Simulations of the Hazard Detection System for Approach Trajectories of the Morpheus Lunar Lander

Abstract

The Hazard Detection System is part of a suite of sensors and algorithms designed to autonomously land a vehicle on unknown terrain while avoiding any hazards. This paper describes the simulations built to predict the performance of the Hazard Detection System to support flight testing onboard the Morpheus Lander testbed at the Kennedy Space Center. The paper describes a hardware-in-the-loop simulation that was used to predict system performance under nominal operating conditions, and also a Monte Carlo simulation to predict command timing performance bounds under a wide range of varying conditions.

Flight Testing ALHAT Precision Landing Technologies Integrated Onboard the Morpheus Rocket Vehicle

“…The total process from triggering the mosaic to reporting the safe sites took 11.3-12.9 sec, which was within the pre-flight prediction window of 11.2-14.1 sec developed from detailed Monte Carlo simulations. 26 All DEMs achieved greater than 99.6% data density, with small holes due to shadows from rocks and craters. The flat, gravel-covered landing pad was reconstructed with a standard deviation of 4-6 cm (1-σ) in elevation.…”

Flight testing a Real-Time Hazard Detection System for Safe Lunar Landing on the Rocket-Powered Morpheus Vehicle

“…11,12 In addition, the team performed a large number of simulations in close cooperation with the Morpheus GN&C team to analyze and predict DEM coverage, safe site selection, number of HRN measurements, and timing performance for the planned Morpheus trajectory and flight dynamics. 13 In what follows we describe the performance of the HDS subsystems in more detail.…”

Constrained Autonomous Precision Landing via Dual Quaternions and Model Predictive Control

“…As such, the heritage flight system should enable a dynamic retargeting to avoid the hazards detected by the sensing systems [4]. Such a critical technology is referred to as the Autonomous Landing and Hazard Avoidance Technology (ALHAT) that is currently under development at the Jet Propulsion Laboratory (JPL) [5,6,7,8]. One of the required technologies in AL-HAT is that during the maneuver, the lander spacecraft should allow the sensors to see the landing site (when these sensors are not articulated) as well as including time and altitude margins for adjusting the trajectory based on the information gathered by the sensors [9].…”

“…The aforementioned constraint forms an analogous formulation in terms of unit dual quaternions. This is due to the fact that a unit dual quaternion can be represented either with the inertial frame component or with the body frame component, and both representations lead to the same quantity, as noted by Eq (7)…”