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为使四旋翼飞行器具有更好的室内定点悬停效果及定位精度,提出一种基于视觉辅助与四旋翼飞行器惯性传感器数据融合的控制算法。利用机体下视摄像机获得光流航速信息,与惯性传感器姿态信息数据融合实现良好的室内悬停效果。机体前视摄像机通过ORB算法将当前帧与关键帧进行特征点匹配,以提高四旋翼飞行器的室内定位精度。将PARROT公司的ARDrone 2.0四旋翼飞行器作为实验平台, 采用OpenCV软件对图像进行处理,对控制算法进行验证,结果表明：基于光流和惯性传感器姿态数据的融合确保了四旋翼飞行器控制的安全性,提高了飞行器悬停效果和定位精度。 相似文献
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作为微型无人机的一种,四旋翼飞行器以其简单的机械结构和优越的飞行性能成为科学研究领域中空中机器人的热点之一。文章以四旋翼飞行器为主要研究对象,以四元数理论为基础,推导了飞行器姿态解算算法;利用MEMS技术和嵌入式技术,开展基于无线遥控技术的四旋翼飞行器的硬件设计;运用VRML语言建立四旋翼3D模型,利用LabVIEW软件对该模型进行图像处理和显示,并在与飞行器远程通信的基础上,完成了其作为地面站的主要功能。测试结果表明,系统硬件工作稳定,姿态解算准确,控制算法很好地满足了控制要求,飞行器的稳定性和响应特性较为理想。 相似文献
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四旋翼飞行器作为当今一种非常流行的飞行器,涉及多学科交叉技术以及各个领域。随着相关技术的发展,四旋翼飞行器变得更加小型化与智能化,应用领域也更广。通过研究飞行控制原理与姿态解算,对四旋翼飞行器进行了软件设计。硬件选用STM32F103C8T6作为主控制器,并以MPU6050作为惯性测量模块。软件设计中采用互补融合的控制算法估算六自由度飞行姿态,并采用PID算法进行整定和控制。通过这种姿态融合,可控制飞行器平稳起停和飞行,经实验室调试效果良好。 相似文献
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为更好地掌握四旋翼飞行器姿态测量和姿态变化的过程,设计了一种基于LabVIEW的姿态测量实验系统。该系统以自主研发的四旋翼飞行器控制系统为实验平台,通过获取飞行器的姿态数据,进行解算和上传到PC机,在LabVIEW中实现四旋翼飞行器姿态数据的存贮、波形显示和飞行器姿态的三维动态图形模拟显示等功能。系统测试精度较高、响应灵敏、操作简单、实用性强,可为学生提供一个良好的姿态测量实验平台。 相似文献
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设计了一种四旋翼飞行器的实验系统。电机调速器运用检测反电动势的方法控制三相全桥逆变电路从而调节无刷直流电机的转速。以ARM处理器为主控制器对电机调速器进行控制,从而实现飞行器的平衡和姿态控制。通过四旋翼工作模式的研究,利用加速度传感器和陀螺仪数据进行控制算法设计与研究,实现四旋翼飞行器姿态的控制调节。开发了仿真调试软件系统实时监测传感器的数据和控制量。实验表明,通过合适的控制算法可以四旋翼飞行器的平衡性能和各种飞行姿态,从而为学生提供了新的仿真和实践平台,有利于创新型实验教学任务的顺利开展。 相似文献
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《实验室研究与探索》2016,(10)
为了进一步提高微型四旋翼飞行器的稳定性、转向灵活性与可控性,提出并采用多种传感器、WiFi无线通信、嵌入式微控制器等多种技术,并结合四元数、双闭环PID控制等,设计出一款基于WiFi的微型四旋翼飞行器。详细阐述了该系统构成、硬件设计与软件设计。实践表明,飞行器机身采用"X"型设计,软件系统采用四元数、双闭环PID控制等,其飞行稳定性高、可控性好、转向更灵活。 相似文献
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《赤峰学院学报(自然科学版)》2017,(8)
四旋翼飞行器因其自身多方面的优点,得到了广大企业家与研究者的关注.本文将重点研究四旋翼飞行器的悬停控制问题,首先介绍了四旋翼飞行器的系统结构,随后建立得到悬停状态动力学模型,最后以卡尔曼滤波作为基础,真正实施PID控制工作. 相似文献
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四旋翼飞行器体积小、可悬停、机动灵活,已成为国内外的一个研究热点。为了更加有效便捷地对四旋翼飞行器的飞行控制进行实时仿真,设计了四旋翼飞行器半实物仿真平台。该仿真平台包括上位机、仿真计算机和四旋翼飞行控制器3个部分,四旋翼飞行器对象模型运行在实时仿真计算机中,将飞行控制器作为实物接入仿真回路,提高仿真的实时性和置信度。该半实物仿真平台可以分别对四旋翼飞行器的姿态控制、位置控制进行仿真,并可将仿真结果直接应用于实际飞行。 相似文献
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In this paper, a nonlinear dynamic MIMO model of a 6-DOF underactuated quad rotor rotorcraft is derived based on Newton-Euler formalism. The derivation comprises determining equations of motion of the quad rotor in three dimensions and seeking to approximate the actuation forces through modeling of the aerodynamic coefficients and electric motor dynamics. The derived model is dynamically unstable, so a sequential nonlinear control strategy is implemented for the quad rotor. The control strategy includes exact feedback linearization technique, using the geometric methods of nonlinear control. The performance of the nonlinear control algorithm is evaluated using simulation and the results show the effectiveness of the proposed control strategy for the quad rotor rotorcraft near quasi-stationary flight. 相似文献
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基于分形的图像压缩算法研究 总被引：1，自引：0，他引：1
张岩 《西安文理学院学报》2009,12(3)
介绍了分形图像压缩理论,传统DCT变换算法和四叉树分形图像压缩算法,改进的分形图像压缩方法,分形与小波相结合的图像压缩算法,彩色图像压缩算法以及对分形图像压缩未来发展的展望. 相似文献
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针对二值图像的几何相似性,本文提出一种基于等腰直角三角形的压缩算法。该算法以四叉树为数据结构,以达到减小中间结点的开销;同时该算法的时间复杂度和空间复杂度均低于采用JBIG标准来压缩二值图像。其压缩比可提高15%;同时适用于复杂图像。 相似文献
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Carol A. Christensen 《教育心理学》2005,25(5):441-453
There is a strong relationship between orthographic–motor integration related to handwriting and students' ability to produce creative and well‐structured written text. This relationship is thought to be due to the cognitive load which results when attention is required by writers to write letters and words on the page. Lack of automaticity in orthographic–motor integration means that writers do not have sufficient cognitive resources to accomplish the more demanding aspects of text production such as ideation, text monitoring, and pragmatic awareness. A systematic handwriting program can significantly improve the quality of written text by young children experiencing problems with orthographic–motor integration. This study investigated the effectiveness of a handwriting program in remediating older students' problems in orthographic–motor integration and consequently enhancing their written language skills. Two groups of students in Grades 8 and 9 were provided with either practice in handwriting or daily completion of a written journal. There were no differences between the two groups at pre‐test. However, at post‐test, the handwriting group had significantly higher scores in orthographic–motor integration as well as for the length and quality of the text they wrote. 相似文献
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Participants with attention-deficit/hyperactivity disorder (ADHD) are often impaired in visuomotor tasks. However, little is known about the contribution of modal impairment in motor function relative to central processing deficits or whether different processes underlie the impairment in ADHD combined (ADHD-C) versus ADHD inattentive (ADHD-I) subtype. The present study analyzes performance on the Visual Motor Integration Test relative to less effortful motor tests as well as on measures of energetics. Both ADHD groups showed evidence of impaired motor function on both visual-motor integration (VMI) and the less effortful motor tests. The ADHD-C group performed below the ADHD-I group on VMI, but their performance correlated highly with the measures of the energetic pools of arousal and effort. Different mechanisms may underlie impaired fine motor skills in ADHD. Central processing deficits contribute significantly to the deficit of ADHD-C but do not explain the motor impairment in ADHD-I. 相似文献
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Close interrelation of motor development and cognitive development and of the cerebellum and prefrontal cortex 总被引：18，自引：0，他引：18
Diamond A 《Child development》2000,71(1):44-56
Motor development and cognitive development may be fundamentally interrelated. Contrary to popular notions that motor development begins and ends early, whereas cognitive development begins and ends later, both motor and cognitive development display equally protracted developmental timetables. When cognitive development is perturbed, as in a neurodevelopmental disorder, motor development is often adversely affected. While it has long been known that the striatum functions as part of a circuit with dorsolateral prefrontal cortex, it is suggested here that the same is true for the cerebellum and that the cerebellum may be important for cognitive as well as motor functions. Like prefrontal cortex, the cerebellum reaches maturity late. Many cognitive tasks that require prefrontal cortex also require the cerebellum. To make these points, evidence is summarized of the close co-activation of the neocerebellum and dorsolateral prefrontal cortex in functional neuroimaging, of similarities in the cognitive sequelae of damage to dorsolateral prefrontal cortex and the neocerebellum, of motor deficits in "cognitive" developmental disorders, and of abnormalities in the cerebellum and in prefrontal cortex in the same developmental disorders. 相似文献
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对很多人来说,常春藤的名校更具魅力,毕竟那里可是被历史证明造就社会精英的地方,不过,我更喜欢适合自己的,尽管开始的时候有那么一点不适应,那么一点不习惯,但一切都在改变,我很庆幸自己当时的选择。 相似文献
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本讨论稀土永磁同步电动机空载反电动势R的取值是电磁设计的关键所在．它关系列永磁同步电动机运行性能的效率和功率因数的大小，采用变压变频(VVVF)交流调遣系统，可以保持电源的频率f与电源的电压U以及与空载反电动势E0的对应关系，结合稀土永磁同步电动机的设计值和试验实测值。阐明变压变频(VVVF)交流调速系统是稀土永磁同步电动机的最佳调速方法。 相似文献
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滕敏 《连云港职业技术学院学报》2006,19(3):13-15
地形实时绘制和交互式可视化是虚拟现实、地理信息系统、计算机图形学、科学计算可视化等技术的关键问题。本文对地表模型的实时生成和简化方法进行了研究和分析,提出了基于自适应四叉树视相关多分辨率地形生成方法。 相似文献