VALENZUELA, W. A. V.; http://lattes.cnpq.br/5539218691799154; VALENZUELA, Walter Andrés Vermehren.
Résumé:
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.