Hsu Y.-LLin J.-HChan C.-YCHENG-WEI CHEN2023-06-092023-06-092021https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124796682&doi=10.1109%2fCCTA48906.2021.9659048&partnerID=40&md5=d87e2dde0555962a2cab0d2356257f88https://scholars.lib.ntu.edu.tw/handle/123456789/632192When a lunar lander touches down, a large impact force may have undesirable effects such as rebounding and overturning. To ensure a safe landing, active momentum exchange impact dampers (AMEIDs) are introduced in this work to enable soft-landing control. For the purpose of designing and evaluating different control strategies applied to the AMEIDs, a two-dimensional lunar lander model is derived using Lagrangian mechanics. The model is validated via a free-fall landing experiment. Using the lander dynamical model, we design a suboptimal control law by solving the discrete-time state-dependent Riccati equation (D-SDRE). The landing response of D-SDRE based controller is compared to that of open-loop control and PID control, respectively. The simulation results show that the DSDRE method mitigates the landing instability and reduces the side-slip phenomenon. © 2021 IEEE.Damping; Equations of state; Landing; Moon; Riccati equations; Three term control systems; Discrete time; Equation based; Impact force; Landing control; Lunar Lander; Momentum exchange impact damper; Soft landing; State-dependent Riccati equation; Touch downs; Undesirable effects; Control theoryconference paper10.1109/CCTA48906.2021.96590482-s2.0-85124796682