TraQuad: A Modular Tracked Legged Multimodal Quadrupedal Robot

The authors have developed a novel multimodal robot named TraQuad, which integrates the features of legged and tracked robots. This robot aims to combine agility, maneuverability, traction, and efficiency for traversing various environments. Legged locomotion allows the robot to select optimal contact points on the terrain, while tracked locomotion enables faster movement over relatively simpler uneven terrains with greater efficiency. TraQuad can turn about its central vertical axis and execute sharp turns with a 0.25 m turn radius. It can climb steep slopes of 31<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> at a velocity of 0.9 m/s. Utilizing multimodal locomotion, it can climb rocks and overcome obstacles by either skipping or stepping on them. Climbing rocks 1.75 times the height of the tracks requires a peak torque of 5.14 N<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\cdot$</tex-math></inline-formula>m, whereas stepping on a block of the same height requires a peak torque of 8.15 N<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\cdot$</tex-math></inline-formula>m. Skipping a block 1.5 times the height of tracks requires a peak torque of 11.8 N<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\cdot$</tex-math></inline-formula>m. This demonstrates that climbing obstacles while maintaining contact with them is more economical than stepping on them, proving the viability of tracked-legged locomotion. These advancements highlight the potential of TraQuad as a robust solution for navigating diverse and challenging environments.