This invention relates to a
visual observation construction method based on orthogonal
ray projection in tangent space, belonging to the field of
computer vision and
robot state
estimation technology. The invention proposes an orthogonal
ray projection error model defined within the tangent space of the observation
ray. Specifically, the method involves: transforming two-dimensional observation points in the image into observation rays on a unit sphere, constructing an
orthogonal basis in the tangent space of these rays; projecting the three-dimensional
landmark points to be estimated onto this tangent space basis, and calculating the orthogonal distance between these
landmark points and the observation rays as the residual. This method geometrically eliminates the explicit dependence of residual calculation on scalar depth, making the
error function linear with respect to feature point position parameters. The visual
measurement device includes a
feature extraction module, a tangent space construction module, a residual and derivative calculation module, and a state
estimation module. This invention provides an accurate Jacobian matrix, significantly improving the
numerical stability, convergence speed, and
estimation accuracy of visual SLAM and 3D reconstruction systems in scenarios with distant feature points and weak
parallax.