风力驱动球形机器人动力学

风力驱动球形机器人是一种新型移动机器人,适合于危险或人类难以到达的复杂地形环境的探测,因此在环境探测领域具有独特的优势。首先考虑了碰撞接触点无滑动和有滑动的情况,采用Kane方法建立了风力驱动球形机器人弹跳动力学模型,该模型可以直接分析机器人碰撞后的运动情况。然后给出了机器人滚动和滑动的运动条件,运用牛顿力学方法建立了机器人的滚动和滑动动力学模型。最后将弹跳、滚动和滑动运动模式有机结合,并考虑环境中随机风的作用,实现了风力驱动球形机器人的运动仿真。数值仿真结果揭示了环境变化和机器人结构参数变化对其运动性能的影响。     

多星对合作目标的分布式协同导航滤波算法

针对多颗在轨卫星对空间合作目标的协同导航问题,提出了一种适用于协同导航的分布式球面单形-径向容积求积分卡尔曼滤波（DSSRCQKF）算法。为了计算非线性滤波中的高斯加权积分,分别使用球面单形准则和二阶高斯-拉盖尔求积分准则计算球面积分和径向积分,提出了一种新的球面单形-径向容积求积分准则。将该准则嵌入分布式卡尔曼滤波框架中,结合协同导航的非线性数学模型,给出适用于协同导航的DSSRCQKF算法,该算法要求每颗导航星仅与其邻居星进行通信,通过数据的分布式融合实现对目标星轨道状态的一致估计,从而避免了传统集中式处理中较高的通信和计算压力。仿真实验结果表明,与分布式卡尔曼滤波相比,本文算法将对合作目标的实时定位精度提高了11 m,定速精度提高了0.02 m/s,从而验证了本文算法的有效性。      

超导陀螺转子偏移建模与测试方案

根据球形差动电容传感器测量微位移的原理,针对八电极结构的超导陀螺仪分析了每对测量电极上悬浮转子偏移量与电容变化量间的关系.通过无量纲化和微位移范围内线性化处理及利用最小二乘算法,建立了转子偏移测量模型.给出了基于该模型的超导陀螺转子偏移测试方案及其各参数间的关系.分析了影响陀螺转子偏移测量精度的因素.超导陀螺转子偏移测试方案的特点是为保证悬浮转子的零电位而采用4对测试电极的电极分布法,能同时测量出转子偏移的大小和偏移方向.实验结果表明,差动电容传感器的分布电容、陀螺转子的零电位和模型误差等是影响测量精度的主要因素.提出了降低相应因素不良影响的方法及输出电压与转子偏移量呈线性关系模型的适应范围.     

SHAKING: Adjusted spherical harmonics adding KrigING method for near real-time ionospheric modeling with multi-GNSS observations

Precise positioning based on Global Navigation Satellite System (GNSS) technique requires high accuracy ionospheric total electron content (TEC) correction models to account for the ionospheric path delay errors. We present an adjusted Spherical Harmonics Adding KrigING method (SHAKING) approach for regional ionospheric vertical TEC (VTEC) modeling in real time. In the proposed SHAKING method, the VTEC information over the sparse observation data area is extrapolated by the Adjusted Spherical Harmonic (ASH) function, and the boundary distortion in regional VTEC modeling is corrected by the stochastic VTEC estimated using Kriging interpolation. Using real-time GPS, GLONASS and BDS-2/3 data streams of the Crust Movement Observation Network of China (CMONOC), the SHAKING-based regional ionospheric VTEC maps are re-constructed over China and its boundary regions. Compared to GNSS VTECs derived from the independent stations, the quality of SHAKING solution improves by 13–31% and 6–33% with respect to the ASH-only solution during high and low geomagnetic periods, respectively. Compared to the inverse distance weighting (IDW) generated result, significant quality improved of SHAKING-based VTEC maps is also observed, especially over the edge areas with an improvement of 60–80%. Overall, the proposed SHAKING method exhibits notable advantage over the existing regional VTEC modeling techniques, which can be used for regional TEC modeling and associated high-precision positioning applications.