LOITER "hangs" copter with little authority

ArduCopter Copter 4.0
1

Hi all,

i’m using 4.0.2. With latest drones i’m setting up, i noticed that in loiter mode, when i leave sticks after an horizontal translation, it takes a lot to stop and it does it very weakly. With previous drones with 3.6.9 stop was very authoritative and powerful. Here’s my PSC params:

PSC_ACC_XY_FILT,2
PSC_ACCZ_D,0
PSC_ACCZ_FF,0
PSC_ACCZ_FLTD,0
PSC_ACCZ_FLTE,20
PSC_ACCZ_FLTT,0
PSC_ACCZ_I,0.5
PSC_ACCZ_IMAX,800
PSC_ACCZ_P,0.7
PSC_ANGLE_MAX,0
PSC_POSXY_P,2
PSC_POSZ_P,1
PSC_VELXY_D,0.5
PSC_VELXY_D_FILT,5
PSC_VELXY_FILT,5
PSC_VELXY_I,1
PSC_VELXY_IMAX,1000
PSC_VELXY_P,1.5
PSC_VELZ_P,4

any idea on how to have a stronger stop when loiter?
Thanks

2

Di you try changing the LOITER BREAK parameters?

3

Try something like:
LOIT_ACC_MAX,600
LOIT_BRK_ACCEL,300
LOIT_BRK_DELAY,0.3 <- the major difference
LOIT_BRK_JERK,300

I think these were the default values, as a comparison:
LOIT_ACC_MAX,500
LOIT_BRK_ACCEL,250
LOIT_BRK_DELAY,1
LOIT_BRK_JERK,500

4

here’s how LOIT params are today:

LOIT_ACC_MAX,800
LOIT_ANG_MAX,0
LOIT_BRK_ACCEL,150
LOIT_BRK_DELAY,0
LOIT_BRK_JERK,500
LOIT_SPEED,1200

i will try your suggestion

5

just a little update, i think i fixed it (to be sure i need to do some more flight with stronger wind)

basically, it was LOIT_BRK_ACCEL,150 . Raised to 250 it seems to hold much better

6

I would not have 0 for LOIT_BRK_DELAY , try 0.3

7

why? I tried both and i feel 0 is perfect. I don’t like that delay before stopping… is there any drawback?

8

I just had some natural aversion to a zero there, picturing divide by zero errors or some such, or making Loiter too twitchy. If it works, it works.

9

sadly, it seems not to be the loit acc parameter. i have another copter behaving same, with 250 as loit acc.

10

You should change LOIT_BRK_* parameters, not LOIT_ACC

11

LOIT_BRK_DELAY = 0
LOIT_BRK_JERK = 1000
LOIT_BRK_ACC = 250

all those values are ok, tried on many drones previously