CRIIS - Other Publications

Permanent URI for this collection

http://localhost:4000/handle/123456789/284

Browse

Browsing CRIIS - Other Publications by Author "Conceicao,AGS"
  • Item
    Perception-Driven Multi-Robot Formation Control
    ( 2013) Ahmad,A ; Nascimento,T ; Conceicao,AGS ; António Paulo Moreira ; Lima,P
    Maximizing the performance of cooperative perception of a tracked target by a team of mobile robots while maintaining the team's formation is the core problem addressed in this work. We propose a solution by integrating the controller and the estimator modules in a formation control loop. The controller module is a distributed non-linear model predictive controller and the estimator module is based on a particle filter for cooperative target tracking. A formal description of the integration followed by simulation and real robot results on two different teams of homogeneous robots are presented. The results highlight how our method successfully enables a team of homogeneous robots to minimize the total uncertainty of the tracked target's cooperative estimate while complying with the performance criteria such as keeping a pre-set distance between the team-mates and/or the target and obstacle avoidance.
  • Item
    A set of novel modifications to improve algorithms from the A* family applied in mobile robotics
    ( 2013) do Nascimento,TP ; Pedro Gomes Costa ; Paulo José Costa ; António Paulo Moreira ; Conceicao,AGS
    This paper presents a set of novel modifications that can be applied to any grid-based path planning algorithm from the A* family used in mobile robotics. Five modifications are presented regarding the way the robot sees an obstacle and its target to plan the robot's path. The modifications make it possible for the robot to get to the target faster than traditional algorithms, as well as to avoid obstacles that move as fast as (or even faster than) the robot. Some simulations were made using a crowded and highly dynamic environment with twelve randomly moving obstacles. In these first simulations, a middle sized 5DPO robot was used. Also, real experiments were made with a small-sized version of a 5DPO robot to validate the algorithm's effectiveness. In all simulations and real robot experiments the objects are considered to be moving at a constant speed. Finally, we present an overall discussion and conclusion of this paper. © 2012 The Brazilian Computer Society.