# Controller output querstion

**URL:** <https://discuss.bluerobotics.com/t/controller-output-querstion/14096>\
**Category:** General Discussion\
**Created:** [April 12, 2023, 1:35pm UTC](https://discuss.bluerobotics.com/t/controller-output-querstion/14096 "2023-04-12T13:35:18Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![suitangxiaoyi](https://avatars.discourse-cdn.com/v4/letter/s/6de8d8/32.png) [@suitangxiaoyi](https://discuss.bluerobotics.com/u/suitangxiaoyi)\
**Post date:** [April 12, 2023, 1:35pm UTC](https://discuss.bluerobotics.com/t/controller-output-querstion/14096/1 "2023-04-12T13:35:18Z")

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Hi, we want to replace the PID controller in Ardusub with a new controller, now we have the forces and moments (F1-F6) that should drive the ROV forward, however we don’t know how to implement these six forces on the thruster, and we don’t seem to have found a function that meets our needs, can anyone point us in the right direction?  
Thanks

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**Author:** ![EliotBR](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/eliotbr/32/6937_2.png) [@EliotBR](https://discuss.bluerobotics.com/u/EliotBR)\
**Post date:** [April 21, 2023, 8:05am UTC](https://discuss.bluerobotics.com/t/controller-output-querstion/14096/2 "2023-04-21T08:05:44Z")

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Hi @suitangxiaoyi,

ArduSub does not consider individual thrusters in its existing control algorithms, and does not operate directly using forces. The available controllers instead operate at the vehicle motion control level, and commanded motion amounts are then converted using a matrix of thruster contribution factors into the commands sent to each “Motor” output (which send those signals to the thruster ESCs).

If you’re trying to test an alternative motion controller then perhaps the most straightforward way to do so is via a custom flight mode, but I’m not really sure. @williangalvani do you have any particular insight here?