I have two questions on the quaternion which I hope could be clarified.(adsbygoogle = window.adsbygoogle || []).push({});

1. The problem statement, all variables and given/known data

Q1)

The multiplicative error quaternion has equation:

q_aposteriori = [δqτ √(1-δqτ * δq)]τ χ q_apriori

I have some data where δqτ * δq > 1 and thus √(1-δqτ * δq) give me an imaginary number, which is supposed to be the scalar fourth component of quaternion. Am I doing anything wrong here, and how can I solve it?

Q2) For numerical integration, can I just integrate quaternion like I will normally do with dynamic equations?

as per usual propagation:

x = x + w*dt

for quartenion:

q = q + qdot*dt

then normalize(q)

is this correct?

2. Relevant equations

The multiplicative error quaternion has equation:

q_aposteriori = [δqτ √(1-δqτ * δq)]τ χ q_apriori

where:

q_aposteriori = quartenion after update

q_aposteriori = quartenion before update

τ = transpose

χ = quaternion multiplication

3. The attempt at a solution

as above

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# Homework Help: Quartenion and Kalman

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