2DOF Solar Tracker

The objective of the project was to design a 2-degree-of-freedom (2DOF) solar panel tracking system that could orient towards a light source based on azimuth and altitude. In order to create the solar panel, a micro servo motor, stepper motor and 2 photoresistors were utilized as the key electronic components of the setup. Comparing the difference of the two photoresistor values, the stepper motor turned in one direction (azimuth). The altitude was found by using a PID controller to keep the micro servo motor angled towards a set light intensity of the used light source. 

The mechanical setup was created by using a spare wheel, ultrasonic sensor micro servo mount and metal supports from a previous project, as well as a cardboard cut out to attach the photoresistors to. 

The photosensor readings were 0 when there was no light present and a maximum value of around 250 when the light source was 1cm away. The setpoint was set to 150 so that the PID controller would orient the panel up to 1m away. The Kp, Ki, Kd values were 0.2, 2 and 0.0003 respectively. When a light source was present the panel would turn left or right to determine the ideal azimuth position and tilt up and down to locate the light source.