Design and Optimization of an Active Leveling System Actuator for Lunar Lander Application

Abstract

This work proposes a systematic methodology for designing an active leveling system (ALS) actuator for lunar landing application. The ALS actuator is integrated into an inverted tripod leg layout, exploiting a honeycomb crushable damper as a shock absorber. The proposed ALS actuator is fitted within the leg’s primary strut and features a custom permanent-magnet synchronous machine rigidly coupled with a lead screw. The actuator aims to both provide proper leg deployment functioning and compensate for the different shock absorber deformations during landing. The leg dynamic behavior is simulated through a parameterized multi-body model to investigate different landing scenarios. First, a parametric sensitivity approach is used to optimize the transmission system and the electric machine characteristics. Then, the electric motor model is numerically validated and optimized through electromagnetic finite element analysis. To validate the proposed ALS design methodology, a virtual test bench is used to assess the ALS performances under different load scenarios. It is found that the proposed methodology is able to yield a compact, well-sized actuator which is numerically validated with the EL3 platform as a case study.