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E=λE_stereo+E_imu

Open Ginger-Light opened this issue 4 years ago • 4 comments

Hi,

Thanks for sharing the code.

I have the issue, I try to find the λ factor before E_stereo in the code, In detail, it shoulb be in void EnergyFunctional::solveSystemF() but I didn't find it.

Excuse me, it was not added λ here, or I was not carefulty enough to find it.

Thanks again for your code

Ginger-Light avatar Dec 28 '20 02:12 Ginger-Light

The λ factor in the objective function actually goes into the information matrix(W) in G-N normal equation (J^TWJ x = -JWr), so you can find the λ factor in double PointFrameResidual::linearizeStereo(CalibHessian* HCalib) which is located in Residuals.cpp.

float lambda = stereo_weight;

Wish this might help! :)

studennis911988 avatar Dec 28 '20 03:12 studennis911988

The λ factor in the objective function actually goes into the information matrix(W) in G-N normal equation (J^TWJ x = -JWr), so you can find the λ factor in double PointFrameResidual::linearizeStereo(CalibHessian* HCalib) which is located in Residuals.cpp.

float lambda = stereo_weight;

Wish this might help! :)

My friend! Thank u very much!

This is Lagrange Multiplier, right?

Ginger-Light avatar Dec 28 '20 03:12 Ginger-Light

It has nothing to do with Lagrange Multiplier. Since DSO is a direct method, it can't normalized the norm of visual and imu residual to the non-dimensional terms( Mahalanobis distance)as it's typically done in featured-based VIO system, so VI-DSO just uses a λ to weight between visual and imu energy function.

studennis911988 avatar Dec 28 '20 03:12 studennis911988

It has nothing to do with Lagrange Multiplier. Since DSO is a direct method, it can't normalized the norm of visual and imu residual to the non-dimensional terms( Mahalanobis distance)as it's typically done in featured-based VIO system, so VI-DSO just uses a λ to weight between visual and imu energy function.

Thank you for helping me understand this!

Ginger-Light avatar Dec 28 '20 04:12 Ginger-Light