Guilherme Fernandes

Rehabilitation robotics and serious games: An initial architecture for simultaneous players

Traditional rehabilitation treatment includes repetitive and tedious exercises for the patient. The use of computer games can motivate and engage the patients attention, making the rehabilitation process more pleasant and attractive. In this context, this paper proposes an architecture that allows multiple users to take part simultaneously on a state of the art rehabilitation process using robots and computer games. The main components of this architecture are the impedance control system adopted by the therapy robots, the client-server communication structure (Telerehabilitation server) and the human machine interface based on a serious game. Preliminary experimental tests, involving a cooperative game with two users and individual robots, clearly demonstrate how the experience of the players may be influenced by impedance control.

A robust manipulation strategy based on impedance control parameters changes and smooth trajectories

This paper proposes a new manipulation strategy that combines smooth trajectories with an impedance controller which parameters are adapted in time of execution. The proposal uses a single control law during all manipulation phases, i.e. when the robot is in contact with the object, and during regrasping when the robot moves freely in space. The manipulator impedance changes during the different manipulation phases and this is achieved modifying mass, stiffness and damping parameters of the controller. Controller stability is further enhanced by the adoption of smooth trajectories that are generated using a compact and computationally light Squeezed Screws Planner. Additionally, the approach shows good response to the occurrence of unplanned contact or collisions. Experimental results with an industrial manipulator unscrewing a jar cap, provides interesting data about performance and show the benefits of the adopted manipulation strategy.

Environment Exploration for Impedance Control Based Manipulators: Initial Experimental Study on Object Position Detection with Stable Contact

Robotic manipulation under unstructured environments still is an open challenge to the research community. Lots of effort have been addressed to visual perception and remarkable progress has been achieved in the area. However, the information obtained from vision systems is frequently incomplete and noisy, incapacitating robotic systems to complete their target tasks in some cases. Moreover, little attention has been given to the use of exploration by touch as an approach to enrich environment perception, mainly due to difficulties that arrive from stable physical interaction with the environment. This work presents the experimental results from an initial study on the capability of an impedance controlled manipulator perceiving its surrounding environment using touch as source of information. The experiments culminate on a repeatability test which indicates that such a method provides higher precision information in comparison with 3D vision systems. The experimental procedures consider different impedance parameters during establishment and loss of contact. Considering the obtained results, different surface approach heuristic are evaluated to determine the most appropriated to, firstly, establish a stable contact with the environment and secondly, as a consequence, to perform spatial measures.

An Overview of International Human Trafficking in Brazil

This chapter aims to present an overview of international trafficking in persons in Brazil. The chapter will present a general overview of the Brazilian law dealing with the issue of international trafficking in persons, analysed from the perspective of international norms. The government action in the formulation of public policies on human trafficking is also analysed by the Brazilian National Policy for Combating Trafficking in Persons and the National Plan to Combat Traffic in Persons. At the end we show some data obtained from criminal investigations of the Brazilian Federal Police, the agency responsible for investigating crimes of international trafficking in persons.