Environmental Control Systems Evolution Current Systems the Future

Environmental Control Systems Evolution, Current Systems, the Future Click on images to go to original URL

What can be regulated? • • Temperature (heat/cooling systems) Humidity Supplemental Lighting Photoperiod (day length extension or black cloth) • Atmospheric composition (CO 2 enrichment) • Irrigation • Nutrient Delivery (Fertilization)

Types of Controls • • • Manual On/off Switches Step Controllers Dedicated Microprocessors Computers (Integrated Control)

Manual Greenhouse Control • Common before 1950 to have people 24/7 to monitor temperature (winter) • Manual ventilation, heat valves • Manual pulling of shade cloth • Manual sun shades • Hand watering

On/Off Switches • • Simple For heating and cooling based on a thermostat Problems with accuracy May still be suitable for simple season extension houses • Many styles and manufacturers available

Step Controller • Advancement over on/off switch • Instead of just one option there are multiple stages possible (for example) • Stage 1 – louvered vent opens • Stage 2 – exhaust fan on opposite wall on low speed • Stage 3 – exhaust fan on opposite wall on high speed • Not expandable • Not good for complicated temperature control schemes • Can be difficult to ‘set up’ and ‘change’

Dedicated Microprocesssors

Computers • Despite cost effectiveness and ease of use 85% of greenhouses still have some manual controls • Cost 5 to 7 K and up • Very expandable • System can grow with your operation • Data can be easily made available to others for troubleshooting • Integrated record keeping

IFAC TECHNICAL BOARD AUGUST, 2003 IFAC EMERGING AREAS PROJECT CC 8: BIO & ECOLOGICAL SYSTEMS (APPLICATIONS) Keith Godfrey (for Ewart Carson)

TC 8. 1 Control and Automation in Agriculture • “Speaking animals” Automated measurement of the responses of individual animals to differing feeding and climate regimes so as to optimise their management • “Speaking plants” Automated measurement of plant responses to different treatments for the purpose of automatic control of processes in the soil-substrate-plant continuum • Automation of harvesting and handling of crops Developments required due to a lack of skilled, affordable labour • Automation for tracking and tracing of products and of the production condition Stage of maturity, variability, treatments etc.