共查询到19条相似文献,搜索用时 109 毫秒
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C8051F020的微型旋翼飞行器实验平台的控制系统 总被引:1,自引:0,他引:1
提出了一种与传统桨距角递推算法不同的基于高速摄影和图像处理的桨距角测定方法。根据实验要求,开发了一个以微型旋翼飞行器的非对称变距装置为测试主体的实验平台,并设计了一套基于C8051F020的微型旋翼飞行器实验平台的控制系统。该控制系统以C8051F020单片机为微控制器,用微型位置传感器来检测螺旋桨主轴的相位信息,并利用C8051F020单片机内部的PCA捕捉功能采集位置传感器的输出信号,得到螺旋桨主轴的四个相位;利用单片机输出的PWM方波信号控制电机的转速,以达到对螺旋桨电机进行加速的目的;利用单片机内部产生的PCA捕捉中断来触发高速摄像机的拍摄,以实现飞机加速与拍摄的同步。该控制系统结构紧凑,系统可靠性高。最后通过该控制系统来控制微型飞行器仿真飞机前飞的状态,得到该状态下桨叶的变距曲线,证明所提出的桨距角测定方法和由此开发的实验平台在测量桨距角中是有效的,达到了预期目标。 相似文献
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四旋翼微型飞行器的区间二型模糊神经网络自适应控制 总被引:2,自引:1,他引:1
针对四旋翼微型飞行器控制系统中存在不确定性、外界干扰等影响控制精度的问题,提出了基于区间二型模糊神经网络(IT_IIFNN)的四旋翼微型飞行器自适应控制方案.首先,根据四旋翼微型飞行器的动力学模型,设计了基于IT_IIFNN的四旋翼微型飞行器自适应控制器,该控制器由两部分构成,其中IT_IIFNN用来在线逼近系统不确定性;鲁棒补偿器用来实时补偿IT_IIFNN的逼近误差以及外界干扰.其次,利用Lyapunov稳定理论证明此飞行器控制系统闭环稳定性.最后,通过四旋翼微型飞行器样机来验证IT_IIFNN自适应控制器的优越性.验证结果显示,在加入风速为1.5 m/s的外界干扰条件下,跟踪误差可近似达到10-2.结果表明,IT_IIFNN自适应控制器具有良好的跟踪精度、稳定性及鲁棒性. 相似文献
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四旋翼飞行器旋翼产生的升力是在基值的基础上附加一系列频率特性和旋翼转速有关的高频分量。由于它会对飞行器的控制产生扰动,本文研究了这类高频升力分量对飞行器的影响并给出了抑制扰动的方法。首先,基于拉格朗日能量法建立四旋翼飞行器动力学模型;进而分析了高频升力分量与飞行器角速度扰动之间的关系。然后,将角速度反馈环节加入针对有色噪声的卡尔曼滤波器来抑制角速度扰动对控制器的影响。实验结果显示:与改进前相比,采用本文的方法对四旋翼原型机进行悬停控制可使控制量波动减少50%,高频控制量衰减至-17db以下。结果表明:采用本文的方法,可以有效地抑制升力波动对四旋翼飞行器的影响,提高飞行控制效率。 相似文献
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根据国内外旋翼飞行器的发展趋势,提出了三旋翼飞行器的研究方案.首先,介绍了三旋翼无人飞行器的机械结构,分析了它的整体物理力矩,理论解决了力矩相互抵消的问题.其次,对飞行器的起飞、俯仰、滚转、偏航等姿态进行了数学分析,建立了三旋翼无人飞行器的数学模型.最后,利用PID控制法和线性二次高斯(LQG)控制方法设计了三旋翼飞行器的控制器.实验结果表明,PID控制器振荡时间比较长,次数较多,没有达到理想状态;利用LQG方法对控制器进行了改进,对各个通道阶跃函数及脉冲响应函数仿真图的分析显示,系统改进后响应速度有了提高,2 s左右受控达到平衡.本文的研究为无人机的姿态控制提供了理论基础. 相似文献
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湍流发生器是离心式中浓纸浆泵的关键部件,其作用是使纸浆实现流体化并进行气液分离。本文提出一种采用等螺距和变螺距相结合的叶片型线的湍流发生器,推导了其型线方程。为了验证新设计叶片型线湍流发生器的性能,设计了4种不同叶片型线的湍流发生器。基于CFX软件,采用Eeulerian气液两相流模型和RNG k-ε湍流模型,模拟了不同叶片型线的湍流发生器中浓纸浆悬浮液的三维流场,预测了水力性能和气液分离效果,分析了不同叶片型线对湍流发生器性能的影响。结果表明,采用等螺距和变螺距相结合的叶片型线的湍流发生器具有较好的水力性能和气液分离效果。该模型在生产实际中得到了应用。 相似文献
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主要对定桨距风力发电系统进行研究,介绍了定桨距风力机发电系统的组成及其运行启动等。得出了采用小电机使桨叶具有较高的气动效率,提高了发电机的运行效率。 相似文献
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V. S. Vishnevskii 《Journal of Machinery Manufacture and Reliability》2010,39(6):516-522
The mechanism of excitation of rotary parametric oscillations during nonuniform fluid flow in a partially filled wing with
a pivotal bearing and elastic connections is examined. It is experimentally revealed that at a certain flow velocity, intensive
wing oscillations are excited with an eigenfrequency approximately twice as high as rotary oscillations alone. When the air
cushion is removed and the wing is filled completely by the liquid, these oscillations stop. It is shown that significant
modulation of the mass moment of inertia with a period equal to the half-period of self-oscillations appear due to significant
displacements of the air cushion and liquid displacement towards the peripheral segments of an incompletely filled wing during
rotary oscillations. Therefore, the parametric intensification of rotary oscillations of a wing in nonuniform liquid flow
at a frequency approximately twice as high as the eigenfrequency can take place. The intensive rotary oscillations of an incompletely
filled wing, which are excited by a nonuniform liquid flow, can be efficiently used for driving the different mechanisms in
machine manufacturing, power engineering and the shipbuilding industry 相似文献
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This paper presents surface-profiling based gear pitch deviation measurement for an involute spur gear. A rotary profiling system, which consists of an air-bearing spindle and a displacement sensor with a diamond stylus, is employed to measure gear pitch deviation. In measurement of gear pitch deviation, an eccentric error between a gear axis and a motion axis of the rotary stage in the profiling system would affect accuracy of gear profile measurement. In this paper, at first, the influence of the eccentric error on measurement of gear pitch deviation is estimated in computer simulation based on a geometric model of the profiling system. After that, a new scanning method named “opposite-direction dual scanning method” is proposed so that a steep profile of gear flank surface with a local slope of up to 90° can be measured by the developed rotary profiling system. For compensating distortions in the measured gear tooth profile, which are induced not only by the eccentric error but also by a probe offset introduced by the proposed scanning method, a self-calibration and compensation method is applied. To verify the feasibility of the proposed method, measurement of gear pitch deviation of a master involute spur gear with a certificate data is carried out. Measurement uncertainty of the proposed method is also analyzed. 相似文献
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Yoonsu Nam Jeong-gi Kim Carlo L. Bottasso 《Journal of Mechanical Science and Technology》2011,25(6):1613-1619
The rotational speed of a wind turbine is limited by the noise constraint of the blade tip speed. The larger the rotor diameter
is, the smaller the rotor speed becomes. Therefore, there exists a transition region connecting the max-Cp operation with
the power regulation operation. A conventional pitch schedule in this region involves using a fixed pitch. However, if the
variable pitch instead of the fixed one is allowed, more electric power can be extracted from the wind. The benefit of using
this strategy is analyzed from the point of how much the electric energy can be gained by applying the variable pitch schedule
in this transition region. 相似文献
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根据复杂回转刀具的几何特征,建立了回转刀具刃型通用数学模型。设计了复杂回转刀具刃型曲线模型,利用回转刀具刃型通用数学模型推导了复杂刀具刃型曲线方程。基于空间任意点的螺旋运动,建立了多段刃型的连续性模型,并通过了实例验证。 相似文献
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针对离心通风机机翼形叶片复杂的型线造型,分析了叶片的结构形成;利用先进的三维设计软件Pro/ENGINEER对叶片进行实体建模,避免了传统的风机叶片手工设计画图效率低、误差大的缺陷,实现了风机叶片的快速、准确成型,提高设计开发的效率和精度。 相似文献