uav package delivery example: question about stateflow chart "Guidance mode selector"

The uav package delivery example of the uav toolbox contains a stateflow chart for switching between different waypoint modes. The chart outputs a status, which serves as the "isModeDone" input of the UAV path manager block. The chart contains a substate called "land" which connects to the superstate "GuidanceLogic" with the following condition and action: [Pose(3)>=-0.1]{Status = 2;}. Does this mean that whenever the condition is true, the parameter "status" will be set to a value of 2? If so, I do not understand why. Pose(3) seems to refer to the altitude of the UAV, which is usually greater than -0.1 during flight. This means that whenever the state "land" is activated, the "status" parameter is immediately set to 2, which in turn ends the simulation. In other words, the simulation will be terminated even before the uav has actually landed. Hopefully, I have explained myself clearly. It would be great if anyone could clarify this to me.

Answer 1

[Jianxin Sun]

Hi Sander,

The Pose(3) is the z value of the UAV pose in NED frame, meaning that Pose(3) is -altitude. The condition Pose(3) >= -0.1 should be translated as altitude <= 0.1, which leads to simulation stop.

Thanks,

Jianxin