In networked control systems (NCS), the main problem is time delays induced by communication network, which can deteriorate the performance of the systems, even cause the systems instability. If we know the exact netw...In networked control systems (NCS), the main problem is time delays induced by communication network, which can deteriorate the performance of the systems, even cause the systems instability. If we know the exact network delays, we can compensate for their effect by modifying the parameters of the controller. Hence how to get the knowledge of these delays in the network is critical. This paper analyzed the different characteristics of network delays from sensor to controller and from controller to actuator and presented the methods of online evaluation of these delays. The experiment shows these methods are valid.展开更多
Nonsmooth finite-time stabilizing control laws have been developed for the double integrator system. The objective of this paper is to further explore the finite-time tracking control problem of a general form of unce...Nonsmooth finite-time stabilizing control laws have been developed for the double integrator system. The objective of this paper is to further explore the finite-time tracking control problem of a general form of uncertain secondorder affine nonlinear system with the new forms of terminal sliding mode （TSM）. Discontinuous and continuous finite-time controllers are also developed respectively without the singularity problem. Complete robustness can be acquired with the former, and enhanced robustness compared with the conventional boundary layer method can be expressed as explicit bounded function with the latter. Simulation results on the stabilizing and tracking problems are presented to demonstrate the effectiveness of the control algorithms.展开更多
In this paper,a series of new techniques are used to optimize typical laser scanning sensor.The integrated prototype is compared with traditional approach to demonstrate the much improved performance.In the research a...In this paper,a series of new techniques are used to optimize typical laser scanning sensor.The integrated prototype is compared with traditional approach to demonstrate the much improved performance.In the research and development,camera calibration is achieved by extracting characteristic points of the laser plane,so that the calibra- tion efficiency is improved significantly.With feedback control of its intensity,the laser is automatically adjusted for different material.A modified algorithm is presented to improve the accuracy of laser stripe extraction.The fusion of data extracted from left and right camera is completed with re-sampling technique.The scanner is integrated with a robot arm and some other machinery for on-line measurement and inspection,which provides a flexible measurement tool for reverse engineering.展开更多
In this paper, an indirect adaptive fuzzy output feedback controller with supervisory mode for a class of unknown nonlinear systems is developed. The proposed approach does not need the availability of the state varia...In this paper, an indirect adaptive fuzzy output feedback controller with supervisory mode for a class of unknown nonlinear systems is developed. The proposed approach does not need the availability of the state variables, moreover, a supervisory controller is appended to the adaptive fuzzy controller to force the state to be within the constraint set. Therefore, if the adaptive fuzzy controller cannot maintain the stability, the supervisory controller starts to work to guarantee stability. On the other hand, if the adaptive fuzzy controller works well, the supervisory controller will be de-activated. The overall adaptive fuzzy control scheme guarantees the stability of the whole closed-loop systems. The simulation results confirm the effectiveness of the proposed method.展开更多
[Objectives]This study was conducted to investigate the differences of main nutrient components in 29 different varieties of Chinese chestnut.[Methods]The protein contents,starch contents,Vc contents,soluble sugar con...[Objectives]This study was conducted to investigate the differences of main nutrient components in 29 different varieties of Chinese chestnut.[Methods]The protein contents,starch contents,Vc contents,soluble sugar contents and inorganic element contents in the 29 different varieties of Chinese chestnut in the north were detected and compared.[Results]The main nutrient components in the 29 varieties of Chinese chestnut were as follows:amylose content 47.16%-63.27%,protein content 3.23%-7.58%,soluble sugar content 7.23%-16.17%,Vc content 2.42-9.42 mg/100 g,Fe content 7.20-17.28 mg/kg,K content 3611-8940 mg/kg,Zn content 4.43-9.24 mg/kg,Ca content 120-304 mg/kg,and P content 752-1658 mg/kg.In general,four varieties,"Dabanhong","Yanbao","Duanzhi"and"Jinhua",have higher nutritional components.[Conclusions]This study provides a theoretical basis for the processing,utilization,storage,purchase,breeding and scientific management of Chinese chestnut in the future.展开更多
文摘In networked control systems (NCS), the main problem is time delays induced by communication network, which can deteriorate the performance of the systems, even cause the systems instability. If we know the exact network delays, we can compensate for their effect by modifying the parameters of the controller. Hence how to get the knowledge of these delays in the network is critical. This paper analyzed the different characteristics of network delays from sensor to controller and from controller to actuator and presented the methods of online evaluation of these delays. The experiment shows these methods are valid.
基金the National Natural Science Foundation of China (No.60674061).
文摘Nonsmooth finite-time stabilizing control laws have been developed for the double integrator system. The objective of this paper is to further explore the finite-time tracking control problem of a general form of uncertain secondorder affine nonlinear system with the new forms of terminal sliding mode （TSM）. Discontinuous and continuous finite-time controllers are also developed respectively without the singularity problem. Complete robustness can be acquired with the former, and enhanced robustness compared with the conventional boundary layer method can be expressed as explicit bounded function with the latter. Simulation results on the stabilizing and tracking problems are presented to demonstrate the effectiveness of the control algorithms.
文摘In this paper,a series of new techniques are used to optimize typical laser scanning sensor.The integrated prototype is compared with traditional approach to demonstrate the much improved performance.In the research and development,camera calibration is achieved by extracting characteristic points of the laser plane,so that the calibra- tion efficiency is improved significantly.With feedback control of its intensity,the laser is automatically adjusted for different material.A modified algorithm is presented to improve the accuracy of laser stripe extraction.The fusion of data extracted from left and right camera is completed with re-sampling technique.The scanner is integrated with a robot arm and some other machinery for on-line measurement and inspection,which provides a flexible measurement tool for reverse engineering.
基金Supported by National Natural Science Foundation of P. R. China (60274019)National Key Basic Research and Development Program of P. R. China (2002CB312200)
文摘In this paper, an indirect adaptive fuzzy output feedback controller with supervisory mode for a class of unknown nonlinear systems is developed. The proposed approach does not need the availability of the state variables, moreover, a supervisory controller is appended to the adaptive fuzzy controller to force the state to be within the constraint set. Therefore, if the adaptive fuzzy controller cannot maintain the stability, the supervisory controller starts to work to guarantee stability. On the other hand, if the adaptive fuzzy controller works well, the supervisory controller will be de-activated. The overall adaptive fuzzy control scheme guarantees the stability of the whole closed-loop systems. The simulation results confirm the effectiveness of the proposed method.
基金Supported by Hebei Talent Project Training Fund(A201901128).
文摘[Objectives]This study was conducted to investigate the differences of main nutrient components in 29 different varieties of Chinese chestnut.[Methods]The protein contents,starch contents,Vc contents,soluble sugar contents and inorganic element contents in the 29 different varieties of Chinese chestnut in the north were detected and compared.[Results]The main nutrient components in the 29 varieties of Chinese chestnut were as follows:amylose content 47.16%-63.27%,protein content 3.23%-7.58%,soluble sugar content 7.23%-16.17%,Vc content 2.42-9.42 mg/100 g,Fe content 7.20-17.28 mg/kg,K content 3611-8940 mg/kg,Zn content 4.43-9.24 mg/kg,Ca content 120-304 mg/kg,and P content 752-1658 mg/kg.In general,four varieties,"Dabanhong","Yanbao","Duanzhi"and"Jinhua",have higher nutritional components.[Conclusions]This study provides a theoretical basis for the processing,utilization,storage,purchase,breeding and scientific management of Chinese chestnut in the future.
