Coronary artery systems are a kind of complex biological systems. Their chaotic phenomena can lead to serious health problems and illness development. From the perspective of engineering, this paper investigates the c...Coronary artery systems are a kind of complex biological systems. Their chaotic phenomena can lead to serious health problems and illness development. From the perspective of engineering, this paper investigates the chaos suppression problem. At first, nonlinear dynamics of coronary artery systems are presented. To suppress the chaotic phenomena, the method of derivative-integral terminal sliding mode control is adopted. Since coronary artery systems suffer from uncertainties, the technique of disturbance observer is taken into consideration. The stability of such a control system that integrates the derivative-integral terminal sliding mode controller and the disturbance observer is proven in the sense of Lyapunov. To verify the feasibility and effectiveness of the proposed strategy, simulation results are illustrated in comparison with a benchmark.展开更多
This paper first researches the system's response-feature due to the sliding regime related to the slope of a switching line, and then makes an investigation on the existence condition and hitting condition. Based...This paper first researches the system's response-feature due to the sliding regime related to the slope of a switching line, and then makes an investigation on the existence condition and hitting condition. Based on these conditions, the paper proposes a switching function that can realize an error adaptive variable structure control (AVSC) successfully. For eliminating the chattering of the sliding regime, this VSS introduces a dead zone, in which the PID control is applied. The composition of the PID control and the AVSC is called composite control of linear / AVSC. When the control signal is a large one, the AVSC is applied in the majority, and when the signal is a low one, the PID control is applied. Finally, an example of overload control of an anti-ship aerodynamic missile is illustrated to show the application of the composite control.展开更多
In this paper,a new parallel controller is developed for continuous-time linear systems.The main contribution of the method is to establish a new parallel control law,where both state and control are considered as the...In this paper,a new parallel controller is developed for continuous-time linear systems.The main contribution of the method is to establish a new parallel control law,where both state and control are considered as the input.The structure of the parallel control is provided,and the relationship between the parallel control and traditional feedback controls is presented.Considering the situations that the systems are controllable and incompletely controllable,the properties of the parallel control law are analyzed.The parallel controller design algorithms are given under the conditions that the systems are controllable and incompletely controllable.Finally,numerical simulations are carried out to demonstrate the effectiveness and applicability of the present method.Index Terms-Continuous-time linear systems,digital twin,parallel controller,parallel intelligence,parallel systems.展开更多
We define here the concept of head boundedness,head normal form and head confluence of term rewriting systems that allow infinite derivations.Head confluence is weaker than confluence,but suffi- cient to guarantee the...We define here the concept of head boundedness,head normal form and head confluence of term rewriting systems that allow infinite derivations.Head confluence is weaker than confluence,but suffi- cient to guarantee the correctness of lazy implementations of equational logic programming languages. Then we prove several results.First,if a left-linear system is locally confluent and head-bounded,then it is head-confluent.Second,head-confluent and head-bounded systems have the head Church-Rosser proper- ty.Last,if an orthogonal system is head-terminating,then it is bead-bounded.These results can be ap- plied to generalize equational logic programming languages.展开更多
Generally speaking,confluence property is not preserved when Term Rewriting Systems(TRSs) are combined,even if they are canonical.In this paper we give some sufficient conditions for ensuring the confluence property o...Generally speaking,confluence property is not preserved when Term Rewriting Systems(TRSs) are combined,even if they are canonical.In this paper we give some sufficient conditions for ensuring the confluence property of combined left-linear,overlapping TRSs.展开更多
Using lock-in amplifer and proportional, integral, and derivative (PID) electric circuit, the frequency of diode laser is stabilized on a highly mechanical stable Fabry-Perot (FP) cavity transmission peak. When the fr...Using lock-in amplifer and proportional, integral, and derivative (PID) electric circuit, the frequency of diode laser is stabilized on a highly mechanical stable Fabry-Perot (FP) cavity transmission peak. When the frequency locking system is on, the frequency tunable range of the laser is about 4 GHz around the D1 transition of Rb. The laser frequency tuning is implemented by scanning the FP cavity length. The fluctuation of frequency of the output laser is less than 1 MHz, and the drift of the center frequency is less than 1.5 MHz in 1.5 min. This system has great potential of the application in the experimental investigation of the interaction between light and atoms, especially, for the case of far off the atomic resonance.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(2018MS29)
文摘Coronary artery systems are a kind of complex biological systems. Their chaotic phenomena can lead to serious health problems and illness development. From the perspective of engineering, this paper investigates the chaos suppression problem. At first, nonlinear dynamics of coronary artery systems are presented. To suppress the chaotic phenomena, the method of derivative-integral terminal sliding mode control is adopted. Since coronary artery systems suffer from uncertainties, the technique of disturbance observer is taken into consideration. The stability of such a control system that integrates the derivative-integral terminal sliding mode controller and the disturbance observer is proven in the sense of Lyapunov. To verify the feasibility and effectiveness of the proposed strategy, simulation results are illustrated in comparison with a benchmark.
文摘This paper first researches the system's response-feature due to the sliding regime related to the slope of a switching line, and then makes an investigation on the existence condition and hitting condition. Based on these conditions, the paper proposes a switching function that can realize an error adaptive variable structure control (AVSC) successfully. For eliminating the chattering of the sliding regime, this VSS introduces a dead zone, in which the PID control is applied. The composition of the PID control and the AVSC is called composite control of linear / AVSC. When the control signal is a large one, the AVSC is applied in the majority, and when the signal is a low one, the PID control is applied. Finally, an example of overload control of an anti-ship aerodynamic missile is illustrated to show the application of the composite control.
基金supported in part by the National Key Research and Development Program of China(2018AAA0101502,2018YFB1702300)the National Natural Science Foundation of China(61722312,61533019,U1811463,61533017)。
文摘In this paper,a new parallel controller is developed for continuous-time linear systems.The main contribution of the method is to establish a new parallel control law,where both state and control are considered as the input.The structure of the parallel control is provided,and the relationship between the parallel control and traditional feedback controls is presented.Considering the situations that the systems are controllable and incompletely controllable,the properties of the parallel control law are analyzed.The parallel controller design algorithms are given under the conditions that the systems are controllable and incompletely controllable.Finally,numerical simulations are carried out to demonstrate the effectiveness and applicability of the present method.Index Terms-Continuous-time linear systems,digital twin,parallel controller,parallel intelligence,parallel systems.
基金supported by the National Nature Science Foundation of China(61304223)the Aeronautical Science Foundation of China(2016ZA52009)the Research Fund for the Doctoral Program of Higher Education of China(20123218120015)
基金The project is supported by the National Natural Science Foundation of China.
文摘We define here the concept of head boundedness,head normal form and head confluence of term rewriting systems that allow infinite derivations.Head confluence is weaker than confluence,but suffi- cient to guarantee the correctness of lazy implementations of equational logic programming languages. Then we prove several results.First,if a left-linear system is locally confluent and head-bounded,then it is head-confluent.Second,head-confluent and head-bounded systems have the head Church-Rosser proper- ty.Last,if an orthogonal system is head-terminating,then it is bead-bounded.These results can be ap- plied to generalize equational logic programming languages.
基金This work was supported partly by The National Science FoundationThe Ministry of Electronic Industries and High Technology Program under The National Commission of Science & Technology.
文摘Generally speaking,confluence property is not preserved when Term Rewriting Systems(TRSs) are combined,even if they are canonical.In this paper we give some sufficient conditions for ensuring the confluence property of combined left-linear,overlapping TRSs.
文摘Using lock-in amplifer and proportional, integral, and derivative (PID) electric circuit, the frequency of diode laser is stabilized on a highly mechanical stable Fabry-Perot (FP) cavity transmission peak. When the frequency locking system is on, the frequency tunable range of the laser is about 4 GHz around the D1 transition of Rb. The laser frequency tuning is implemented by scanning the FP cavity length. The fluctuation of frequency of the output laser is less than 1 MHz, and the drift of the center frequency is less than 1.5 MHz in 1.5 min. This system has great potential of the application in the experimental investigation of the interaction between light and atoms, especially, for the case of far off the atomic resonance.