A multi-locomotion clustered tensegrity mobile robot with fewer actuators

Abstract

Mobile robots with multi locomotion modes have excellent terrain adaptability. However, traditional multi-locomotion mobile robots are usually actuated by a large number of motors, making their structures heavy and bulky. As a result, the controls become complex, the load-to-mass ratio is low, and the energy consumption is high. Inspired by the bio-mechanism of worms, a novel tensegrity-based multi-locomotion mobile robot, named TJUBot, has been designed. It is actuated by only two motors, yet it has the potential to realize three locomotion modes: earthworm-like, inchworm-like, and tumbling locomotion. The design of these three locomotion modes has been implemented based on kinematic and dynamic models, and the driving law of the two motors under each locomotion mode has been established. Notably, the robot’s locomotion has been analyzed under five different terrains. A laboratory prototype of TJUBot has been developed, and experiments demonstrate that the robot can adjust to five types of terrains using the three locomotion modes. For instance, on flat ground, it achieves a maximum velocity of 2.34 BL/min, and it can pass through confined spaces with a minimum height of 1.26 BH. Moreover, the robot can climb slopes with a maximum angle of 7°, overcome obstacles with a maximum height of 0.52 BH, and traverse gaps with a maximum width as 0.35 BL. Herein, BL and BH represent the body length and body height of the robot, respectively. In addition, TJUBot exhibits outstanding performance in terms of its load-to-mass ratio, which is measured at 5.56, and its low energy consumption of 0.69J/m, as observed in experiments. The promising results obtained from these experiments indicate that TJUBot holds significant potential for applications in multi-terrain environments.