Linus Penzlien and I have been working with Rusty at Blue Robotics to properly configure the ArduSub firmware to appropriately drive the horizontal and vertical Thrusters in my six thruster configuration depending on the desired ROV motion input from the GCS (QGC) gamepad joystick inputs.
Validation of the BBBMINI six servo outputs, when driven by the GSC gamepad joystick inputs, was accomplished by communicating with the BBBMINI over a UDP LAN connection and using a R/C receiver PWM output tester to verify the servo PWM output values in relation to the expected PWM values.
An example BBBMINI servo output verses expected output Correlation Chart is in an attached pdf file below. It can be seen that the BBBMINI servo outputs verses expected outputs are not correct for Thrusters 1, 3, and 4 for the Forward ROV direction. This discrepancy can be easily corrected using the MOTOR_MOTION parameters in the QGC default parameter list to reverse the BBBMINI servo PWM outputs to achieve the correct Thruster output direction.
Having validated the ArduSub firmware for my six Thruster ROV configuration, I moved on to completing the Navigation Controller Tray that will reside in the Navigation Controller WTC.
The Blue Robotics ROV-side Tether Interface Board and the BBBMINI are attached to a removable sub tray that is attached to the main Navigation Controller Tray. The Signal Junction Board is permanently mounted at the rear of the Navigation Controller Tray and is not attached to the sub tray. See photos below:
Navigation Controller Tray and Signal Junction Board at the rear with the BBBMINI and the ROV-side Tether Interface Board on the Sub Tray
Navigation Controller Tray mocked up in the Navigation Controller WTC
The next step will be to complete the mechanical and electrical installation of the Navigation Controller Tray in the Navigation Controller WTC. This will include connection of the Signal Junction Board individual thruster PWM control signal cables to their respective Thruster Cable Penetrator Control Signal cables, connection of the Tether four twisted pairs to the ROV-side Interface Board, and the connection of the ROV-side power input cable to the Cable Penetrator Power Cable wires coming from the Battery Compartment WTC.
More to come.
Thruster Correlation Chart Forward Motion.pdf (188.4 KB)