Methodic design of a measurement and control system for climate control in horticulture

Many papers describe applications of advanced controllers in greenhouses. As control literature focusses on control algorithms, the layout of the measurement and control system is usually underexposed. Unfortunately, commercially available greenhouse climate control systems do not have the necessary flexibility to accommodate these types of controllers. This paper describes a systematic approach to the design of a flexible measurement and control system, that can be adjusted to suit most control research in horticulture. Individual functions within a measurement and control system are identified and alternative solutions are given. The approach is applied to the design of the measurement and control system for the Watergy greenhouse. The controllers (in software) are versatile and setpoints can be generated by the easy-to-use user interface as well as by external software (like Matlab). Data is centrally stored and the system is easy to expand. It has been shown that the system has functioned robustly for the last 3 years. It has the capability to serve as basis for research and testing of various advanced control strategies in the Watergy system with adaptive model-based control as a final goal.