A two time-scale, receding horizon, optimal controller for greenhouse lettuce cultivation is extended with on-line parameter estimation to handle ill-known or time-varying parameters of the greenhouse-crop model. By means of simulations, the possible improvement of performance and reduction of constraint violation, introduced by this extension, are investigated. Moreover, uncommon issues in the adaptive controller design due to the two time-scales are considered and handled in this paper. The estimated parameters are selected based on their uncertainty and performance sensitivity. Using a recently developed very efficient algorithm, the selected parameters are checked for identifiability first. Finally the possibility of real-time implementation of the adaptive two time-scale receding horizon optimal controller is investigated.
- Adaptive control
- Greenhouse cultivation
- Receding horizon optimal control
- Time-scale decomposition