Alexander Carballo

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This paper describes an implementation of a mobile robot system for autonomous navigation in outdoor concurred walkways. The task was to navigate through non-modified pedestrian paths with people and bicycles passing by. The robot has multiple redundant sensors which include wheel encoders, an IMU, a DGPS and four laser scanner sensors. All the computation(More)
Effective detection of people is a basic requirement for robot coexistence in human environments. In our previous work [1] we proposed a method for people detection and position estimation using multiple layers of Laser Range Finders (LRF) in a mobile robot. We extend our work by introducing laser reflection intensity as a novel feature for people(More)
In this study, we examined the effects of water deficit on the elongation of radicles of maize seedlings and on the accumulation of solutes in the radicle apices of two maize varieties: VS-22 (tolerant) and AMCCG-2 (susceptible). Sections of radicle corresponding to the first 2 mm of the primary roots were marked with black ink, and the seedlings were(More)
— This work presents our method for people detection on the surroundings of a mobile robot by using two layers of multiple LRFs, allowing to simultaneously detect two set of different features for every person: chest and legs areas. A person model is created according to the association of these features and a volume representation allows to estimate the(More)
This work proposes a new method people detection and position estimation from a mobile robot by fusion of multiple laser range finders arranged in two layers. Sensors facing opposite directions in a single row (layer) are fused to produce 360deg scan data of robotpsilas surroundings, then data from every layer is further fused to create a 3D model of people(More)
In recent years, Web Caching has been considered one of the key areas to improve web usage efficiency. However, caching web objects proposes many considerations about the validity of the cache. Ideally, it would be valuable to have a consistent cache, where no invalid relationships among objects are held. Several alternatives have been offered to keep(More)
Time is crucial in applications such as sensor data fusion, autonomous mobility and SLAM. However clocks at end systems are rarely synchronized and often running at different speeds. Lack of synchronization therefore reduces the accuracy of sensor readings. The SOKUIKI scanning laser range finder allows acquiring time values by timestamping range readings.(More)