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Quaternion convention #19

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simonlynen opened this Issue Aug 9, 2013 · 5 comments

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simonlynen commented Aug 9, 2013

I know it is a highly controversal topic, however I am not happy with having different quaternion notations around in the lab. Aslam/aslam visual inertial uses sm kinematics which uses JPL. The msf/helis use eigen which is hamilton. Should we unify this at some point?

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markusachtelik commented Aug 9, 2013

Ok, so let's start the discussion ;)
As most of you know, I'm a high supporter of Hamilton,

  • Eigen uses it
  • ROS uses it
  • In my opinion, transformations are more intuitive
  • Just fixed / checked / changed everything to Hamilton for my thesis
  • With the definition of the error in msf, the error terms in the Jacobians end up being the same anyway
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stephanweiss commented Aug 9, 2013

My "unbiased" vote goes for JPL notation ;-)

Jokes aside. I am surprised that sm and aslam use JPL notation, given the efforts "we" did to change ssf and msf to Hamilton. I think there is no need to figure out why they used JPL notation but I feel we should go with the Hamilton notation - just because everyone else does. To my knowledge JPL papers are so far the only ones that do not use Hamilton.


From: Markus Achtelik [notifications@github.com]
Sent: Friday, August 09, 2013 1:42 AM
To: ethz-asl/sensor_fusion
Subject: Re: [sensor_fusion] Quaternion convention (#19)

Ok, so let's start the discussion ;)
As most of you know, I'm a high supporter of Hamilton,

  • Eigen uses it
  • ROS uses it
  • In my opinion, transformations are more intuitive
  • Just fixed / checked / changed everything to Hamilton for my thesis
  • With the definition of the error in msf, the error terms in the Jacobians end up being the same anyway


Reply to this email directly or view it on GitHubhttps://github.com//issues/19#issuecomment-22382396.

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omaris commented Aug 9, 2013

For what it's worth, google ceres uses the hamiltonian convention too..

On 09.08.2013, at 18:45, stephanweiss notifications@github.com wrote:

My "unbiased" vote goes for JPL notation ;-)

Jokes aside. I am surprised that sm and aslam use JPL notation, given the
efforts "we" did to change ssf and msf to Hamilton. I think there is no
need to figure out why they used JPL notation but I feel we should go with
the Hamilton notation - just because everyone else does. To my knowledge
JPL papers are so far the only ones that do not use Hamilton.


From: Markus Achtelik [notifications@github.com]
Sent: Friday, August 09, 2013 1:42 AM
To: ethz-asl/sensor_fusion
Subject: Re: [sensor_fusion] Quaternion convention (#19)

Ok, so let's start the discussion ;)
As most of you know, I'm a high supporter of Hamilton,

  • Eigen uses it
  • ROS uses it
  • In my opinion, transformations are more intuitive
  • Just fixed / checked / changed everything to Hamilton for my thesis
  • With the definition of the error in msf, the error terms in the Jacobians
    end up being the same anyway


Reply to this email directly or view it on GitHub<
https://github.com/ethz-asl/sensor_fusion/issues/19#issuecomment-22382396>.


Reply to this email directly or view it on
GitHubhttps://github.com//issues/19#issuecomment-22407678
.

@simonlynen

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simonlynen commented Aug 9, 2013

This depends on which Quaternion parameterization you pass for the respective parameter blocks :)


From: Sammy Omari [notifications@github.com]
Sent: Friday, August 09, 2013 18:56
To: ethz-asl/sensor_fusion
Cc: Lynen Simon
Subject: Re: [sensor_fusion] Quaternion convention (#19)

For what it's worth, google ceres uses the hamiltonian convention too..

On 09.08.2013, at 18:45, stephanweiss notifications@github.com wrote:

My "unbiased" vote goes for JPL notation ;-)

Jokes aside. I am surprised that sm and aslam use JPL notation, given the
efforts "we" did to change ssf and msf to Hamilton. I think there is no
need to figure out why they used JPL notation but I feel we should go with
the Hamilton notation - just because everyone else does. To my knowledge
JPL papers are so far the only ones that do not use Hamilton.


From: Markus Achtelik [notifications@github.com]
Sent: Friday, August 09, 2013 1:42 AM
To: ethz-asl/sensor_fusion
Subject: Re: [sensor_fusion] Quaternion convention (#19)

Ok, so let's start the discussion ;)
As most of you know, I'm a high supporter of Hamilton,

  • Eigen uses it
  • ROS uses it
  • In my opinion, transformations are more intuitive
  • Just fixed / checked / changed everything to Hamilton for my thesis
  • With the definition of the error in msf, the error terms in the Jacobians
    end up being the same anyway


Reply to this email directly or view it on GitHub<
https://github.com/ethz-asl/sensor_fusion/issues/19#issuecomment-22382396>.


Reply to this email directly or view it on
GitHubhttps://github.com//issues/19#issuecomment-22407678
.


Reply to this email directly or view it on GitHubhttps://github.com//issues/19#issuecomment-22408323.

@simonlynen

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simonlynen commented Aug 9, 2013

U. Minnesota uses JPL


From: stephanweiss [notifications@github.com]
Sent: Friday, August 09, 2013 18:45
To: ethz-asl/sensor_fusion
Cc: Lynen Simon
Subject: Re: [sensor_fusion] Quaternion convention (#19)

My "unbiased" vote goes for JPL notation ;-)

Jokes aside. I am surprised that sm and aslam use JPL notation, given the efforts "we" did to change ssf and msf to Hamilton. I think there is no need to figure out why they used JPL notation but I feel we should go with the Hamilton notation - just because everyone else does. To my knowledge JPL papers are so far the only ones that do not use Hamilton.


From: Markus Achtelik [notifications@github.com]
Sent: Friday, August 09, 2013 1:42 AM
To: ethz-asl/sensor_fusion
Subject: Re: [sensor_fusion] Quaternion convention (#19)

Ok, so let's start the discussion ;)
As most of you know, I'm a high supporter of Hamilton,

  • Eigen uses it
  • ROS uses it
  • In my opinion, transformations are more intuitive
  • Just fixed / checked / changed everything to Hamilton for my thesis
  • With the definition of the error in msf, the error terms in the Jacobians end up being the same anyway


Reply to this email directly or view it on GitHubhttps://github.com//issues/19#issuecomment-22382396.


Reply to this email directly or view it on GitHubhttps://github.com//issues/19#issuecomment-22407678.

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