Hello,
I have this NDI-Controller for the lateral motion of an aircraft modelled in Simuink and want to determine its stabiity margins. I am strugging in how to linearize the open feedback loop. I placed an ‘looptransfer’ analysis point after my Control Allocation, hence the control input. When I now linearize the open-loop with the Model Linearizer, and determine the margins in MATLAB with ‘allmargin(-linsys)’, it says, that my open-loop is not stable.

For me it seems, like I am using the Matlab Linearizer not correctly, as my outputs of the feedback loop seem stable. The same to all the poles.

Does anyone have an idea, how I should linearize the feedback loop to receive the correct gain & phase margins? Would be so helpful.
Thanks a lot.

Cheers,
FloHello,
I have this NDI-Controller for the lateral motion of an aircraft modelled in Simuink and want to determine its stabiity margins. I am strugging in how to linearize the open feedback loop. I placed an ‘looptransfer’ analysis point after my Control Allocation, hence the control input. When I now linearize the open-loop with the Model Linearizer, and determine the margins in MATLAB with ‘allmargin(-linsys)’, it says, that my open-loop is not stable.

For me it seems, like I am using the Matlab Linearizer not correctly, as my outputs of the feedback loop seem stable. The same to all the poles.

Does anyone have an idea, how I should linearize the feedback loop to receive the correct gain & phase margins? Would be so helpful.
Thanks a lot.

Cheers,
Flo Hello,
I have this NDI-Controller for the lateral motion of an aircraft modelled in Simuink and want to determine its stabiity margins. I am strugging in how to linearize the open feedback loop. I placed an ‘looptransfer’ analysis point after my Control Allocation, hence the control input. When I now linearize the open-loop with the Model Linearizer, and determine the margins in MATLAB with ‘allmargin(-linsys)’, it says, that my open-loop is not stable.

For me it seems, like I am using the Matlab Linearizer not correctly, as my outputs of the feedback loop seem stable. The same to all the poles.

Does anyone have an idea, how I should linearize the feedback loop to receive the correct gain & phase margins? Would be so helpful.
Thanks a lot.

Cheers,
Flo model linearizer, simulink, matlab, margins, allmargins, stabiity, gain margin, feedback, open-loop, open loop, plant, looptransfer, control design, poles MATLAB Answers — New Questions

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