2020-08-02, 04:56 PM
So things had been going well with my setup so far this season (RPI4 with OP2, IMU 9255, Sean's controller connected to ST4000 wheel pilot). I had the AP running reasonably well for the last 1.5 months with just some adjustments to P and D gains, all other gains 0. I always run in compass mode. I can't put my finger on when it happened, but there's been a big change for the worse. With the AP engaged, the AP will wait for the course to be off by 20 deg or so and then make a big change in the other direction: 1/4 to 1/2 a turn on the wheel. It will then make another huge correction in the other direction, overshoot the desired course by 20 to 40 deg, wait at that course for 2 sec, make another huge correction the other way. Left this way, it will continue to make big 20 to 50 deg S turns. Each turn is a big correction, never small. I spent a couple hours fooling around with it yesterday. The boat was in light air and small seas, one of the those days where the boat will go for a long time in a straight line with the wheel locked. With all kinds of adjustments to P, D, DD and PR, the best I could do was to get the S turns down to +/-25 deg. The "desired course" and "current course" always appear stable.
My next move was going to be new install on an SD card and start from scratch. Before I do, any thoughts on what could have happened here, or how I even start to troubleshoot?
My next move was going to be new install on an SD card and start from scratch. Before I do, any thoughts on what could have happened here, or how I even start to troubleshoot?