Saavedra-Ruiz et al. Table 2. Controller Errors in the Landing Process Controller RMSE P Standard deviation RMSE PD Standard deviation RMSE PID Standard deviation 31.6203 41.5917 31.8581 28.9982 41.8702 Centroid X [px] Centroid Y [px] Angle [deg] 30.3725 34.0250 32.9310 40.2214 37.2056 29.0585 29.0283 6.7023 6.1946 11.3106 9.4058 7.7358 6.9005 Figure 9. Error in the P, PD, and PID controllers for Xði¼1:3Þ