Rover QuickTune tunes the steering (aka turn rate) and speed controller gains for rovers and boats
The script is designed to be used in Circle mode and updates the following parameters
ATC_STR_RAT_P ATC_STR_RAT_I ATC_STR_RAT_D ATC_STR_RAT_FF ATC_STR_RAT_FLTD ATC_STR_RAT_FLTT ATC_SPEED_P ATC_SPEED_I ATC_SPEED_D CRUISE_SPEED CRUISE_THROTTLE
Install this script in the autopilot's SD card's APM/scripts directory Set SCR_ENABLE to 1 and reboot the autopilot Set RTUN_ENABLE to 1 (default)
Set RCx_OPTION = 300 where "x" refers to the transmitter's 2 or 3 position switch use to start/stop/save tuning. E.g. if channel 6 is used set RC6_OPTION = 300
If necessary, the RTUN_RC_FUNC parameter can be set to another number (e.g. 302 for scripting3) to avoid RCx_OPTION conflicts with other scripts.
By default the tune is saved a few seconds after completion. To control saving of the tune manually set RTUN_AUTO_SAVE to 0
Arm the vehicle and switch to Circle mode Optionally set CIRC_SPEED (or WP_SPEED) to about half the vehicle's max speed Optionally set CIRC_RADIUS to a value at least twice the vehicle's turning radius Note the above parmaters only take effect when the vehicle is switched into Circle mode
Move the RC switch to the middle position to begin the tuning process. Text messages should appear on the ground station's messages area showing progress
During tuning the steering or throttle output are compared to the response for at least 10 seconds. A message may appear stating the steering, turn rate, throttle or speed are too low in which case the vehicle speed should be increased (Mission Planner's Action tab "Change Speed" button may be used) or the radius should be reduced.
By default the gains will be tuned in this order:
- ATC_STR_RAT_FF, then ATC_STR_RAT_P and I are set to ratios of the FF
- CRUISE_SPEED and CRUISE_THROTTLE, then ATC_SPEED_P and I are set to ratios of the FF
The script will also adjust filter settings:
- ATC_STR_RAT_FLTD and FLTT will be set to half of the INS_GYRO_FILTER value
Once tuning is complete "RTUN: tuning done" will be displayed Save the tune by raising the RC switch to the high position
If the RC switch is moved high (ie. Save Tune) before the tune is completed the tune will pause, and any parameters completed will be saved and the current value of the one being actively tuned will remain active. You can resume tuning by returning the switch again to the middle position. If the RC switch is moved to the low position, the parameter currently being tuned will be reverted but any previously saved parameters will remain.
If you move the switch to the low position at any time in the tune before gains are saved, then all parameters will be reverted to their original values. Parameters will also be reverted if you disarm before saving.
If the pilot gives steering or throttle input during tuning then tuning is paused for 4 seconds. Tuning restarts once the pilot returns to the input to the neutral position.
The script has the following parameters to configure its behaviour
Set to 1 to enable the script
The RCx_OPTIONS function number to be used to start/stop tuning By default RCx_OPTIONS of 300 (scripting1) is used
The axes that will be tuned. The default is 3 meaning steering and speed This parameter is a bitmask, so set 1 to tune just steering. 2 for just speed
Ratio between measured response and FF gain. Raise this to get a higher FF gain The default of 0.9 is good for most users.
Ratio between steering FF and P gains. Raise this to get a higher P gain, 0 to leave P unchanged The default of 0.2 is good for most users.
Ratio between steering FF and I gains. Raise this to get a higher I gain, 0 to leave I unchanged The default of 0.2 is good for most users.
Ratio between measured response and CRUISE_THROTTLE value. Raise this to get a higher CRUISE_THROTTLE value The default of 1.0 is good for most users.
Ratio between speed FF and P gain. Raise this to get a higher P gain, 0 to leave P unchanged The default of 1.0 is good for most users.
Ratio between speed FF and I gain. Raise this to get a higher I gain, 0 to leave I unchanged The default of 1.0 is good for most users.
This enables automatic setting of the PID filters based on the INS_GYRO_FILTER value. Set to zero to disable this feature.
Enables automatic saving of the gains this many seconds after the tuning completes unless the pilot move the RC switch low to revert the tune. Setting this to a non-zero value allows you to use quicktune with a 2-position switch, with the switch settings as low and mid positions. A zero value disables auto-save and you need to have a 3 position switch.