To improve the soft-landing crash performance of the movable lander (ML), this study presents an investigation of a newly designed gradual energy-absorbing structure subjected to impact loads using an ML for theoretical calculation and numerical simulations. In this work, we present a novel computational approach to optimizing the energy absorption (EA) of the ML. Our framework takes as inputting the geometrical parameter (GP) as well as EA. The finite element model of the HB1, HB2, and HB3 was established and effectively verified using numerical simulation and experimental data. The relationship between the GP of the buffer material and the EA was obtained through static experiment and impact experiment, and the cushioning performance of the lander was optimized according to the ML load mass, contact speed, and EA function. According to the optimization results, we chose an outer diameter of 240 mm, an inner diameter of 50 mm, heights of HB1 = 140 mm, HB2 = 110 mm, and HB3 = 225 as the collocation, and completed the numerical simulation of three different cases. By comparing the results of theoretical calculation and numerical simulation experiments, it can be found that the overload response rates of the main body in 4 type landing, 2-2 type landing, and 1-2-1 type landing are 4.72 G, 2.61 G, and 2.33 G, respectively. It also laid the foundation for the theoretical and methodological research of the ML and manned lander in the future.

Because the current research on the lander mostly has focused on the traditional lander, the Soft Landing and Walking Integration (SLWI) lunar lander has yet not been studied. To solve the problem, first, a novel type of mobile landing mechanism is proposed and its kinematics is deduced. Second, in order to ensure the motion stability of the mechanism, the cubic spline curve is used to scheme the key points of the SLWI, and based on the weighted coefficient method, an optimal time-jerk pedestal trajectory planning model is established. Finally, the adaptive genetic algorithm (AGA) is used to search the global optimal solution of time-jerk trajectory planning model. Simulation shows that the motion performance of the mechanism is continuous and stable, which proves the rationality and effectiveness of the foot trajectory planning method. At the same time, the AGA converges to the optimal solution. Thus, the blindness of the initial optimization can be greatly reduced and the amount of computation can be saved. It also laid a theoretical foundation for the follow-up research of SLWI lunar lander.

In many traditional soft-landing missions, researchers design the lander and the rover as two separate individuals, which has its limitations. At present, research on landers mainly focuses on the performance analysis of those who cannot move, and the motion of legged mobile lander has not yet been studied. In this paper, a novel Mobile Landing Mechanism (MLM) is proposed. Firstly, the monte-Carlo method is used to solve the workspace, and the motion feasibility of the mechanism is verified. Secondly, combining with the constraints of velocity, acceleration and secondary acceleration of each driving joint of the MLM, the trajectory of its joint space is planned by using cubic spline curve. And based on the weighted coefficient method, an optimal time-jerk pedestal trajectory planning model is established. Finally, by comparing the genetic algorithm (GA) with the adaptive genetic algorithm (AGA), an optimization algorithm is proposed to solve the joint trajectory optimization problem of the MLM, which can obtain better trajectory under constraints. Simulation shows that the motion performance of the mechanism is continuous and stable, which proves the rationality and effectiveness of the foot trajectory planning method.

Reusable launch vehicles (RLVs) are a solution for effective and economic transportation in future aerospace exploration. However, RLVs are limited to being used under simple landing conditions (small landing velocity and angle) due to their poor adaptability and the high rocket acceleration of current landing systems. In this paper, an adaptive RLV landing system with semi-active control is proposed. The proposed landing system can adjust the damping forces of primary strut dampers through semi-actively controlled currents in accordance with practical landing conditions. A landing dynamic model of the proposed landing system is built. According to the dynamic model, an light and effective RLV landing system is parametrically designed based on the response surface methodology. Dynamic simulations validate the proposed landing system under landing conditions including the highest rocket acceleration and the greatest damper compressions. The simulation results show that the proposed landing system with semi-active control has better landing performance than current landing systems that use passive liquid or liquid–honeycomb dampers. Additionally, the flexibility and friction of the structure are discussed in the simulations. Compared to rigid models, flexible models decrease rocket acceleration by 51% and 54% at the touch down moments under these two landing conditions, respectively. The friction increases rocket acceleration by less than 1%. However, both flexibility and friction have little influence on the distance between the rocket and ground, or the compression strokes of the dampers.

For the needs of manned landing, station construction, and material transfer in future lunar exploration missions, the paper proposes a landing–moving integrated gear (LMIG) for mobile lunar lander (MLL), establishes and optimizes the models of cushioning energy-absorbing and movement planning, respectively, and conducts the prototype tests. First, the design requirements of LMIG are given, and the system composition of LMIG and the configuration design of each subsystem are introduced. Second, the effective energy-absorbing model of the aluminum honeycomb is established and experimentally verified, a three-stage aluminum honeycomb buffer is designed and experimentally verified, and the buffer mechanism of LMIG is verified by simulations under various landing conditions. Furthermore, the kinematic and dynamic models of LMIG are established, the moving gait is designed by the center of gravity trajectory planning method, and the driving trajectory during the stepping process is optimized with the goal of minimal jerk of motion. Finally, a cushioning test prototype and a walking test scaled prototype of LMIG are developed, and single leg drop test and ground walking test are carried out. The results show that the established model of LMIG is reasonable, the designed buffer and gait of LMIG are effective, the developed prototypes of LMIG have good cushioning and movement performance, the LMIG’s maximum value of overload acceleration is 6.5 g , and the moving speed is 108 m/h, which meets the design requirements.