Invention:
This technology is a technique to improve the accuracy and performance of autonomous planetary landing vehicles. Measurements from a stabilized seeker implementing a sensor capable of range and closing speed measurements is used to construct a velocity field that, when tracked in six degrees of freedom, will bring the lander to a pinpoint soft landing at the designated landing site, at an upright attitude with negligible rotational velocity. This site can either be illuminated by an optical beacon, or can be selected using terrain hazard avoidance software operating on suitable measurements. A possible hardware configuration for a landing site identified by a landing beacon is a Doppler LIDAR rangefinder with boresight axis aligned with a camera’s optical axis. A possible implementation using software to identify a safe landing site would be a flash LIDAR unit, either fixed in the body frame or gimbaled, where appropriate software would use the flash LIDAR image to select a safe landing site. One aspect of the invention is implementing the guidance and control system using deep reinforcement learning. This method supports multiple divert maneuvers during the descent phase, often required when the classification of a landing site as safe or unsafe changes during the descent as the flash LIDAR resolution increases. Another aspect of the invention is the periodic adjustment of the seeker platform attitude during the descent to keep the landing site centered in the seeker field of view.
Background:
Technical developments have progressively enabled the increased use of automated landers for use in scientific and exploratory missions to the moon and other planets. Furthermore, the US is planning a human return to the surface of the moon in the coming years.
One challenge in descent to the surface of a planet is the reliable and resource-efficient landing in a safe area during descent. For example, there may be obstructions or other conditions that require selection of a different landing site. This technology creates an efficient method of targeting a landing site, improving the performance of the guidance system.
Applications:
- Planetary landing
- Asteroid close proximity missions
- Rendezvous missions
Advantages:
- Improved performance
- Can be used with both gimbaled and strapdown seekers
