I am trying to set up a differential drive rover . I have a cube orange running ardurover firmware and a herelink remote for control.
I have set the parameters to SERVO1_FUNCTION = 73 and SERVO3_FUNCTION = 74. I have also played around with the herelink Mode1 and Mode 2 to get it work the way I want it but not much success. I am using huge BLDC motors with Roboteq dual channel controller which has the ability to keep the two pwm signals separate or mix them in 3 different modes. I am assuming that the cube orange does the mixing and sends different pwm signals to each motor for steering, so I have left the motor controller in separate mode.
Here’s my question: Does Ardurover use ROLL as the command to turn the rover? Coming from airplane mindset, I thought YAW would be the turn signal?
I have the ability to read the pwm signals sent tot he motor controller and I can notice that when i use the yaw control, i do not see different pwm values for each motor, however if i use roll, i see differening values on the controller and indeed the wheels turn at different speeds, indicating a turn. Does this seem correct?
Also, how does this affect auto mode? Would having ROLL for turn cause issues in AUTO Mode or I can keep moving forward step by step to get to auto mode? Seems like steering mode is next for me.
Thanks
Yes, ArduPilot Rover’s steering input (from the RC) actually does come in from channel 1 (which is normally the Roll channel). Yaw input (which is normally channel 4) might have been a more logical choice but that decision was made a long long time ago. Also rover specific RC systems often use channel 1 for steering (I think).
The RC input channels don’t affect the motor output so Auto mode won’t be affected.
Instead of Steering mode, I’d test Acro mode next. Personally I never use Steering mode.
Hello @rmackay9 ! Thanks for your response to my question. I now understand the yaw vs roll issue. I am building a HUUUUUUGE rover… it is almost the size of a small/medium car. The tuning instructions @ Tuning Process Instructions — Rover documentation seem easy to follow on smaller rover, but for a rover of my size, i cannot drive it around in circles in manual mode in a smooth manner. Do you have any suggestions for that?
The tricky thing about these big rovers is that they tend to be very slow as well which puts them well outside the regular tuning parameters. Also very slow means that the vehicle’s movements tend to get lost in the noise from the GPS.
In any case, I think in the short-term using the regular tuning procedure is the best thing to do. In particular setting GCS_PID_MASK so that you can monitor the desired turn rate vs actual in real time.
I’d also say that it would be best to tune on a smooth surface to again reduce noise.
