You can find the full paper on arXiv and the accompanying open-source implementation on GitHub . Other "Rollbot" Projects
Depending on your specific interest, "Rollbot" also refers to: rollbot.zip
Rollbot: a Spherical Robot Driven by a Single Actuator - GitHub You can find the full paper on arXiv
This paper details the design of a minimalist spherical robot that uses only one actuator to achieve controlled rolling motion. rollbot.zip