With the method of group test, fourty pairs of carburization-quenching gears made from 16NCD13 steel for aerocraft were tested to research the contacting fatigue strength on tooth flank. As a result, the samples of fa...With the method of group test, fourty pairs of carburization-quenching gears made from 16NCD13 steel for aerocraft were tested to research the contacting fatigue strength on tooth flank. As a result, the samples of fatigue life at the moments when the pitting appears and reaches failure criterion were obtained at four stressing levels respectively. The distribution rule of fatigue life were distinguished, and the distribution parameters were estimated by statistical analysis. Based on that, the R-S-N curves with confidence 95% of contacting fatigue on gear tooth flank were evaluated. Therefore, the basic data were provided for the reliability design of the gears and prediction of their life.展开更多
Aimed at designing the unpower aerocraft attitude control system in a simple and practical way, the guaranteed cost control is adopted. To eliminate the steady-error, a novel tracking control approach--augmented state...Aimed at designing the unpower aerocraft attitude control system in a simple and practical way, the guaranteed cost control is adopted. To eliminate the steady-error, a novel tracking control approach--augmented state feedback tracking guaranteed cost control is proposed. Firstly, the unpower aerocraft is modeled as a linear system with norm bounded parameter uncertain, then the linear matrix inequality based state feedback guaranteed cost control law is combined with the augmented state feedback tracking control from a new point of view. The sufficient condition of the existence of the augmented state feedback tracking guaranteed cost control is derived and converted to the feasible problem of the linear matrix inequality. Finally, the proposed approach is applied to a specified unpower aerocraft. The six dimensions of freedom simulation results show that the proposed approach is effective and feasible.展开更多
Owing to the effect of crosswind, initial disturbance and the deviation of engine parameters.etc in the initial aviation, vari- able rolling velocity aerocraft will produce attitude angle deviation in the ideal orient...Owing to the effect of crosswind, initial disturbance and the deviation of engine parameters.etc in the initial aviation, vari- able rolling velocity aerocraft will produce attitude angle deviation in the ideal orientations. This paper adopts AVR microcontroller atmega16 and relevant signal process circuit to design the attitude controller and take the method of frequency discrimination and am- plitude discrimination to process attitude angle deviation of aerocraft. Accordingly, it amends attitude angle deviation of aerocraft ef- fect and implements the self- adapting attitude control of aerocraft’s rolling velocity.展开更多
This paper intends to provide theoretical basis for matching design of hydraulic load simulator （HLS） with aerocraft actuator in hardware-in-loop test, which is expected to help actuator designers overcome the obsta...This paper intends to provide theoretical basis for matching design of hydraulic load simulator （HLS） with aerocraft actuator in hardware-in-loop test, which is expected to help actuator designers overcome the obstacles in putting forward appropriate requirements of HLS. Traditional research overemphasizes the optimization of parameters and methods for HLS controllers. It lacks deliberation because experimental results and project experiences indicate different ultimate performance of a specific HLS. When the actuator paired with this HLS is replaced, the dynamic response and tracing precision of this HLS also change, and sometimes the whole system goes so far as to lose control. Based on the influence analysis of the preceding phenomena, a theory about matching design of aerocraft actuator with HLS is presented, together with two paired new concepts of ＂Standard Actuator＂ and ＂Standard HLS＂. Further research leads to seven important conclusions of matching design, which suggest that appropriate stiffness and output torque of HLS should be carefully designed and chosen for an actuator. Simulation results strongly support that the proposed principle of matching design can be anticipated to be one of the design criteria for HLS, and successfully used to explain experimental phenomena and project experiences.展开更多
The paper presents a novel control design,which is based on the idea of active disturbance rejection control(ADRC),for a kind of flexible aerocraft whose contolled variable cannot be measured directly.Since the origin...The paper presents a novel control design,which is based on the idea of active disturbance rejection control(ADRC),for a kind of flexible aerocraft whose contolled variable cannot be measured directly.Since the original frame of ADRC can-not be directly applied,the paper puts forward a new extended state observer(ESO)and the corresponding ADRC law.In order to assign the poles of the closed loop system to ideal positions such that the vibration can be quickly suppressed,an elastic damping term is added into feedback law.The advantages of the new ESO for fectively estimating both the rigid mode and elastic mode from the measurements are discussed.Moreover,the analysis on the stabiliy.the relative stability and the steady state of the closed-loop system is given.Finally,the efectiveness and robustness of the proposed ADRC are verified by simulations.展开更多
针对低慢小飞行器在综合处置中威胁环境复杂、多学科关键技术交互密切等现状,引入美国国防部体系架构框架(Department of Defense Architecture Framework,DoDAF)对低慢小飞行器综合处置体系进行顶层设计。对其视角视图进行“补充、裁...针对低慢小飞行器在综合处置中威胁环境复杂、多学科关键技术交互密切等现状,引入美国国防部体系架构框架(Department of Defense Architecture Framework,DoDAF)对低慢小飞行器综合处置体系进行顶层设计。对其视角视图进行“补充、裁剪、融合”,定义了各视角的建模顺序及各视角下视图的建模方法,形成一套面向各类复杂体系分析与设计问题完备的构建方法及一套体系架构快速设计方法。并以一种新型多元载荷协同作战的低慢小飞行器综合处置体系进行建模与仿真,验证了该方法能为低慢小飞行器的综合处置作战提供系统全面的描述和可靠的概念模型支撑、该模型可为作战体系架构设计与装备技术发展提供牵引。展开更多
文摘With the method of group test, fourty pairs of carburization-quenching gears made from 16NCD13 steel for aerocraft were tested to research the contacting fatigue strength on tooth flank. As a result, the samples of fatigue life at the moments when the pitting appears and reaches failure criterion were obtained at four stressing levels respectively. The distribution rule of fatigue life were distinguished, and the distribution parameters were estimated by statistical analysis. Based on that, the R-S-N curves with confidence 95% of contacting fatigue on gear tooth flank were evaluated. Therefore, the basic data were provided for the reliability design of the gears and prediction of their life.
基金the Spaceflight Innovation Foundation (20060115)the National Natural Science Foundation(60674105)
文摘Aimed at designing the unpower aerocraft attitude control system in a simple and practical way, the guaranteed cost control is adopted. To eliminate the steady-error, a novel tracking control approach--augmented state feedback tracking guaranteed cost control is proposed. Firstly, the unpower aerocraft is modeled as a linear system with norm bounded parameter uncertain, then the linear matrix inequality based state feedback guaranteed cost control law is combined with the augmented state feedback tracking control from a new point of view. The sufficient condition of the existence of the augmented state feedback tracking guaranteed cost control is derived and converted to the feasible problem of the linear matrix inequality. Finally, the proposed approach is applied to a specified unpower aerocraft. The six dimensions of freedom simulation results show that the proposed approach is effective and feasible.
基金This item is sponsored by science and technologydevelopment project of Beijing education commit-teeNO: KM200510772012
文摘Owing to the effect of crosswind, initial disturbance and the deviation of engine parameters.etc in the initial aviation, vari- able rolling velocity aerocraft will produce attitude angle deviation in the ideal orientations. This paper adopts AVR microcontroller atmega16 and relevant signal process circuit to design the attitude controller and take the method of frequency discrimination and am- plitude discrimination to process attitude angle deviation of aerocraft. Accordingly, it amends attitude angle deviation of aerocraft ef- fect and implements the self- adapting attitude control of aerocraft’s rolling velocity.
基金the Aviation Science Foundation (No. 20110951009) of ChinaNational Nature Science Foundation for Distinguished Young Scholars ( No. 50825502 ) of China for the financial support
文摘This paper intends to provide theoretical basis for matching design of hydraulic load simulator （HLS） with aerocraft actuator in hardware-in-loop test, which is expected to help actuator designers overcome the obstacles in putting forward appropriate requirements of HLS. Traditional research overemphasizes the optimization of parameters and methods for HLS controllers. It lacks deliberation because experimental results and project experiences indicate different ultimate performance of a specific HLS. When the actuator paired with this HLS is replaced, the dynamic response and tracing precision of this HLS also change, and sometimes the whole system goes so far as to lose control. Based on the influence analysis of the preceding phenomena, a theory about matching design of aerocraft actuator with HLS is presented, together with two paired new concepts of ＂Standard Actuator＂ and ＂Standard HLS＂. Further research leads to seven important conclusions of matching design, which suggest that appropriate stiffness and output torque of HLS should be carefully designed and chosen for an actuator. Simulation results strongly support that the proposed principle of matching design can be anticipated to be one of the design criteria for HLS, and successfully used to explain experimental phenomena and project experiences.
基金This work was supported by the National Key R&D Program of China(No.2018YFA0703800)the National Center for Mathematics and Interdisciplinary Sciences,Chinese Acad-emy of Sciences.
文摘The paper presents a novel control design,which is based on the idea of active disturbance rejection control(ADRC),for a kind of flexible aerocraft whose contolled variable cannot be measured directly.Since the original frame of ADRC can-not be directly applied,the paper puts forward a new extended state observer(ESO)and the corresponding ADRC law.In order to assign the poles of the closed loop system to ideal positions such that the vibration can be quickly suppressed,an elastic damping term is added into feedback law.The advantages of the new ESO for fectively estimating both the rigid mode and elastic mode from the measurements are discussed.Moreover,the analysis on the stabiliy.the relative stability and the steady state of the closed-loop system is given.Finally,the efectiveness and robustness of the proposed ADRC are verified by simulations.
文摘针对低慢小飞行器在综合处置中威胁环境复杂、多学科关键技术交互密切等现状,引入美国国防部体系架构框架(Department of Defense Architecture Framework,DoDAF)对低慢小飞行器综合处置体系进行顶层设计。对其视角视图进行“补充、裁剪、融合”,定义了各视角的建模顺序及各视角下视图的建模方法,形成一套面向各类复杂体系分析与设计问题完备的构建方法及一套体系架构快速设计方法。并以一种新型多元载荷协同作战的低慢小飞行器综合处置体系进行建模与仿真,验证了该方法能为低慢小飞行器的综合处置作战提供系统全面的描述和可靠的概念模型支撑、该模型可为作战体系架构设计与装备技术发展提供牵引。
