Abstract— Visual-inertial SLAM (VI-SLAM) requires a good
initial estimation of the initial velocity, orientation with respect
to gravity and gyroscope and accelerometer biases. In this paper
we build on the initialization method proposed by Martinelli
[1] and extended by Kaiser et al. [2], modifying it to be
more general and efficient. We improve accuracy with several
rounds of visual-inertial bundle adjustment, and robustify the
method with novel observability and consensus tests, that
discard erroneous solutions. Our results on the EuRoC dataset
show that, while the original method produces scale errors
up to 156%, our method is able to consistently initialize in
less than two seconds with scale errors around 5%, which can
be further reduced to less than 1% performing visual-inertial
bundle adjustment after ten seconds
