"VTOL land too short" problems

Jan_Kryca · September 16, 2022, 3:28pm

Hello All,

I’m having issues arming my quadplane model. I am getting the “VTOL land too short, min 198m” Pre-Arm error, which is not allowing me to arm my VTOL airplane. The error only happens when there is an Auto mission loaded on the Cube Orange on the drone. The mission is just a simple VTOL takeoff, a couple of waypoints (no transitions), VTOL land, and the furthest waypoint is 50m from takeoff point, and the total distance is just a ~200m square.

Can someone please explain what causes this error, and how can I fix it?

Here is the link to the line of code in ArduPlane that I believe throws this error:

github.com

ArduPilot/ardupilot/blob/64c60c8149d12f9073666741e6085bc5497a2841/ArduPlane/AP_Arming.cpp#L429


      
                          break;
                      }
                      if ((cmd.id == MAV_CMD_NAV_VTOL_LAND || cmd.id == MAV_CMD_NAV_LAND) &&
                          prev_cmd.id == MAV_CMD_NAV_WAYPOINT) {
                          const float dist = cmd.content.location.get_distance(prev_cmd.content.location);
                          const float tecs_land_speed = plane.TECS_controller.get_land_airspeed();
                          const float landing_speed = is_positive(tecs_land_speed)?tecs_land_speed:plane.aparm.airspeed_cruise_cm*0.01;
                          const float min_dist = 0.75 * plane.quadplane.stopping_distance(sq(landing_speed));
                          if (dist < min_dist) {
                              ret = false;
                              check_failed(ARMING_CHECK_MISSION, report, "VTOL land too short, min %.0fm", min_dist);
                          }
                      }
                      prev_cmd = cmd;
                  }
              }
          #endif
              return ret;
          }

Thanks for any help!

suleyman_11 · February 20, 2023, 8:04pm

hello . i am getting the same error.did you find a answer?

rupert · March 17, 2023, 4:23pm

I had this same issue. My home location was set far from the drone and had waypoints loaded that were also far away. Sending a waypoint nearby reset my home location and this error went away.