircraft respect to high Reyn...This paper focuses on the investigation of the attachment line instability for Hybrid Laminar Flow Control(HLFC),one of the most promising drag reduction technologies for modern transport aircraft respect to high Reynolds numbers and large sweep angles.The attachment line instability also plays an important role during laminar-turbulent transition control and HLFC design on a swept wing.The overview of historical research is presented and knowledge gaps are pointed out as the conclusion.展开更多
A modularized, network, reconfigurable architecture and design method of embedded control module is proposed. This control module uses a TMS320F2812 chip as the core, and intro- duces modularization, network, reconfig...A modularized, network, reconfigurable architecture and design method of embedded control module is proposed. This control module uses a TMS320F2812 chip as the core, and intro- duces modularization, network, reconfigurable theory to the design of control module to better meet the flexible and reconfigurable control need of assembly line. The design method of the control module is verified by constructing a control experiment based on controlling of precision x - y displace- ment platform through a CAN bus. Experimental results show that the controlling repeat position accuracy of precision x - y platform by control module is 0. 5 μm and the position error is less than 1μm which meet the needs of micro-adjustment pose of assembly line.展开更多
After giving a short review of the methods used for detecting and monitoring in general systems, this paper describes the way of communication between computer and Computer Numerical Control (CNC) Machining Center (MC...After giving a short review of the methods used for detecting and monitoring in general systems, this paper describes the way of communication between computer and Computer Numerical Control (CNC) Machining Center (MC). Based on these, the paper addresses the means of performing in cycle measurement for manufacturing quality, provides an approach of improving the state of manufacturing process by achieving the real time change of control parameters according to the level of manufacturing process, and discusses the technique of implementing in process dimensional errors compensation corresponding to the in cycle measurement. The results of the experiments show that the frame design is successful and the operation is reliable. The system is taking shape nowadays.展开更多
For decades, the power system was highly centralized. With the growing integration of distributed generations into the system, there is a necessity for bi-directional communication methods to monitor and control the r...For decades, the power system was highly centralized. With the growing integration of distributed generations into the system, there is a necessity for bi-directional communication methods to monitor and control the remote assets. The primary objective of this paper is to develop a communication link for monitoring and controlling a grid-connected inverter in a remote location. Furthermore, the paper presents developments that have been incorporated to improve the communication link. The literature survey indicates that LoRa is superior compared to other technologies, but has some security and reliability issues. This paper also presents an encryption algorithm to improve the security of the LoRa link. Local data storage added to the system before transmitting data increases the system reliability. A display at the transmission end is added to improve the user-friendliness of the communication link. A Powerline Communication link is parallelly added to the LoRa link to improve the reliability. Finally, tests are conducted with an actual inverter and the results are presented. The tests show that the developed communication link has improved security and reliability, while its open nature makes it highly scalable and adaptable for employment in other smart grid applications.展开更多
The control design, based on self-adaptive PID with genetic algorithms(GA) tuning on-line was investigated, for the temperature control of industrial microwave drying rotary device with the multi-layer(IMDRDWM) and wi...The control design, based on self-adaptive PID with genetic algorithms(GA) tuning on-line was investigated, for the temperature control of industrial microwave drying rotary device with the multi-layer(IMDRDWM) and with multivariable nonlinear interaction of microwave and materials. The conventional PID control strategy incorporated with optimization GA was put forward to maintain the optimum drying temperature in order to keep the moisture content below 1%, whose adaptation ability included the cost function of optimization GA according to the output change. Simulations on five different industrial process models and practical temperature process control system for selenium-enriched slag drying intensively by using IMDRDWM were carried out systematically, indicating the reliability and effectiveness of control design. The parameters of proposed control design are all on-line implemented without iterative predictive calculations, and the closed-loop system stability is guaranteed, which makes the developed scheme simpler in its synthesis and application, providing the practical guidelines for the control implementation and the parameter design.展开更多
An integrated metallurgical model was developed to predict microstructure evolution and mechanical properties of low-carbon steel plates produced by TMCP. The metallurgical phenomena occurring during TMCP and mechanic...An integrated metallurgical model was developed to predict microstructure evolution and mechanical properties of low-carbon steel plates produced by TMCP. The metallurgical phenomena occurring during TMCP and mechanical properties were predicted for different process parameters. In the later passes full recrystallization becomes difficult to occur and higher residual strain remains in austenite after rolling. For the reasonable temperature and cooling schedule, yield strength of 30 mm plain carbon steel plate can reach 310 MPa. The first on-line application of prediction and control of microstructure and properties (PCMP) in the medium plate production was achieved. The predictions of the system are in good agreement with measurements.展开更多
Cavity beam position monitor(BPM) is widely used in a precise electron beam position measurement. Based on high performance oscilloscope-embedded EPICS input/output controller,we developed an on-line cavity BPM signal...Cavity beam position monitor(BPM) is widely used in a precise electron beam position measurement. Based on high performance oscilloscope-embedded EPICS input/output controller,we developed an on-line cavity BPM signal processing system for fast data acquisition solution when designing a cavity BPM.Also,methods for extracting the position information from cavity pickup signals and calibration algorithm are included in this solution.展开更多
The line control for multiple intersections is a hot spot in the area of transportation. According to the principle of system analysis and coordination, a method about fuzzy line control for multiple intersections is ...The line control for multiple intersections is a hot spot in the area of transportation. According to the principle of system analysis and coordination, a method about fuzzy line control for multiple intersections is proposed. The system is made of two control units, one is the basic control unit for every single intersection, and the other is used for the function of coordination.展开更多
Since small unmanned helicopter flight attitude control process has strong time-varying characteristics and there are random disturbances,the conventional control methods with unchanged parameters are often unworkable...Since small unmanned helicopter flight attitude control process has strong time-varying characteristics and there are random disturbances,the conventional control methods with unchanged parameters are often unworkable.An on-line adaptive fuzzy control system(AFCS)was designed,in a way that does not depend on a process model of the plant or its approximation in the form of a Jacobian matrix.Neither is it necessary to know the desired response at each instant of time.AFCS implement a simultaneous on-line tuning of fuzzy rules and output scale of fuzzy control system.The two cascade controller design with an inner(attitude controller)and outer controller(navigation controller)of the small unmanned helicopter was proposed.At last,an attitude controller based on AFCS was implemented.The flight experiment showed that the proposed fuzzy logic controller provides quicker response,smaller overshoot,higher precision,robustness and adaptive ability.It satisfies the needs of autonomous flight.展开更多
The prevention and control of catheter line-associated bloodstream infections (CLABSI) have become the key content of medical care and have become the core improvement goal of nursing quality control. However, the pre...The prevention and control of catheter line-associated bloodstream infections (CLABSI) have become the key content of medical care and have become the core improvement goal of nursing quality control. However, the prevention and control status of CLABSI in hospitals of different grades in Guangxi is not clear. In this study, we aim to investigate central venous catheter (CVC) placement and disinfectant use in second and third-level hospitals in Guangxi. This survey was conducted on the second and third-level hospitals in Guangxi, China from 13th April 2021 to 19th April 2021. The results show that a total of 283 questionnaires were collected, including 206 secondary hospitals and 77 tertiary hospitals. In terms of the CVC, tertiary hospitals were able to place CVC entirely under the guidance of B-ultrasound, which was 24 (31.6%) and secondary hospitals were 26 (20.6%). In secondary hospitals, Most CVC placements were performed in operating rooms 94 (74.6%) and 65 (85.5%) on the third level hospital, but 32.5% of secondary hospitals and 48.7% of tertiary hospitals were selected at the bedside of patients in general wards, and 27.8% of the second-level hospital, 43.4% of third-level hospitals was done in general ward treatment rooms, only 61.9% of secondary hospitals and 64.5% of tertiary hospitals could fully achieve the maximum sterile barrier. In terms of skin disinfectants, only 36.0% of tertiary hospitals and 16.4% of second-level CVC-operators chose > 0.5% chlorhexidine alcohol. In conclusion, the prevention and control of catheter line-associated bloodstream infections (CLABSI) in Guangxi are not ideal. The prevention and control department should increase training, implement guidelines and standardize management to reduce the incidence of CLABSI.展开更多
In this paper, a new principle for an adaptive line driver using Fuzzy logic is presented. This type of line driver can adapt its output impedance and gain, automatically to the applied load using a fuzzy logic contro...In this paper, a new principle for an adaptive line driver using Fuzzy logic is presented. This type of line driver can adapt its output impedance and gain, automatically to the applied load using a fuzzy logic controller (FLC). This results in automatically corrected output impedance for different cables with terminations. Also, the line driver output impedance and gain become insensitive to process and line variations. As an example, a line driver for ADSL application has been designed. The circuit operates from a 3.3 v in a 0.35 um standard CMOS technology. The power consumption of FLC is about 1 mW. The circuit dissipates 106 mW and exhibits a -62 dB THD for a 3.2-Vpp signal at 5 MHz across a 75 ohms Load. It has a relatively high -3 dB bandwidth (240 MHz) with good phase margin of about 67 degrees in a 10 pF load capacitor.展开更多
In the Ethernet lossless Data Center Networks (DCNs) deployedwith Priority-based Flow Control (PFC), the head-of-line blocking problemis still difficult to prevent due to PFC triggering under burst trafficscenarios ev...In the Ethernet lossless Data Center Networks (DCNs) deployedwith Priority-based Flow Control (PFC), the head-of-line blocking problemis still difficult to prevent due to PFC triggering under burst trafficscenarios even with the existing congestion control solutions. To addressthe head-of-line blocking problem of PFC, we propose a new congestioncontrol mechanism. The key point of Congestion Control Using In-NetworkTelemetry for Lossless Datacenters (ICC) is to use In-Network Telemetry(INT) technology to obtain comprehensive congestion information, which isthen fed back to the sender to adjust the sending rate timely and accurately.It is possible to control congestion in time, converge to the target rate quickly,and maintain a near-zero queue length at the switch when using ICC. Weconducted Network Simulator-3 (NS-3) simulation experiments to test theICC’s performance. When compared to Congestion Control for Large-ScaleRDMA Deployments (DCQCN), TIMELY: RTT-based Congestion Controlfor the Datacenter (TIMELY), and Re-architecting Congestion Managementin Lossless Ethernet (PCN), ICC effectively reduces PFC pause messages andFlow Completion Time (FCT) by 47%, 56%, 34%, and 15.3×, 14.8×, and11.2×, respectively.展开更多
In the designed automatic balancing head, a non contact induction transformer is used to deliver driving energy to solve the problem of current fed and controlling on line. Computer controlled automatic balancing expe...In the designed automatic balancing head, a non contact induction transformer is used to deliver driving energy to solve the problem of current fed and controlling on line. Computer controlled automatic balancing experiments with phase magnitude control tactics were performed on a flexible rotor system. Results of the experiments prove that the energy feeding method and the control tactics are effective in the automatic balancing head for vibration controlling.展开更多
基金funding from the researchers supporting project number(RSP2022R474)King Saud University,Riyadh,Saudi Arabia.
文摘In a controlled indoor environment,line tracking has become the most practical and reliable navigation strategy for autonomous mobile robots.A line tracking robot is a self-mobile machine that can recognize and track a painted line on thefloor.In general,the path is set and can be visible,such as a black line on a white surface with high contrasting colors.The robot’s path is marked by a distinct line or track,which the robot follows to move.Several scientific contributions from the disciplines of vision and control have been made to mobile robot vision-based navigation.Localization,automated map generation,autonomous navigation and path tracking is all becoming more frequent in vision applications.A visual navigation line tracking robot should detect the line with a camera using an image processing technique.The paper focuses on combining computer vision techniques with a proportional-integral-derivative(PID)control-ler for automatic steering and speed control.A prototype line tracking robot is used to evaluate the proposed control strategy.
基金Supported by Fundamental Research Foundation of GXAAS(GNK2013YM02)~~
文摘[Objective] The aim was to test the controlling effect of cleaning steriliza- tion system, material conveying system, and fermentation jar cooling system with equip- ments of fruit wine production line introduced in this study and its auto-control sys- tem field assembled and debugged. [Method] Based on controlling equipment and setting parameters on the configuration interface, the operation state of the control equipments could be real-time monitored and controlled with the help of configura- tion software. [Result] The result showed that the equipment system could reduce the temperature into 12 ℃ with the error of +0.5 ℃within 110 minutes when the fermentation temperature is set at 12 ℃ in real production. [Conclusion] The auto- control system of fruit wine production line was easy to be assembled and de- bugged to meet demands of different fruit wine productions.
基金jointly supported by the National Fundamental Research(973)Program of China(Grant Nos.2015CB452801 and 2013CB430100)the Jiangsu Meteorological Bureau Research Fund Project for the Youth(Grant Nos.Q201514 and Q201407)+3 种基金the Shandong Institute of Meteorological Sciences Research Fund Project(Grant No.SDQXKF2015M10)the Jiangsu Provincial Key Technology R&D Program(Grant No.BE2013730)the Jiangsu Meteorological Bureau Key Research Fund Project(Grant No.KZ201502)the National Key Technology R&D Program(Grant No.2014BAG01B01)
文摘Different choices of control variables in variational assimilation can bring about different influences on the analyzed atmospheric state. Based on the WRF model's three-dimensional variational assimilation system, this study compares the be- havior of two momentum control variable options-streamfunction velocity potential (ψ-χ) and horizontal wind components (U-V)-in radar wind data assimilation for a squall line case that occurred in Jiangsu Province on 24 August 2014. The wind increment from the single observation test shows that the ψ-χ control variable scheme produces negative increments in the neighborhood around the observation point because streamfunction and velocity potential preserve integrals of velocity. On the contrary, the U-V control variable scheme objectively reflects the information of the observation itself. Furthermore, radial velocity data from 17 Doppler radars in eastern China are assimilated. As compared to the impact of conventional observation, the assimilation of radar radial velocity based on the U-V control variable scheme significantly improves the mesoscale dynamic field in the initial condition. The enhanced low-level jet stream, water vapor convergence and low-level wind shear result in better squall line forecasting. However, the ψ-χ control variable scheme generates a discontinuous wind field and unrealistic convergence/divergence in the analyzed field, which lead to a degraded precipitation forecast.
基金Project(2006AA04Z202)supported by the National High Technology Research and Development Program of ChinaProject(51105281)supported by the National Natural Science Foundation of China
文摘In order to ensure that the off-line arm of a two-arm-wheel combined inspection robot can reliably grasp the line in case of autonomous obstacle crossing,a control method is proposed for line grasping based on hand-eye visual servo.On the basis of the transmission line's geometrical characteristics and the camera's imaging principle,a line recognition and extraction method based on structure constraint is designed.The line's intercept and inclination are defined in an imaging space to represent the robot's change of pose and a law governing the pose decoupling servo control is developed.Under the integrated consideration of the influence of light intensity and background change,noise(from the camera itself and electromagnetic field)as well as the robot's kinetic inertia on the robot's imaging quality in the course of motion and the grasping control precision,a servo controller for grasping the line of the robot's off-line arm is designed with the method of fuzzy control.An experiment is conducted on a 1:1 simulation line using an inspection robot and the robot is put into on-line operation on a real overhead transmission line,where the robot can grasp the line within 18 s in the case of autonomous obstacle-crossing.The robot's autonomous line-grasping function is realized without manual intervention and the robot can grasp the line in a precise,reliable and efficient manner,thus the need of actual operation can be satisfied.
文摘This paper presents an adaptive gain-scheduled backstepping control(AGSBC) scheme for the balance control of an underactuated mechanical power-line inspection(PLI) robotic system with two degrees of freedom and a single control input.First, a nonlinear dynamic model of the balance adjustment process of the PLI robot is constructed, and then the model is linearized at a nominal equilibrium point to overcome the computational infeasibility of the conventional backstepping technique. Second, to solve generalized stabilization control issue for underactuated systems with multiple equilibrium points,an equilibrium manifold linearized model is developed using a scheduling variable, and then a gain-scheduled backstepping control(GSBC) scheme for expanding the operational area of the controlled system is constructed. Finally, an adaptive mechanism is proposed to counteract the impact of external disturbances. The robust stability of the closed-loop system is ensured by Lyapunov theorem. Simulation results demonstrate the effectiveness and high performance of the proposed scheme compared with other control schemes.
基金supported by State Grid Corporation of China,Projects under Grant 520626200031National Natural Science Foundation of China,No.51877200。
文摘Half-wavelength transmission can transmit large-scale renewable energy over very long distances.This paper proposes an improved steady-state voltage-control method for half-wavelength transmission systems considering largescale wind-power transmission.First,the unique voltage characteristics of half-wavelength lines are deduced based on the distributed parameter model.In the secondary voltage-control level,reactive power-transmission limits of half-wavelength lines are introduced as another control objective except for tracing the pilot bus voltage reference.Considering the uncertainty and fluctuation of wind power,the overvoltage risk-assessment method of half-wavelength lines is presented to determine specific voltage-control strategies.Simulation results demonstrate that the proposed voltage-control method delivers superior tracking performance according to a voltage reference value and prevents the overvoltage risk of halfwavelength lines effectively in different wind-power penetrations.
基金supported by the National Natural Science Foundation of China (7127217671302028)+1 种基金the Fundamental Scientific Research Funds for the Central Universities (HEUCF110914)the Heilongjiang Postdoctoral Fund (3236310094)
文摘Methods of the comprehensive evaluation have been studied for many years. However, the change speed of evaluated objects was rarely considered by the existing evaluation methods. An evaluation matrix is proposed to remedy this deficiency. Firstly, the change speed state (CSS) of the evaluated objects is analyzed based on double inspiriting control lines (DICLs), and a matrix of the CSS is constructed. Then, 72 elements in the matrix are analyzed, and formulas describing each CSS are given. The efficiency of the proposed evaluation matrix is proved when the CSS merges with the change speed trend (CST) in the dynamic comprehensive evaluation. Finally, a computing example shows that the proposed evaluation matrix is feasible in the dynamic comprehensive evaluation with the speed feature.
文摘This paper focuses on the investigation of the attachment line instability for Hybrid Laminar Flow Control(HLFC),one of the most promising drag reduction technologies for modern transport aircraft respect to high Reynolds numbers and large sweep angles.The attachment line instability also plays an important role during laminar-turbulent transition control and HLFC design on a swept wing.The overview of historical research is presented and knowledge gaps are pointed out as the conclusion.
基金Supported by National Defense Basic Scientific Research Project(A092000000)High Quality CNC Machine Tool and Basic Manufacturing Equipment Scientific Major Project(2012ZX04010-061)
文摘A modularized, network, reconfigurable architecture and design method of embedded control module is proposed. This control module uses a TMS320F2812 chip as the core, and intro- duces modularization, network, reconfigurable theory to the design of control module to better meet the flexible and reconfigurable control need of assembly line. The design method of the control module is verified by constructing a control experiment based on controlling of precision x - y displace- ment platform through a CAN bus. Experimental results show that the controlling repeat position accuracy of precision x - y platform by control module is 0. 5 μm and the position error is less than 1μm which meet the needs of micro-adjustment pose of assembly line.
文摘After giving a short review of the methods used for detecting and monitoring in general systems, this paper describes the way of communication between computer and Computer Numerical Control (CNC) Machining Center (MC). Based on these, the paper addresses the means of performing in cycle measurement for manufacturing quality, provides an approach of improving the state of manufacturing process by achieving the real time change of control parameters according to the level of manufacturing process, and discusses the technique of implementing in process dimensional errors compensation corresponding to the in cycle measurement. The results of the experiments show that the frame design is successful and the operation is reliable. The system is taking shape nowadays.
文摘For decades, the power system was highly centralized. With the growing integration of distributed generations into the system, there is a necessity for bi-directional communication methods to monitor and control the remote assets. The primary objective of this paper is to develop a communication link for monitoring and controlling a grid-connected inverter in a remote location. Furthermore, the paper presents developments that have been incorporated to improve the communication link. The literature survey indicates that LoRa is superior compared to other technologies, but has some security and reliability issues. This paper also presents an encryption algorithm to improve the security of the LoRa link. Local data storage added to the system before transmitting data increases the system reliability. A display at the transmission end is added to improve the user-friendliness of the communication link. A Powerline Communication link is parallelly added to the LoRa link to improve the reliability. Finally, tests are conducted with an actual inverter and the results are presented. The tests show that the developed communication link has improved security and reliability, while its open nature makes it highly scalable and adaptable for employment in other smart grid applications.
基金Project(51090385) supported by the Major Program of National Natural Science Foundation of ChinaProject(2011IB001) supported by Yunnan Provincial Science and Technology Program,China+1 种基金Project(2012DFA70570) supported by the International Science & Technology Cooperation Program of ChinaProject(2011IA004) supported by the Yunnan Provincial International Cooperative Program,China
文摘The control design, based on self-adaptive PID with genetic algorithms(GA) tuning on-line was investigated, for the temperature control of industrial microwave drying rotary device with the multi-layer(IMDRDWM) and with multivariable nonlinear interaction of microwave and materials. The conventional PID control strategy incorporated with optimization GA was put forward to maintain the optimum drying temperature in order to keep the moisture content below 1%, whose adaptation ability included the cost function of optimization GA according to the output change. Simulations on five different industrial process models and practical temperature process control system for selenium-enriched slag drying intensively by using IMDRDWM were carried out systematically, indicating the reliability and effectiveness of control design. The parameters of proposed control design are all on-line implemented without iterative predictive calculations, and the closed-loop system stability is guaranteed, which makes the developed scheme simpler in its synthesis and application, providing the practical guidelines for the control implementation and the parameter design.
基金This work was financially supported by the High Technology Development Program(No.2001AA339030)the National Natural Science Foundation of China(No.50334010).
文摘An integrated metallurgical model was developed to predict microstructure evolution and mechanical properties of low-carbon steel plates produced by TMCP. The metallurgical phenomena occurring during TMCP and mechanical properties were predicted for different process parameters. In the later passes full recrystallization becomes difficult to occur and higher residual strain remains in austenite after rolling. For the reasonable temperature and cooling schedule, yield strength of 30 mm plain carbon steel plate can reach 310 MPa. The first on-line application of prediction and control of microstructure and properties (PCMP) in the medium plate production was achieved. The predictions of the system are in good agreement with measurements.
基金Supported by National Natural Science Foundation(Grant No.11075198)
文摘Cavity beam position monitor(BPM) is widely used in a precise electron beam position measurement. Based on high performance oscilloscope-embedded EPICS input/output controller,we developed an on-line cavity BPM signal processing system for fast data acquisition solution when designing a cavity BPM.Also,methods for extracting the position information from cavity pickup signals and calibration algorithm are included in this solution.
文摘The line control for multiple intersections is a hot spot in the area of transportation. According to the principle of system analysis and coordination, a method about fuzzy line control for multiple intersections is proposed. The system is made of two control units, one is the basic control unit for every single intersection, and the other is used for the function of coordination.
基金sponsored by The National High-tech Research and Development Program(Project No.2007AA041503 and 2007AA404260)the Research Program of Shanghai Science and Technology Committee (Project No.07dz05813)State Leading Academic Discipline,Shanghai Leading Aca-demic Discipline
文摘Since small unmanned helicopter flight attitude control process has strong time-varying characteristics and there are random disturbances,the conventional control methods with unchanged parameters are often unworkable.An on-line adaptive fuzzy control system(AFCS)was designed,in a way that does not depend on a process model of the plant or its approximation in the form of a Jacobian matrix.Neither is it necessary to know the desired response at each instant of time.AFCS implement a simultaneous on-line tuning of fuzzy rules and output scale of fuzzy control system.The two cascade controller design with an inner(attitude controller)and outer controller(navigation controller)of the small unmanned helicopter was proposed.At last,an attitude controller based on AFCS was implemented.The flight experiment showed that the proposed fuzzy logic controller provides quicker response,smaller overshoot,higher precision,robustness and adaptive ability.It satisfies the needs of autonomous flight.
文摘The prevention and control of catheter line-associated bloodstream infections (CLABSI) have become the key content of medical care and have become the core improvement goal of nursing quality control. However, the prevention and control status of CLABSI in hospitals of different grades in Guangxi is not clear. In this study, we aim to investigate central venous catheter (CVC) placement and disinfectant use in second and third-level hospitals in Guangxi. This survey was conducted on the second and third-level hospitals in Guangxi, China from 13th April 2021 to 19th April 2021. The results show that a total of 283 questionnaires were collected, including 206 secondary hospitals and 77 tertiary hospitals. In terms of the CVC, tertiary hospitals were able to place CVC entirely under the guidance of B-ultrasound, which was 24 (31.6%) and secondary hospitals were 26 (20.6%). In secondary hospitals, Most CVC placements were performed in operating rooms 94 (74.6%) and 65 (85.5%) on the third level hospital, but 32.5% of secondary hospitals and 48.7% of tertiary hospitals were selected at the bedside of patients in general wards, and 27.8% of the second-level hospital, 43.4% of third-level hospitals was done in general ward treatment rooms, only 61.9% of secondary hospitals and 64.5% of tertiary hospitals could fully achieve the maximum sterile barrier. In terms of skin disinfectants, only 36.0% of tertiary hospitals and 16.4% of second-level CVC-operators chose > 0.5% chlorhexidine alcohol. In conclusion, the prevention and control of catheter line-associated bloodstream infections (CLABSI) in Guangxi are not ideal. The prevention and control department should increase training, implement guidelines and standardize management to reduce the incidence of CLABSI.
文摘In this paper, a new principle for an adaptive line driver using Fuzzy logic is presented. This type of line driver can adapt its output impedance and gain, automatically to the applied load using a fuzzy logic controller (FLC). This results in automatically corrected output impedance for different cables with terminations. Also, the line driver output impedance and gain become insensitive to process and line variations. As an example, a line driver for ADSL application has been designed. The circuit operates from a 3.3 v in a 0.35 um standard CMOS technology. The power consumption of FLC is about 1 mW. The circuit dissipates 106 mW and exhibits a -62 dB THD for a 3.2-Vpp signal at 5 MHz across a 75 ohms Load. It has a relatively high -3 dB bandwidth (240 MHz) with good phase margin of about 67 degrees in a 10 pF load capacitor.
基金supported by the National Natural Science Foundation of China (No.62102046,62072249,62072056)JinWang,YongjunRen,and Jinbin Hu receive the grant,and the URLs to the sponsors’websites are https://www.nsfc.gov.cn/.This work is also funded by the National Science Foundation of Hunan Province (No.2022JJ30618,2020JJ2029).
文摘In the Ethernet lossless Data Center Networks (DCNs) deployedwith Priority-based Flow Control (PFC), the head-of-line blocking problemis still difficult to prevent due to PFC triggering under burst trafficscenarios even with the existing congestion control solutions. To addressthe head-of-line blocking problem of PFC, we propose a new congestioncontrol mechanism. The key point of Congestion Control Using In-NetworkTelemetry for Lossless Datacenters (ICC) is to use In-Network Telemetry(INT) technology to obtain comprehensive congestion information, which isthen fed back to the sender to adjust the sending rate timely and accurately.It is possible to control congestion in time, converge to the target rate quickly,and maintain a near-zero queue length at the switch when using ICC. Weconducted Network Simulator-3 (NS-3) simulation experiments to test theICC’s performance. When compared to Congestion Control for Large-ScaleRDMA Deployments (DCQCN), TIMELY: RTT-based Congestion Controlfor the Datacenter (TIMELY), and Re-architecting Congestion Managementin Lossless Ethernet (PCN), ICC effectively reduces PFC pause messages andFlow Completion Time (FCT) by 47%, 56%, 34%, and 15.3×, 14.8×, and11.2×, respectively.
文摘In the designed automatic balancing head, a non contact induction transformer is used to deliver driving energy to solve the problem of current fed and controlling on line. Computer controlled automatic balancing experiments with phase magnitude control tactics were performed on a flexible rotor system. Results of the experiments prove that the energy feeding method and the control tactics are effective in the automatic balancing head for vibration controlling.