Nonstop update of mission critical robotic services

Upgrade of software is essential work for mission critical applications while system downtime for maintenance must be minimized. This paper presents the design and implementation of a method to upgrade binary modules for mission critical robotic services without stopping the running services. The base of the proposed method is thread swapping techniques and a programming paradigm of thread replaceability. Case studies present actual service suspension time which is often addressed in dynamic updating for server applications but rare for real physical applications.