Rapid control prototyping of automatic climate control systems

Automatic climate control systems in vehicle applications are very complex systems. There is a variety of connections to and from other vehicle systems (engine and engine cooling, cabin, passengers and HMI, environment). The control algorithms are currently based on classic control concepts with a huge set of expert rules. The design and test of these expert rules during simulated and real driving conditions is a key factor for a successful development (time, costs and quality) of an automatic climate control system. This paper presents experiences that have been made during the design of a rapid control prototyping (RCP) system for an automatic climate control system. The advantages and drawbacks of a model-based control system specification are discussed. The concept of bypassing on CAN is shown. Suggestions for future improvements of the applied standard tools are made. Further more, the importance of real-time plant models (RTL) for hardware-in-the-loop applications, model-based control concepts and online diagnosis tools are discussed. Concepts for the derivation of RTL models from more detailed, but non real-time software models are presented.