Carla Pinto vai apresentar três comunicações na 9th International Conference of Numerical Analysis and Applied Mathematics (ICNAAM 2011), que se realiza entre 19-25 de Setembro, em Halkidiki, Grécia. A docente do Departamento de Matemática (DMA) é ainda responsável pela coorganização do simpósio “Dynamical Systems: a Framework for Robot Locomotion”, no âmbito da conferência.
“Impact of Discrete Corrections in a Modular Approach for Trajectory Generation in Quadruped Robots” Online generation of trajectories in robots is a very complex task that involves the combination of different types of movements, i.e., distinct motor primitives. The later are used to model complex behaviors in robots, such as locomotion in irregular terrain and obstacle avoidance. In this paper, we consider two motor primitives: rhythmic and discrete. We study the effect on the robots'' gaits of superimposing the two motor primitives, considering two distinct types of coupling. Additionally, we simulate two scenarios, where the discrete primitive is inserted in all of the four limbs, or is inserted in ipsilateral pairs of limbs. Numerical results show that amplitude and frequency of the periodic solutions, corresponding to the gaits trot and pace, are almost constant for diffusive and synaptic couplings.
“A New CPG Model for the Generation of Modular Trajectories of Hexapod Robots” Legged robots are often used in a large variety of tasks, in different environments. Nevertheless, due to the large number of degrees-of-freedom to be controlled, online generation of trajectories in these robots is very complex. In this paper, we consider a modular approach to online generation of trajectories, based on biological concepts, namely Central Pattern Generators (CPGs). We introduce a new CPG model for hexapod robots'' rhythms, based in the work of Golubitsky {\em et al} (1998). Each neuron/oscillator in the CPG consists of two modules/primitives: rhythmic and discrete. We study the effect on the robots'' gaits of superimposing the two motor primitives, considering two distinct types of coupling. We conclude, from the simulation results, that the amplitude and frequency of periodic solutions, identified with hexapods'' tripod and metachronal gaits, remain constant for the two couplings, after insertion of the discrete part.
“A Modular Approach for Trajectory Generation in Biped Robots” Robot locomotion has been a major research issue in the last decades. In particular, humanoid robotics has had a major breakthrough. The motivation for this study is that bipedal locomotion is superior to wheeled approaches on real terrain and situations where robots accompany or replace humans. Some examples are, on the development of human assisting device, such as prosthetics, orthotics, and devices for rehabilitation, rescue of wounded troops, help at the office, help as maidens, accompany and assist elderly people, amongst others. Generating trajectories online for these robots is a hard process, that includes different types of movements, i.e., distinct motor primitives. In this paper, we consider two motor primitives: rhythmic and discrete. We study the effect on a bipeds robots'' gaits of inserting the discrete part as an offset of the rhythmic primitive, in synaptic and diffusive couplings. Numerical results show that amplitude and frequency of the periodic solution, corresponding to the gait run are almost constant in all cases studied here.
As comunicações foram desenvolvidas em colaboração Diana Rocha (bolseira ISEP), Cristina Santos (Universidade do Minho) e Vítor Matos (UM).
DYNAMICAL SYSTEMS: A FRAMEWORK FOR ROBOT LOCOMOTION Robot locomotion for any type of robots has been an interesting and challenging research issue in the last few years. The increasing use of robots to perform difficult tasks in dynamic and hard environments, sometimes inaccessible to humans, makes this study very important and relevant. In this symposia, we focus on the use of the dynamical systems theory to address some still open questions regarding locomotion skills in robots. Dynamical systems exhibit some properties which makes them well suited to real-time robotic applications, such as movement generation for legged; modular and wheeled platforms; balance control; grasping; reaching, etc. The organizers aim to provide a venue where researchers, scientists, engineers and practitioners throughout the world can present and discuss the latest achievements, future challenges and exciting new dynamical systems models that will enable to improve the locomotion skills of future robots.
Instituto Superior de Engenharia do Porto