I have a good book called "Doing Hard Time" by Bruce Powel Douglass - he uses quite a few different types of UML diagrams, but I think Chapter 8 on "Architectural Design" is most relevant here. The Concurrent Sequence Diagram on p378 is also known as a swim lane diagram; he then shows the same (robot -based) example as a Concurrent Collaboration Diagram and a Concurrent Timing Diagram. He also describes a lot of real-time patterns like watchdogs and monitor-actuators. He provides a swim-lane representation of each pattern.