today I was trying to tune the steering PID on my skid steered boat. According to the manual http://ardupilot.org/rover/docs/rover-tuning-steering-rate.html.
First of all I’v checked(and set ACRO_TURN_RATE )the max turn rate on manual mode(like on video) - it was about 30 degrees/s.
In manual mode the turn speed is good but when the boat is in Acro mode the turn speed is very low. I’v tuned the ATC_STR_RAT_FF parameter to about 2-2.5 to get a similar performance to manual mode(about30deg/s). The problem is that then the pid_desired value is about 12 degrees/s and pid archived - 30 - as I need it to be. This is a problem when I introduce the I parameter - the error between desired/archived is building up and all the other bad things happen.
The pid desired value gets 12 when the RC steering stick is on maximum value. Why is the pid desired value so low on maximum RC stick movement? As I understand I need to change something that is responsible for RC_IN - pid desired mapping - what is it?