Greenhouse Networked Control System Design Methodology to Minimize Cost & Downtime

Smart greenhouses enable the cultivation of various crops in different environmental conditions. Wireless Sensor Networks (WSNs) and Networked Control Systems (NCSs) could be utilized within greenhouses to access, control and monitor different environmental parameters. This paper studies a greenhouse with a special focus on the wireless NCS. It first shows how to use the 2.4GHz frequency band while minimizing Access Point (AP) cost and maintaining an acceptable Packet Loss Rate (PLR). Second, fault-tolerant AP architectures are studied, and a metric is proposed which incorporates AP failure and repair rates, as well as NCS information efficiency to help management select an appropriate architecture, to minimize profit loss. This metric is shown to produce some counter-intuitive results. Finally, Riverbed simulations are used to obtain the minimum sensor transmission power to produce the minimum acceptable PLR in the context of the 2.4GHz band. This power is much lower than that for the 5GHz band; this will prolong sensor battery lifetime.