Development of a Lizard-Inspired Robot for Mars Surface Exploration

Abstract

Exploring Mars is beneficial to increasing our knowledge, understanding the possibility of ancient microbial life there, and discovering new resources beyond the Earth to prepare for future human missions to Mars. To assist ambitious uncrewed missions to Mars, specific types of planetary rovers have been developed for performing tasks on Mars’ surface. Due to the fact that the surface is composed of granular soils and rocks of various sizes, contemporary rovers can have difficulties in moving on soft soils and climbing over rocks. To overcome such difficulties, this research develops a quadruped creeping robot inspired by the locomotion characteristics of the desert lizard. This biomimetic robot features a flexible spine, which allows swinging movements during locomotion. The leg structure utilizes a four-linkage mechanism, which ensures a steady lifting motion. The foot consists of an active ankle and a round pad with four flexible toes that are effective in grasping soils and rocks. To determine robot motions, kinematic models relating to foot, leg, and spine are established. Moreover, the coordinated motions between the trunk spine and leg are numerically verified. In addition, the mobility on granular soils and rocky surface are experimentally demonstrated, which can imply that this biomimetic robot is suitable for Mars surface terrains.

Biomimetic lizard robot for adapting to Martian surface terrain

“…The toe structures are redesigned so as to increase grasping force. The stability of spine, legs and the joints for torque transmission have been improved over that of initial prototype [23]. In addition, the robot electronical system is considered.…”

“…Figures 1(a)-(c) presents the biomimetic structures of spine, leg and foot based on a desert lizard [25]. The spine exhibits a symmetrical three-segment structure with four joints for pitch and bending motions, respectively, as the prior models [22,23]. The improvement in the current design is that each segment connects with the adjacent one via staggered placement of servos and a cross-shaped bracket (figure 1(a)).…”

“…For the foot structure in figure 1(c), the new feature is that gear transmissions are employed instead of driven by ropes to gain high grasping torques [23]. The hind of the claw is designed to be a small spur gear of 11 teeth (Gear 1).…”

“…This paper contributes a biomimetic quadruped robot that is capable of traversing granular and rocky terrains of Martian surface analog. Compared to previous robots [22,23], the grasping forces of foot are significantly improved with the gear transmission. The structures for mechanical joints are consolidated and especially the connections for torque transmission are optimized.…”

“…While biomimetic robots can improve transversal abilities over various terrains [20,21], our research team's focus has been chosen to be on biomimetic quadrupedal robots for planetary exploration [22,23]. The key features of our robots include flexible spine that bends in coordination with leg motions [24], and flexible toes capable of freely grasping surfaces.…”