43 documents found, page 1 of 5
A modular framework to generate robust biped locomotion: from planning to control
Kasaei, Mohammadreza; Ahmadi, Ali; Lau, Nuno; Pereira, ArturBiped robots are inherently unstable because of their complex kinematics as well as dynamics. Despite many research efforts in developing biped locomotion, the performance of biped locomotion is still far from the expectations. This paper proposes a model-based framework to generate stable biped locomotion. The core of this framework is an abstract dynamics model which is composed of three masses to consider th...
Deriving and improving CMA-ES with information geometric trust regions
Abdolmaleki, Abbas; Price, Bob; Lau, Nuno; Reis, L. P.; Neumann, GerhardCMA-ES is one of the most popular stochastic search algorithms. It performs favourably in many tasks without the need of extensive parameter tuning. The algorithm has many beneficial properties, including automatic step-size adaptation, efficient covariance updates that incorporates the current samples as well as the evolution path and its invariance properties. Its update rules are composed of well established...
Contextual covariance matrix adaptation evolutionary strategies
Abdolmaleki, Abbas; Price, Bob; Lau, Nuno; Reis, L. P.; Neumann, GerhardMany stochastic search algorithms are designed to optimize a fixed objective function to learn a task, i.e., if the objective function changes slightly, for example, due to a change in the situation or context of the task, relearning is required to adapt to the new context. For instance, if we want to learn a kicking movement for a soccer robot, we have to relearn the movement for different ball locations. Such...
Learning a humanoid kick with controlled distance
Abdolmaleki, Abbas; Simões, David; Lau, Nuno; Reis, L. P.; Neumann, GerhardWe investigate the learning of a flexible humanoid robot kick controller, i.e., the controller should be applicable for multiple contexts, such as different kick distances, initial robot position with respect to the ball or both. Current approaches typically tune or optimise the parameters of the biped kick controller for a single context, such as a kick with longest distance or a kick with a specific distance....
Invited paper: multimodal interface for an intelligent wheelchair
Reis, Luís Paulo; Faria, Brigida Monica; Vasconcelos, Sérgio; Lau, NunoSince the demographics of population, with respect to age, are continuously changing, politicians and scientists start to pay more attention to the needs of senior individuals. Additionally, the well-being and needs of disabled individuals are also becoming highly valued in the political and entrepreneurial society. Intelligent wheelchairs are adapted electric wheelchairs with environmental perception, semi-aut...
Intelligent wheelchair driving: bridging the gap between virtual and real intel...
Faria, Brígida Mónica; Reis, Luís Paulo; Lau, Nuno; Moreira, António Paulo; Petry, Marcelo; Ferreira, Luís MiguelWheelchairs are important locomotion devices for handicapped and senior people. With the increase in the number of senior citizens and the increment of people bearing physical deficiencies, there is a growing demand for safer and more comfortable wheelchairs. So the new Intelligent Wheelchair (IW) concept was introduced. Like many other robotic systems, the main capabilities of an intelligent wheelchair should ...
A methodology for creating an adapted command language for driving an intellige...
Faria, Brigida Monica; Reis, Luís Paulo; Lau, NunoIntelligent wheelchairs (IW) are technologies that can increase the autonomy and independence of elderly people and patients suffering from some kind of disability. Nowadays the intelligent wheelchairs and the human-machine studies are very active research areas. This paper presents a methodology and a Data Analysis System (DAS) that provides an adapted command language to an user of the IW. This command langua...
Special Issue Robótica 2014
Lau, Nuno; Moreira, António Paulo; Ventura, Rodrigo; Faria, Brígida MónicaThis special issue presents extended and revised versions of a selection of papers presented on the IEEE International Conference on Autonomous Robot Systems and Competitions (ICARSC-2014), that took place 14-15 May 2014 in the city of Espinho, Portugal.
3D Map and DGPS Validation for a Vineyard Autonomous Navigation System
Contente, Olga; Aranha, José; Martinho, José; Morgado, José Francisco; Reis, Manuel; Fereira, Paulo; Morais, Raul; Lau, NunoAn autonomous DGPS navigation system must use an accurate threedimensional (3D) digital map. However, it is crucial to validate it using data collected in the field. One possible way to validate the map is to employ a vehicle driven by an expert to ensure that the trajectory is plotted within the boundaries of navigation paths. It is essential to take this care, especially when the terrain is very highly uneven...
User modeling and command language adapted for driving an intelligent wheelchair
Faria, Brígida Mónica; Reis, Luís Paulo; Lau, NunoThe importance and concern given to the autonomy and independence of elderly people and patients suffering from some kind of disability has been growing significantly in the last few decades. Intelligent wheelchairs (IW) are technologies that can increase the autonomy and independence of this kind of population and are nowadays a very active research area. This paper presents a Data Analysis System (DAS) that p...