Robô bípede acionado com ligas de memória de forma.

Abstract

This project has designed a mechanism is a virtual bipedal mobile robot platform with six degrees of freedom, composed of a succession of rigid links interconnected by joints that allow movement in three dimensional space, with the possibility of use of the actuators with linear trajectories of shape memory alloy wire. To achieve the goal was modeled and simulated successfully operate a mechanical biped locomotion with three degrees of freedom for each member with the pressure center located on a surface of contact between the foot or feet and the floor, walking through a horizontal plane. The determination of the motion equation has been achieved by the Newton-Euler dynamics equations. Then, it is evaluated using actuators with shape memory alloys with linear action. Glimpsing the possibility of application in mobile robotics actuators with linear trajectories, in the locomotion distance which go beyond the workspace of the fixed manipulators and in maintenance and inspection processes through of sensors in difficult and unstructured terrain. With the objective of obtaining a lightweight platform, actuators with high strength-weight ratio, which can intelligently adapt to changing situations, and has future capabilities to supplant obstacles, it was decided to design a biped platform with the possibility of using linear actuators consist wire material with shape memory. The shape memory alloys are thermomechanical materials that have a crystalline structure that can take different forms at different temperatures, i. e., may be deformed when heated and cooled. Have the capacity to undergo large strains compared with other materials and recover strains reaching about 8% of its length. Some of its properties are high strength achieved in relation to weight, small size and volume, as well as its low cost compared to conventional actuators, in addition to having silent operation. In this work, the analysis of shape memory alloys was focused on electrical stimulation allowed to model the basic actuation behavior of the material, thus allowing the computation power required for the actuation. The heat transfer model was presented, for the application of the stimulus of an electric current to vary the temperature of the material. Was presented in a general way, a proposed project of implementation of electronic instrumentation, meeting the goal established in this engineering project for the development of a bipedal robot. The complete practical implementation of this project, with certainty, will happen in future work.