Summary

This project was the second solar tracker I designed, and it is a parallel robotic system rather than the serial one in my previous project. This design used two motor-controlled cable spools and one spring-tensioned cable spool to maintain tension. Using trigonometry and 3D rotation quaternions, I solved the inverse kinematic problems and calculated the length of the two motor cables required to achieve the target azimuth and elevation. To make a smooth path between two directions, I calculated a rotation vector and rotated the panel’s angle along that path until it reached the final angle. A test of this is in the video below, where the panel moves between several different angles.

The CAD of this project is below, and here is the CODE required to drive this design. You may need to modify some of the lengths to ensure proper calibration.