Building robot control programs which function as intended is a challenging task. Roboticists have developed architectures to provide principles, constraints and primitives which simplify the building of these correct, well structured systems. A number of established and prevalent behavioural architectures for robot control make use of explicit parallelism with message passing. Expressing these architectures in terms of a process-oriented programming language, such as occam-π, allows us to distil design rules, structures and primitives for use in the development of process architectures for robot control.