On July 27, the optical navigation sensor on the Tianwen-1 Mars probe developed by China Aerospace Science and Technology Group took pictures 1.2 million kilometers away from the earth, and at the same time said goodbye to Earth and Moon Home. Tianwen-1 used the optical navigation sensor to image the earth and the moon, and obtained a clear picture of the moon. In this black-and-white photo, the earth and the moon are large and one small, both in the shape of a crescent, and they accompany each other in the vast universe.
The probe is in space, just like a ship sailing on the vast ocean, the difference is that there is no satellite navigation system to guide it after leaving the earth. Different from traditional radio navigation, optical autonomous navigation can acquire navigation information such as position and speed through image target recognition and feature extraction. This is also one of the important technologies that will support our country to move further into the universe in the future.
On the basis of accurate positioning based on ground radio navigation, the research team of the Eighth Academy of China Aerospace Science and Technology Corporation equipped the detector with optical navigation sensors and carried out engineering verification of optical navigation methods related to deep space exploration. This optical navigation sensor is installed on the rover and can image Mars during its approach to Mars, use Mars images to calculate the centroid position and apparent radius of Mars, and use the estimation algorithm to obtain the rover's real-time position relative to Mars. And speed information. The Earth-Moon imaging was completed by the autonomous exposure and shooting of the optical navigation sensor.
"The optical navigation sensor is like the'eyes' of the detector." The optical navigation expert of the Eighth Hospital Control Institute drew an analogy. "With these bright'eyes', the detector also has the ability to see itself. Flying towards the destination."
During the process of the rover approaching Mars, the eighth academy’s development team used the navigation sensor equipped with a telephoto lens as a "clairvoyance", which can identify Mars at a distance of up to 10 million kilometers, and can adapt itself to Mars from the point of view. The target-to-area target, from weak target to strong target Mars image extraction, so as to realize that even without external navigation information, it can autonomously find the way forward in deep space flight. With bright "eyes", "Tianwen No.1" can look at Mars and then step on the "brake". This optical autonomous navigation technology will also lay a solid foundation for my country's subsequent deep space exploration missions.
Yu Jianbin