In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control flexibility.In addition,digital hydraulic technology(DHT)has been verified as a reasonabl...In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control flexibility.In addition,digital hydraulic technology(DHT)has been verified as a reasonable method to optimize system dynamic performance.Integrating these two technologies into one component can combine their advantages together.However,few works focused on it.In this paper,a twin spools valve with switching technologycontrolled pilot stage(TSVSP)is presented,which applied DHT into its pilot stage while appending IMC into its main stage.Based on this prototype valve,a series of numerical and experiment analysis of its IMC performance with both simulated load and excavator boom cylinder are carried out.Results showed fast and robust performance of pressure and flow compound control with acceptable fluctuation phenomenon caused by switching technology.Rising time of flow response in excavator cylinder can be controlled within 200 ms,meanwhile,the recovery time of rod chamber pressure under suddenly changed condition is optimized within 250 ms.IMC system based on TSVSP can improve both dynamic performance and robust characteristics of the target actuator so it is practical in valve-cylinder system and can be applied in mobile machineries.展开更多
The previous operation of the ZLS-Burris gravity meter using a PDA already provides a significant improvement of the operation of a metal spring gravity meter. But in the practical field work the observer usually wish...The previous operation of the ZLS-Burris gravity meter using a PDA already provides a significant improvement of the operation of a metal spring gravity meter. But in the practical field work the observer usually wishes more information about the measurement and the collected data. This situation sug- gested an improvement of the software and computer hardware. The goal was to develop a small useful PC tool that eliminates these deficits. However, it resulted in a very extensive application software, which was developed during 2011-2015. Along the way, some unwanted effects of the original control circuit were detected. Therefore as a last step a complete new control circuit for the feedback system was developed. This new circuit is fast and smooth and without resonance effects to the system. The algorithm parameters can be specifically adapted to the specific gravity meter. The software has a security system that ensures the user, depending on his level of knowledge, a limited access to the software options. Furthermore, a customer project management system is integrated. The observer, the gravity meters, the projects and maps can be assigned. Several ZLS Burris gravity meters can be managed. A large station data management is integrated. Every station has up to more than twenty parameters, such as the mandatory coordinates or supplementary pictures of the station. External storage and documentation of the measurements are possible with extra modules. In addition the maintenance of the gravity meter system is significantly improved. The motor control of the early ZLS Burris gravity meter is also improved. The complete rotation is displayed on the screen. Finally, two survey examples show the advantages of the software related to the accuracy and the time needed for a measurement.展开更多
Aiming at the shortcomings of the separate meter in and separate meter out?hydraulic system, a new type of independent metering control system is proposed by referring to the principle of load-sensing system. The valv...Aiming at the shortcomings of the separate meter in and separate meter out?hydraulic system, a new type of independent metering control system is proposed by referring to the principle of load-sensing system. The valve group unit in the system is designed, and the AMESim/Matlab cosimulation model of the component and system is established. The actuator speed control, energy consumption and anti-flow saturation characteristics of the system are discussed. The simulation result shows that the system proposed in this article can achieve?better performances.展开更多
An iterative learning control scheme is developed to the traffic densitycontrol in a macroscopic level freeway environment. With rigorous analysis, the proposed intelligentcontrol scheme guarantees the asymptotic conv...An iterative learning control scheme is developed to the traffic densitycontrol in a macroscopic level freeway environment. With rigorous analysis, the proposed intelligentcontrol scheme guarantees the asymptotic convergence of the traffic density to the desired one. Thecontrol scheme is applied to a freeway model, and simulation results confirm the efficacy of theproposed approach.展开更多
After heat is metered in each house unit,the heating system is regulated by variable flow.The temperature of the return w ater is controlled to regulate the flow to realize the temperature regulation.According to the ...After heat is metered in each house unit,the heating system is regulated by variable flow.The temperature of the return w ater is controlled to regulate the flow to realize the temperature regulation.According to the characteristics of the temperature control w ith big inertia,pure time-delay and degeneration,a fuzzy adaptive PID controller is designed w ith the advantages of the fuzzy control and PID algorithm,and the simulation model is established according to the characteristics of heating metering system.Simulation results show that the fuzzy adaptive PID controller proposed has small overshoot,short oscillation cycle,high precision and strong anti-jamming capability in comparison w ith conventional PID controller,w hich could meet the requirement of the dynamic and steady-state performance of the heating process.展开更多
The current microgrid power management system is undergoing a significant and drastic overhaul. The integration of existing electrical infrastructure with an information and communication network is an inherent and si...The current microgrid power management system is undergoing a significant and drastic overhaul. The integration of existing electrical infrastructure with an information and communication network is an inherent and significant need for microgrid classification and operation in this case. Microgrid technology’s most important features: 1) Full duplex communication;2) Advanced metering infrastructure;3) Renewable and energy resource integration;4) Distribution automation and complete monitoring, as well as overall power system control. A microgrid’s communication infrastructure is made up of several hierarchical communication networks. Microgrid applications can frequently be found in numerous aspects of energy consumption. Because it provides a spontaneous communicational network, the Internet of Things plays a fundamental and crucial role in Microgrid infrastructure. This paper covers the deployment of a comprehensive energy management system for microgrid communication infrastructure based on the Internet of Things (IoT). This paper discusses microgrid operations and controls using the Internet of Things (IoT) architecture. Microgrids make use of IoT-enabled technologies, in conjunction with power grid equipment, which are enabling local networks to provide additional services on top of the essential supply of electricity to local networks that operate in parallel with or independently of the regional grid. Local balancing, internal blockage management, and request for support marketplace or grid operator activities are examples of auxiliary services provided by the microgrid that can add value to each end-user and other true stakeholders. Different technologies, architectures, and applications that use IoT as a key element with the main purpose of preserving and regulating innovative smart microgrids in accordance with modern optimization features and regulations are designed to update and improve efficiency, resiliency, and economics.展开更多
For purpose of achieving the desired thermal comfort level and reducing the economic cost of maintaining the thermal comfort of green residential building,an energy efficient thermal comfort control strategy based on ...For purpose of achieving the desired thermal comfort level and reducing the economic cost of maintaining the thermal comfort of green residential building,an energy efficient thermal comfort control strategy based on economic model predictive control(EMPC)for green residential buildings which adopts household heat metering is presented.Firstly,the nonlinear thermal comfort model of heating room is analyzed and obtained.A practical nonlinear thermal comfort prediction model is obtained by using an approximation method.Then,the economic cost function and optimization problem of energy-saving under the necessary thermal comfort requirements are constructed to realize the optimal economic performance of the dynamic process.The energy efficient thermal comfort MPC(EETCMPC)is designed.Finally,the comparison and analysis between EETCMPC and Double-layer Model Predictive Control(DMPC)is simulated.The simulation results reveal that when the clothing insulation is typical,the energy efficiency of EETCMPC is 8.9%and 11.6%,respectively,in the two simulation scenarios.When the clothing insulation varies with temperature,the energy efficiency of EETCMPC is 7.29%and 9.15%,respectively,and the total energy consumption is reduced by about 1.65%and 14.6%,respectively,compared with the typical clothing insulation.The economic performance is improved in the thermal comfort dynamic process of heating room.展开更多
This study presents the results of the preliminary tests performed using a kerma-area product (KAP) meter in order to verify its usefulness as a monitor chamber in a clinical X ray system, which will be used in ioniza...This study presents the results of the preliminary tests performed using a kerma-area product (KAP) meter in order to verify its usefulness as a monitor chamber in a clinical X ray system, which will be used in ionization chambers’ quality control program. The tests performed were repeatability, surface measurement uniformity, linearity with tube current, measurement variation changing the distance and field size, KAP chamber radiation attenuation, and energy dependence. The KAP meter has presented a good repeatability (a maximum variation of 0.4%);its surface has a homogeneous response (a maximum variation of 1.0% among the different irradiated regions);the response is linear with the tube current and the variation of the PKA along the distance is less than 3.43%. On the other hand, the results obtained for chamber attenuation and energy dependence show that some corrections must be applied when the measurements are made. The results have shown a good performance of the KAP meter, confirming that it is possible to use this instrument as a monitor chamber. However, it is important to highlight that some correction factors for energy dependence and chamber radiation attenuation must be considered.展开更多
Nutrient application systems are designed to apply a relatively uniform amount of a fertilizer to agricultural fields. However, considerable variation in soil texture and other characteristics often occurs within and ...Nutrient application systems are designed to apply a relatively uniform amount of a fertilizer to agricultural fields. However, considerable variation in soil texture and other characteristics often occurs within and across production fields, which could have a major impact on fertilizer management strategies. Therefore, uniform application of a fertilizer over the entire field can be both costly and environmentally unsound. Due to their rugged and fool-proof design, crankshaft type piston pumps are widely used in agriculture. The on-the-go outlet flow of these pumps can only be varied by changing the drive shaft speed for each pump stroke setting. But only a limited range of flow rates can be achieved by changing the drive shaft speed. There is a need for an electronic controller, which can adjust the pump stroke on-the-go, for real-time, variable-rate application of crop nutrients. The Clemson “Electro-me-chanical controller for adjusting pump stroke on-the-go” was designed to replace the current manual stroke adjustment system on positive displacement piston pumps. This affordable system can be retrofitted on most John Blue - piston pumps for real-time adjustment of the pump stroke and can be controlled using pre-described position sequences (map-based) or real-time sensor commands (such as optical, pressure, and flow sensors) combined with fertilizer calculation algorithms. In addition, it can adjust pump stroke manually, using an eclectic dial from the tractor’s cab.展开更多
We investigate the problem of coordinated chaos control on an urban expressway based on pinning synchronization of complex networks. A node coupling model of an urban expressway based on complex networks has been esta...We investigate the problem of coordinated chaos control on an urban expressway based on pinning synchronization of complex networks. A node coupling model of an urban expressway based on complex networks has been established using the cell transmission model（CTM）. The pinning controller corresponding to multi-ramp coordinated controller was designed by using the delayed feedback control（DFC） method, whose objective is to realize periodical orbits from chaotic states. The concrete pinning control nodes corresponding to the subsystems of regulating the inflows from the on-ramps to the mainline were obtained and the parameters of the controller were optimized by using the stability theory of complex networks to ensure the network synchronization. The validity of the proposed coordinated chaos control method was proven via the simulation experiment. The results of the examples indicated that the order motion on urban expressway can be realized, the wide-moving traffic jam can be suppressed, and the operating efficiency is superior to that of the traditional control methods.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52005441,51890885)open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems(Grant No.GZKF-201906)+1 种基金Zhejiang Province Natural Science Foundation of China(Grant No.LQ21E050017)China Postdoctoral Science Foundation(Grant Nos.2021M692777,2021T140594).
文摘In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control flexibility.In addition,digital hydraulic technology(DHT)has been verified as a reasonable method to optimize system dynamic performance.Integrating these two technologies into one component can combine their advantages together.However,few works focused on it.In this paper,a twin spools valve with switching technologycontrolled pilot stage(TSVSP)is presented,which applied DHT into its pilot stage while appending IMC into its main stage.Based on this prototype valve,a series of numerical and experiment analysis of its IMC performance with both simulated load and excavator boom cylinder are carried out.Results showed fast and robust performance of pressure and flow compound control with acceptable fluctuation phenomenon caused by switching technology.Rising time of flow response in excavator cylinder can be controlled within 200 ms,meanwhile,the recovery time of rod chamber pressure under suddenly changed condition is optimized within 250 ms.IMC system based on TSVSP can improve both dynamic performance and robust characteristics of the target actuator so it is practical in valve-cylinder system and can be applied in mobile machineries.
文摘The previous operation of the ZLS-Burris gravity meter using a PDA already provides a significant improvement of the operation of a metal spring gravity meter. But in the practical field work the observer usually wishes more information about the measurement and the collected data. This situation sug- gested an improvement of the software and computer hardware. The goal was to develop a small useful PC tool that eliminates these deficits. However, it resulted in a very extensive application software, which was developed during 2011-2015. Along the way, some unwanted effects of the original control circuit were detected. Therefore as a last step a complete new control circuit for the feedback system was developed. This new circuit is fast and smooth and without resonance effects to the system. The algorithm parameters can be specifically adapted to the specific gravity meter. The software has a security system that ensures the user, depending on his level of knowledge, a limited access to the software options. Furthermore, a customer project management system is integrated. The observer, the gravity meters, the projects and maps can be assigned. Several ZLS Burris gravity meters can be managed. A large station data management is integrated. Every station has up to more than twenty parameters, such as the mandatory coordinates or supplementary pictures of the station. External storage and documentation of the measurements are possible with extra modules. In addition the maintenance of the gravity meter system is significantly improved. The motor control of the early ZLS Burris gravity meter is also improved. The complete rotation is displayed on the screen. Finally, two survey examples show the advantages of the software related to the accuracy and the time needed for a measurement.
文摘Aiming at the shortcomings of the separate meter in and separate meter out?hydraulic system, a new type of independent metering control system is proposed by referring to the principle of load-sensing system. The valve group unit in the system is designed, and the AMESim/Matlab cosimulation model of the component and system is established. The actuator speed control, energy consumption and anti-flow saturation characteristics of the system are discussed. The simulation result shows that the system proposed in this article can achieve?better performances.
文摘An iterative learning control scheme is developed to the traffic densitycontrol in a macroscopic level freeway environment. With rigorous analysis, the proposed intelligentcontrol scheme guarantees the asymptotic convergence of the traffic density to the desired one. Thecontrol scheme is applied to a freeway model, and simulation results confirm the efficacy of theproposed approach.
基金Project Supported by Education Department of Liaoning Province(LT2012005)
文摘After heat is metered in each house unit,the heating system is regulated by variable flow.The temperature of the return w ater is controlled to regulate the flow to realize the temperature regulation.According to the characteristics of the temperature control w ith big inertia,pure time-delay and degeneration,a fuzzy adaptive PID controller is designed w ith the advantages of the fuzzy control and PID algorithm,and the simulation model is established according to the characteristics of heating metering system.Simulation results show that the fuzzy adaptive PID controller proposed has small overshoot,short oscillation cycle,high precision and strong anti-jamming capability in comparison w ith conventional PID controller,w hich could meet the requirement of the dynamic and steady-state performance of the heating process.
文摘The current microgrid power management system is undergoing a significant and drastic overhaul. The integration of existing electrical infrastructure with an information and communication network is an inherent and significant need for microgrid classification and operation in this case. Microgrid technology’s most important features: 1) Full duplex communication;2) Advanced metering infrastructure;3) Renewable and energy resource integration;4) Distribution automation and complete monitoring, as well as overall power system control. A microgrid’s communication infrastructure is made up of several hierarchical communication networks. Microgrid applications can frequently be found in numerous aspects of energy consumption. Because it provides a spontaneous communicational network, the Internet of Things plays a fundamental and crucial role in Microgrid infrastructure. This paper covers the deployment of a comprehensive energy management system for microgrid communication infrastructure based on the Internet of Things (IoT). This paper discusses microgrid operations and controls using the Internet of Things (IoT) architecture. Microgrids make use of IoT-enabled technologies, in conjunction with power grid equipment, which are enabling local networks to provide additional services on top of the essential supply of electricity to local networks that operate in parallel with or independently of the regional grid. Local balancing, internal blockage management, and request for support marketplace or grid operator activities are examples of auxiliary services provided by the microgrid that can add value to each end-user and other true stakeholders. Different technologies, architectures, and applications that use IoT as a key element with the main purpose of preserving and regulating innovative smart microgrids in accordance with modern optimization features and regulations are designed to update and improve efficiency, resiliency, and economics.
基金supported by the Key Technologies R&D Program of Henan Province(Nos.202102210335/212102210026/212102210509/222102220095/212102110218)the Key Scientific and Technological Project(Social Development Field)of Henan Province,China(No.212102310093)+1 种基金the Key Scientific Research Projects of Institutions of Higher Education in Henan Province(No.20B413007)the Science and Technology Program of Henan Province Department of Housing and Urban Rural Construction(No.K-1916).
文摘For purpose of achieving the desired thermal comfort level and reducing the economic cost of maintaining the thermal comfort of green residential building,an energy efficient thermal comfort control strategy based on economic model predictive control(EMPC)for green residential buildings which adopts household heat metering is presented.Firstly,the nonlinear thermal comfort model of heating room is analyzed and obtained.A practical nonlinear thermal comfort prediction model is obtained by using an approximation method.Then,the economic cost function and optimization problem of energy-saving under the necessary thermal comfort requirements are constructed to realize the optimal economic performance of the dynamic process.The energy efficient thermal comfort MPC(EETCMPC)is designed.Finally,the comparison and analysis between EETCMPC and Double-layer Model Predictive Control(DMPC)is simulated.The simulation results reveal that when the clothing insulation is typical,the energy efficiency of EETCMPC is 8.9%and 11.6%,respectively,in the two simulation scenarios.When the clothing insulation varies with temperature,the energy efficiency of EETCMPC is 7.29%and 9.15%,respectively,and the total energy consumption is reduced by about 1.65%and 14.6%,respectively,compared with the typical clothing insulation.The economic performance is improved in the thermal comfort dynamic process of heating room.
文摘This study presents the results of the preliminary tests performed using a kerma-area product (KAP) meter in order to verify its usefulness as a monitor chamber in a clinical X ray system, which will be used in ionization chambers’ quality control program. The tests performed were repeatability, surface measurement uniformity, linearity with tube current, measurement variation changing the distance and field size, KAP chamber radiation attenuation, and energy dependence. The KAP meter has presented a good repeatability (a maximum variation of 0.4%);its surface has a homogeneous response (a maximum variation of 1.0% among the different irradiated regions);the response is linear with the tube current and the variation of the PKA along the distance is less than 3.43%. On the other hand, the results obtained for chamber attenuation and energy dependence show that some corrections must be applied when the measurements are made. The results have shown a good performance of the KAP meter, confirming that it is possible to use this instrument as a monitor chamber. However, it is important to highlight that some correction factors for energy dependence and chamber radiation attenuation must be considered.
文摘Nutrient application systems are designed to apply a relatively uniform amount of a fertilizer to agricultural fields. However, considerable variation in soil texture and other characteristics often occurs within and across production fields, which could have a major impact on fertilizer management strategies. Therefore, uniform application of a fertilizer over the entire field can be both costly and environmentally unsound. Due to their rugged and fool-proof design, crankshaft type piston pumps are widely used in agriculture. The on-the-go outlet flow of these pumps can only be varied by changing the drive shaft speed for each pump stroke setting. But only a limited range of flow rates can be achieved by changing the drive shaft speed. There is a need for an electronic controller, which can adjust the pump stroke on-the-go, for real-time, variable-rate application of crop nutrients. The Clemson “Electro-me-chanical controller for adjusting pump stroke on-the-go” was designed to replace the current manual stroke adjustment system on positive displacement piston pumps. This affordable system can be retrofitted on most John Blue - piston pumps for real-time adjustment of the pump stroke and can be controlled using pre-described position sequences (map-based) or real-time sensor commands (such as optical, pressure, and flow sensors) combined with fertilizer calculation algorithms. In addition, it can adjust pump stroke manually, using an eclectic dial from the tractor’s cab.
基金Supported by National Natural science Foundation-of P.R.Chlna （60474038, 60774022）, Specialized Research Fund for the Doctoral Program of Higher Educatlon（20060004002）
基金Project supported by the National Natural Science Foundation of China(Grant No.50478088)the Natural Science Foundation of Hebei Province,China(Grant No.E2015202266)
文摘We investigate the problem of coordinated chaos control on an urban expressway based on pinning synchronization of complex networks. A node coupling model of an urban expressway based on complex networks has been established using the cell transmission model（CTM）. The pinning controller corresponding to multi-ramp coordinated controller was designed by using the delayed feedback control（DFC） method, whose objective is to realize periodical orbits from chaotic states. The concrete pinning control nodes corresponding to the subsystems of regulating the inflows from the on-ramps to the mainline were obtained and the parameters of the controller were optimized by using the stability theory of complex networks to ensure the network synchronization. The validity of the proposed coordinated chaos control method was proven via the simulation experiment. The results of the examples indicated that the order motion on urban expressway can be realized, the wide-moving traffic jam can be suppressed, and the operating efficiency is superior to that of the traditional control methods.
