Robotic systems compute data from multiple sensors to perform several actions (e.g., path planning, object detection). FPGA - based architectures for such systems may consist of several accelerators to process compute-intensive algorithms. Designing and implementing such complex systems tends to be an arduous task. This work proposes a modeling approach to generate architectures for such applications, compliant with existing robotics middlewares (e.g., ROS, ROS2). The challenge is to have a compact, yet expressive description of the system with just enough information to generate all required components and to integrate existing algorithms. This system model must be generalizable, so it is not application-dependent, and it must exploit the benefits of FPGAs over software solutions. Previous work mainly focused on individual accelerators rather than all components involved in a system and their interactions. The proposed approach exploits the advantages of model-driven engineering and model-based code generation to produce all components, i.e., message converters acting as middleware interfaces and wrappers to integrate algorithms. Data type and data flow analysis are performed to derive the necessary information to generate the components and their connections. Solutions to several identified challenges for generating entire systems from such models are evaluated using four different use cases.