Memorias de investigación
Tracking and Intercepting Pedestrians: A Robotic Approach to Surveillance of Critical Infrastructures

Research Areas
  • Autonomic robots,
  • Exterior robots,
  • Cooperative robots

This dissertation presents an approach for the inclusion of technologies from the field of robotics into security and surveillance of outdoor critical infrastructures. Nowadays, the systems used for these tasks are mainly reactive, meaning that they rely on alarms based on static sensors that require constant monitoring and a response from human operators. Therefore, the use of robotic systems can improve the capabilities of detecting and reacting to disruptions while reducing the risk for human operators. The global objective of this work is to develop a system capable of performing a high level task in the context of security systems: the detection, tracking and interception of an intruder moving around, in an outdoors critical infrastructure. Moreover, the work should be focused not only on developing algorithms and strategies but also on testing them with real robots in realistic scenarios. During the Thesis, a modular system has been developed to carry out the global mission, thus, the process has been divided into several modules, namely: pedestrian detection, tracking, trajectory prediction, planning for interception and autonomous navigation. This modular design allowed developing and testing the modules independently from each other. Moreover, it also allowed us to use them in combination with external algorithms or to apply them to different applications. Furthermore, in order to facilitate the integration of the modules and real experimentation, software and communications architectures have been developed. The pedestrians detection module is based on the fusion of information from two different sources: a 2D-laser scanner and a camera. This module introduces two main novelties: the first one is the inclusion of an adaptive technique for projection of the region-of-interest, which addresses the problem of vertically localizing a projection from the laser into an image plane. The second one consists on introducing of a probability calibration step, applied before performing the fusion of information provided by both sensors, this allows reducing redundancy and correlation between two information sources. The next module included in this work is the pedestrian tracking. It keeps updated a list of detected pedestrians, including their position and velocities. In order to do that, the algorithm processes the observations and determines whether or not each observation corresponds to a previously detected pedestrian. The main novelty on this algorithm is the introduction of a discriminative tracking procedure, where the uncertainty of the detection is taken into account. This means that, highly certain detections are used to confirm the presence of a human in the scene, meanwhile uncertain ones are used to keep track of its position over large areas. The trajectory prediction module uses a comparison of the observed trajectory against possible routes in combination with a simple modeling of the movements, to obtain a long-term prediction of the future trajectory of the pedestrian. Its main contribution is that it does not require any previous observation of pedestrian trajectories to obtain the prediction. Moreover, it can be adapted to any scenario since it only requires a cost-map of the infrastructure environment. Also, the integration of a motion model allows estimating a long term time-stamped prediction, which is required by the interception task. The path planning for interception module constructs a tree of possible trajectories and evaluates each one of them in terms of their probability of intercepting the intruder according to its predicted trajectory. Subsequently, it extracts a route that likely intercepts a pedestrian, while avoiding both static and dynamic obstacles. The contribution in this case consisted on the modification and adaptation for this task, of an algorithm previously used for navigation in dynamic environments under uncertainty.
Mark Rating
Sobresaliente cum laude

Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Robótica y Cibernética
  • Departamento: Automática, Ingeniería Eléctrica y Electrónica e Informática Industrial
  • Centro o Instituto I+D+i: Centro de Automática y Robótica (CAR). Centro Mixto UPM-CSIC