The goal of this paper is to enhance a practical nominal characteristic trajectory following(NCTF) controller that is specifically designed for two-mass point-to-point positioning systems. A nominal characteristics tr...The goal of this paper is to enhance a practical nominal characteristic trajectory following(NCTF) controller that is specifically designed for two-mass point-to-point positioning systems. A nominal characteristics trajectory contained in the NCTF controller acts as movement/motion reference and a compensator is utilized to force the object to detect and follow the reference/desired trajectory. The object must follow and track closely and should be as fast as possible. The NCTF controller is designed with two different intelligent based compensator approaches which are fuzzy logic and extended minimal resource allocation network. The proposed controller which is NCTF are compared with the conventional proportional integral compensator. Then the results of simulation are discussed for the positioning performances. The inertia variations due to the effect of the design parameters are also assessed to see the robustness of controllers. The results show that the NCTF control method designed from an intelligent based compensator has a better positioning performance in terms of percentage of overshoot, settling time, and steady state error than the classical based compensator.展开更多
The accurate quantification of human error probability(HEP) has long been a main pursuit for most human reliability analysis(HRA) methods. This paper proposes a strategy to analyzeand predict human error on the basis ...The accurate quantification of human error probability(HEP) has long been a main pursuit for most human reliability analysis(HRA) methods. This paper proposes a strategy to analyzeand predict human error on the basis of a further modification of theexisting cognitive reliability and error analysis method (CREAM)in HRA. Through providing a broader definition for the key parametersused in the quantification method, this paper produces arelatively flexible strategy to determine the nominal HEP (HEP0).Basing on this strategy, the actual quantification of HEP in CREAMis able to be applied to more verified conditions. To prove the validityof the method proposed, a case study of spacecraft launch isalso introduced, in which the prediction derived from the method isproved consistent with real field data.展开更多
To meet the requirements of modern air combat,an integrated fire/flight control(IFFC)system is designed to achieve automatic precision tracking and aiming for armed helicopters and release the pilot from heavy target ...To meet the requirements of modern air combat,an integrated fire/flight control(IFFC)system is designed to achieve automatic precision tracking and aiming for armed helicopters and release the pilot from heavy target burden.Considering the complex dynamic characteristics and the couplings of armed helicopters,an improved automatic attack system is con-structed to integrate the fire control system with the flight con-trol system into a unit.To obtain the optimal command signals,the algorithm is investigated to solve nonconvex optimization problems by the contracting Broyden Fletcher Goldfarb Shanno(C-BFGS)algorithm combined with the trust region method.To address the uncertainties in the automatic attack system,the memory nominal distribution and Wasserstein distance are introduced to accurately characterize the uncertainties,and the dual solvable problem is analyzed by using the duality the-ory,conjugate function,and dual norm.Simulation results verify the practicality and validity of the proposed method in solving the IFFC problem on the premise of satisfactory aiming accu-racy.展开更多
文摘The goal of this paper is to enhance a practical nominal characteristic trajectory following(NCTF) controller that is specifically designed for two-mass point-to-point positioning systems. A nominal characteristics trajectory contained in the NCTF controller acts as movement/motion reference and a compensator is utilized to force the object to detect and follow the reference/desired trajectory. The object must follow and track closely and should be as fast as possible. The NCTF controller is designed with two different intelligent based compensator approaches which are fuzzy logic and extended minimal resource allocation network. The proposed controller which is NCTF are compared with the conventional proportional integral compensator. Then the results of simulation are discussed for the positioning performances. The inertia variations due to the effect of the design parameters are also assessed to see the robustness of controllers. The results show that the NCTF control method designed from an intelligent based compensator has a better positioning performance in terms of percentage of overshoot, settling time, and steady state error than the classical based compensator.
基金supported by the National Natural Science Foundation of China(7117100871571004)
文摘The accurate quantification of human error probability(HEP) has long been a main pursuit for most human reliability analysis(HRA) methods. This paper proposes a strategy to analyzeand predict human error on the basis of a further modification of theexisting cognitive reliability and error analysis method (CREAM)in HRA. Through providing a broader definition for the key parametersused in the quantification method, this paper produces arelatively flexible strategy to determine the nominal HEP (HEP0).Basing on this strategy, the actual quantification of HEP in CREAMis able to be applied to more verified conditions. To prove the validityof the method proposed, a case study of spacecraft launch isalso introduced, in which the prediction derived from the method isproved consistent with real field data.
基金supported by the National Natural Science Foundation of China(62373187)Forward-looking Layout Special Projects(ILA220591A22).
文摘To meet the requirements of modern air combat,an integrated fire/flight control(IFFC)system is designed to achieve automatic precision tracking and aiming for armed helicopters and release the pilot from heavy target burden.Considering the complex dynamic characteristics and the couplings of armed helicopters,an improved automatic attack system is con-structed to integrate the fire control system with the flight con-trol system into a unit.To obtain the optimal command signals,the algorithm is investigated to solve nonconvex optimization problems by the contracting Broyden Fletcher Goldfarb Shanno(C-BFGS)algorithm combined with the trust region method.To address the uncertainties in the automatic attack system,the memory nominal distribution and Wasserstein distance are introduced to accurately characterize the uncertainties,and the dual solvable problem is analyzed by using the duality the-ory,conjugate function,and dual norm.Simulation results verify the practicality and validity of the proposed method in solving the IFFC problem on the premise of satisfactory aiming accu-racy.
