Design of A digital PI controller for room temperature on Wireless Sensor and Actuator Network (WSAN) system

In the Wireless Sensor and Actuator Network (WSAN) system, a sensor node must have the function to turn on the actuator in order to move or control an equipment besides monitoring the measured parameter. With the addition function to control the actuator, the WSAN system will have a form of closed loop system. This paper propose a WSAN system in which the sensor nodes and actuator nodes are combined into a single node. It is useful to handle some cases that have a fast response time of monitoring results without waiting for the order from the central station. This WSAN configuration is a closed loop system so it needs a digital controller for controlling the actuator to achieve stability. We propose a digital Proportional Integral (PI) as a controller to overcome this closed loop system with 5% for the maximum overshoot criteria and 5 second for settling time criteria. By using the equality root characteristics method from the poles, then the PI constant can be determined in order to obtain an output system response. The result showed that the digital PI controller can produce the desired output response and through the Jury test, the stability of the system can be seen.