# The Subsea Micro-Drilling Vehicle's Dynamic Analysis during Landing
## 1 Introduction  
Numerous mineral resources, such as oil, flammable ice, polymetallic nodules, cobalt-rich crusts, and polymetallic sulfides, are found on the seafloor [1]. As terrestrial resources become increasingly scarce, the research and development of seabed mineral resource exploration and mining equipment have become a hot topic of discussion in this field [2, 3]. In recent years, Germany, the United States, and Japan have conducted research and development initiatives to enable underwater tracked robots to be used in more challenging underwater terrains [4]. Jacobs University in Germany has developed Wally, a tracked robot sent to the seabed by an operational Remotely Operated Vehicle (ROV). The presence of a base station ROV that this robot uses for recharging increases its underwater operational time [5]. The Benthic Rover robot, developed by the Monterrey Bay Aquarium Research Institute (MBARI) in the United States, has been designed to be independently deployed, with the capacity to be lowered to the seafloor from a support vessel via free diving [6]. The ABISMO ROV robot, developed in Japan, uses a launcher connected to the support ship. Electrical energy is provided to the vehicle through a high-powered photoelectric composite cable connected to the launcher [7]. [PERSON] [8] designed a crawler robot that can adapt to deep-sea terrain, and the crawler is equipped to carry a platform that can extract multi-point sediments. A new kind of underwater robot called the subsea micro-drilling vehicle (SMDV) combines a mobile crawler chassis with a coring tool to handle long-distance driving operations and multi-point seabed coring tasks. When the vehicle reaches its objectivelanding area, a launcher attached to the support ship will lower it to a predetermined height using a secondary armored umbilical line and let it fall, using its gravity for a hard landing. The SMDV is at risk from a hard landing because it could result in operational disruption from sinking or overturning and damage to the track chassis and other vital parts from the powerful force created upon contact with the substrate. Therefore, it is crucial for the practical deployment of the hard landing method to evaluate its impacts. The focus of research into the dynamic effects of tracked machinery is primarily in the domain of military hardware. [PERSON] [9] developed a finite element model of the airdrop equipment-airbag system to explore the connection between the initial velocity, tilt angle, and pitch angle of airdrop tank equipment at landing and the highest pressure of the airbag. [PERSON] [10] investigated the impact conditions of the tracked paratrooper fighting vehicle in airdrop and established the whole vehicle dynamics model and airdrop buffer model using multi-body dynamics and other modeling methods to study the dynamic load response characteristics of the whole tracked vehicle under impact conditions. [PERSON] [11] employed the ADAMS Collision Process Dynamic Model to assess the anti-rollover capability of tank equipment under various attitude angles and impact velocities, synthesizing the effect of attitude angle and impact velocity on the stability of the tank equipment upon landing and contrasting the findings with the results of oblique impact experiments. For marine equipment research, [PERSON] [12] designed an underwater landing robot in marine equipment and ran simulations of its motion, rotation, and straight-line dynamics. [PERSON] [13] created a dynamic model of the benthic biological lander's frame, did static and dynamic analyses, and used experimental data from sea trials to verify the frame's impact resistance. [PERSON] [14] created a footed robot with six legs and constructed coordinate systems for each. He then conducted dynamics simulation experiments on the underwater buffer landing process using a joint simulation of Matlab and ADAMS, which was crucial for the robot's cable-free diving. Most researchers have focused on the kinematic performance of the driving process of deep-sea machinery of the crawler type.