Design and Gait Research on Soft Quadruped Robots with Pneumatic Drive

What is it about?

Unlike the rigid robots we’re used to, soft robots are inherently flexible and more agile in movement—in theory, they have unlimited degrees of freedom in how they move. Thanks to this "softness" and agility, they perform better than rigid robots when navigating complex environments like steep slopes or rough terrain. The quadruped soft robot we designed is based on the deformation principles of honeycomb structures, with its four legs controlled by air pressure to stretch and bend. To accurately describe how the legs move, we created two mathematical models through geometric analysis—one for the leg’s vertical elongation and another for its movement when bending. We then built an experimental platform specifically to test the performance of one leg: things like its elasticity, hysteresis performance under force, how far it can stretch, and how much it can bend. The test results confirmed that our mathematical models are accurate.Finally, using a tool called LabVIEW, we designed two types of gait programs—static and dynamic. With these programs, we can easily control the quadruped soft robot to take steps and achieve walking movement.

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Why is it important?

The paper clarifies the robot's structural design principle (drawing on the deformation characteristics of honeycomb networks) and drive control method (controlling the deformation movement of the legs by adjusting air pressure) — this is the physical foundation for the robot to achieve "flexible movement" and also the key design feature that distinguishes it from flexible robots with other drive methods (such as motor-driven ones). The paper focuses on elaborating how to design "static gait programs" and "dynamic gait programs" using LabVIEW software, and realize the control of the robot's walking movement based on these programs. This link translates the achievements of "design, modeling, and verification" into practical functions, completing the closed loop from "theory and hardware" to a "movable robot".