An automated commercial greenhouse uses a sensor-actuator control system to maintain optimal growing conditions for rare orchids.
Identify two different sensors that could be used in this greenhouse to monitor environmental parameters.
Identify two different actuators that could be used in this greenhouse to alter physical conditions.
Describe how the sensors, Analogue-to-Digital Converter (ADC), microprocessor, and actuators interact in a closed-loop control system to regulate the temperature when it rises above a preset maximum limit of 28°C.
The greenhouse operator interacts with the system using a stationary control panel and a portable handheld inspection tablet.
The stationary control panel is located inside the humid greenhouse where workers frequently wear thick rubber gloves. Compare the suitability of an infra-red touchscreen and a capacitive touchscreen for this control panel.
Explain two advantages of choosing an Organic Light Emitting Diode (OLED) display over a Light Emitting Diode backlit Liquid Crystal Display (LED-backlit LCD) for the portable handheld inspection tablet.