A generic approach to model the kinematics and aerodynamics of flapping wing ornithopter has been followed, to model and analyze a flapping bi- and quad-wing ornithopter and to mimic flapping wing biosystems to produc...A generic approach to model the kinematics and aerodynamics of flapping wing ornithopter has been followed, to model and analyze a flapping bi- and quad-wing ornithopter and to mimic flapping wing biosystems to produce lift and thrust for hovering and forward flight. Considerations are given to the motion of a rigid and thin bi-wing and quad-wing ornithopter in flapping and pitching motion with phase lag. Basic Unsteady Aerodynamic Approach incorporating salient features of viscous effect and leading-edge suction are utilized. Parametric study is carried out to reveal the aerodynamic characteristics of flapping bi- and quad-wing ornithopter flight characteristics and for comparative analysis with various selected simple models in the literature, in an effort to develop a flapping bi- and quad-wing ornithopter models. In spite of their simplicity, results obtained for both models are able to reveal the mechanism of lift and thrust, and compare well with other work.展开更多
扑翼飞行器通过模仿昆虫及鸟类的扑翼运动,在低雷诺数环境下具有优异的气动效率和机动性。而扑旋翼飞行器在扑翼运动的基础上实现了机翼的被动旋转运动,具备更好的悬停及垂直起降能力,是近些年新兴的研究热点。本文系统综述了扑翼微型...扑翼飞行器通过模仿昆虫及鸟类的扑翼运动,在低雷诺数环境下具有优异的气动效率和机动性。而扑旋翼飞行器在扑翼运动的基础上实现了机翼的被动旋转运动,具备更好的悬停及垂直起降能力,是近些年新兴的研究热点。本文系统综述了扑翼微型飞行器(Flapping‑wing micro air vehicles,FWMAVs)及扑旋翼微型飞行器(Flapping‑wing rotor micro air vehicles,FWRMAVs)在系统建模与控制方法方面近几年的研究进展,分析了仿昆虫扑翼飞行机理中的非定常空气动力学理论,并探讨了已有的基于仿昆虫的FWMAVs及FWRMAVs系统建模及控制方法。最后,提出了目前FWMAVs在飞行动力学和控制方法上面临的柔性翼气动力建模和非定常扰动抑制等问题,分析了FWRMAVs缺乏对其飞行动力学特性和主动姿态控制等方面研究的问题,同时本文对该领域未来进一步的研究做出了展望。展开更多
固定翼微型飞行器(Micro air vehicle,MAV)速度低、转动惯量小,飞行过程中在大气扰动下迎角易发生较大变化,俯仰角又会在迎角恢复力矩作用下振荡,纵向静稳定性对MAV的俯仰姿态控制品质有一定的影响。为了提高MAV的俯仰姿态控制品质,本...固定翼微型飞行器(Micro air vehicle,MAV)速度低、转动惯量小,飞行过程中在大气扰动下迎角易发生较大变化,俯仰角又会在迎角恢复力矩作用下振荡,纵向静稳定性对MAV的俯仰姿态控制品质有一定的影响。为了提高MAV的俯仰姿态控制品质,本文首先提出了一种不同纵向静稳定性下MAV俯仰姿态控制品质的评估方法,该方法定义俯仰角振荡过程中的方差与极差来表征俯仰姿态控制品质,之后以控制品质最优为目标分别对不同静稳定性下MAV飞行姿态控制系统的控制参数进行调整。通过研究不同静稳定性下的最优控制品质变化规律,获得MAV纵向静稳定性对俯仰姿态控制品质的影响。结果表明,俯仰姿态控制品质与纵向静稳定性之间呈现一定的非线性规律,纵向静稳定性或静不稳定性的增强都将导致MAV在大气扰动下俯仰姿态的振荡程度增强,取得纵向中立稳定的MAV将有着最优的俯仰姿态控制品质。展开更多
文摘A generic approach to model the kinematics and aerodynamics of flapping wing ornithopter has been followed, to model and analyze a flapping bi- and quad-wing ornithopter and to mimic flapping wing biosystems to produce lift and thrust for hovering and forward flight. Considerations are given to the motion of a rigid and thin bi-wing and quad-wing ornithopter in flapping and pitching motion with phase lag. Basic Unsteady Aerodynamic Approach incorporating salient features of viscous effect and leading-edge suction are utilized. Parametric study is carried out to reveal the aerodynamic characteristics of flapping bi- and quad-wing ornithopter flight characteristics and for comparative analysis with various selected simple models in the literature, in an effort to develop a flapping bi- and quad-wing ornithopter models. In spite of their simplicity, results obtained for both models are able to reveal the mechanism of lift and thrust, and compare well with other work.
文摘扑翼飞行器通过模仿昆虫及鸟类的扑翼运动,在低雷诺数环境下具有优异的气动效率和机动性。而扑旋翼飞行器在扑翼运动的基础上实现了机翼的被动旋转运动,具备更好的悬停及垂直起降能力,是近些年新兴的研究热点。本文系统综述了扑翼微型飞行器(Flapping‑wing micro air vehicles,FWMAVs)及扑旋翼微型飞行器(Flapping‑wing rotor micro air vehicles,FWRMAVs)在系统建模与控制方法方面近几年的研究进展,分析了仿昆虫扑翼飞行机理中的非定常空气动力学理论,并探讨了已有的基于仿昆虫的FWMAVs及FWRMAVs系统建模及控制方法。最后,提出了目前FWMAVs在飞行动力学和控制方法上面临的柔性翼气动力建模和非定常扰动抑制等问题,分析了FWRMAVs缺乏对其飞行动力学特性和主动姿态控制等方面研究的问题,同时本文对该领域未来进一步的研究做出了展望。
文摘固定翼微型飞行器(Micro air vehicle,MAV)速度低、转动惯量小,飞行过程中在大气扰动下迎角易发生较大变化,俯仰角又会在迎角恢复力矩作用下振荡,纵向静稳定性对MAV的俯仰姿态控制品质有一定的影响。为了提高MAV的俯仰姿态控制品质,本文首先提出了一种不同纵向静稳定性下MAV俯仰姿态控制品质的评估方法,该方法定义俯仰角振荡过程中的方差与极差来表征俯仰姿态控制品质,之后以控制品质最优为目标分别对不同静稳定性下MAV飞行姿态控制系统的控制参数进行调整。通过研究不同静稳定性下的最优控制品质变化规律,获得MAV纵向静稳定性对俯仰姿态控制品质的影响。结果表明,俯仰姿态控制品质与纵向静稳定性之间呈现一定的非线性规律,纵向静稳定性或静不稳定性的增强都将导致MAV在大气扰动下俯仰姿态的振荡程度增强,取得纵向中立稳定的MAV将有着最优的俯仰姿态控制品质。
