3D Locomotion and Autonomous Navigation in OSCAR: Advancing Origami-Enabled Mobile Robots for Complex Terrain Traversal

Abstract

Soft mobile robots offer distinct advantages for navigating complex terrains because of their inherent flexibility, which enables exceptional adaptability and versatility. However, their compliant bodies introduce significant challenges, such as motion uncertainties and unpredictable interactions with their environment, that are difficult to control. Furthermore, the complex dynamics of soft mobile robots complicate the realisation of full autonomy, a challenge that is further exacerbated by the limited sensing and proprioception capabilities employed in the field.

This thesis aims to advance the field of autonomous origami-enabled mobile robots, a subclass of soft mobile robots, by enhancing their capability to traverse complex terrains and improving their viability for real-world applications. Previous work from the Bio-inspired Adaptive Morphology Laboratory (BAM Lab) developed an Origami-Enabled Soft Crawling Autonomous Robot (OSCAR) in pursuit of this goal. OSCAR is a novel soft mobile robot that leverages origami-inspired mechanisms to mimic the crawling motion of caterpillars. Hence, building upon that foundation, this work enhances OSCAR’s capabilities by enabling traversal of complex three-dimensional spaces without relying on external sensors, paving the way for implementation of truly autonomous navigation.

OSCAR’s mechanical stability is first enhanced with a double-celled design, and vertical actuation is introduced by employing four origami towers per cell. These upgrades improve stability, maneuverability, and locomotion range, enabling complex three-dimensional terrain traversal in the updated version called the Slinky Origami-Enabled Soft Crawling Autonomous Robot (SOSCAR). Afterwards, control systems are developed to realise the new mechanical design and demonstrate vertical obstacle avoidance. Finally, internal sensing mechanisms, using Time-of-Flight distance sensors and Inertial Measurement Units, are integrated to provide proprioception, or self-awareness, that enable closed-loop positional feedback control. Whereas previous versions of OSCAR relied on external sensors for control, all sensing in SOSCAR is fully integrated onboard the robot.

Ultimately, this thesis presents a soft mobile robot that integrates the necessary elements for future implementation of autonomous navigation in complex three-dimensional terrains. As a result, it advances the real-world readiness of origami-enabled robots and highlights their potential for operating in challenging environments.