VISUAL IMU BASED RELATIVE ATTITUDE MEASURING SYSTEM

A system comprises a chassis of a vehicle, a movable member movably coupled to the chassis, a feature board attached to the vehicle, and a visual IMU mounted on the vehicle. The visual IMU includes a camera having a field of view that includes the feature board. An auxiliary IMU is also mounted on the vehicle. A processor onboard the vehicle is in communication with the visual IMU and auxiliary IMU. The processor hosts a program module including a visual-inertial algorithm that performs a process comprising: receive visual information from the camera, the visual information including features detected in images of the feature board captured by the camera; receive inertial measurements from visual IMU and the auxiliary IMU, the inertial measurements including acceleration data and angular rate data; and estimate orientation of the movable member with respect to the chassis by integrating the visual information with the inertial measurements.