Future aerospace vehicles （ASV） are designed to fly in both inner and extra atmospheric fields, which requires autonomous adaptability to the uncertainties emanated from abrupt faults and continuously time-varying e...Future aerospace vehicles （ASV） are designed to fly in both inner and extra atmospheric fields, which requires autonomous adaptability to the uncertainties emanated from abrupt faults and continuously time-varying environments. An autonomous control reconfiguration scheme is presented for ASV to deal with the uncertainties on the base of control effectiveness estimation. The on-line estimation methods for the time-varying control effectiveness of linear control system are investigated. Some sufficient conditions for the estimable system are given for different cases. There are proposed corresponding on-line estimation algorithms which are proved to be convergent and robust to noise using the least-square-based methods. On the ground of fuzzy logic and linear programming, the control allocation algorithms, which are able to implement the autonomous control reconfiguration through the redundant actuators, are put forward. Finally, an integrated system is developed to verify the scheme and algorithms by way of numerical simulation and analysis.展开更多
This study was conducted to explore and seek high-efficiency and safe green control techniques on sugarcane borers,promote green control of diseases and pests of sugarcane and build a resource-conserving,environmental...This study was conducted to explore and seek high-efficiency and safe green control techniques on sugarcane borers,promote green control of diseases and pests of sugarcane and build a resource-conserving,environmentally friendly and sustainable governance system of diseases and pests of sugarcane.A new sex pheromone trap of sugarcane borers,abamectin· Bacillus thuringiensis (Bt) and tebufenozide were selected and applied in field trials.The use of the new sex pheromone trap of sugarcane borers (6 traps/hm 2) in combination with 0.05% abamectin·10 billion active gemmae/g B.thuringiensis (Bt) WP (1.8 kg/hm 2) or new sex pheromone trap of sugarcane borers (6 traps/hm 2) in combination with 200 g/L tebufenozide SC (1.5 L/hm 2) were the best in the sugarcane production.New sex pheromone trap of sugarcane borers should be installed in early march,and biological agents were mixed with water 900 kg per hectare and sprayed evenly sugarcane plants at the beginning of April.Their control effects of dead heart rate and bored stalk rate could be more than 69.98% and 49.09%,respectively,which were superior to that of the control pesticide 3.6% bisultap GR (90 kg/hm 2).The results showed that new sex pheromone trap of sugarcane borers in combination with abamectin· B.thuringiensis (Bt) or tebufenozide was the optimum mode of green control techniques on sugarcane borers.When it was alternately or coordinately used with other technology,it could delay the emergence and development of drug resistance,and it was worthy of widespread popularization and application in sugarcane area.展开更多
With the increasingly severe global warming, investments in clean technology, reforestation and political action have been studied to reduce CO2 emission. In this study, a nonlinear stochastic model is proposed to des...With the increasingly severe global warming, investments in clean technology, reforestation and political action have been studied to reduce CO2 emission. In this study, a nonlinear stochastic model is proposed to describe the dynamics of CO2 emission with control inputs: clean technology, reforestation and carbon tax, under stochastic uncertainties. For the efficient resources management, a robust tracking control is designed to force resources tracking a desired reference output. The worst-case effect of stochastic parametric fluctuations, external disturbances and uncertain initial conditions on the tracking performance is considered and minimized from the dynamic game theory perspective. This stochastic game problem, in which one player (stochastic uncertainty) maximizes the tracking error and another player (control input) minimizes the tracking error, could be equivalent to a robust minimax tracking problem. To avoid solving the HJI, a fuzzy model is proposed to approximate the nonlinear CO2 emission model. Then the nonlinear stochastic game problem could be easily solved by fuzzy stochastic game approach via LMI technique.展开更多
There is considerable safety potential in ensuring that motorists respect the speed limits. High speeds increase the number and severity of accidents. Technological development over the last 20 years has enabled the d...There is considerable safety potential in ensuring that motorists respect the speed limits. High speeds increase the number and severity of accidents. Technological development over the last 20 years has enabled the development of systems that allow automatic speed control. The first generation of automatic speed control was point-based, but in recent years a potentially more effective alternative automatic speed control method has been introduced. This method is based upon records of drivers’ average travel speed over selected sections of the road and is normally called average speed control or section control. This article discusses the different methods for automatic speed control and presents an evaluation of the safety effects of average speed control, documented through changes in speed levels and accidents before and after the implementation of average speed control at selected sites in the UK. The study demonstrates that the introduction of average speed control results in statistically significant and substantial reductions both in speed and in number of accidents. The evaluation indicates that average speed control has a higher safety effect than point-based automatic speed control.展开更多
In this paper, we introduce a new Control Lyapunov Function (CLF) approach for controlling the behavior of nonlinear uncertain HIV-1 models. The uncertainty is in decay parameters and also external control setting. CL...In this paper, we introduce a new Control Lyapunov Function (CLF) approach for controlling the behavior of nonlinear uncertain HIV-1 models. The uncertainty is in decay parameters and also external control setting. CLF is then applied to different strategies. One such strategy considers input into infected cells population stage and the other considers input into a virus population stage. Furthermore, by adding noise to the HIV-1 model a realistic comparison between control strategies is presented to evaluate the system’s dynamics. It has been demonstrated that nonlinear control has effectiveness and robustness, in reducing virus loading to an undetectable level.展开更多
基金National Natural Science Foundation of China (90205011, 60674103)
文摘Future aerospace vehicles （ASV） are designed to fly in both inner and extra atmospheric fields, which requires autonomous adaptability to the uncertainties emanated from abrupt faults and continuously time-varying environments. An autonomous control reconfiguration scheme is presented for ASV to deal with the uncertainties on the base of control effectiveness estimation. The on-line estimation methods for the time-varying control effectiveness of linear control system are investigated. Some sufficient conditions for the estimable system are given for different cases. There are proposed corresponding on-line estimation algorithms which are proved to be convergent and robust to noise using the least-square-based methods. On the ground of fuzzy logic and linear programming, the control allocation algorithms, which are able to implement the autonomous control reconfiguration through the redundant actuators, are put forward. Finally, an integrated system is developed to verify the scheme and algorithms by way of numerical simulation and analysis.
基金Supported by Sugar Crop Research System(CARS-170303)Training Project of Yunling Industry and Technology Leading Talents“Control of Sugarcane Harmful Organisms”(2018LJRC56)Special Fund of Agricultural Industry Research System in Yunnan Province
文摘This study was conducted to explore and seek high-efficiency and safe green control techniques on sugarcane borers,promote green control of diseases and pests of sugarcane and build a resource-conserving,environmentally friendly and sustainable governance system of diseases and pests of sugarcane.A new sex pheromone trap of sugarcane borers,abamectin· Bacillus thuringiensis (Bt) and tebufenozide were selected and applied in field trials.The use of the new sex pheromone trap of sugarcane borers (6 traps/hm 2) in combination with 0.05% abamectin·10 billion active gemmae/g B.thuringiensis (Bt) WP (1.8 kg/hm 2) or new sex pheromone trap of sugarcane borers (6 traps/hm 2) in combination with 200 g/L tebufenozide SC (1.5 L/hm 2) were the best in the sugarcane production.New sex pheromone trap of sugarcane borers should be installed in early march,and biological agents were mixed with water 900 kg per hectare and sprayed evenly sugarcane plants at the beginning of April.Their control effects of dead heart rate and bored stalk rate could be more than 69.98% and 49.09%,respectively,which were superior to that of the control pesticide 3.6% bisultap GR (90 kg/hm 2).The results showed that new sex pheromone trap of sugarcane borers in combination with abamectin· B.thuringiensis (Bt) or tebufenozide was the optimum mode of green control techniques on sugarcane borers.When it was alternately or coordinately used with other technology,it could delay the emergence and development of drug resistance,and it was worthy of widespread popularization and application in sugarcane area.
文摘With the increasingly severe global warming, investments in clean technology, reforestation and political action have been studied to reduce CO2 emission. In this study, a nonlinear stochastic model is proposed to describe the dynamics of CO2 emission with control inputs: clean technology, reforestation and carbon tax, under stochastic uncertainties. For the efficient resources management, a robust tracking control is designed to force resources tracking a desired reference output. The worst-case effect of stochastic parametric fluctuations, external disturbances and uncertain initial conditions on the tracking performance is considered and minimized from the dynamic game theory perspective. This stochastic game problem, in which one player (stochastic uncertainty) maximizes the tracking error and another player (control input) minimizes the tracking error, could be equivalent to a robust minimax tracking problem. To avoid solving the HJI, a fuzzy model is proposed to approximate the nonlinear CO2 emission model. Then the nonlinear stochastic game problem could be easily solved by fuzzy stochastic game approach via LMI technique.
文摘There is considerable safety potential in ensuring that motorists respect the speed limits. High speeds increase the number and severity of accidents. Technological development over the last 20 years has enabled the development of systems that allow automatic speed control. The first generation of automatic speed control was point-based, but in recent years a potentially more effective alternative automatic speed control method has been introduced. This method is based upon records of drivers’ average travel speed over selected sections of the road and is normally called average speed control or section control. This article discusses the different methods for automatic speed control and presents an evaluation of the safety effects of average speed control, documented through changes in speed levels and accidents before and after the implementation of average speed control at selected sites in the UK. The study demonstrates that the introduction of average speed control results in statistically significant and substantial reductions both in speed and in number of accidents. The evaluation indicates that average speed control has a higher safety effect than point-based automatic speed control.
文摘In this paper, we introduce a new Control Lyapunov Function (CLF) approach for controlling the behavior of nonlinear uncertain HIV-1 models. The uncertainty is in decay parameters and also external control setting. CLF is then applied to different strategies. One such strategy considers input into infected cells population stage and the other considers input into a virus population stage. Furthermore, by adding noise to the HIV-1 model a realistic comparison between control strategies is presented to evaluate the system’s dynamics. It has been demonstrated that nonlinear control has effectiveness and robustness, in reducing virus loading to an undetectable level.
