Precisão em posicionamento de manipulador não condutor acionado por músculos artificiais pneumáticos.

Abstract

With the population growth and the evergrowing energy dependency, the contemporary society have been facing new challenges to maintain yourself. The use of robotics in various fields is each time more common, contributing to surpass these new challenges. However, there are still cases where applying conventional robotics is prohibitive, such as in high electric and magnetic field environments, found, for example, in electric energy distribution systems and in magnetic resonance imaging machines. That's because conductive and ferromagnetic components can cause serious problems, like burns, shortcuts and even be throwed at high velocities. Knowing these difficulties, this work proposes the construction of a robotic manipulator capable of acting in these high electric and magnetic field environments. To build such manipulator, however, it's necessary to study the mechanic structure, the actuators, the sensors and the controller. In the case of the mechanic structure and sensors, there exists non-conductive and non-magnetic alternatives available. The controller is, in general, a microcomputer or an electric device, therefore, conductive. One alternative is to keep the controller far away from the risk environment. But to test this hypothesis, it's necessary to have a non-conductive and non-ferromagnetic actuator. Because of that, this work proposes the construction of an actuator free of conductive and magnetic materials, based on the McKibben pneumatic artificial muscle. Pneumatic artificial muscles are available commercially, but they have metallic components. Besides, the accurate control of these actuators is difficult for their high non-linearities. To verify the viability of applying artificial muscles on a non-conductive manipulator, tests were conducted with artificial muscle prototypes built with compatible materials. The design and dimensioning of the artificial muscle are covered. Finally, the PID controller is implemented to evaluate the muscle's controllability and its viability for tasks that need position accuracy.

Pneumatic artificial muscles: model, design, fabrication, sensing and control strategies for electromagnetic risk applications.

“…For a MRI-guided surgical manipulator, for example, the electromagnetic risk region is inside the MRI scanner and surroundings (zone IV). PAMs built with compatible materials can be used to power the system, such as the one in (SCAFF, 2015), and compatible sensors (which are discussed in chapter 5) can be used in the manipulator, which is the critical system. Pneumatic hoses and optical fiber cables can transmit power and signals, respectively, from the non critical system to the critical system, forming the communication and power interface.…”