I. Introduction
Multiple targets tracking plays an important role in various applications, such as surveillance, human motion analysis, traffic flow analysis and others. Multi-target tracking is much easier when the targets are distinctive or not interacting with each other because it can be solved by using multiple independent trackers. However, for the targets similar in appearance, obtaining the correct trajectories of them becomes significantly more challenging when they interact. Specifically, for the laser-based human tracking systems [1]–[3] (as shown in Fig. 1), which cannot provide the color information of targets, maintaining the correct tracking seems to be an impossible mission when the well-known “merge/split” condition occurs (as shown in Fig. 2). Hence, the goals of this research are: 1) to devise a new method that will help obtain a better tracking performance with laser scanner than those obtained from previous methods when the interactions occur; 2) to make a new attempt to solve the “merge/split” problem in the laser based multi-target tracking.