In this article, a iterative tuning of the PI trajectory controller of an AGV is performed using as performance parameters the gain and phase margins of the closed loop system. Three case studies are analyzed, with different specifications of margins for the same system. The AGV system it is a naturally unstable system, it is not possible to use methods that require open-loop information. For this reason, closed loop relay methods were used to estimate system margins. The results achieved validate the tuning method used. The performance criteria provided fast convergence and kept the system stable.