Efficient approximations of the multi-sensor labelled multi-Bernoulli filter

Abstract

In this paper, we propose two efficient, approximate formulations of the multi-sensor labelled multi-Bernoulli (LMB) filter, which both allow the sensors’ measurement updates to be computed in parallel. Our first filter is based on the direct mathematical manipulation of the multi-sensor, multi-object Bayes filter’s posterior distribution. Unfortunately, it requires the division of probability distributions and its extension beyond linear Gaussian applications is not obvious. Our second filter approximates the multi-sensor, multi-object Bayes filter’s posterior distribution using the geometric average of each sensor’s measurement-updated distribution. This filter can be used under non-linear conditions; however, it is not as accurate as our first filter. In both cases, we approximate the LMB filter’s measurement update using an existing loopy belief propagation algorithm. Both filters have a constant complexity in the number of sensors, and linear complexity in both number of measurements and objects. This is an improvement on an iterated-corrector LMB (IC-LMB) filter, which has linear complexity in the number of sensors. The proposed filters are of interest when tracking many objects using several sensors, where filter run-time is more important than filter accuracy. Simulations indicate that the filters’ loss of accuracy compared to the IC-LMB filter is not significant.