My company (SeaView Systems) has the first Seaeye Falcon Dr that we bought in 2005. It’s a great ROV but the the auto depth and heading are pretty ordinary so we converted it to run the thrusters, camera tilt and lights on a Pixhawk with Ardusub and QgroundControl. The Falcon uses an RS485 bus with each component having its own address. We used a microcontroller to convert the Pixhawks’ thruster,tilt and light PWM outputs to the corresponding Falcon RS485 address commands.
The first project I used it on was for a survey where we had to follow cables and perform transects. I used a Subsonus USBL system for positioning. The Subsonus also gives navigation for guided mode, position hold and waypoint tracking but I didn’t have time to tune the PID’s on that job.
That is just fantastic!! How did you integrate the commands from the pixhawk to 485 and have you been able to adjust the PID’s to get a stable AP command to follow heading and depth commands?
I connected each PWM channel on the Pixhawk to a channel on the microcontroller. The microcontroller’s firmware takes the PWM channel input and converts it to the command for the RS485 address for that thruster/tilt motor/light. The RS485 from the microcontroller is connected to the Falcon’s RS485 Bus.
Heading and depth commands were nice and stable and didn’t need much PID tweaking. Guided Mode, Position Hold Mode and following waypoints have been harder to tune because of the lack of time available before the operation began.
This is the only image I have of the microcontroller connected to the Pixhawk.
