System:
CubeOrange+, Herelink Transmitter and receiver, Ardurover v4.5.6, OmniPlus, (boat with bow and stern thrusters, 2 main motors, and (rudders.)) Motors and thrusters are bi-direction.
Herelink TX settings, sticks (MODE 2) looking at sbus1 outputs:-
Right horizontal ‘X’ stick right output (ch1) increasing to the right.
Right vertical ‘Y’ (rev) stick up output (ch2) increasing to the right.
Left horizontal ‘Z’ stick right output (ch4) increasing to the right.
Left vertical ‘R’ (rev) stick up output (ch3) increasing to the right.
“Up or right” moves the sbus1 outputs to increasing to the right.
Open Mission Planner, and connect to Orange+:- Setup, Radio Control tab
RH (roll) stick right 1515 to 1927 “on Roll (RC1)”
RV (elev) stick up 1515 to 1927 “on Pitch (RC2)”
LH (rudd) stick right 1515 to 1927 “on Yaw (RC4)”
LV (thr) stick up 1515 to 1927 “on Throttle (RC3)”
Armed system: and checked on Setup Outputs tab:-
LV throttle up channel 2 (motor 2) changes from 1500 to 1900
channel 4 (motor 4) changes from 1500 to 1900
RH roll to right channel 1 (motor 1) changes from 1500 to 1900
channel 3 (motor 3) changes down from 1500 to 1100
LH yaw to right channel 1 (motor 1) changes from 1500 to 1900
channel 3 (motor 3) changes from 1500 to 1900 (parallel to ch1)
If the throttle is not at stationary at > or < 1500micros, then changes to either the roll or yaw sticks, in either direction reduces the output to the main motor channels, ch2 and ch4. (Both channels are reduced by the same amount.)
Questions are:-
Should the roll stick, right horizontal, give a differential output change on the output channels, while the yaw stick, left horizontal, gives a parallel output change on the output channels?
Should the roll and yaw reduce throttle output, equally on both main drive motors, regardless of going ahead or astern, and regardless of roll or yaw moving left or right?
Could there be an option for a rudder action, from the yaw signal? All my boats have rudders.
Could there be an option for differential mixing of a yaw signal into the main motor action? My boats can turn on the spot, just using main motors, differentially, which can aid low yaw control from the thrusters.
The first item is not really an issue, as by reversing one of the thrusters, at the motor terminals, means a roll signal moves the boat sideways, while the yaw signal will turn the boat, clockwise or anti-clockwise, respectively. I was surprised by this as I actually prefer mode 4, but had set everything for mode 2, as Herelink seemed to prefer that. In the olden days, of course, most boats were only 2 channel, left stick throttle, and right for rudder. But for consistency of names etc…
The last 2 items I can compensate for, by taking the pwm signals from the thrusters, Ch1 and Ch3, run them through an Arduino, to extract a pure yaw signal, which I can mix with one of the main motor channel 2 or channel 4, pwm’s to produce a differential mix to the main motors. The yaw pwm signal will output to the rudder servo, while the mix of the yaw and throttle will output to the main motors separately. The boat with combined thrusters, differential motors, and rudders, give very powerful yaw control, at all speeds. I use rudder/throttle mixing on Arduino or transmitter mixing, and it works well, even for boats that don’t have rudders! It would be a neater solution to have main motor differentials and rudder action included within ArduRover, but maybe that is a future wish list?
A note is that rudder action is low at low speeds, but significant at greater increasing speeds, while traditional built-in bow and stern thrusters are less effective as speeds rise, as the forward speed causes water to rush past the thruster intakes, reducing their effectiveness!