SLAM100问
基础问题 What are the different ways to represent rotations in 3D space? Discuss the differences between the SO(3) matrix, Quaternion, Axis-angle, and Euler angle representations. What problems does gimbal lock pose in the expression of 3D rotations? What mathematical constraints are applicable to SO(3) matrices? Describe the structure of the SE(3) matrix. What is the significance of the bottom row ([0,0,0,1]) in the SE(3) matrix? What sensors are suitable for SLAM (Simultaneous Localization and Mapping)? Compare tightly-coupled fusion and loosely-coupled fusion in this context. Why is non-linear optimization used in SLAM? Where do we encounter non-linearity in Visual-SLAM? Where is non-linearity found in LiDAR SLAM? What optimization methods are applicable for non-linear optimization in SLAM? Compare gradient descent, Newton-Raphson, Gauss-Newton, and Levenberg-Marquardt methods. What is the trust-region method? What is loop closure and how is it achieved in SLAM? Define and differentiate the motion model and observation model in SLAM. What is RANSAC? Explain the concept of a robust kernel (or M-estimator). Discuss the Kalman filter and particle filter. Highlight the differences between the Kalman filter (KF) and the Extended Kalman filter (EKF). Contrast filter-based SLAM with graph-based SLAM. Define the information matrix and covariance matrix in the context of SLAM. What is the Schur complement? Compare LU, Cholesky, QR, SVD, and Eigenvalue decomposition. Which methods are commonly used in SLAM and why? Why is least squares optimization favored? Explain how Maximum-a-posteriori (MAP) and Maximum Likelihood Estimation (MLE) are applied in SLAM. What representations are used to describe a map or structure in SLAM? Which map representation would you choose for path planning and why? Distinguish between sparse mapping and dense mapping. Explain the concepts of Lie groups and Lie algebra. What are the Exp/Log maps? How can multiple maps be merged into a single map in SLAM? What is Inverse Depth Parameterization? Describe pose graph optimization in SLAM. Define drift in SLAM. What is scale drift? How can computational costs be reduced in SLAM? What is keyframe-based optimization? Why is a Look-Up Table (LUT) considered an effective strategy? What is relocalization in SLAM? How does relocalization differ from loop closure detection? What does marginalization entail in the context of SLAM? Explain the concept of IMU pre-integration in SLAM. 旋转在三维空间中有哪些表示方法？ ...