The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow ...The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.展开更多
Recently,unmanned aerial vehicle(UAV)-aided free-space optical(FSO)communication has attracted widespread attentions.However,most of the existing research focuses on communication performance only.The authors investig...Recently,unmanned aerial vehicle(UAV)-aided free-space optical(FSO)communication has attracted widespread attentions.However,most of the existing research focuses on communication performance only.The authors investigate the integrated scheduling of communication,sensing,and control for UAV-aided FSO communication systems.Initially,a sensing-control model is established via the control theory.Moreover,an FSO communication channel model is established by considering the effects of atmospheric loss,atmospheric turbulence,geometrical loss,and angle-of-arrival fluctuation.Then,the relationship between the motion control of the UAV and radial displacement is obtained to link the control aspect and communication aspect.Assuming that the base station has instantaneous channel state information(CSI)or statistical CSI,the thresholds of the sensing-control pattern activation are designed,respectively.Finally,an integrated scheduling scheme for performing communication,sensing,and control is proposed.Numerical results indicate that,compared with conventional time-triggered scheme,the proposed integrated scheduling scheme obtains comparable communication and control performance,but reduces the sensing consumed power by 52.46%.展开更多
The integrated energy systems(IESs)offer a practical solution for achieving low-carbon targets in residential buildings.However,IES encounters several challenges related to increased energy consumption and costs due t...The integrated energy systems(IESs)offer a practical solution for achieving low-carbon targets in residential buildings.However,IES encounters several challenges related to increased energy consumption and costs due to fluctuations in renewable energy generation.Leveraging building flexibility to address these power fluctuations within IES is a promising strategy,which requires coordinated control between air-conditioning systems and other IES components.This study proposes a cross-time-scale control framework that contains optimal scheduling and on-the-fly flexible control to reduce the cost impacts of a residential IES system equipped with photovoltaic(PV)panels,batteries,a heat pump,and a domestic hot water tank.The method involves three key steps:solar irradiance prediction,day-ahead optimal scheduling of energy storage,and intra-day flexible control of the heat pump.The method is validated through a high-fidelity residential building model with actual weather and energy usage data in Frankfurt,Germany.Results reveal that the proposed method limits the cost increase to just 2.67% compared to the day-ahead schedule,whereas the cost could increase by 7.39% without the flexible control.Additionally,computational efficiency is enhanced by transforming the mixed-integer programming(MIP)into nonlinear programming(NLP)problem via introducing action-exclusive constraints.This approach offers valuable support for residential IES operations.展开更多
The current research of master cylinder pressure estimation mainly relies on hydraulic characteristic or vehicle dynamics.But they are not independently applicable to any environment and have their own scope of applic...The current research of master cylinder pressure estimation mainly relies on hydraulic characteristic or vehicle dynamics.But they are not independently applicable to any environment and have their own scope of application.In addition,about the master cylinder pressure control,there are few studies that can simultaneously balance pressure building accuracy,speed,and prevent pressure overshoot and jitter.In this paper,an adaptative fusion method based on electro-hydraulic characteristic and vehicle mode is proposed to estimate the master cylinder pressure.The fusion strategy is mainly based on the prediction performance of two algorithms under different vehicle speeds,pressures,and ABS states.Apart from this,this article also includes real-time prediction of the friction model based on RLS to improve the accuracy of the electro-hydraulic mode.In order to simultaneously balance pressure control accuracy,response speed,and prevent overshoot and jitter,this article proposes an adaptative LQR controller for MC pressure control which uses fuzzy-logic controller to adjust the weights of LQR controller based on target pressure and difference compared with actual pressure.Through mode-in-loop and hardware-in-loop tests in ramp,step and sinusoidal response,the whole estimation and control system is verified based on real hydraulic system and the performance is satisfactory under these scenes.This research proposes an adaptative pressure estimation and control architecture for integrated electro-hydraulic brake system which could eliminate pressure sensors in typical scenarios and ensure the comprehensive performance of pressure control.展开更多
This paper presents a scheme of integrated guidance and autopilot design for homing missiles against ground fixed targets. An integrated guidance and control model in the pitch plane is formulated and further changed ...This paper presents a scheme of integrated guidance and autopilot design for homing missiles against ground fixed targets. An integrated guidance and control model in the pitch plane is formulated and further changed into a normal form by nonlinear coordinate transformation. By adopting the sliding mode control approach, an adaptive nonlinear control law of the system is designed so that the missile can hit the target accurately with a desired impact attitude angle. The stability analysis of the closed-loop system is also conducted. The numerical simulation has confirmed the usefulness of the proposed design scheme.展开更多
The real-time capability of integrated flight/propulsion optimal control (IFPOC) is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gr...The real-time capability of integrated flight/propulsion optimal control (IFPOC) is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gramming (SQP). Firstly, a steady-state hybrid aero-engine model is designed in the whole flight envelope with a dramatic enhancement of real-time capability. Secondly, the aero-engine performance seeking control including the maximum thrust mode and the minimum fuel-consumption mode is performed by SQP. Finally, digital simu- lations for cruise and accelerating flight are carried out. Results show that the proposed method improves real- time capability considerably with satisfactory effectiveness of optimization.展开更多
[ Objective ] The paper was to explore the damage, occurrence pattern and integrated control methods of oriental fruit fly [ Bactrocera dorsalis ( Hen- del) ] in Nanning region of Guangxi Province. [ Method ] Using ...[ Objective ] The paper was to explore the damage, occurrence pattern and integrated control methods of oriental fruit fly [ Bactrocera dorsalis ( Hen- del) ] in Nanning region of Guangxi Province. [ Method ] Using fixed system survey method, with fruit fly attractants as the materials, the occurrence dynamic of oriental fruit fly adult in guava orchard was investigated. The control effects of the methods such as fruit fly attractants, fruit bagging, cleaning park to pick up fallen fruit and timely spraying pesticide against the pest were also studied. [ Result] Oriental fruit fly had two damage peak periods in Nanning region of Guangxi Prov- ince (May to June, August to September). Through the integrated control measures of trapping agent for male flies, timely spraying, fruit bagging and cleaning park to pick up fallen fruit, the population density in guava orchard dropped significantly. The fruit damage rates of guava in research base were only 6.67% -7.33% during the peak period of oriental fruit fly in June 2008, while they were 90.53% -98.00% in control area, obtaining good control effect against the pest. [ Con- dttalon ] The method used in the study preliminarily restored the yield losses of guava, which also provided basis for the preparation of overall strategy against orien- tal fruit fly in the region.展开更多
A novel integrated guidance and autopilot design method is proposed for homing missiles based on the adaptive block dynamic surface control approach. The fully integrated guidance and autopilot model is established by...A novel integrated guidance and autopilot design method is proposed for homing missiles based on the adaptive block dynamic surface control approach. The fully integrated guidance and autopilot model is established by combining the nonlinear missile dynamics with the nonlinear dynamics describing the pursuit situation of a missile and a target in the three-dimensional space. The integrated guidance and autopilot design problem is further converted to a state regulation problem of a time-varying nonlinear system with matched and unmatched uncertainties. A new and simple adaptive block dynamic surface control algorithm is proposed to address such a state regulation problem. The stability of the closed-loop system is proven based on the Lyapunov theory. The six degrees of freedom (6DOF) nonlinear numerical simulation results show that the proposed integrated guidance and autopilot algorithm can ensure the accuracy of target interception and the robust stability of the closed-loop system with respect to the uncertainties in the missile dynamics.展开更多
Integrated guidance and control for homing missiles utilizing adaptive dynamic surface control approach is considered based on the three channels independence design idea. A time-varying integrated guidance and contro...Integrated guidance and control for homing missiles utilizing adaptive dynamic surface control approach is considered based on the three channels independence design idea. A time-varying integrated guidance and control model with unmatched uncertainties is first formulated for the pitch channel, and an adaptive dynamic surface control algorithm is further developed to deal with these unmatched uncertainties. It is proved that the proposed feedback controller can ensure not only the accuracy of target interception, but also the stability of the missile dynamics. Then, the same control approach is further applied to the control design of the yaw and roll channels. The 6-degree-of-freedom (6-DOF) nonlinear missile simulation results demonstrate the feasibility and advantage of the proposed integrated guidance and control design scheme.展开更多
Aimed at the guidance requirements of some missiles which attack targets with terminal impact angle at the terminal point,a new integrated guidance and control design scheme based on variable structure control approac...Aimed at the guidance requirements of some missiles which attack targets with terminal impact angle at the terminal point,a new integrated guidance and control design scheme based on variable structure control approach for missile with terminal impact angle constraint is proposed.First,a mathematical model of an integrated guidance and control model in pitch plane is established,and then nonlinear transformation is employed to transform the mathematical model into a standard form suitable for sliding mode control method design.A sufficient condition for the existence of linear sliding surface is given in terms of linear matrix inequalities(LMIs),based on which the corresponding reaching motion controller is also developed.To verify the effectiveness of the proposed integrated design scheme,the numerical simulation of missile is made.The simulation results demonstrate that the proposed guidance and control law can guide missile to hit the target with desired impact angle and desired flight attitude angle simultaneously.展开更多
The morphing technology of hypersonic vehicle improved the flight performance by changing aerodynamic characteristics with shape deformations,but the design of guidance and control system with morphing laws remained t...The morphing technology of hypersonic vehicle improved the flight performance by changing aerodynamic characteristics with shape deformations,but the design of guidance and control system with morphing laws remained to be explored.An Integrated of Guidance,Control and Morphing(IGCM)method for Hypersonic Morphing Vehicle(HMV)was developed in this paper.The IGCM method contributed to an effective solution of morphing characteristic to improve flight performance and reject the disturbance for guidance and control system caused by the morphing system for HMV in gliding phase.The IGCM models were established based on the motion models and aerodynamic models of the variable span vehicle.Then the IGCM method was designed by adaptive block dynamic surface back-stepping method with stability proof.The parallel controlled simulations’results showed the effectiveness in accomplishing the flight mission of IGCM method in glide phase with smaller terminal errors.The velocity loss of HMV was reduced by 32.8%which inferred less flight time and larger terminal flight velocity than invariable span vehicle.Under the condition of large deviations of aerodynamic parameters and atmospheric density,the robustness of IGCM method with variable span was verified.展开更多
This paper addresses an integrated relative position and attitude control strategy for a pursuer spacecraft flying to a space target in proximity operation missions. Relative translation and rotation dynamics are both...This paper addresses an integrated relative position and attitude control strategy for a pursuer spacecraft flying to a space target in proximity operation missions. Relative translation and rotation dynamics are both presented, and further integratedly considered due to mutual couplings, which results in a six degrees-of-freedom (6-DOF) control system. In order to simultaneously achieve relative position and attitude requirements, an adaptive backstepping control law is designed, where a command filter is introduced to overcome 'explosion of terms'. Within the Lyapunov framework, the proposed controller is proved to ensure the ultimate boundedness of relative position and attitude signals, in the presence of external disturbances and unknown system parameters. Numerical simulation demonstrates the effect of the designed control law.展开更多
This paper considers the guidance and control problem of a flight vehicle with sidewindow detection. In order to guarantee the target remaining in the seeker's sight of view, the line of sight and the attitude of the...This paper considers the guidance and control problem of a flight vehicle with sidewindow detection. In order to guarantee the target remaining in the seeker's sight of view, the line of sight and the attitude of the flight vehicle should be under some constraints caused by the sidewindow, which leads to coupling between the guidance and the attitude dynamics model. To deal with the side-window constraints and the coupling, a novel Integrated Guidance and Control(IGC)design approach is proposed. Firstly, the relative motion equations are derived in the body-Line of Sight(LOS) coordinate system. And the guidance and control problem of the flight vehicle is formulated into an IGC problem with state constraints. Then, based on the singular perturbation method, the IGC problem is decomposed into the control design of the quasi-steady-state subsystem and the boundary-layer subsystem which can be designed separately. Finally, the receding horizon control is applied to the control design for the two subsystems. Simulation results show the effectiveness of the proposed approach.展开更多
OBJECTIVE:To systematically review the benefits of integrated traditional and Western medicine therapies based on the Hamilton depression scale(HAMD) following syndrome differentiation of depression.METHODS:We searche...OBJECTIVE:To systematically review the benefits of integrated traditional and Western medicine therapies based on the Hamilton depression scale(HAMD) following syndrome differentiation of depression.METHODS:We searched six English and Chinese electronic databases for randomized clinical trials(RCTs) on integrated traditional and Western medicine for treatment of depression.Two authors extracted data and independently assessed the trial quality.RevMan 5 software was used for data analyses with an effect estimate presented as weighted mean difference(WMD) with a 95% confidence interval(CI).RESULTS:Seven RCTs with 576 participants were identified for this review.All trials were eligible for the meta-analysis and were evaluated as unclear or having a risk of bias.Meta-analysis showed,compared with Western medicine alone,integrated traditional and Western medicine based on syndrome differentiation could improve the effect of treatment represented by the HAMD [WMD=-2.39,CI(-2.96,-1.83),Z=8.29,P<0.00001].There were no reported serious adverse effects that were related to integrated traditional and Western medicine based therapies in these trials.CONCLUSIONS:Integrated traditional and Western medicine based therapies for the syndrome differentiation of depression significantly improved the HAMD,illustrating that combining therapies from integrated traditional and Western medicine for treatment of depression is better than Western medicine alone.However,further large,rigorously designed trials are warranted due to the insufficient methodological rigor seen in the trials included in this study.展开更多
Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system s...Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance.展开更多
The article focuses on the design and application of an active reconfigurable controller that mitigates the effects of gust load and actuator faults on a flexible aircraft.A novel integrated adaptive output feedback s...The article focuses on the design and application of an active reconfigurable controller that mitigates the effects of gust load and actuator faults on a flexible aircraft.A novel integrated adaptive output feedback scheme is investigated to address the actuator faults.The real-time fault values provided by the fault estimation module are considered in the reconfigurable control law to improve the fault-tolerant capability.The estimate values of faults and control gains are calculated by analyzing the stability of the overall system.The proposed controller is simulated using a flexible aircraft model with a discrete‘1-cosine’gust,and the results show that it can effectively mitigate the wing root moments and recover the flight maneuver stability after the aircraft suffered from gusts.展开更多
Based on the two-dimensional (2D) system theory, an integrated predictive iterative learning control (2D-IPILC) strategy for batch processes is presented. First, the output response and the error transition model ...Based on the two-dimensional (2D) system theory, an integrated predictive iterative learning control (2D-IPILC) strategy for batch processes is presented. First, the output response and the error transition model predictions along the batch index can be calculated analytically due to the 2D Roesser model of the batch process. Then, an integrated framework of combining iterative learning control (ILC) and model predictive control (MPC) is formed reasonably. The output of feedforward ILC is estimated on the basis of the predefined process 2D model. By min- imizing a quadratic objective function, the feedback MPC is introduced to obtain better control performance for tracking problem of batch processes. Simulations on a typical batch reactor demonstrate that the satisfactory tracking performance as well as faster convergence speed can be achieved than traditional proportion type (P- t-we) ILC despite the model error and disturbances.展开更多
Di erential braking and active steering have already been integrated to overcome their shortcomings. However, existing research mainly focuses on two-axle vehicles and controllers are mostly designed to use one contro...Di erential braking and active steering have already been integrated to overcome their shortcomings. However, existing research mainly focuses on two-axle vehicles and controllers are mostly designed to use one control method to improve the other. Moreover, many experiments are needed to improve the robustness; therefore, these control methods are underutilized. This paper proposes an integrated control system specially designed for multi-axle vehicles, in which the desired lateral force and yaw moment of vehicles are determined by the sliding mode control algorithm. The output of the sliding mode control is distributed to the suitable wheels based on the abilities and potentials of the two control methods. Moreover, in this method, fewer experiments are needed, and the robustness and simultaneity are both guaranteed. To simplify the optimization system and to improve the computation speed, seven simple optimization subsystems are designed for the determination of control outputs on each wheel. The simulation results show that the proposed controller obviously enhances the stability of multi-axle trucks. The system improves 68% of the safe velocity, and its performance is much better than both di erential braking and active steering. This research proposes an integrated control system that can simultaneously invoke di erential braking and active steering of multi-axle vehicles to fully utilize the abilities and potentials of the two control methods.展开更多
Tobacco black shank is one of the devastating diseases of tobacco. In recent years, this disease widely occurred in most tobacco-growing areas, which caused disastrous losses and has severely threatened the sustainabl...Tobacco black shank is one of the devastating diseases of tobacco. In recent years, this disease widely occurred in most tobacco-growing areas, which caused disastrous losses and has severely threatened the sustainable development of flue-cured tobacco. In order to lay a theoretical foundation for the better control of tobacco black shank, the occurrence characteristics and integrated control strategis of this disease were systematically discussed according to the aspects of agricultural control, chemical control, biological control, etc.展开更多
Combining with the development of automated manual transmission (AMT), the various throttle control demands are analyzed under different working conditions of AMT such as tracking acceleration pedal, start, shift an...Combining with the development of automated manual transmission (AMT), the various throttle control demands are analyzed under different working conditions of AMT such as tracking acceleration pedal, start, shift and so on. Based on simulation, the responding throttle control strategies are proposed, and a simple but effective throttle control method is presented. The testing results have proved that the strategies are effective for improving the pedal tracking precision and the qualities of start and shift.展开更多
基金supported in part by Natural Science Foundation of Jiangsu Province under Grant BK20230255Natural Science Foundation of Shandong Province under Grant ZR2023QE281.
文摘The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.
文摘Recently,unmanned aerial vehicle(UAV)-aided free-space optical(FSO)communication has attracted widespread attentions.However,most of the existing research focuses on communication performance only.The authors investigate the integrated scheduling of communication,sensing,and control for UAV-aided FSO communication systems.Initially,a sensing-control model is established via the control theory.Moreover,an FSO communication channel model is established by considering the effects of atmospheric loss,atmospheric turbulence,geometrical loss,and angle-of-arrival fluctuation.Then,the relationship between the motion control of the UAV and radial displacement is obtained to link the control aspect and communication aspect.Assuming that the base station has instantaneous channel state information(CSI)or statistical CSI,the thresholds of the sensing-control pattern activation are designed,respectively.Finally,an integrated scheduling scheme for performing communication,sensing,and control is proposed.Numerical results indicate that,compared with conventional time-triggered scheme,the proposed integrated scheduling scheme obtains comparable communication and control performance,but reduces the sensing consumed power by 52.46%.
基金supported by the National Key Research and Development Program of China(2022YFB4200902)。
文摘The integrated energy systems(IESs)offer a practical solution for achieving low-carbon targets in residential buildings.However,IES encounters several challenges related to increased energy consumption and costs due to fluctuations in renewable energy generation.Leveraging building flexibility to address these power fluctuations within IES is a promising strategy,which requires coordinated control between air-conditioning systems and other IES components.This study proposes a cross-time-scale control framework that contains optimal scheduling and on-the-fly flexible control to reduce the cost impacts of a residential IES system equipped with photovoltaic(PV)panels,batteries,a heat pump,and a domestic hot water tank.The method involves three key steps:solar irradiance prediction,day-ahead optimal scheduling of energy storage,and intra-day flexible control of the heat pump.The method is validated through a high-fidelity residential building model with actual weather and energy usage data in Frankfurt,Germany.Results reveal that the proposed method limits the cost increase to just 2.67% compared to the day-ahead schedule,whereas the cost could increase by 7.39% without the flexible control.Additionally,computational efficiency is enhanced by transforming the mixed-integer programming(MIP)into nonlinear programming(NLP)problem via introducing action-exclusive constraints.This approach offers valuable support for residential IES operations.
基金Supported by National Natural Science Foundation of China(Grant Nos.52202494,52202495)Chongqing Special Project for Technological Innovation and Application Development(Grant No.CSTB2022TIAD-DEX0014).
文摘The current research of master cylinder pressure estimation mainly relies on hydraulic characteristic or vehicle dynamics.But they are not independently applicable to any environment and have their own scope of application.In addition,about the master cylinder pressure control,there are few studies that can simultaneously balance pressure building accuracy,speed,and prevent pressure overshoot and jitter.In this paper,an adaptative fusion method based on electro-hydraulic characteristic and vehicle mode is proposed to estimate the master cylinder pressure.The fusion strategy is mainly based on the prediction performance of two algorithms under different vehicle speeds,pressures,and ABS states.Apart from this,this article also includes real-time prediction of the friction model based on RLS to improve the accuracy of the electro-hydraulic mode.In order to simultaneously balance pressure control accuracy,response speed,and prevent overshoot and jitter,this article proposes an adaptative LQR controller for MC pressure control which uses fuzzy-logic controller to adjust the weights of LQR controller based on target pressure and difference compared with actual pressure.Through mode-in-loop and hardware-in-loop tests in ramp,step and sinusoidal response,the whole estimation and control system is verified based on real hydraulic system and the performance is satisfactory under these scenes.This research proposes an adaptative pressure estimation and control architecture for integrated electro-hydraulic brake system which could eliminate pressure sensors in typical scenarios and ensure the comprehensive performance of pressure control.
基金Major Program of National Natural Science Founda-tion of China (60710002)Program for Changjiang Scholars and Innovative Research Team in University
文摘This paper presents a scheme of integrated guidance and autopilot design for homing missiles against ground fixed targets. An integrated guidance and control model in the pitch plane is formulated and further changed into a normal form by nonlinear coordinate transformation. By adopting the sliding mode control approach, an adaptive nonlinear control law of the system is designed so that the missile can hit the target accurately with a desired impact attitude angle. The stability analysis of the closed-loop system is also conducted. The numerical simulation has confirmed the usefulness of the proposed design scheme.
基金Supported by the Aeronautical Science Foundation of China(2010ZB52011)the Funding of Jiangsu Innovation Program for Graduate Education(CXLX11-0213)the Nanjing University of Aeronautics and Astronautics Research Funding(NS2010055)~~
文摘The real-time capability of integrated flight/propulsion optimal control (IFPOC) is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gramming (SQP). Firstly, a steady-state hybrid aero-engine model is designed in the whole flight envelope with a dramatic enhancement of real-time capability. Secondly, the aero-engine performance seeking control including the maximum thrust mode and the minimum fuel-consumption mode is performed by SQP. Finally, digital simu- lations for cruise and accelerating flight are carried out. Results show that the proposed method improves real- time capability considerably with satisfactory effectiveness of optimization.
基金Supported by Educational Commission of Guangxi Province of China (GJR(2007)No.70)~~
文摘[ Objective ] The paper was to explore the damage, occurrence pattern and integrated control methods of oriental fruit fly [ Bactrocera dorsalis ( Hen- del) ] in Nanning region of Guangxi Province. [ Method ] Using fixed system survey method, with fruit fly attractants as the materials, the occurrence dynamic of oriental fruit fly adult in guava orchard was investigated. The control effects of the methods such as fruit fly attractants, fruit bagging, cleaning park to pick up fallen fruit and timely spraying pesticide against the pest were also studied. [ Result] Oriental fruit fly had two damage peak periods in Nanning region of Guangxi Prov- ince (May to June, August to September). Through the integrated control measures of trapping agent for male flies, timely spraying, fruit bagging and cleaning park to pick up fallen fruit, the population density in guava orchard dropped significantly. The fruit damage rates of guava in research base were only 6.67% -7.33% during the peak period of oriental fruit fly in June 2008, while they were 90.53% -98.00% in control area, obtaining good control effect against the pest. [ Con- dttalon ] The method used in the study preliminarily restored the yield losses of guava, which also provided basis for the preparation of overall strategy against orien- tal fruit fly in the region.
基金the Fundamental Research Funds for the Central Universities(No.HIT.NSRIF.2013039)the National Natural Science Foundation of China(Nos.61203125 and 61021002)
文摘A novel integrated guidance and autopilot design method is proposed for homing missiles based on the adaptive block dynamic surface control approach. The fully integrated guidance and autopilot model is established by combining the nonlinear missile dynamics with the nonlinear dynamics describing the pursuit situation of a missile and a target in the three-dimensional space. The integrated guidance and autopilot design problem is further converted to a state regulation problem of a time-varying nonlinear system with matched and unmatched uncertainties. A new and simple adaptive block dynamic surface control algorithm is proposed to address such a state regulation problem. The stability of the closed-loop system is proven based on the Lyapunov theory. The six degrees of freedom (6DOF) nonlinear numerical simulation results show that the proposed integrated guidance and autopilot algorithm can ensure the accuracy of target interception and the robust stability of the closed-loop system with respect to the uncertainties in the missile dynamics.
基金supported by National Natural Science Foundation of China (No. 60710002, No. 60974044)
文摘Integrated guidance and control for homing missiles utilizing adaptive dynamic surface control approach is considered based on the three channels independence design idea. A time-varying integrated guidance and control model with unmatched uncertainties is first formulated for the pitch channel, and an adaptive dynamic surface control algorithm is further developed to deal with these unmatched uncertainties. It is proved that the proposed feedback controller can ensure not only the accuracy of target interception, but also the stability of the missile dynamics. Then, the same control approach is further applied to the control design of the yaw and roll channels. The 6-degree-of-freedom (6-DOF) nonlinear missile simulation results demonstrate the feasibility and advantage of the proposed integrated guidance and control design scheme.
基金supported by the Nationa Natural Science Foundation of China(60434010)Outstanding Youth Fund of Heilongjiang Province(JC200606)
文摘Aimed at the guidance requirements of some missiles which attack targets with terminal impact angle at the terminal point,a new integrated guidance and control design scheme based on variable structure control approach for missile with terminal impact angle constraint is proposed.First,a mathematical model of an integrated guidance and control model in pitch plane is established,and then nonlinear transformation is employed to transform the mathematical model into a standard form suitable for sliding mode control method design.A sufficient condition for the existence of linear sliding surface is given in terms of linear matrix inequalities(LMIs),based on which the corresponding reaching motion controller is also developed.To verify the effectiveness of the proposed integrated design scheme,the numerical simulation of missile is made.The simulation results demonstrate that the proposed guidance and control law can guide missile to hit the target with desired impact angle and desired flight attitude angle simultaneously.
文摘The morphing technology of hypersonic vehicle improved the flight performance by changing aerodynamic characteristics with shape deformations,but the design of guidance and control system with morphing laws remained to be explored.An Integrated of Guidance,Control and Morphing(IGCM)method for Hypersonic Morphing Vehicle(HMV)was developed in this paper.The IGCM method contributed to an effective solution of morphing characteristic to improve flight performance and reject the disturbance for guidance and control system caused by the morphing system for HMV in gliding phase.The IGCM models were established based on the motion models and aerodynamic models of the variable span vehicle.Then the IGCM method was designed by adaptive block dynamic surface back-stepping method with stability proof.The parallel controlled simulations’results showed the effectiveness in accomplishing the flight mission of IGCM method in glide phase with smaller terminal errors.The velocity loss of HMV was reduced by 32.8%which inferred less flight time and larger terminal flight velocity than invariable span vehicle.Under the condition of large deviations of aerodynamic parameters and atmospheric density,the robustness of IGCM method with variable span was verified.
基金supported by Innovative Team Program of the National Natural Science Foundation of China (No.61021002)
文摘This paper addresses an integrated relative position and attitude control strategy for a pursuer spacecraft flying to a space target in proximity operation missions. Relative translation and rotation dynamics are both presented, and further integratedly considered due to mutual couplings, which results in a six degrees-of-freedom (6-DOF) control system. In order to simultaneously achieve relative position and attitude requirements, an adaptive backstepping control law is designed, where a command filter is introduced to overcome 'explosion of terms'. Within the Lyapunov framework, the proposed controller is proved to ensure the ultimate boundedness of relative position and attitude signals, in the presence of external disturbances and unknown system parameters. Numerical simulation demonstrates the effect of the designed control law.
基金supported by National Natural Science Foundation of China (Nos. 61473099 and 61333001)
文摘This paper considers the guidance and control problem of a flight vehicle with sidewindow detection. In order to guarantee the target remaining in the seeker's sight of view, the line of sight and the attitude of the flight vehicle should be under some constraints caused by the sidewindow, which leads to coupling between the guidance and the attitude dynamics model. To deal with the side-window constraints and the coupling, a novel Integrated Guidance and Control(IGC)design approach is proposed. Firstly, the relative motion equations are derived in the body-Line of Sight(LOS) coordinate system. And the guidance and control problem of the flight vehicle is formulated into an IGC problem with state constraints. Then, based on the singular perturbation method, the IGC problem is decomposed into the control design of the quasi-steady-state subsystem and the boundary-layer subsystem which can be designed separately. Finally, the receding horizon control is applied to the control design for the two subsystems. Simulation results show the effectiveness of the proposed approach.
基金supported by the National Natural Science Foundation of China (81072756,30672578)the Chinese National Funds for Distinguished Young Scientists (30825046)+1 种基金the Hi-Tech Research and Development Program of China (2008AA02Z406)the Program for Innovative Research Teams in Beijing University of Chinese Medicine (2011CXTD-07)
文摘OBJECTIVE:To systematically review the benefits of integrated traditional and Western medicine therapies based on the Hamilton depression scale(HAMD) following syndrome differentiation of depression.METHODS:We searched six English and Chinese electronic databases for randomized clinical trials(RCTs) on integrated traditional and Western medicine for treatment of depression.Two authors extracted data and independently assessed the trial quality.RevMan 5 software was used for data analyses with an effect estimate presented as weighted mean difference(WMD) with a 95% confidence interval(CI).RESULTS:Seven RCTs with 576 participants were identified for this review.All trials were eligible for the meta-analysis and were evaluated as unclear or having a risk of bias.Meta-analysis showed,compared with Western medicine alone,integrated traditional and Western medicine based on syndrome differentiation could improve the effect of treatment represented by the HAMD [WMD=-2.39,CI(-2.96,-1.83),Z=8.29,P<0.00001].There were no reported serious adverse effects that were related to integrated traditional and Western medicine based therapies in these trials.CONCLUSIONS:Integrated traditional and Western medicine based therapies for the syndrome differentiation of depression significantly improved the HAMD,illustrating that combining therapies from integrated traditional and Western medicine for treatment of depression is better than Western medicine alone.However,further large,rigorously designed trials are warranted due to the insufficient methodological rigor seen in the trials included in this study.
基金Supported by National Natural Science Foundation of China(Grant No.51605417)Key Project of Hebei Provincial Natural Science Foundation,China(Grant No.E2016203264)State Key Laboratory of Fluid Power and Mechatronic Systems(Zhejiang University)Open Fund Project(Grant No.GZKF-201502)
文摘Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance.
基金supported by the National Key Research and Development Plan of China(No.2019YFB1706001)the National Natural Science Foundation of China(No.61773001)。
文摘The article focuses on the design and application of an active reconfigurable controller that mitigates the effects of gust load and actuator faults on a flexible aircraft.A novel integrated adaptive output feedback scheme is investigated to address the actuator faults.The real-time fault values provided by the fault estimation module are considered in the reconfigurable control law to improve the fault-tolerant capability.The estimate values of faults and control gains are calculated by analyzing the stability of the overall system.The proposed controller is simulated using a flexible aircraft model with a discrete‘1-cosine’gust,and the results show that it can effectively mitigate the wing root moments and recover the flight maneuver stability after the aircraft suffered from gusts.
基金Supported in part by the State Key Development Program for Basic Research of China(2012CB720505)the National Natural Science Foundation of China(61174105,60874049)
文摘Based on the two-dimensional (2D) system theory, an integrated predictive iterative learning control (2D-IPILC) strategy for batch processes is presented. First, the output response and the error transition model predictions along the batch index can be calculated analytically due to the 2D Roesser model of the batch process. Then, an integrated framework of combining iterative learning control (ILC) and model predictive control (MPC) is formed reasonably. The output of feedforward ILC is estimated on the basis of the predefined process 2D model. By min- imizing a quadratic objective function, the feedback MPC is introduced to obtain better control performance for tracking problem of batch processes. Simulations on a typical batch reactor demonstrate that the satisfactory tracking performance as well as faster convergence speed can be achieved than traditional proportion type (P- t-we) ILC despite the model error and disturbances.
基金National Natural Science Foundation of China(Grant No.51505178)China Postdoctoral Science Foundation(Grant No.2014M561289)
文摘Di erential braking and active steering have already been integrated to overcome their shortcomings. However, existing research mainly focuses on two-axle vehicles and controllers are mostly designed to use one control method to improve the other. Moreover, many experiments are needed to improve the robustness; therefore, these control methods are underutilized. This paper proposes an integrated control system specially designed for multi-axle vehicles, in which the desired lateral force and yaw moment of vehicles are determined by the sliding mode control algorithm. The output of the sliding mode control is distributed to the suitable wheels based on the abilities and potentials of the two control methods. Moreover, in this method, fewer experiments are needed, and the robustness and simultaneity are both guaranteed. To simplify the optimization system and to improve the computation speed, seven simple optimization subsystems are designed for the determination of control outputs on each wheel. The simulation results show that the proposed controller obviously enhances the stability of multi-axle trucks. The system improves 68% of the safe velocity, and its performance is much better than both di erential braking and active steering. This research proposes an integrated control system that can simultaneously invoke di erential braking and active steering of multi-axle vehicles to fully utilize the abilities and potentials of the two control methods.
基金Supported by Project of Yunnan Tobacco Company of Science and Technology(2014YN20)
文摘Tobacco black shank is one of the devastating diseases of tobacco. In recent years, this disease widely occurred in most tobacco-growing areas, which caused disastrous losses and has severely threatened the sustainable development of flue-cured tobacco. In order to lay a theoretical foundation for the better control of tobacco black shank, the occurrence characteristics and integrated control strategis of this disease were systematically discussed according to the aspects of agricultural control, chemical control, biological control, etc.
基金This project is supported by Provincial Open Foundation of Key Lab forAutomobile of Jiangsu, China (No.KJS02076) and 985 Project of AutomotiveEngineering Innovation Platform of Jilin University, China.
文摘Combining with the development of automated manual transmission (AMT), the various throttle control demands are analyzed under different working conditions of AMT such as tracking acceleration pedal, start, shift and so on. Based on simulation, the responding throttle control strategies are proposed, and a simple but effective throttle control method is presented. The testing results have proved that the strategies are effective for improving the pedal tracking precision and the qualities of start and shift.