In this paper, we study the existence and global attractivity of positive peri- odic solutions of a Logistic growth system with feedback control and deviating arguments. A sufficient condition is derived for the exist...In this paper, we study the existence and global attractivity of positive peri- odic solutions of a Logistic growth system with feedback control and deviating arguments. A sufficient condition is derived for the existence of a unique peri- odic solution with strictly positive components which is globally asymptotically stable by using the method of coincidence degree and Liapunov functional. Some new results are obtained. The known results are improved and generalized.展开更多
Three big field projects, independent irrigation and drainage facilities, and a blocking net, which are auxiliary projects of a green planting and breeding pattern composed of rice and red swamp crawfish （Procambarus...Three big field projects, independent irrigation and drainage facilities, and a blocking net, which are auxiliary projects of a green planting and breeding pattern composed of rice and red swamp crawfish （Procambarus clarkii）, spatial and temporal coupling technology of ＂planting rice in one season and breeding red swamp crawfish in three seasons＂, green fertilization technology, green prevention and control technology, control technology of water level, and throwing technology of bait in Lixiahe region of Jiangsu Province were introduced successively, which can provide technical support for the development of ecological planting and breeding patterns and realization of green production in paddy fields.展开更多
Platoon formation of highway vehicles is a critical foundation for autonomous or semiautonomous vehicle control for enhanced safety,improved highway utility,increased fuel economy,and reduced emission toward intellige...Platoon formation of highway vehicles is a critical foundation for autonomous or semiautonomous vehicle control for enhanced safety,improved highway utility,increased fuel economy,and reduced emission toward intelligent transportation systems.Platoon control encounters great challenges from vehicle control,communications,team coordination,and uncertainties.This paper introduces a new method for coordinated control of platoons by using integrated network consensus decisions and vehicle control.To achieve suitable coordination of the team vehicles based on terrain and environmental conditions,the emerging technology of network consensus control is modified to a weighted and constrained consensus-seeking framework.Algorithms are introduced and their convergence properties are established.The methodology employs neighborhood information through on-board sensors and V2 V or V2 I communications,but achieves global coordination of the entire platoon.The ability of the methods in terms of robustness,disturbance rejection,noise attenuation,and cyber-physical interaction is analyzed and demonstrated with simulated case studies.展开更多
A coordination control strategy is developed for 3-bearing swivel duct （3BSD） nozzles. A 3BSD nozzle＇s deflection angle and direction are changed through rotations of three revolute pairs. There is a nonlinear rela...A coordination control strategy is developed for 3-bearing swivel duct （3BSD） nozzles. A 3BSD nozzle＇s deflection angle and direction are changed through rotations of three revolute pairs. There is a nonlinear relationship between the deflection an- gle/direction and the rotation angles. The rotation speed of a revolute pair is limited by the power of the actuator. The moment of inertia and the aerodynamic load for each revolute pair are different and time-varying. A high-precision control system of 3BSD nozzles is required for applications on vertical and/or short take-off and landing （V/STOL） aircrafts. Difficulties of co- ordination control of 3BSD nozzles are distinct travel ranges, speed constraints, time^xarying dynamic models, and disturb- ances. The proposed control strategy is a combination of the characteristic model and tlF e dynamic control allocation method. A dynamic control allocation module is used as the coordination supervisor, which is aware of the kinematic model, the con- straints, and the dynamic models of the revolute pairs. Second-order characteristic models are used to represent the dynamic behavior of the revolute pairs. The gradient projection algorithm is modified for parameter estimation. A modified all-coefficient adaptive controller is developed to reject the disturbances. Experimental results of a scaled 3BSD nozzle indi- cate that the coordination control strategy is effective.展开更多
This paper develops an event-triggered resilient consensus control method for the nonlinear multiple unmanned systems with a data-based autoregressive integrated moving average(ARIMA)agent state prediction mechanism a...This paper develops an event-triggered resilient consensus control method for the nonlinear multiple unmanned systems with a data-based autoregressive integrated moving average(ARIMA)agent state prediction mechanism against periodic denial-of-service(Do S)attacks.The state predictor is used to predict the state of neighbor agents during periodic Do S attacks and maintain consistent control of multiple unmanned systems under Do S attacks.Considering the existing prediction error between the actual state and the predicted state,the estimated error is regarded as the uncertainty system disturbance,which is dealt with by the designed disturbance observer.The estimated result is used in the design of the consistent controller to compensate for the system uncertainty error term.Furthermore,this paper investigates dynamic event-triggered consensus controllers to improve resilience and consensus under periodic Do S attacks and reduce the frequency of actuator output changes.It is proved that the Zeno behavior can be excluded.Finally,the resilience and consensus capability of the proposed controller and the superiority of introducing a state predictor are demonstrated through numerical simulations.展开更多
A control system aims at vibration reduction in a two-span rotor system with two shear mode magnetorheological （MRF） dampers is designed. A finite element model of the MRF damper- rotor system is built and used to a...A control system aims at vibration reduction in a two-span rotor system with two shear mode magnetorheological （MRF） dampers is designed. A finite element model of the MRF damper- rotor system is built and used to analyze the rotor vibration characteristics. Based on Hooke and Jeeves algorithm and the numerical simulation analysis, an optimal appropriate controller is proposed and designed. Experimental results show that rotor vibration caused by unbalance is well controlled （ first critical speed region 37% , second critical speed region 42% ）. To reflect advantages of optimi- zing strategy presented and validate the intelligent optimization control technology, detailed experi- ments were developed on a two-span rotor-vibration-control platform. The influence on accuracy, rapidity and stability of optimizing control for rotor vibration are analyzed. It provides a powerful technical support for the extension and application in target and control for shafting vibration.展开更多
We consider first order quasilinear hyperbolic systems with vertical characteristics. It was shown in [4] that such systems can be exactly controllable with the help of internal controls applied to the equations corr...We consider first order quasilinear hyperbolic systems with vertical characteristics. It was shown in [4] that such systems can be exactly controllable with the help of internal controls applied to the equations corresponding to zero eigenvalues. However, it is possible that, for physical or engineering reasons, we can not put any control on the equations corresponding to zero eigenvalues. In this paper, we will establish the exact controllability only by means of physically meaningfnl internal controls applied to the equations corresponding to non-zero eigenvalues. We also show the exact controllability for a very simplified model by means of switching controls.展开更多
Abstract-The ineffective utilization of power resources has attracted much attention in current years. This paper proposes a real-time distributed load scheduling algorithm considering constraints of power supply. Fir...Abstract-The ineffective utilization of power resources has attracted much attention in current years. This paper proposes a real-time distributed load scheduling algorithm considering constraints of power supply. Firstly, an objective function is designed based on the constraint, and a base load forecasting model is established when aggregating renewable generation and non-deferrable load into a power system, which aims to transform the problem of deferrable loads scheduling into a distributed optimal control problem. Then, to optimize the objective function, a real-time scheduling algorithm is presented to solve the proposed control problem. At every time step, the purpose is to minimize the variance of differences between power supply and aggregate load, which can thus ensure the effective utilization of power resources. Finally, simulation examples are provided to illustrate the effectiveness of the proposed algorithm.展开更多
Dynamic Models for predicting the concentration profiles of the reactants and product in a Continuous Stirred Tank Reactor for the transesterification of used cooking oil (triglyceride) to biodiesel has been developed...Dynamic Models for predicting the concentration profiles of the reactants and product in a Continuous Stirred Tank Reactor for the transesterification of used cooking oil (triglyceride) to biodiesel has been developed using the principle of conservation of mass. The developed system of differential equations were integrated numerically using fourth order Runge-Kutta algorithm embedded in ode 45 solver of 7.5 Mathlab program. The models were validated by solving the model equations with kinetic data and other relevant data from literatures. The results and trends were similar and in agreement with those from these literatures. Simulations of the reactor to (±) step changes in the inlet flowrates of the reactants (used cooking oil and methanol) showed great effect on biodiesel production, (instability—oscillations and reduction in output concentration of biodiesel). A feedback control strategy was developed with a Proportional-Integral (PI) Controller and a close loop model was developed for control studies. The closed loop response of the reactor output (biodiesel concentration) showed continuous oscillatory response with offset. Hence the controller parameters (proportional gain <em>K</em><em><sub>c</sub></em> and integral time <img src="Edit_b22777c4-287e-4ff4-a82a-0b5c9393b5ab.bmp" alt="" />) were tuned using the “On-Line Trial and Error Method” implemented using MathLab Simulink to obtain optimum values that ensured quick stability of the closed-loop system, reduced or no oscillatory response and no offset. The optimum controller parameters were: proportional gain <em style="white-space:normal;">K</em><em style="white-space:normal;"><sub>c</sub></em> =8.306 and integral time <img src="Edit_7ad87ff7-7563-48b0-865b-70efc6c433cd.bmp" alt="" />= 17.157 minutes. <p> <br /> </p>展开更多
From the symplectic representation of an autonomous nonlinear dynamical system with holonomic con- straints, i.e., those that can be represented through a symplectic form derived from a Hamiltonian, we present a new p...From the symplectic representation of an autonomous nonlinear dynamical system with holonomic con- straints, i.e., those that can be represented through a symplectic form derived from a Hamiltonian, we present a new proof on the realization of the symplectic feedback action, which has several theoretical advantages in demonstrating the uniqueness and existence of this type of solution. Also, we propose a technique based on the interpretation, construction and character- ization of the pull-back differential on the symplectic manifold as a member of a one-parameter Lie group. This allows one to synthesize the control law that governs a certain system to achieve a desired behavior; and the method developed from this is applied to a classical system such as the inverted pendulum.展开更多
文摘In this paper, we study the existence and global attractivity of positive peri- odic solutions of a Logistic growth system with feedback control and deviating arguments. A sufficient condition is derived for the existence of a unique peri- odic solution with strictly positive components which is globally asymptotically stable by using the method of coincidence degree and Liapunov functional. Some new results are obtained. The known results are improved and generalized.
基金Supported by Gaoyou Demonstration and Extension Base of Modern Agricultural(Rice and Wheat)Industrial Technology System in Jiangsu(SXGC[2017]168)Funds for Independent Innovation of Jiangsu Province(CX17(2007),KF(17)1022)+1 种基金Key Research and Development Plan Project(BE2017332)Agricultural Standardization Pilot Project of Jiangsu Province([2017]46)~~
文摘Three big field projects, independent irrigation and drainage facilities, and a blocking net, which are auxiliary projects of a green planting and breeding pattern composed of rice and red swamp crawfish （Procambarus clarkii）, spatial and temporal coupling technology of ＂planting rice in one season and breeding red swamp crawfish in three seasons＂, green fertilization technology, green prevention and control technology, control technology of water level, and throwing technology of bait in Lixiahe region of Jiangsu Province were introduced successively, which can provide technical support for the development of ecological planting and breeding patterns and realization of green production in paddy fields.
基金supported by the USA National Science Foundation under Grant No.CNS-1136007
文摘Platoon formation of highway vehicles is a critical foundation for autonomous or semiautonomous vehicle control for enhanced safety,improved highway utility,increased fuel economy,and reduced emission toward intelligent transportation systems.Platoon control encounters great challenges from vehicle control,communications,team coordination,and uncertainties.This paper introduces a new method for coordinated control of platoons by using integrated network consensus decisions and vehicle control.To achieve suitable coordination of the team vehicles based on terrain and environmental conditions,the emerging technology of network consensus control is modified to a weighted and constrained consensus-seeking framework.Algorithms are introduced and their convergence properties are established.The methodology employs neighborhood information through on-board sensors and V2 V or V2 I communications,but achieves global coordination of the entire platoon.The ability of the methods in terms of robustness,disturbance rejection,noise attenuation,and cyber-physical interaction is analyzed and demonstrated with simulated case studies.
基金supported by the National Natural Science Foundation of China(Grant Nos.60974339,61104082)
文摘A coordination control strategy is developed for 3-bearing swivel duct （3BSD） nozzles. A 3BSD nozzle＇s deflection angle and direction are changed through rotations of three revolute pairs. There is a nonlinear relationship between the deflection an- gle/direction and the rotation angles. The rotation speed of a revolute pair is limited by the power of the actuator. The moment of inertia and the aerodynamic load for each revolute pair are different and time-varying. A high-precision control system of 3BSD nozzles is required for applications on vertical and/or short take-off and landing （V/STOL） aircrafts. Difficulties of co- ordination control of 3BSD nozzles are distinct travel ranges, speed constraints, time^xarying dynamic models, and disturb- ances. The proposed control strategy is a combination of the characteristic model and tlF e dynamic control allocation method. A dynamic control allocation module is used as the coordination supervisor, which is aware of the kinematic model, the con- straints, and the dynamic models of the revolute pairs. Second-order characteristic models are used to represent the dynamic behavior of the revolute pairs. The gradient projection algorithm is modified for parameter estimation. A modified all-coefficient adaptive controller is developed to reject the disturbances. Experimental results of a scaled 3BSD nozzle indi- cate that the coordination control strategy is effective.
基金supported by the National Natural Science Foundation of China(Nos.61833013,62003162,62233009)Natural Science Foundation of Jiangsu Province of China(Nos.BK20200416,BK20222012)+5 种基金China Postdoctoral Science Foundation(Nos.2020TQ0151,2020M681590)Fundamental Research Funds for the Central Universities(No.NS2021025)Industry-University Research Innovation Foundation for the Chinese Ministry of Education(No.2021ZYA02005)Science and Technology on Space Intelligent Control Laboratory(No.HTKJ2022KL502015)Aeronautical Science Foundation of China(No.20200007018001)Natural Sciences and Engineering Research Council of Canada
文摘This paper develops an event-triggered resilient consensus control method for the nonlinear multiple unmanned systems with a data-based autoregressive integrated moving average(ARIMA)agent state prediction mechanism against periodic denial-of-service(Do S)attacks.The state predictor is used to predict the state of neighbor agents during periodic Do S attacks and maintain consistent control of multiple unmanned systems under Do S attacks.Considering the existing prediction error between the actual state and the predicted state,the estimated error is regarded as the uncertainty system disturbance,which is dealt with by the designed disturbance observer.The estimated result is used in the design of the consistent controller to compensate for the system uncertainty error term.Furthermore,this paper investigates dynamic event-triggered consensus controllers to improve resilience and consensus under periodic Do S attacks and reduce the frequency of actuator output changes.It is proved that the Zeno behavior can be excluded.Finally,the resilience and consensus capability of the proposed controller and the superiority of introducing a state predictor are demonstrated through numerical simulations.
基金Supported by the National Program on Key Basic Research Project(973Program)(2012CB026000)Ph.D Programs Foundation of Ministry of Education of China(20110010110009)
文摘A control system aims at vibration reduction in a two-span rotor system with two shear mode magnetorheological （MRF） dampers is designed. A finite element model of the MRF damper- rotor system is built and used to analyze the rotor vibration characteristics. Based on Hooke and Jeeves algorithm and the numerical simulation analysis, an optimal appropriate controller is proposed and designed. Experimental results show that rotor vibration caused by unbalance is well controlled （ first critical speed region 37% , second critical speed region 42% ）. To reflect advantages of optimi- zing strategy presented and validate the intelligent optimization control technology, detailed experi- ments were developed on a two-span rotor-vibration-control platform. The influence on accuracy, rapidity and stability of optimizing control for rotor vibration are analyzed. It provides a powerful technical support for the extension and application in target and control for shafting vibration.
文摘We consider first order quasilinear hyperbolic systems with vertical characteristics. It was shown in [4] that such systems can be exactly controllable with the help of internal controls applied to the equations corresponding to zero eigenvalues. However, it is possible that, for physical or engineering reasons, we can not put any control on the equations corresponding to zero eigenvalues. In this paper, we will establish the exact controllability only by means of physically meaningfnl internal controls applied to the equations corresponding to non-zero eigenvalues. We also show the exact controllability for a very simplified model by means of switching controls.
文摘Abstract-The ineffective utilization of power resources has attracted much attention in current years. This paper proposes a real-time distributed load scheduling algorithm considering constraints of power supply. Firstly, an objective function is designed based on the constraint, and a base load forecasting model is established when aggregating renewable generation and non-deferrable load into a power system, which aims to transform the problem of deferrable loads scheduling into a distributed optimal control problem. Then, to optimize the objective function, a real-time scheduling algorithm is presented to solve the proposed control problem. At every time step, the purpose is to minimize the variance of differences between power supply and aggregate load, which can thus ensure the effective utilization of power resources. Finally, simulation examples are provided to illustrate the effectiveness of the proposed algorithm.
文摘Dynamic Models for predicting the concentration profiles of the reactants and product in a Continuous Stirred Tank Reactor for the transesterification of used cooking oil (triglyceride) to biodiesel has been developed using the principle of conservation of mass. The developed system of differential equations were integrated numerically using fourth order Runge-Kutta algorithm embedded in ode 45 solver of 7.5 Mathlab program. The models were validated by solving the model equations with kinetic data and other relevant data from literatures. The results and trends were similar and in agreement with those from these literatures. Simulations of the reactor to (±) step changes in the inlet flowrates of the reactants (used cooking oil and methanol) showed great effect on biodiesel production, (instability—oscillations and reduction in output concentration of biodiesel). A feedback control strategy was developed with a Proportional-Integral (PI) Controller and a close loop model was developed for control studies. The closed loop response of the reactor output (biodiesel concentration) showed continuous oscillatory response with offset. Hence the controller parameters (proportional gain <em>K</em><em><sub>c</sub></em> and integral time <img src="Edit_b22777c4-287e-4ff4-a82a-0b5c9393b5ab.bmp" alt="" />) were tuned using the “On-Line Trial and Error Method” implemented using MathLab Simulink to obtain optimum values that ensured quick stability of the closed-loop system, reduced or no oscillatory response and no offset. The optimum controller parameters were: proportional gain <em style="white-space:normal;">K</em><em style="white-space:normal;"><sub>c</sub></em> =8.306 and integral time <img src="Edit_7ad87ff7-7563-48b0-865b-70efc6c433cd.bmp" alt="" />= 17.157 minutes. <p> <br /> </p>
文摘From the symplectic representation of an autonomous nonlinear dynamical system with holonomic con- straints, i.e., those that can be represented through a symplectic form derived from a Hamiltonian, we present a new proof on the realization of the symplectic feedback action, which has several theoretical advantages in demonstrating the uniqueness and existence of this type of solution. Also, we propose a technique based on the interpretation, construction and character- ization of the pull-back differential on the symplectic manifold as a member of a one-parameter Lie group. This allows one to synthesize the control law that governs a certain system to achieve a desired behavior; and the method developed from this is applied to a classical system such as the inverted pendulum.
