Abstract:Aiming at the problems that GPS cannot be used and INS status error diverges too fast due to signal loss in GNSS during military war, indoor and underwater, a visual aid navigation method based on continuous frame time difference was proposed. In order to restrain the rapid divergence of state errors and improve the performance of INS in long endurance work, the continuous frame difference method of machine vision was analyzed and improved in calculation. A time-difference vision/inertia combined system was designed and simulated. Results Compared with pure INS, RMSE reduced by 19.0% in the northbound position and 32.1% in the eastbound error, indicating that this method effectively inhibited the error divergence of pure inertial navigation speed and position, and extended the available time of inertial navigation.