Using a Spline To Model the Motion Of a 4-man Fireteam During Building Clearing Exercises

This paper examines the problem of tracking positions of a fireteam (4-5 men) as they perform building clearing exercises in order to predict future motion of the team. This was done by examining the team as a single entity rather than 4 or 5 separate entities. A team model was used under the assumption that the team stays together as a group and moves in specific patterns. The model chosen for this experiment was a spline curve. This spline curve allowed for movement in straight lines through hallways as well as curving around corners. Two experiments were conducted to help predict the future motion of the team. The first experiment extended the curve created by the current team member positions. Five different extensions were examined: a straight line extension, a straight line extension from the tangent formed at the last team member, a curve in which the curvature of the spline remained the same through the extension, a curve in which the curvature dissipates through the extension, and a curve in which the curvature increases through the extension. The distance of the team from the predicted line was measured. The second experiment performed measured how well the team retained their configuration as they moved. This was done by taking the area difference between the spline created at the current location and the spline at future locations. The results of the experiments show that applying a geometric model to the team and examining their movement as a whole instead of as separate entities can be useful in predicting the future positions of the team members. In a hallway, extending the curve does well for predicting time into the future, 1.75 seconds, but not as well for distance, only 20 cm. The configuration of the team remains relatively constant since they are moving in a line. As for entering the room, the extension methods do well for distance, 32 cm, but only 0.3 seconds. This means that team does a good job of playing “follow-the-leader” into the iii room. The configuration changes due to the quick acceleration of the team; however it is mainly caused by a “stretching” of the team configuration. For the room data the prediction method for movement is minimal, 18 cm and 0.2 seconds, due to the fact that they spread out to cover the entire room. This also causes a large change in configuration. Overall, the spline model has some merit for predicting the team’s future positions as they enter the room; however, the experiments show that this model warrants further development.