| Título: | Requirement derivation method for a legged robot with series-elastic actuators |
| Autor: | Daniela Vacarini de Faria |
| Programa: | Engenharia Aeronáutica e Mecânica |
| Área de Concentração: | Sistemas Aeroespaciais e Mecatrônica |
| Orientador : | Luiz Carlos Sandoval Góes |
| Coorientador : | Marcos Ricardo Omena de Albuquerque Maximo |
| Ano de Publicação : | 2019 |
| Curso : | Mestrado Acadêmico |
| Assuntos : | Atuadores |
| t | Dinâmica de robôs |
| t | Impedância |
| t | Controle com realimentação |
| t | Controle |
| Resumo : | In this dissertation a methodology for requirement derivation of the dynamical requirements of a series elastic actuator to be applied to a legged robot is presented. The leg model consists of a mechanism composed of three links - representing the thigh, shin and foot - and two Series Elastics Actuators (SEA) - representing the knee and ankle. The paw, i.e. the point of contact between the robot and the ground, is not actuated and does not slip. The Center of Mass (CoM) is considered to be placed on the shoulder of the robot. In order to study the robot movement and actuators performance, the stance phase of a running gait is modeled according to the Spring Loaded Inverted Pendulum (SLIP) method. To make sure that sufficient extent of running patterns is covered, the SLIP parameters are sampled inside a predefined range using Improved Distributed Hypercube Sampling method. The number of samples used in this study is selected through a convergence test. The leg performance is then studied through a comparison between the CoM trajectory obtained simulating the mechanism with ideal actuators on its joints and with SEAs. The ideal actuators are considered ones capable of providing all torque needed by the controllers. To control the leg, a closed loop Impedance Controller is used to calculate the torque required by each joint that allows the system to behave as a spring, thus mimicking the spring-like behavior of the leg during the SLIP movement. Also, there is a nested closed loop Force Controller to control the torque output of the SEAs. The SEAs are modeled by a parametric transfer function that is also presented in this work. |
| Data de Defesa : | 02/12/2019 |
| Texto na íntegra : | [Visualizar] |