Payload place gave up without releasing the load
What ArduPilot says:
- … PLDP_RNG_MAX set and rangefinder not enabled
- … Reached maximum descent
The copter was lowering a load and stopped before touchdown; it climbs back to the height it started from with the load still attached, and the mission goes on. “Reached maximum descent”: it came down by the maximum descent set in the mission command without feeling the load touch. “PLDP_RNG_MAX set and rangefinder not enabled”: PLDP_RNG_MAX tells it to release only below that rangefinder height, and there is no working downward rangefinder.
What to do, most likely first
The maximum descent in the mission command is smaller than the real height above the ground.
CheckCompare the command's first parameter (metres) with the height above ground at the placing point.
FixSet the command's maximum descent to the height you place from plus a margin, or fly the placing point lower.
The load is too light for the copter to feel it touch: the thrust hardly changes.
CheckIn the log the throttle (CTUN.ThO) barely drops when the load reaches the ground.
FixRaise
PLDP_THRESHtowards 0.9 for light loads, and test over open ground first.PLDP_RNG_MAXis set, but no downward rangefinder is set up or it is not healthy.FixFit and set up a downward rangefinder (
RNGFND1_TYPE,RNGFND1_ORIENT25), or setPLDP_RNG_MAXto 0 to release on the thrust test alone.
Parameters to look at
| Parameter | What it is |
|---|---|
PLDP_RNG_MAX | Payload Place maximum range finder altitude |
PLDP_THRESH | Payload Place thrust ratio threshold |
PLDP_SPEED_DN | Payload Place decent speed |
RNGFND1_TYPE | Rangefinder type |
RNGFND1_ORIENT | Rangefinder orientation |
Where to do it:Mission Energy Check
The code that sends it
… PLDP_RNG_MAX set and rangefinder not enabled
ArduCopter/mode_auto.cpp PayloadPlace::run() · Open in ArduPilot Copter-4.7.1
… Reached maximum descent
ArduCopter/mode_auto.cpp PayloadPlace::run() · Open in ArduPilot Copter-4.7.1