The exploitation of oil resources has now extended to ultra-deep formations,with depths even exceeding 10,000 m.During drilling operations,the bottomhole temperature(BHT)can surpass 240℃.Under such high-temperature c...The exploitation of oil resources has now extended to ultra-deep formations,with depths even exceeding 10,000 m.During drilling operations,the bottomhole temperature(BHT)can surpass 240℃.Under such high-temperature conditions,measurement while drilling(MWD)instruments are highly likely to malfunction due to the inadequate temperature resistance of their electronic components.As a wellbore temperature control approach,the application of thermal insulated drill pipe(TIDP)has been proposed to manage the wellbore temperature in ultra-deep wells.This paper developed a temperature field model for ultra-deep wells by coupling the interactions of multiple factors on the wellbore temperature.For the first time,five distinct TIDP deployment methods were proposed,and their corresponding wellbo re temperature variation characte ristics were investigated,and the heat transfer laws of the ultra-deep wellbore-formation system were quantitatively elucidated.The results revealed that TIDP can effectively restrain the rapid rise in the temperature of the drilling fluid inside the drill string by reducing the heat flux of the drill string.Among the five deployment methods,the method of deploying TIDP from the bottomhole upwards exhibits the best performance.For a 12,000 m simulated well,when6000 m of TIDP are deployed from the bottomhole upwards,the BHT decreases by 52℃,while the outlet temperature increases by merely 1℃.This not only achieves the objective of wellbore temperature control but also keeps the temperature of the drilling fluid at the outlet of annulus at a relatively low level,thereby reducing the requirements for the heat exchange equipment on the ground.The novel findings of this study provide significant guidance for wellbore temperature control in ultra-deep and ultra-high-temperature wells.展开更多
The temperature-Altitude Test System(TATS)supplies various testing environments.The traditional PID method controls the temperature in TATS Temperature-Pressure Cabin(TPC)over a long adjusting time and with a large ov...The temperature-Altitude Test System(TATS)supplies various testing environments.The traditional PID method controls the temperature in TATS Temperature-Pressure Cabin(TPC)over a long adjusting time and with a large overshoot.In order to solve this problem simply,a temperature control strategy with temperature difference corresponding factors is presented through a dynamic analysis and modeling of TPC temperature change.The TPC temperature descending process is simulated,and the results show that this control strategy can allot the proportion of PID heating controller and PID cooling controller in the whole control process and TPC temperature can be controlled at a set point quickly and effectively.展开更多
As one of the key units of space CCD camera,the temperature range and stability of CCD components affect the image's indexes.Reasonable thermal design and robust thermal control devices are needed.One kind of temp...As one of the key units of space CCD camera,the temperature range and stability of CCD components affect the image's indexes.Reasonable thermal design and robust thermal control devices are needed.One kind of temperature control loop heat pipe(TCLHP) is designed,which highly meets the thermal control requirements of CCD components.In order to study the dynamic behaviors of heat and mass transfer of TCLHP,particularly in the orbital flight case,a transient numerical model is developed by using the well-established empirical correlations for flow models within three dimensional thermal modeling.The temperature control principle and details of mathematical model are presented.The model is used to study operating state,flow and heat characteristics based upon the analyses of variations of temperature,pressure and quality under different operating modes and external heat flux variations.The results indicate that TCLHP can satisfy the thermal control requirements of CCD components well,and always ensure good temperature stability and uniformity.By comparison between flight data and simulated results,it is found that the model is to be accurate to within 1℃.The model can be better used for predicting and understanding the transient performance of TCLHP.展开更多
Closed production systems,such as plant factories and vertical farms,have emerged to ensure a sustainable supply of fresh food,to cope with the increasing consumption of natural resource for the growing population.In ...Closed production systems,such as plant factories and vertical farms,have emerged to ensure a sustainable supply of fresh food,to cope with the increasing consumption of natural resource for the growing population.In a plant factory,a microclimate model is one of the direct control components of a whole system.In order to better realize the dynamic regulation for the microclimate model,energy-saving and consumption reduction,it is necessary to optimize the environmental parameters in the plant factory,and thereby to determine the influencing factors of atmosphere control systems.Therefore,this study aims to identify accurate microclimate models,and further to predict temperature change based on the experimental data,using the classification and regression trees(CART)algorithm.A random forest theory was used to represent the temperature control system.A mechanism model of the temperature control system was proposed to improve the performance of the plant factories.In terms of energy efficiency,the main influencing factors on temperature change in the plant factories were obtained,including the temperature and air volume flow of the temperature control device,as well as the internal relative humidity.The generalization error of the prediction model can reach 0.0907.The results demonstrated that the proposed model can present the quantitative relationship and prediction function.This study can provide a reference for the design of high-precision environmental control systems in plant factories.展开更多
Enzyme activity is easily influenced by temperature,resulting in accuracy decline of enzymatic detection of pesticide residues.In this study,a controller which controls the internal temperature of the pesticide residu...Enzyme activity is easily influenced by temperature,resulting in accuracy decline of enzymatic detection of pesticide residues.In this study,a controller which controls the internal temperature of the pesticide residues detector was simulated and analyzed.The mathematical model of temperature control was established by the application of the heat transfer theory.Against models with characteristics of large inertia and large hysteresis,a Smith fuzzy PID controller was proposed by combining the Smith predictor with the fuzzy PID controller.The PID controller,the fuzzy PID controller,and the Smith fuzzy PID controller were simulated in MATLAB,respectively in the same step signal given with amplitude of 1.The performance indexes(percent overshoot,settling time,and steady-state error)of various controllers were presented as follows:the PID controller(19%,250 s,0.0001),the fuzzy PID controller(11%,450 s,0.0001),and the Smith fuzzy PID controller(0%,140 s,0).From 1180 s to 1230 s,an interference signal with amplitude of 5 was added to test interference immunity.The PID controller and the fuzzy PID controller had greater fluctuations,but the Smith fuzzy PID controller had no fluctuations.The recovery time of each controller was described below:the PID controller(200 s),the fuzzy PID controller(300 s),and the Smith fuzzy PID controller(120 s).Robustness of the controller was tested by adjusting the time constant and the delay time.The performance indexes of the controllers were shown as follows:the PID controller(38%,450 s,0.0001),the fuzzy PID controller(23%,880 s,0.00025),and the Smith fuzzy PID controller(1%,150 s,0).The results of simulation showed that the performance indexes of the Smith fuzzy PID controller were better than that of the other controllers.Besides,the robustness and interference immunity are stronger than other controllers as well.The Smith fuzzy PID controller can accurately control the internal temperature of the pesticide residues detector to provide the best temperature for enzymatic detection.展开更多
In the process of construction and operation, large volume concrete structures often generate large temperature stress, which in turn leads to cracks. Before the construction of concrete structures, in order to select...In the process of construction and operation, large volume concrete structures often generate large temperature stress, which in turn leads to cracks. Before the construction of concrete structures, in order to select timely and reasonable temperature control and crack prevention measures, this paper takes the upper lock head of the Datengxia Water Control Project as an example, and uses three-dimensional finite element method to simulate and recheck and calculate the temperature field and creep stress field according to the construction progress, latest material parameters and accurate boundary conditions. The analysis results show that the overall stress of the concrete at the upper gate head is not large after the temperature control measures formulated in this paper are adopted, which meets the requirements of concrete crack prevention, indicating that the temperature control measures formulated are appropriate.展开更多
A finite element method(FEM) for the numerical simulation of the columnar part of the mould-temperature-control solidification(MTCS) process was presented. The latent heat was taken into account and 3D transient heat ...A finite element method(FEM) for the numerical simulation of the columnar part of the mould-temperature-control solidification(MTCS) process was presented. The latent heat was taken into account and 3D transient heat transfer analysis was carried out by using the developed FEM software. The relative errors between the numerical and experimental data are less than 6%. Three MTCS cases were computed with this method. The first case only opens the cooling channels in the bottom of the mold. The second case individually controls the separate 7 groups of cooling channels by giving 7 control points. When the temperature of a control point reaches the preset value of 400℃, the corresponding channel will be opened. The third case opens all the cooling channels at the same time. The results indicate that in the second case, the solid-liquid interface keeps near-planar. The growth velocity of the solid-liquid interface is 0.3-0.4 mm/s, which is greater than 0.1-0.3 mm/s of the first case, performing better than the others. Thus the forming quality and efficiency part interior can be improved by mold-temperature-control and the numerical model is validated. The numerical simulation of MTCS can provide an available tool for the advanced investigation on the defect improvement and the crystal’s quality.展开更多
This paper described an effective method to implement human & hardware in the loop simulation(HHILS), which is based on MATLAB system and can be used to study human driving actions in the abrupt situation and vehi...This paper described an effective method to implement human & hardware in the loop simulation(HHILS), which is based on MATLAB system and can be used to study human driving actions in the abrupt situation and vehicle stability control(VSC). A hybrid control algorithm, which makes full use of the advantages of robust control and fuzzy logic, was adopted in VSC system. The results of HHILS show that HHILS’ application on the vehicle handling and VSC resarch is feasible. These results also confirm that the handling performance of the vehicle with VSC is improved obviously compared to the vehicle without VSC.展开更多
As the pivotal test equipment of aero-engines design,finalization,improvement,modification,etc.,the Altitude Ground Test Facilities(AGTF)plays an important role in the research and development of the aero-engines.With...As the pivotal test equipment of aero-engines design,finalization,improvement,modification,etc.,the Altitude Ground Test Facilities(AGTF)plays an important role in the research and development of the aero-engines.With the rapid development of advanced high-performance aeroengine,the increasing demand of high-altitude simulation test is driving AGTF to improve its test ability and level of automation and intelligence.The modeling method,simulation tool,and control technology are the key factors to support the improvement of the AGTF control system.The main purpose of this paper is to provide an overview of modeling methods,simulation tools,and control technologies in AGTF control system for future research.First,it reviews the evolution of AGTF in the world,from the early formative stage to integration stage.Then,the mathematical modeling method of AGTF for control application is overviewed.Furthermore,the simulation tools used in the AGTF control system are overviewed from numerical simulation to hardware-in-loop simulation and further to semi-physical simulation.Meanwhile,the control technologies used in the AGTF control system are summarized from single-variable control to multivariable integrated control,and from classical control theory to modern control theory.Finally,recommendations for future research are outlined.Therefore,this review article provides extensive literature information for the modeling,simulation,and control design of AGTF for control application.展开更多
Coupled turbulent flow, temperature fields of the twin-roll casting strip process were simulated by three-dimensional finite element method. Based on the heat balance calculation and using inverse methods between the ...Coupled turbulent flow, temperature fields of the twin-roll casting strip process were simulated by three-dimensional finite element method. Based on the heat balance calculation and using inverse methods between the simulations and real experiments, the relational models among casting speed, location, and coefficient of heat transfer between molten metal and rolls in different regions are given. In the simulation, the calculated surface temperatures are in good agreement with the measured values. An on-line model of kiss point is derived by simulations and the geometry of molten pool, corresponding control strategy is also proposed.展开更多
Through simulation analyses of vacuum counter-pressure casting fuzzy control systems based on MATLAB, fuzzy control systems designed by simulation can track technical route established well. When transmission function...Through simulation analyses of vacuum counter-pressure casting fuzzy control systems based on MATLAB, fuzzy control systems designed by simulation can track technical route established well. When transmission functions of vacuum counter-pressure casting controlled objects are changed in operation, fuzzy control systems can carry on self-regulation and stabilize quickly, and embody the advantages of fleet response velocity and little adjusting quantity. The design of vacuum counter-pressure casting fuzzy control systems is accelerated and improved greatly by simulation based on MATLAB. Meanwhile, their design is accurate and reliable. Moreover, microstructure and properties of thin-wall aluminum alloy castings are improved effectively by using fuzzy control systems.展开更多
To improve the precision of the filling pressure curve of differential pressure casting controlled with PID controller,the model of differential pressure casting process is established and two pressure-difference cont...To improve the precision of the filling pressure curve of differential pressure casting controlled with PID controller,the model of differential pressure casting process is established and two pressure-difference control systems using PID algorithm and Dahlin algorithm are separately designed in MATLAB. The scheduled pressure curves controlled with PID algorithm and Dahlin algorithm,respectively,are comparatively simulated in MATLAB. The simulated pressure curves obtained show that the control precision with Dahlin algorithm is higher than that with PID algorithm in the differential pressure casting process,and it was further verified by production practice.展开更多
Electrode down-time is an important factor affecting the efficiency and stability of electrical discharge machining(EDM) process. In the research, a way of simulating the regulation of the electrode down-time in an ED...Electrode down-time is an important factor affecting the efficiency and stability of electrical discharge machining(EDM) process. In the research, a way of simulating the regulation of the electrode down-time in an EDM adaptive control system has been studied. All the simulations are performed on Matlab. The simulation results demonstrate that this adaptive controller by regulating electrode down-time can direct the gap state to follow the specified reference gap state with or without disturbances. Finally, the adaptive control scheme is also validated by experiments. The significance of the simulation of an EDM adaptive control system lies on the fact that it provides a convenient way to guide the actual production and provides a new study method for the research of EDM control strategy with no regard of experimental conditions.展开更多
After steam discharge in heavy oil reservoirs,the distribution of temperature,pressure,and permeability in different wells becomes irregular.Flow channels can easily be produced,which affect the sweep efficiency of th...After steam discharge in heavy oil reservoirs,the distribution of temperature,pressure,and permeability in different wells becomes irregular.Flow channels can easily be produced,which affect the sweep efficiency of the oil displacement.Previous studies have shown that the salting-out plugging method can effectively block these channels in high-temperature reservoirs,improve the suction profile,and increase oil production.In the present study,the optimal dosage of the plugging agent is determined taking into account connection transmissibility and inter-well volumes.Together with the connectivity model,a water flooding simulation model is introduced.Moreover,a non-gradient stochastic disturbance algorithm is used to obtain the optimal plugging agent dosage,which provides the basis for the high-temperature salting-out plugging agent adjustment in the field.展开更多
We use cellular automata for simulating a series of topology control algorithms in Wireless Sensor Networks (WSNs) using various programming environments. A cellular automaton is a decentralized computing model provid...We use cellular automata for simulating a series of topology control algorithms in Wireless Sensor Networks (WSNs) using various programming environments. A cellular automaton is a decentralized computing model providing an excellent platform for performing complex computations using only local information. WSNs are composed of a large number of distributed wireless sensor nodes operating on batteries. The objective of the topology control problem in WSNs is to select an appropriate subset of nodes able to monitor a region at a minimum energy consumption cost and, therefore, extend network lifetime. Herein, we present topology control algorithms based on the selection—in a deterministic or randomized way—of an appropriate subset of sensor nodes that must remain active. We use cellular automata for conducting simulations in order to evaluate the performance of these algorithms and investigate the effect/role of the neighbourhood selection in the efficient application of our algorithms. Furthermore, we implement our simulations in Matlab, Java and Python in order to investigate in which ways the selection of an appropriate programming environment can facilitate experimentation and can result in more efficient application of our algorithms.展开更多
The inverted pendulum is a classic problem in dynamics and control theory and is widely used as a benchmark for testing control algorithms. This paper studies the use of fuzzy control method to study the stability con...The inverted pendulum is a classic problem in dynamics and control theory and is widely used as a benchmark for testing control algorithms. This paper studies the use of fuzzy control method to study the stability control problem of a triple inverted pendulum system. By the linear model of the system, the feedback weight matrix of the LQR optimal control and the feedback parameters of the linear optimal control are designed to determine the parameters of the fuzzy controller. The simulation results show that the proposed method can achieve the stability control of the three stage inverted pendulum, and has good dynamic performance with simple parameter selection.展开更多
Nowadays the actual parking situation is becoming more and more complex. Because of the inexpert driving skill of novice drivers, there is often collision in the parking process. Fortunately, with the development of p...Nowadays the actual parking situation is becoming more and more complex. Because of the inexpert driving skill of novice drivers, there is often collision in the parking process. Fortunately, with the development of path planning and intelligent control technology, the appearance of the automatic parking control system will provide a good solution to the narrow parking problems. Here with the help of MATLAB/Simulink, we build a simulation platform, and then respectively simulate the parallel parking and vertical parking process, to seek for the best initial parking point and path.展开更多
The control strategy is one of the most important renewable technology,and an increasing number of multi-MW wind turbines are being developed with a variable speed-variable pitch(VS-VP)technology.The main objective of...The control strategy is one of the most important renewable technology,and an increasing number of multi-MW wind turbines are being developed with a variable speed-variable pitch(VS-VP)technology.The main objective of adopting a VS-VP technology is to improve the fast response speed and capture maximum energy.But the power generated by wind turbine changes rapidly because of the continuous fluctuation of wind speed and direction.At the same time,wind energy conversion systems are of high order,time delays and strong nonlinear characteristics because of many uncertain factors.Based on analyzing the all dynamic processes of wind turbine,a kind of layered multi-mode optimal control strategy is presented which is that three control strategies:bang-bang,fuzzy and adaptive proportional integral derivative(PID)are adopted according to different stages and expected performance of wind turbine to capture optimum wind power,compensate the nonlinearity and improve the wind turbine performance at low,rated and high wind speed.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.U22B2072)Research Project of China Petroleum Science and Technology Innovation Fund(Grant No.2025DQ02-0144)。
文摘The exploitation of oil resources has now extended to ultra-deep formations,with depths even exceeding 10,000 m.During drilling operations,the bottomhole temperature(BHT)can surpass 240℃.Under such high-temperature conditions,measurement while drilling(MWD)instruments are highly likely to malfunction due to the inadequate temperature resistance of their electronic components.As a wellbore temperature control approach,the application of thermal insulated drill pipe(TIDP)has been proposed to manage the wellbore temperature in ultra-deep wells.This paper developed a temperature field model for ultra-deep wells by coupling the interactions of multiple factors on the wellbore temperature.For the first time,five distinct TIDP deployment methods were proposed,and their corresponding wellbo re temperature variation characte ristics were investigated,and the heat transfer laws of the ultra-deep wellbore-formation system were quantitatively elucidated.The results revealed that TIDP can effectively restrain the rapid rise in the temperature of the drilling fluid inside the drill string by reducing the heat flux of the drill string.Among the five deployment methods,the method of deploying TIDP from the bottomhole upwards exhibits the best performance.For a 12,000 m simulated well,when6000 m of TIDP are deployed from the bottomhole upwards,the BHT decreases by 52℃,while the outlet temperature increases by merely 1℃.This not only achieves the objective of wellbore temperature control but also keeps the temperature of the drilling fluid at the outlet of annulus at a relatively low level,thereby reducing the requirements for the heat exchange equipment on the ground.The novel findings of this study provide significant guidance for wellbore temperature control in ultra-deep and ultra-high-temperature wells.
文摘The temperature-Altitude Test System(TATS)supplies various testing environments.The traditional PID method controls the temperature in TATS Temperature-Pressure Cabin(TPC)over a long adjusting time and with a large overshoot.In order to solve this problem simply,a temperature control strategy with temperature difference corresponding factors is presented through a dynamic analysis and modeling of TPC temperature change.The TPC temperature descending process is simulated,and the results show that this control strategy can allot the proportion of PID heating controller and PID cooling controller in the whole control process and TPC temperature can be controlled at a set point quickly and effectively.
文摘As one of the key units of space CCD camera,the temperature range and stability of CCD components affect the image's indexes.Reasonable thermal design and robust thermal control devices are needed.One kind of temperature control loop heat pipe(TCLHP) is designed,which highly meets the thermal control requirements of CCD components.In order to study the dynamic behaviors of heat and mass transfer of TCLHP,particularly in the orbital flight case,a transient numerical model is developed by using the well-established empirical correlations for flow models within three dimensional thermal modeling.The temperature control principle and details of mathematical model are presented.The model is used to study operating state,flow and heat characteristics based upon the analyses of variations of temperature,pressure and quality under different operating modes and external heat flux variations.The results indicate that TCLHP can satisfy the thermal control requirements of CCD components well,and always ensure good temperature stability and uniformity.By comparison between flight data and simulated results,it is found that the model is to be accurate to within 1℃.The model can be better used for predicting and understanding the transient performance of TCLHP.
文摘Closed production systems,such as plant factories and vertical farms,have emerged to ensure a sustainable supply of fresh food,to cope with the increasing consumption of natural resource for the growing population.In a plant factory,a microclimate model is one of the direct control components of a whole system.In order to better realize the dynamic regulation for the microclimate model,energy-saving and consumption reduction,it is necessary to optimize the environmental parameters in the plant factory,and thereby to determine the influencing factors of atmosphere control systems.Therefore,this study aims to identify accurate microclimate models,and further to predict temperature change based on the experimental data,using the classification and regression trees(CART)algorithm.A random forest theory was used to represent the temperature control system.A mechanism model of the temperature control system was proposed to improve the performance of the plant factories.In terms of energy efficiency,the main influencing factors on temperature change in the plant factories were obtained,including the temperature and air volume flow of the temperature control device,as well as the internal relative humidity.The generalization error of the prediction model can reach 0.0907.The results demonstrated that the proposed model can present the quantitative relationship and prediction function.This study can provide a reference for the design of high-precision environmental control systems in plant factories.
基金supported by the National Natural Science Fund Project(31471413)Project A funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)+2 种基金Natural Science Fund Project of Jiangsu Province(BK20141165)China Postdoctoral Science Foundation funded project(2014M561594)Jiangsu Planned Projects for Postdoctoral Research Funds(1401175C).
文摘Enzyme activity is easily influenced by temperature,resulting in accuracy decline of enzymatic detection of pesticide residues.In this study,a controller which controls the internal temperature of the pesticide residues detector was simulated and analyzed.The mathematical model of temperature control was established by the application of the heat transfer theory.Against models with characteristics of large inertia and large hysteresis,a Smith fuzzy PID controller was proposed by combining the Smith predictor with the fuzzy PID controller.The PID controller,the fuzzy PID controller,and the Smith fuzzy PID controller were simulated in MATLAB,respectively in the same step signal given with amplitude of 1.The performance indexes(percent overshoot,settling time,and steady-state error)of various controllers were presented as follows:the PID controller(19%,250 s,0.0001),the fuzzy PID controller(11%,450 s,0.0001),and the Smith fuzzy PID controller(0%,140 s,0).From 1180 s to 1230 s,an interference signal with amplitude of 5 was added to test interference immunity.The PID controller and the fuzzy PID controller had greater fluctuations,but the Smith fuzzy PID controller had no fluctuations.The recovery time of each controller was described below:the PID controller(200 s),the fuzzy PID controller(300 s),and the Smith fuzzy PID controller(120 s).Robustness of the controller was tested by adjusting the time constant and the delay time.The performance indexes of the controllers were shown as follows:the PID controller(38%,450 s,0.0001),the fuzzy PID controller(23%,880 s,0.00025),and the Smith fuzzy PID controller(1%,150 s,0).The results of simulation showed that the performance indexes of the Smith fuzzy PID controller were better than that of the other controllers.Besides,the robustness and interference immunity are stronger than other controllers as well.The Smith fuzzy PID controller can accurately control the internal temperature of the pesticide residues detector to provide the best temperature for enzymatic detection.
文摘In the process of construction and operation, large volume concrete structures often generate large temperature stress, which in turn leads to cracks. Before the construction of concrete structures, in order to select timely and reasonable temperature control and crack prevention measures, this paper takes the upper lock head of the Datengxia Water Control Project as an example, and uses three-dimensional finite element method to simulate and recheck and calculate the temperature field and creep stress field according to the construction progress, latest material parameters and accurate boundary conditions. The analysis results show that the overall stress of the concrete at the upper gate head is not large after the temperature control measures formulated in this paper are adopted, which meets the requirements of concrete crack prevention, indicating that the temperature control measures formulated are appropriate.
文摘A finite element method(FEM) for the numerical simulation of the columnar part of the mould-temperature-control solidification(MTCS) process was presented. The latent heat was taken into account and 3D transient heat transfer analysis was carried out by using the developed FEM software. The relative errors between the numerical and experimental data are less than 6%. Three MTCS cases were computed with this method. The first case only opens the cooling channels in the bottom of the mold. The second case individually controls the separate 7 groups of cooling channels by giving 7 control points. When the temperature of a control point reaches the preset value of 400℃, the corresponding channel will be opened. The third case opens all the cooling channels at the same time. The results indicate that in the second case, the solid-liquid interface keeps near-planar. The growth velocity of the solid-liquid interface is 0.3-0.4 mm/s, which is greater than 0.1-0.3 mm/s of the first case, performing better than the others. Thus the forming quality and efficiency part interior can be improved by mold-temperature-control and the numerical model is validated. The numerical simulation of MTCS can provide an available tool for the advanced investigation on the defect improvement and the crystal’s quality.
文摘This paper described an effective method to implement human & hardware in the loop simulation(HHILS), which is based on MATLAB system and can be used to study human driving actions in the abrupt situation and vehicle stability control(VSC). A hybrid control algorithm, which makes full use of the advantages of robust control and fuzzy logic, was adopted in VSC system. The results of HHILS show that HHILS’ application on the vehicle handling and VSC resarch is feasible. These results also confirm that the handling performance of the vehicle with VSC is improved obviously compared to the vehicle without VSC.
基金This study was co-supported by the National Science and Technology Major Project,China(No.J2019-V-0010-0104)Zhejiang Provincial Natural Science Foundation of China(No.LQ23E060007).
文摘As the pivotal test equipment of aero-engines design,finalization,improvement,modification,etc.,the Altitude Ground Test Facilities(AGTF)plays an important role in the research and development of the aero-engines.With the rapid development of advanced high-performance aeroengine,the increasing demand of high-altitude simulation test is driving AGTF to improve its test ability and level of automation and intelligence.The modeling method,simulation tool,and control technology are the key factors to support the improvement of the AGTF control system.The main purpose of this paper is to provide an overview of modeling methods,simulation tools,and control technologies in AGTF control system for future research.First,it reviews the evolution of AGTF in the world,from the early formative stage to integration stage.Then,the mathematical modeling method of AGTF for control application is overviewed.Furthermore,the simulation tools used in the AGTF control system are overviewed from numerical simulation to hardware-in-loop simulation and further to semi-physical simulation.Meanwhile,the control technologies used in the AGTF control system are summarized from single-variable control to multivariable integrated control,and from classical control theory to modern control theory.Finally,recommendations for future research are outlined.Therefore,this review article provides extensive literature information for the modeling,simulation,and control design of AGTF for control application.
基金supported by National Key Research Development Planning Project of China (2004CB619108).
文摘Coupled turbulent flow, temperature fields of the twin-roll casting strip process were simulated by three-dimensional finite element method. Based on the heat balance calculation and using inverse methods between the simulations and real experiments, the relational models among casting speed, location, and coefficient of heat transfer between molten metal and rolls in different regions are given. In the simulation, the calculated surface temperatures are in good agreement with the measured values. An on-line model of kiss point is derived by simulations and the geometry of molten pool, corresponding control strategy is also proposed.
基金Project(BB200300088) supported by the Commission of Science Technology and Industry for National Defence Fund ofChina
文摘Through simulation analyses of vacuum counter-pressure casting fuzzy control systems based on MATLAB, fuzzy control systems designed by simulation can track technical route established well. When transmission functions of vacuum counter-pressure casting controlled objects are changed in operation, fuzzy control systems can carry on self-regulation and stabilize quickly, and embody the advantages of fleet response velocity and little adjusting quantity. The design of vacuum counter-pressure casting fuzzy control systems is accelerated and improved greatly by simulation based on MATLAB. Meanwhile, their design is accurate and reliable. Moreover, microstructure and properties of thin-wall aluminum alloy castings are improved effectively by using fuzzy control systems.
文摘To improve the precision of the filling pressure curve of differential pressure casting controlled with PID controller,the model of differential pressure casting process is established and two pressure-difference control systems using PID algorithm and Dahlin algorithm are separately designed in MATLAB. The scheduled pressure curves controlled with PID algorithm and Dahlin algorithm,respectively,are comparatively simulated in MATLAB. The simulated pressure curves obtained show that the control precision with Dahlin algorithm is higher than that with PID algorithm in the differential pressure casting process,and it was further verified by production practice.
文摘Electrode down-time is an important factor affecting the efficiency and stability of electrical discharge machining(EDM) process. In the research, a way of simulating the regulation of the electrode down-time in an EDM adaptive control system has been studied. All the simulations are performed on Matlab. The simulation results demonstrate that this adaptive controller by regulating electrode down-time can direct the gap state to follow the specified reference gap state with or without disturbances. Finally, the adaptive control scheme is also validated by experiments. The significance of the simulation of an EDM adaptive control system lies on the fact that it provides a convenient way to guide the actual production and provides a new study method for the research of EDM control strategy with no regard of experimental conditions.
基金supported by China Postdoctoral Science Foundation(No.2021M702304)Shandong Provincial Natural Science Foundation Youth Fund(No.ZR2021QE260).
文摘After steam discharge in heavy oil reservoirs,the distribution of temperature,pressure,and permeability in different wells becomes irregular.Flow channels can easily be produced,which affect the sweep efficiency of the oil displacement.Previous studies have shown that the salting-out plugging method can effectively block these channels in high-temperature reservoirs,improve the suction profile,and increase oil production.In the present study,the optimal dosage of the plugging agent is determined taking into account connection transmissibility and inter-well volumes.Together with the connectivity model,a water flooding simulation model is introduced.Moreover,a non-gradient stochastic disturbance algorithm is used to obtain the optimal plugging agent dosage,which provides the basis for the high-temperature salting-out plugging agent adjustment in the field.
文摘We use cellular automata for simulating a series of topology control algorithms in Wireless Sensor Networks (WSNs) using various programming environments. A cellular automaton is a decentralized computing model providing an excellent platform for performing complex computations using only local information. WSNs are composed of a large number of distributed wireless sensor nodes operating on batteries. The objective of the topology control problem in WSNs is to select an appropriate subset of nodes able to monitor a region at a minimum energy consumption cost and, therefore, extend network lifetime. Herein, we present topology control algorithms based on the selection—in a deterministic or randomized way—of an appropriate subset of sensor nodes that must remain active. We use cellular automata for conducting simulations in order to evaluate the performance of these algorithms and investigate the effect/role of the neighbourhood selection in the efficient application of our algorithms. Furthermore, we implement our simulations in Matlab, Java and Python in order to investigate in which ways the selection of an appropriate programming environment can facilitate experimentation and can result in more efficient application of our algorithms.
文摘The inverted pendulum is a classic problem in dynamics and control theory and is widely used as a benchmark for testing control algorithms. This paper studies the use of fuzzy control method to study the stability control problem of a triple inverted pendulum system. By the linear model of the system, the feedback weight matrix of the LQR optimal control and the feedback parameters of the linear optimal control are designed to determine the parameters of the fuzzy controller. The simulation results show that the proposed method can achieve the stability control of the three stage inverted pendulum, and has good dynamic performance with simple parameter selection.
文摘Nowadays the actual parking situation is becoming more and more complex. Because of the inexpert driving skill of novice drivers, there is often collision in the parking process. Fortunately, with the development of path planning and intelligent control technology, the appearance of the automatic parking control system will provide a good solution to the narrow parking problems. Here with the help of MATLAB/Simulink, we build a simulation platform, and then respectively simulate the parallel parking and vertical parking process, to seek for the best initial parking point and path.
基金Science & Technology Development Foundation of Shanghai,China(No.062158017)Postdoctoral Foundation of Shanghai,China(No.05R214133)Postdoctoral Foundation of China(No.2005038435)
文摘The control strategy is one of the most important renewable technology,and an increasing number of multi-MW wind turbines are being developed with a variable speed-variable pitch(VS-VP)technology.The main objective of adopting a VS-VP technology is to improve the fast response speed and capture maximum energy.But the power generated by wind turbine changes rapidly because of the continuous fluctuation of wind speed and direction.At the same time,wind energy conversion systems are of high order,time delays and strong nonlinear characteristics because of many uncertain factors.Based on analyzing the all dynamic processes of wind turbine,a kind of layered multi-mode optimal control strategy is presented which is that three control strategies:bang-bang,fuzzy and adaptive proportional integral derivative(PID)are adopted according to different stages and expected performance of wind turbine to capture optimum wind power,compensate the nonlinearity and improve the wind turbine performance at low,rated and high wind speed.
