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Search Results: 1 - 10 of 323438 matches for " robust control<br>移动卫星天线 "
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Adaptive robust controller of mobile satellite antenna systems
移动卫星天线的自适应鲁棒控制系统

LI Guo,HU Jian-fei,YU Da-tai,
李果
,胡剑飞,余达太

控制理论与应用 , 2007,
Abstract: The use of the adaptive robust controller for improving control performance and stability of mobile satellite antenna systems is investigated in this paper.An adaptive robust control system of mobile satellite antennas is presented. The adaptive robust controller is designed according to the mobile satellite antenna systems model.The proposed adaptive controller and the corresponding robust adaptive law not only keep the closed-loop system robustly stable,but also provide the expected performance.Finally,the effectiveness of the algorithm is verified by experimental results,demonstrating that the control performance and stability of mobile satellite antenna systems are improved,and the control system maintains satisfactory control performance despite the change of road surface condition.
移动卫星天线的自适应鲁棒控制系统
李果,胡剑飞,余达太
控制理论与应用 , 2007, DOI: 10.7641/j.issn.1000-8152.2007.2.027
Abstract: 为了改善移动卫星天线的控制性能和稳定性,本文进行移动卫星天线的自适应鲁棒控制系统的研究.首先针对移动卫星天线数学模型,设计自适应鲁棒控制器和控制系统.所提出的自适应鲁棒控制律和控制系统不仅保证了闭环系统的稳定性,而且实现了所期望的性能.最后通过试验结果证明该控制算法的有效性.尽管外界环境道路条件的变化不同,移动卫星天线控制系统表现了满意的控制性能.
基于不同参考框架的GPS卫星天线校验
陈俊平,胡一帆,张帅,刘姣
- , 2018, DOI: 10.11908/j.issn.0253-374x.2018.10.018
Abstract: 重新估计了基于不同参考框架的GPS卫星天线 PCO(相位中心偏差)和PCV(相位中心变化)参数.计算过程中,通过固定测站天线的PCO和PCV,并将测站坐标强约束至不同的参考框架之下,降低了GPS卫星天线参数和接收机天线参数以及参考框架参数之间的相关性.结果显示,基于不同参考框架的同类型卫星天线PCV差异的平均值为0.726 mm;与IGS发布值差异的平均值为0.844 mm;基于新公布的IGS14参考框架的GPS卫星天线PCO估计结果与IGS (国际GNSS服务)发布值差异的平均值为-14.4 mm,基于IGb08参考框架的卫星天线PCO估计结果与IGS发布值差异的平均值为-16.8 mm.以上结果表明,本措施提高了GPS卫星相位中心PCO/PCV的一致性,从而也能提高GNSS(global navigation satellite system) 技术用于框架传递的连续性.
GPS satellites antenna PCO(phase center offset) and PCV(phase center variation) were re estimated based on station coordinates under different reference frames. The correlations among GPS satellite antenna parameters, receiver antenna parameters and reference frame scales were reduced by fixing receiver antenna PCO/PCV and constraining station coordinate to given reference frame tightly. Results show that the mean difference of block specific satellite antenna PCV based on different reference frames is 0.726 mm. Comparing with the satellite antenna PCV released by IGS based on IGS00, the mean block specific PCV difference between IGS value and the re estimated is 0.844 mm. Comparing to the IGS values, GPS re estimated satellite antenna PCO has an average bias of -14.4 mm and -16.8 mm for the re estimated satellite antenna PCO based on IGS14 and IGS08, respectively. The re estimated PCO/PCV values could improve their iner consistency and contribute to the GNSS based reference frames densification
北斗导航卫星相位中心修正
Antenna Phase Center Correction for BeiDou Navigation Satellite

常志巧, 胡小工, 郭睿, 周善石, 何峰, 董恩强, 李晓杰, 董文丽
CHANG Zhiqiao
, HU Xiaogong, GUO Rui, ZHOU Shanshi, HE Feng, DONG Enqiang, LI Xiaojie, DONG Wenli

- , 2018, DOI: 10.13203/j.whugis20160140
Abstract: 北斗卫星导航系统(BeiDou navigation satellite system,BDS)发播电文时利用卫星钟差a0参数修正了B3频点相位中心与质心差异的大部分偏差,利用卫星群延时间参数(timing group delay,Tgd)修正不同频点相位中心的差异部分。该方法实质是利用各向同性的卫星钟差修正具有各向异性的天线相位中心偏差,改正精度有限。为进一步提高广播星历精度,提出了先对卫星位置进行相位中心改正,再对相位中心的轨迹进行广播星历拟合的处理方法,分别比较了两种改正方法对用户距离误差(user range error,URE)以及精密单点定位精度的影响。分析表明,两种方法都能使URE和定位精度得到提高,且新方法比利用卫星钟差a0参数的修正精度提高了约76%,定位精度提高了约12.5%,同时新方法的改正精度不受时空因素影响。利用广播星历拟合修正天线相位中心与不进行天线相位中心比较,定位精度提高约38.1%。最后分析了Tgd参数修正各频点天线相位中心不一致的残差,影响在毫米级,可以用于修正相位中心的频间差异
附有运动轨迹约束条件的整周模糊度快速分解算法
袁伟,熊永良,黄丁发
武汉大学学报(信息科学版) , 2009,
Abstract: ?分析对比了gps数据处理中使用的天线相位中心的相对改正方式和绝对改正方式,使用绝对改正模式具有更多的优点,而使用不同的天线相位改正模式时,会对gps数据处理结果产生影响。利用bernesegps软件对某城市cors系统网的实例数据进行了计算,结果表明,采用不同的相位中心改正方式对坐标结果在高程方向会造成cm级的影响,网的尺度比会变化6.4ppb,对流层天顶方向总延迟的估计值之间的差别为-6.9±4.0mm。
卫星天线复合材料框架的铺层优化设计
Layup design optimization of composite frame for satellite antenna

陶扬,王春洁,付志方
- , 2017, DOI: 10.13700/j.bh.1001-5965.2016.0392
Abstract: 摘要 为了改善卫星天线复合材料框架的结构动力学性能,提出了一种针对卫星天线框架复合材料铺层的两阶段优化设计方法。阶段Ⅰ以各铺层的角度为设计变量进行铺层顺序优化,框架基频的最大化为优化目标,铺层数的最大值为约束条件。其中设计变量用一种多进制码来表示,并将多进制码映射为连续变量,应用粒子群优化(PSO)算法对阶段Ⅰ优化模型进行求解。在阶段Ⅰ优化结果的基础上,阶段Ⅱ主要是优化复合材料的层数,以基频最大化与质量最小化为优化目标建立多目标拓扑优化模型,应用第2代非劣排序遗传算法(NSGA-Ⅱ)进行求解。为了验证该方法的有效性,对某大型卫星天线复合材料框架进行优化设计,结果表明:该方法能有效地减小天线板复合材料框架的质量,并提高基频。
Abstract:A two-phase optimization method for layup design of composite frame for satellite antenna is introduced to improve the structural dynamics performance of the composite frame. Phase Ⅰ focused on generating a new ply layout by optimizing the ply orientation angle and stacking sequences, while the number of plies is the upper bound of the constraints. The objective of the first phase was to maximize the fundamental frequency of the frame. Design variables were n-nary codes which were mapped to continuous variables. The optimization model of phase Ⅰ was solved by the particle swarm optimization (PSO) algorithm. Phase Ⅱ aimed to reduce the number of plies for the ply layout optimized in phase Ⅰ. A multi-objective topology optimization model was built to minimize the mass of the frame and maximize the fundamental frequency. The optimization model was solved by the non-dominated sorting genetic algorithm Ⅱ (NSGA-Ⅱ). To verify the feasibility of optimization method, the example of a frame of large satellite antenna was conducted. The result shows that the two-phase optimization can effectively reduce the mass of the frame of large satellite antenna and also improve the fundamental frequency.
不同太阳、月亮坐标算法对GNSS部分系统误差的影响研究
蒋振伟,袁运斌,欧吉坤,杨力
大地测量与地球动力学 , 2015, DOI: 10.14075/j.jgg.2015.02.005
Abstract: ?研究天文年历、JPL星历计算的太阳、月亮坐标的差异及对GNSS导航定位的影响。结果表明,不同星历计算的太阳坐标差异最大为5×108m,月亮坐标差异最大为3×106m。天文年历与DE421计算的星固系X方向之间的夹角最大达30′(Y方向与X方向类似)。太阳坐标差异引起的相位绕转改正之间的差异最大达0.3mm,卫星天线相位中心偏差改正之间的差异最大达3mm。太阳、月亮坐标差异导致固体潮改正之间的差异最大达3mm。经实测GPS数据验证,不同星历计算的太阳、月亮坐标差异对PPP的影响可以忽略,建议在PPP中采用计算效率高的天文年历。
串联冗余自由度机构关节角位置的规划算法
吴鹏,洪娟,陈广,徐博
哈尔滨工程大学学报 , 2017, DOI: 10.11990/jheu.201607014
Abstract: 为了建立一种实时求解串联冗余自由度机构关节角位置的方法,解决串联冗余自由度机构逆运动学求解中角位置的求解问题,给出了逆运动学的数值解。根据加权伪逆理论,采用瞬时最优速度表达关节空间角增量的方法,研究了关节空间角位置数值解法,给出了冗余自由度机构连续跟踪期望空间姿态时的关节空间角位置计算方法。在典型运动输入条件下,分别恒定速比关节位置算法和加权逆速度积分方法获得的关节位置和姿态误差进行仿真。为验证算法有效性,以卫星天线姿态稳定系统为研究对象,仿真结果表明,恒定速比关节位置算法在运动学逆解过程中能够保证天线姿态误差Frobenius(弗罗贝尼乌斯)范数小于10-4。仿真结果表明:本文提出的方法能够连续给出冗余自由度机构运动过程中的关节空间角位置的希望值,实现了逆运动学角位置层面的数值解和理想的控制精度。
Robust Leader-follower Formation Control of Mobile Robots Based on a Second Order Kinematics Model
基于二阶运动学模型的移动机器人主从跟踪系统的鲁棒控制

LIU Shi-Cai,TAN Da-Long,LIU Guang-Jun,
刘士才
,谈大龙,刘光军

自动化学报 , 2007,
Abstract: In this paper, we study the problem of modeling and controlling leader-follower formation of mobile robots. First, a novel kinematics model for leader-follower robot formation is formulated based on the relative motion states between the robots and the local motion of the follower robot. Using this model, the relative centripetal and Coriolis accelerations between robots are computed directly by measuring the relative and local motion sensors, and utilized to linearize the nonlinear system equations. A formation controller, consisting of a feedback linearization part and a sliding mode compensator, is designed to stabilize the overall system including the internal dynamics. The control gains are determined by solving a robustness inequality and assumed to satisfy a cooperative protocol that guarantees the stability of the zero dynamics of the formation system. The proposed controller generates the commanded acceleration for the follower robot and makes the formation control system robust to the effect of unmeasured acceleration of the leader robot. Furthermore, a robust adaptive controller is developed to deal with parametric uncertainty in the system. Simulation and experimental results have demonstrated the effectiveness of the proposed control method.
基于改进线性二次型调节器的近地轨道编队卫星鲁棒控制
杏建军, 于洋, 王祎, 郑黎明, 陈子昂
XING Jianjun
, YU Yang, WANG Yi, ZHENG Liming, CHEN Ziang

- , 2016, DOI: 10.11887/j.cn.201603017
Abstract: 为解决编队卫星在近地空间复杂力学环境特别是地球非球形摄动作用下构型易发散的问题,给出一种基于改进线性二次型调节器的编队卫星构型控制方法。该方法先估计近地空间编队卫星构型设计时由未建模摄动力引起的误差最大有界范围,再利用误差最大有界范围的二范数改进经典的线性二次型调节器控制方法,提高经典线性二次型调节器控制器在控制编队卫星构型时的鲁棒性。为评价改进方法的有效性,给出了一种鲁棒性强弱的量化评判标准。仿真结果表明,改进的方法可以大大提高经典线性二次型调节器方法的鲁棒性,增强编队卫星控制方法对各种不确定项的抵御能力。
In order to solve the configuration divergence problems of formation satellites under the complex mechanics environment in near-earth space, especially under the non-spherical perturbation influence, a formation satellites configuration control method based on improved LQR (linear quadratic regulator) was presented. The method estimated the maximum bounded range of error caused by an un-modeled perturbative force in near-earth space formation satellites configuration design, then used the 2-norm of maximum bounded range to improve the classical LQR method and improved the robustness of classical LQR controller in controlling formation satellites configuration. In order to evaluate the effectiveness of improved method, a quantitative criterion for judging the robustness was given. The simulation results show that the improved method can greatly improve the robustness of classical LQR method and improve the resistance ability of formation satellites control methods for all kinds of uncertainty.
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