The design of a software-defined PC interface for mechatronic applications

All mobile robots of reasonable complexity require a diverse range of sensors to gather data from their surroundings, and actuators for locomotion or other specialised applications. A PCs powerful processor is often used to handle high-level functionality which would otherwise be too complex to run in real time on embedded microcontrollers (fiCs). Because a PC does not have native interfaces to support the wide collection of sensors and actuators available, intermediate bridges are designed to enable communication. A multitude of application-specific bridge interfaces have been created, but the vast majority of these lack the flexibility at a fundamental level to adapt to different applications, or even minor changes to the peripheral hardware. This paper outlines the development of a powerful, software-defined Unified Bridge directly connecting a PC to a diverse range of sensors and actuators. High-level PC-side control and data transfer is realised through object-oriented virtual interfaces implemented in an application programming interface (API). This presents the robotic system designer with an abstraction which is easier to conceptualize and manipulate than various low-level hardware ports. Experimental results are presented giving an indication of the data throughput performance of the system. Work is currently underway to integrate the Unified Bridge onto the “Grandmother” robot; the top tier of Victoria University´s fleet of hierarchical search and rescue platforms.