基于无迹变换的无迹四元数估计器姿态更新算法

为了避免无迹四元数估计器(unscented quaternion estimator,USQUE)姿态更新中仍采用线性化传播以及未进行协方差更新的问题,提出了一种基于无迹变换(unscented transformation,UT)的USQUE姿态更新方法,给出了具体的算法步骤,并与4种姿态估计器进行了比较,证明了其有效性。在所提出的方法中,由于UT比线性化方法更精确,故姿态更新比传统方法更精确。此外,在基于UT的姿态更新中也可以更新姿态协方差,而在传统的USQUE中没有考虑这一点。因此,具有姿态协方差更新的USQUE性能优于传统的USQUE。

三轴稳定卫星无陀螺姿态确定算法研究

针对三轴稳定卫星进行了正常飞行模式下无陀螺姿态确定算法研究 ,采用磁强计、地球敏感器和太阳敏感器组合获得姿态数据 ,利用四元数法和高斯 -马尔可夫过程建立了姿态确定估计器算法模型。通过数学仿真证明 ,此姿态确定算法能够对星体姿态进行较精确的估计或校正 ,满足卫星控制精度要求。

卫星姿态测量信息的二阶非线性滤波技术研究

卫星应用任务要求卫星姿态在空间保持高精度定向 ,为此有必要研究精确的递推非线性姿态估计算法。文中针对星光 陀螺这种典型的三轴稳定卫星姿态确定系统模式 ,应用基于二阶泰勒级数近似得到的非线性滤波算法处理姿态测量信息 ,设计了二阶非线性姿态估计器的实现方案。在设计过程中 ,把QUEST法作为矢量观测数据压缩技术有效地结合进姿态估计器中 ,使得在多矢量观测情况下的滤波修正算法得到了简化。相同条件下的仿真测试结果证明 。

Developing rigid constraint for the estimation of pose and structure from a single image

Pose and structure estimation from a single image is a fundamental problem in machine vision and multiple sensor fusion and integration. In this paper we propose using rigid constraints described in different coordinate frames to iteratively estimate structural and camera pose parameters. Using geometric properties of reflected correspondences we put forward a new concept, the reflected pole of a rigid transformation. The reflected pole represents a general analysis of transformations that can be applied to both 2D and 3D transformations. We demonstrate how the concept is applied to calibration by proposing an iterative method to estimate the structural parameters of objects. The method is based on a coarse-to-fine strategy in which initial estimation is obtained through a classical linear algorithm which is then refined by iteration. For a comparative study of performance, we also implemented an extended motion estimation algorithm (from 2D-2D to 3D-2D case) based on epipolar geometry.