Integrated Guidance and Control for Lunar Landing using a Stabilized Seeker
This addresses the challenge of autonomous planetary landing for space missions, representing an incremental improvement with specific operational enhancements.
The paper tackles the problem of precise and safe lunar landing by developing an integrated guidance and control system that uses a stabilized seeker and reinforcement meta learning, achieving robustness to multiple diverts, seeker lag, actuator issues, and center of mass variations.
We develop an integrated guidance and control system that in conjunction with a stabilized seeker and landing site detection software can achieve precise and safe planetary landing. The seeker tracks the designated landing site by adjusting seeker elevation and azimuth angles to center the designated landing site in the sensor field of view. The seeker angles, closing speed, and range to the designated landing site are used to formulate a velocity field that is used by the guidance and control system to achieve a safe landing at the designated landing site. The guidance and control system maps this velocity field, attitude, and rotational velocity directly to a commanded thrust vector for the lander's four engines. The guidance and control system is implemented as a policy optimized using reinforcement meta learning. We demonstrate that the guidance and control system is compatible with multiple diverts during the powered descent phase, and is robust to seeker lag, actuator lag and degradation, and center of mass variation induced by fuel consumption. We outline several concepts of operations, including an approach using a preplaced landing beacon.