The visual measurement system in the parachute used on the Tianwen-1 Mars exploration mission

Abstract

ABSTRACT The parachute of the probe plays an important role in the deceleration of the Mars landing mission. This paper provides an overview of the visual measurement system of the parachute in Tianwen-1 exploration mission. Using two monitoring cameras, the system has captured stereo images during the parachute deployment. The morphological and motion parameters of the parachute are reconstructed by image-based feature tracking and 3D reconstruction methods. To improve the image quality, a super-resolution (SR) reconstruction method based on sparse dictionary coding is proposed. In addition, we use a multi-scale feature tracking method to track the feature points and update the motion parameters. The system has been verified by the test on the Earth and successfully applied on the onboard images. The reconstructed parachute parameters are important in the post-flight performance assessment, and the research results can be used as a regression analysis means for the structural design.