Unity-link: A software-gateware interface for rapid prototyping of experimental robot controllers on FPGAs

In experimental robotics, we are often faced with differing requirements between projects and as a project evolves, making the initial choice of technology difficult, often requiring a continuous and tedious development of the low-level parts of the robotic system. We propose the use of FPGAs as a flexible solution to these low-level issues; We here address the hitherto unresolved issue of interfacing the FPGA-based controllers to high-level robotics software running on a PC. This paper presents the Unity-Link software-gateware stack, which connects high-level software frameworks to our modular, FPGA-based generic hardware. Unity-Link provides simple, unified abstractions for quickly and easily interconnecting PC-based systems with nodes that provide hard real-time control of distributed robotic systems. Unity-Link uses a component-based modular bus structure based on open standards, and interfaces with a library of gateware components, enabling us to create complex applications quickly and efficiently. Automated code generation is used to provide convenient, application-specific interfaces to high-level robotics middleware such as ROS.