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Making custom motor cofiguration


(NICKY) #1

Hi,

We are working on a underwater ROV project using the pixhawk.

we need two vertical thrusters one placed at front of the ROV and one placed at the back of the ROV and the horizontal thrusters placed at sides of the ROV

could you let us know the steps we need to follow to make the necessary changes in the simple ROV module to get our desired motor configuration…

Thank You



(Jacob) #2

You need to make a new motor configuration like this one.

Assuming that the vehicle moves towards the left of the page when going forward…

I will number the motors:
1: bottom of the page
2: top of the page
3: left of the page
4: right of the page

Then the numbers would look something like this:

	MOT_1_ROLL_FACTOR = 0,
	MOT_1_PITCH_FACTOR = 0,
	MOT_1_YAW_FACTOR = -1.0,
	MOT_1_THROTTLE_FACTOR = 0.0,
	MOT_1_FORWARD_FACTOR = 1.0,
	MOT_1_STRAFE_FACTOR = 0.0,

	MOT_2_ROLL_FACTOR = 0,
	MOT_2_PITCH_FACTOR = 0,
	MOT_2_YAW_FACTOR = 1.0,
	MOT_2_THROTTLE_FACTOR = 0.0,
	MOT_2_FORWARD_FACTOR = 1.0,
	MOT_2_STRAFE_FACTOR = 0.0,

	MOT_3_ROLL_FACTOR = 0.0,
	MOT_3_PITCH_FACTOR = 1.0,
	MOT_3_YAW_FACTOR = 0,
	MOT_3_THROTTLE_FACTOR = 1.0,
	MOT_3_FORWARD_FACTOR = 0.0,
	MOT_3_STRAFE_FACTOR = 0.0,

	MOT_4_ROLL_FACTOR = 0.0,
	MOT_4_PITCH_FACTOR = -1.0,
	MOT_4_YAW_FACTOR = 0,
	MOT_4_THROTTLE_FACTOR = 1.0,
	MOT_4_FORWARD_FACTOR = 0.0,
            MOT_4_STRAFE_FACTOR = 0.0

-Jacob


(NICKY) #3

Hello Jacob,

Thanks for the reply on such short notice,

I do get an idea of what you’re saying, But do I need to make the change in the github repository and load a new firmware altogether…?

I’m very new to the github and it seems I need to convert .cpp extensions to .px4

are there steps I can follow to be able to do this…?

we are running short on time, as it took a while to get our hands on the pixhawk…

Thank you…


(Jacob) #4

The quickest way to do what you want would be to modify the file for bluerov locally, just like you had in your pull request (These changes are just for you on your machine, not to put on github ArduSub repository). Then under /ArduSub/Ardusub enter:

$ make px4-v2-bluerov-upload

This will recompile the code with your new motor configuration and upload it to your board.

Also look at this for more information http://ardupilot.org/dev/docs/building-px4-for-linux-with-make.html

-Jacob


(NICKY) #5

I did make the necessary changes in the libraries file where AP_MOTOR file is present and tried to convert the ARDUSUB file to .px4

but I keep getting the following error.

with regards…



(Jacob) #6

First, the directory needs to be named ‘ArduSub’, second, you need to build under ArduSub/ArduSub/

-Jacob


(Phedias Demou) #7

Dear Jacob,

After reconfiguring the motors, would the firmware work with the new controllable DOF without further changes?

Thanks,

Phedias Demou