Copter RTL linear descent and loiter and braking for large quadcopter

ArduCopter Copter 4.5
1

Hi All,

I was flying my quadcopter at 100 m above ground using Acro mode, and when I turn on Return to Launch, the copter comes back at 100 m, and start desending from 100 m; my return to launch altitude is set at 50 m. I did not turn on Smart RTL. Is there a way to start descending immediately when RTL is triggered; when it reaches at home point, it is at 50 m? I have used that for Quadplanes.

Also, at Loiter mode, when I center the stick from forward motion, the quadcopter comes to an abrupt stop. I feel the stop is a bit too abrupt. Is there a way to reduce the acceleration of the stop?

Should I change the following parameters:
LOIT_BRK_ACCEL,250
LOIT_BRK_JERK,500
PSC_JERK_XY,5

The above parameter is directly related to Loiter / braking mode. what about reducing ATC_ACCEL_P_MAX, ATC_ACCEL_R_MAX, and ATC_ACCEL_Y_MAX?

Thanks,

2

Yes, you should.

No, you should not.

3

Another question, does Loiter braking used in RTL braking? Is braking used between waypoints or the copter will steer toward the next waypoint (for a mission flight mode)? When I ask the quadcopter to come back to home, will RTL use Loiter braking setting or the braking setting?

Also, is there an estimate on how low can I set those (LOIT_BRK_ACCEL, LOIT_BRK_JERK, PSC_JERK_XY)? For example, for 13 in or for 15 in, the minimum should be 30% of default. I will try 70% of default for now.

Thanks,

4

WPNAV_ACCEL is used for RTL braking.