We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK


93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Nonlinear control of ventilation rate using sta...
View graph of relations

« Back

Nonlinear control of ventilation rate using state dependent parameter models

Research output: Contribution to journalJournal article


Journal publication date09/2006
JournalBiosystems Engineering
Number of pages12
Original languageEnglish


The objective of this paper is to develop non-linear proportional-integral-plus (PIP) control algorithms for regulating ventilation rate in mechanically ventilated agricultural buildings. State-dependent parameter (SDP) models are developed for an environmental test chamber, representing a section of a livestock building or glasshouse. Here, the system is modelled using the quasi-linear SDP model structure in which the parameters are functionally dependent on other variables in the system. The model is subsequently utilised to develop a new approach to control system design, based on non-linear PIP pole assignment, with a discrete-time Smith Predictor to handle the sampled time delays. Implementation results for the test chamber demonstrate improved control of ventilation rate, with a faster response to disturbances in comparison with both linear and conventional (linearised) scheduled PIP control. The approach has application to a wide class of other non-linear systems, as demonstrated by simulation examples.