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rpng / open_vins

An open source platform for visual-inertial navigation research.
https://docs.openvins.com
GNU General Public License v3.0
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Confusion about the difference of formula in LiMinyang's thesis and openvins Document #283

Closed WenxingPeng closed 1 year ago

WenxingPeng commented 1 year ago

Hi! Thanks for the excellent work you have done! It really improves my understanding of filter-based VIO!

However, when I read the article written by LiMinyang（Vision-aided Inertial Navigation with Rolling-Shutter Cameras）, I find some differences between the formula provided by open_vins document and Li's article.

To be more specific, in the document open_vins provided, the Jacobian of the new IMU clone w.r.t. time offset t_d is given by image

In Li's article, the quaternion part w.r.t t_d is the angular velocity in the Global frame(with bias removed), while in the document open_vins provided, it is the angular velocity in the IMU frame(with bias removed). image

Could you explain the differences and help me out? Thanks a lot!

goldbattle commented 1 year ago

We have different orientation error states (left versus right multiplicative).

On Mon, Oct 31, 2022 at 10:01 AM WenxingPeng @.***> wrote:

Hi! Thanks for the excellent work you have done! It really improves my understanding of filter-based VIO!

However, when I read the article written by LiMinyang（Vision-aided Inertial Navigation with Rolling-Shutter Cameras）, I find some differences between the formula provided by open_vins document and Li's article.

To be more specific, in the document open_vins provided, the Jacobian of the new IMU clone w.r.t. time offset t_d is given by [image: image] https://user-images.githubusercontent.com/49303832/199024559-538b6a9e-66a4-4f48-9171-531304302b82.png

In Li's article, the quaternion part w.r.t t_d is the angular velocity in the Global frame(with bias removed), while in the document open_vins provided, it is the angular velocity in the IMU frame(with bias removed). [image: image] https://user-images.githubusercontent.com/49303832/199025888-3c3bfa3b-c05c-43cc-8520-2f89a5827529.png

Could you explain the differences and help me out? Thanks a lot!

— Reply to this email directly, view it on GitHub https://github.com/rpng/open_vins/issues/283, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAQ6TYSE55ZUCRW2OZFZZFDWF7GKHANCNFSM6AAAAAARTDM2C4 . You are receiving this because you are subscribed to this thread.Message ID: @.***>

WenxingPeng commented 1 year ago

Thanks for your reply! It helps me a lot