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Problems Configuring a Heavy Lift BR2 ROV from the Ground Up


(TCIII) #1

Hi All,

I am presently attempting to properly configure a Heavy Lift BR2 ROV complete with four Lumen Lights and a Newton Gripper for a Marine Biologist here in FL.

I am using the BR version of QGC: 3.2.4 Blue Robotics-Rev 6
The Pixhawk has firmware version 3.5.3 which I believe is the latest version

I have configured the ROV with the BlueROV2 Heavy Lift configuration, have rebooted the Pixhawk, and have verified the change of the configuration to the BlueROV2 Heavy Lift.

I then proceeded to attempt to verify thruster direction per the Configure Motor Directions section. However when I slide the switch to arm thrusters, I can’t get the slider buttons to move downward to energize any given thruster. Since I have not configured any other ROV parameters, is there a unconfigured parameter that is keeping the thrusters from being enabled?

Does the IMU have to be calibrated to be able to enable thruster control functionally because I have not done so yet? Does the Heavy Lift thruster test instructions assume that the IMU has been previously calibrated?

Also, since the installation of the Heavy Lift Kit requires moving the Camera Servo connection to the Pixhawk Aux 2 servo connection and the Lumen Lights to the Pixhawk Aux1 servo connection, is there a table that cross references the Pixhawk Aux Servo Channels to the QGC Channels so that I can reprogram the Camera Servo and Lumen Lights Pixhawk control channels?

Finally, the Voltage and Current Measurement page in the BR2 Software Setup Instructions no longer reflects the current QGC Power page. There is a missing “minimum voltage to arm” parameter in the QGC Power page that is missing from the Software Setup instructions.

Regards,
TCIII AVD


(TCIII) #2

Hi All,

I haves started to answer my own questions however it took a fair amount of digging:

The cross reference between the Pixhawk servo output labels and the QGC servo channels can be found here.

Regards,
TCIII


(TCIII) #3

Hi All,

I have verified that the Camera Tilt Servo and the Lumen Lights are functional. The QGC Summary page shows the Lumen Lights on Channel 9 (Aux1) which is correct, however the Camera Tilt Servo is still shown on RC8 and not Channel 10 (Aux2) where the Heavy Lift installation instructions directed that it be moved to.

However the configuration of the Gripper remains a mystery.

The Gripper instruction suggest connecting the Gripper Servo Control signal to the Pixhawk Aux3 which I have done. However according to the Pixhawk servo output labels to QGC servo channels cross reference table, Aux3 is Servo Channel 11 while the Gripper installation instructions say set servo_3_min momentary and servo _3_max momentary when using Aux3?

Regards,
TCIII AVD


(Kevin) #4

@tciii Ah, I see where the confusion is on our software set-up page from one of the recent changes we made. Can you please click on one of the OS buttons (Windows, Mac, Linux) and you should be able to see the full software setup page. We’ll get that fixed shortly.

Yes, you will need to calibrate the sensors (IMU and Compass) before doing the motor directions. Let us know if that works.

Camera Tilt: I just did a fresh install of ArduSub 3.5.3 and loaded the default Heavy Parameters. Mine was set to Channel 10. I’m not quite sure how you ended up with RC8 and I am unable to replicate.

Gripper: Channel 11 isn’t applicable here, just use the servo_3_min_momentary and servo _3_max_momentary. AUX3 is hard coded if you use these functions.

From the software setup:

where X is the Aux Channel to which the gripper is connected. For example, a Newton Gripper plugged into Aux Channel 3 can be opened and closed with the servo_3_max_momentary and servo_3_min_momentary button functions, respectively.


(Luis Gamez) #5

Hi Kevin!

Actually it had happened to me a few minutes ago, same problem after installing QGC into a new computer to set up a 6 thrusters configuration ROV the servo tilt was not moving at all and i realized the channel was 10 instead of 8.


(TCIII) #6

Hi Kevin,
Thanks for the quick response, much appreciated.

Okay, I will get the IMU/Compass calibrated before proceeding to check and adjust the Thruster direction.

Yes, I agree that the Camera Setup page, like the Lights Setup Page shows Channel 9 for the Lights Output Channel, does indeed show Channel 10 for the Camera Output Channel, however the Camera Tilt Channel in the “Summary” page, on my version of QGC, is showing RC8 instead of RC10 while the Light Channel in the “Summary” page does show Channel 9 as it should.

Okay, I will revisit the Gripper setup instructions to see if I can get it to work with the Joystick Controller buttons.

Regards,
TCIII AVD


(TCIII) #7

Hi Kevin,

I got the Gripper programmed to the Joystick Controller buttons 9 and 10 and when those buttons are shifted, they control the Camera Tilt Servo as in the Gripper Setup instructions.

By the way, the Voltage and Current Measurement page in the BR2 Software Setup Instructions no longer reflects the current QGC Power page. There is a missing “minimum voltage to arm” parameter in the QGC Power page that is missing from the Software Setup instructions.

What should the “minimum voltage to arm” value be if you are using the BR Li-on battery?

Regards,
TCIII AVD


(TCIII) #8

@luisgamez,

The Camera Tilt Servo channel gets moved from channel 8 to channel 10 if you load in the Heavy Lift parameter file for the 8 thruster configuration just like the Lights channel gets moved from channel 7 to channel 9.

Regards,
TCIII AVD


(Kevin) #9

Let me clear up a bit of the confusion. Here are the references for what I am discussing (Jacob can correct me if I’m wrong in any part of this): ArduCopter RC Input Channel Mapping and Ardusub.com RC Input and Output

Due to their reliance on RC receivers, ArduPilot firmwares have selectable RC Inputs from whatever RC receiver is being used. These are not hard coded and can be changed. These are different from selecting the RC Outputs (Main OUT and AUX OUT on the Pixhawk).

When Rusty and Jacob created and modified ArduSub, some of those selectable RC Inputs were still present and selectable in early ArduSub versions and created a lot of confusion for our customers because they had to select the correct RC Input AND RC Output.

Because we use joystick control instead of an RC TX/RX, our software team has been hard coding the RC Inputs so customers can’t change them to a wrong setting. What you are seeing on the “Summary” page is the remnants of the RC Inputs. All you need to make sure is right when you are connecting servo outputs to the Pixhawk is the RC Output pins.


(Kevin) #10

It is set to 0.0 in the default parameters. It is not necessary for operation.


(TCIII) #11

Hi Kevin,

Thanks for the updates, much appreciated.

Since the minimum safe value for the BR Li-on battery is 12 vdc, maybe it would be best to set the minimum voltage to arm to 13 vdc to protect the battery?

I have the Heavy Lift BR2 sensors all calibrated and the thruster motor directions verified and adjusted as necessary. All that is left is to complete the cable management and add the weights and buoyancy/fairings.

Regards,
TCIII AVD


(Kevin) #12

Sure, you can set it to 13, or whatever voltage you are comfortable with. The max voltage of the Li-Ion pack is 16.8, so somewhere in between 12-16.7 VDC. This is just an arming feature, the more useful one is the battery failsafe on the “Safety” tab so you don’t drop below, say 12.2V.