共查询到17条相似文献,搜索用时 109 毫秒
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超大型天线馈源舱柔索支撑结构动力学分析与跟踪控制 总被引:1,自引:0,他引:1
根据悬链线解析表达式推导出柔索两端固定时索端拉力与索长之间的关系,用于求解特定长度的驱动柔索对处于某一位姿的馈源舱作用力,在此基础上应用Newton-Euler法建立了超大型射电望远镜馈源舱柔索支撑系统的简化动力学模型.采用具有二次收敛性的Newton-Raphson迭代法进行求解,得到较快的求解速度以满足实时控制要求.针对该系统的非线性、慢时变、多变量耦合等特点,提出了一种自适应双模糊控制器来实现馈源舱轨迹跟踪.该控制器采用模糊推理完成两组控制器的平稳过渡.最后,通过仿真计算结果验证了该控制策略的有效性. 相似文献
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针对移动机器人在定位过程中,由传感器测量误差和机器人模型引起的位姿误差导致系统定位精度急剧下降的问题,提出了一种多新息卡尔曼滤波算法.在标准卡尔曼滤波的基础上,当传感器测量值存在误差时,引入抗差权因子,通过改变误差测量值的权值提高滤波器的估计精度;当机器人位姿存在误差时,引入自适应因子,通过调整状态协方差矩阵的大小抵制位姿误差引起的滤波发散.同时,引入了多新息,即多个时刻的新息向量,进一步提高此非线性系统的精度.实验表明:当存在测量误差和位姿误差时,该滤波算法能有效提高定位精度. 相似文献
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《计算机辅助设计与图形学学报》2017,(5)
针对维修诱导系统中采用基于3D模型的注册算法跟踪复杂机械设备时要求手动初始化位姿、容易产生误差偏移以及不能自动更新3D模型等诸多问题,提出一种基于边缘特征的3D模型混合跟踪注册算法.首先选取边缘像素数量作为测度标准,采用粒子滤波算法对摄像机位姿进行初始化;然后在持续位姿估计中利用非线性最小平方误差估计算法对位姿进行持续更新,并且通过对模型控制点数量的实时监控消除误差偏移;最后利用关键点匹配实现进程的识别和3D模型实时更新.在原型系统进行实验的结果表明,该算法具有较强的稳定性和较高的效率,能够有效地克服误差偏移. 相似文献
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P3P位姿测量方法的误差分析 总被引:1,自引:0,他引:1
从工程应用的角度出发,在三个控制点构成等腰三角形的条件下,研究P3P位姿测量方法的误差与输入参数误差的关系。首先在理论上推导出测量位姿误差与输入参数误差间的关系,在此基础上通过误差统计分析和直接仿真验证的方式得到在输入误差中,图像坐标的检测误差和像机内参数标定误差对测量位姿误差的影响较大,而目标模型的测量误差对测量位姿误差的影响可以忽略不计的结论。这对位姿测量系统的设计与实现具有一定的指导意义。 相似文献
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为了提升复杂环境中双目视觉里程计的精度,提出一种考虑多位姿估计约束的双目视觉里程计方法.首先,分别建立匹配深度已知点与深度未知点的数学模型,将深度未知点引入2D-2D位姿估计模型,从而充分利用图像信息;然后,基于关键帧地图点改进3D-2D位姿估计模型,并结合当前帧地图点更新关键帧地图点,从而增加匹配点对数,提高位姿估计精度;最后,根据改进的2D-2D及3D-2D位姿估计模型,建立多位姿估计约束位姿估计模型,结合局部光束平差法对位姿估计进行局部优化,达到定位精度高且累积误差小的效果.数据集实验和实际场景在线实验表明,所提出方法满足实时定位要求,且有效地提高了自主定位精度. 相似文献
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针对移动机器人视觉伺服跟踪控制问题,提出一种基于自适应动态规划(Adaptive dynamic programming,ADP)的控制方法.通过移动机器人上的相机拍摄共面特征点的当前图像、期望图像以及参考图像,利用单应性技术得到移动机器人当前的位姿信息与期望的位姿信息(即平移量与旋转角度),从而通过当前与期望的平移旋转之间差值得到系统的开环误差模型.进而,针对此系统设计最优控制器,同时做合适的控制输入变换.在此基础上设计一个基于ADP的视觉伺服控制方法以保证移动机器人完成轨迹跟踪任务.为求出最优控制输入,采用一个评价神经网络近似值函数,通过不断学习逼近哈密顿-雅可比-贝尔曼(Hamilton-Jacobi-Bellman, HJB)方程的解.与以往不同的是,由于系统存在时变项,导致HJB方程也含有时变项,因此需要设计具有时变权值结构的神经网络近似值函数.最终证明在所设计的控制方法作用下,闭环系统是一致最终有界的. 相似文献
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Accuracy synthesis of a multi-level hybrid positioning mechanism for the feed support system in FAST
This study examines the terminal accuracy synthesis of a multi-level hybrid positioning mechanism for the feed support system in a Five-hundred-meter Aperture Spherical Radio Telescope (FAST) project, specifically considering three types of error influence factors such as time-varying barycenter, geometric error, and structural deformation. An error model caused by a time-varying barycenter and that for the entire mechanism are first established, and the physical meaning of the latter is further explained. The three factors that influence terminal accuracy are then analyzed. An efficient approach for acquiring the terminal error boundary over the entire workspace is proposed on the basis of the vector set theory and a linear algebra method. After employing an error compensation method for the first-level mechanism through control strategy, terminal accuracy synthesis is conducted by using a nonlinear optimization algorithm. Both constraints for accuracy and weight are satisfied after introducing measurement systems. Moreover, the proposed method of accuracy analysis and synthesis can be applied to other multi-level hybrid mechanisms. 相似文献
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《国际计算机数学杂志》2012,89(3-4):175-181
This paper studies different heuristics for drawing 2-level hierarchical graphs. Especially, we compare the barycenter and the median heuristics. We show that the barycenter heuristic clearly outperforms the median heuristic, although only the latter has a proved bound for the maximum error done when two vertices are ordered. Moreover, we improve a known heuristic, called the greedy switching, by introducing the barycenter heuristic as a preprocessing phase for it. 相似文献
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宋容 《计算机测量与控制》2022,30(8):96-102
为提高爬壁机器人运动位姿精准度与稳定性,解决现有位姿定位控制系统存在的控制效果不佳的问题,利用大数据聚类分析技术,通过软、硬件结构的设计,实现爬壁机器人位姿定位控制系统的优化。改装爬壁机器人位姿传感器、爬壁机器人驱动元件、爬壁机器人位姿定位控制器的内部连接结构及工作方式,扩大系统存储器的存储空间,通过系统电路的连接完成硬件系统的设计。根据爬壁机器人的组成结构和工作机理,建立机械结构与运动模型。在构建模型下,采集爬壁机器人实时运行数据,利用大数据聚类分析技术处理初始采集数据,判定爬壁机器人的当前位姿。规划爬壁机器人位姿及关节轨迹,结合当前爬壁机器人的运行数据,计算爬壁机器人位姿定位控制量,在控制器的约束下,实现爬壁机器人位姿定位控制功能。通过系统测试实验得出结论:通过设计位姿定位控制系统的应用,爬壁机器人样机的足端轨迹控制误差、关节角度控制误差和占空比控制误差均低于预设值,即设计系统具有良好的位姿定位控制效果。 相似文献
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Addressing the need for robust pinpoint landing capabilities, this paper proposes a monocular navigation scheme based on the Rao-Blackwellized particle filter simultaneous localization and mapping (SLAM) approach. The proposed online navigation scheme provides attitude and position (or pose) estimation during the approach, descent, and landing phase for small celestial body missions. This approach relies on one navigation camera and potentially sparse readings from one or more range sensors (e.g. LIDAR (Light Detection And Ranging)). The concept of the proposed navigation scheme is to maintain several hypotheses of the most likely spacecraft pose and landmarks position and to feed the most likely one to the spacecraft controller at any given time. The proposed system uses a double staged Monte-Carlo simulation that represents the population of all possible spacecraft motions between two camera images taken at successive time steps, and that samples this population over all possible scaling factors, converting each relative motion to world-scaled coordinates in the process. The purpose of this Monte-Carlo based visual pose estimation approach is to offer an alternative solution to the drift error and inaccuracy problems of SLAM kinematic models, odometry motion models, and other conventional dead reckoning techniques. 相似文献
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Existing compliance control methods take the force/moment precision as the only metric but do not explicitly guarantee the pose precision between assembly objects. In this paper, we first find significant time-variant and coupling characteristics in the process of modelling peg-in-hole assembly. Then, piecewise strategy and decoupling control (PSDC) method is proposed to explicitly improve the pose precision between the peg and hole. During designing PSDC controller, given the time-variant characteristic of assembly, piecewise strategy is utilized to improve the rapidity and stability of control, which is the basis of the pose precision. Given the coupling characteristic of assembly, an identification method of modelling error on the equation of output is proposed and the corresponding decoupling module is designed to avoid the system error on the pose between the peg and hole. Finally, the simulation and experiment results demonstrate that PSDC method achieves higher pose precision assembly in a force-guided compliance control framework. 相似文献
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本文用微分算子矩阵法以地操作机的位姿和误差进行了分析,得到了确定机构手位姿、速度、加速度和误差的正解和逆解的矩阵表达式,并以实例验证了公式的正确性,该法的特点是:公式的规律性强,便于计算机自动推导的数值计算。 相似文献