Design of energy efficient hopper by using parallel elasticity and wrapping cam mechanisms

Download

index.pdf

Date

2019

Author

Candan, Sinan Şahin

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

150
views

219
downloads

Improving energy efficiency and control accuracy in legged robot design are important due to demand for complex tasks and prolonged operation time. Solving such a problem can be tackled by the determination of mathematical models, selecting appropriate controllers, integrating actuators and mechanical leg design. Model and control method is selected as Spring Loaded Inverted Pendulum (SLIP) with constant forcing and virtual tunable damping. Parallel elastic and series elastic architectures are considered for actuator integration. Detailed models including realistic effects of drive train for series and parallel elastic actuation are provided along with relevant control methods. Energy loss, transport efficiency, and apex accuracy are compared for those models by forming grids of motor and gearbox selection where optimum voltage is selected for each point. Also, results for different natural frequencies are compared. Gearbox and motor parameters are obtained as continuous functions of single parameters by using catalog data to obtain a continuous grid. Parallel elasticity provides 72% improvement in energy efficiency, 36% improvement in transport efficiency and more than 10 times accuracy compared with series elasticity if the designs are optimum. Mechanical design is based on ATRIAS, which includes a four link leg design that is modified including a wrapping cam mechanism with a tensile spring. Wrapping cam mechanism provides a radial force changing linearly with height. Tensile spring eliminates the problems of buckling and increased leg inertia occuring in compression and leaf springs. A special cam surface is synthesized to match potential energies of SLIP and proposed design. A physical prototype is constructed and tested to show that wrapping cam provides the desired potential energy.

Subject Keywords

Robots, Robots Motion., Legged locomotion, parallel elastic actuator, series elastic actuator, wrapping cam mechanisms, virtual tunable damping, SLIP.

URI

http://etd.lib.metu.edu.tr/upload/12624288/index.pdf
https://hdl.handle.net/11511/44204

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Analysis of wave gaits for energy efficiency Erden, Mustafa Suphi; Leblebicioğlu, Mehmet Kemal (2006-01-01) In this paper an energy efficiency analysis of wave gaits is performed for a six-legged walking robot. A simulation model of the robot is used to obtain the data demonstrating the energy consumption of the robot while walking in different modes and with varying parameters. Based on the analysis of this data some strategies are derived in order to minimize the search effort for determining the parameters of the gaits for an energy efficient walk. The analysis concludes the following: a phase modified version...
Optimal control of a half circular compliant legged monopod Özkan Aydın, Yasemin; Leblebicioğlu, Mehmet Kemal; Saranlı, Afşar; Department of Electrical and Electronics Engineering (2013) Legged robots have complex architecture because of their nonlinear dynamics and unpredictable ground contact characteristics. They can be also dynamically stable and exhibit dynamically dexterous behaviors like running, jumping, flipping which require complex plant models that may sometimes be difficult to build. In this thesis, we focused on half circular compliant legged monopod that can be considered as a reduced-order dynamical model for the hexapod robot, called RHex. The main objective of this thesis ...
Model-based pose estimation of the tool center point of collaborative industrial robots (UR5) using a proposed fiducial marker system Majidi Balanji, Hamid; Turgut, Ali Emre; Department of Mechanical Engineering (2019) Real-time pose estimation of Tool Center Point (TCP) of industrial robots is very important in industrial robotic applications. The TCP pose information is used in many industrial robotic tasks such as calibration and control tasks for on-line TCP pose corrections and improvement of the TCP pose accuracy and repeatability. Nowadays, in industry and robotic research laboratories, laser trackers, optical CMMs, stereo vision and photogrammetry techniques are applied for TCP pose estimation purposes; however, e...
Analysis of wave gaits for energy efficiency Erden, Mustafa Suphi; Leblebicioğlu, Mehmet Kemal (2007-10-01) In this paper an energy efficiency analysis of wave gaits is performed for a six-legged walking robot. A simulation model of the robot is used to obtain the data demonstrating the energy consumption while walking in different modes and with varying parameters. Based on the analysis of this data some strategies are derived in order to minimize the search effort for determining the parameters of the gaits for an energy efficient walk. Then, similar data is obtained from an actual experimental setup, in which ...
Locomotion Gait Optimization For Modular Robots; Coevolving Morphology and Control Pouya, Soha; Aydın Göl, Ebru; Moeckel, Rico; Ijspeert, Auke Jan (2011-01-01) This study aims at providing a control-learning framework capable of generating optimal locomotion patterns for the modular robots. The key ideas are firstly to provide a generic control structure that can be well-adapted for the different morphologies and secondly to exploit and coevolve both morphology and control aspects. A generic framework combining robot morphology, control and environment and on the top of them optimization and evolutionary algorithms are presented. The details of the components and ...

Citation Formats

S. Ş. Candan, “Design of energy efficient hopper by using parallel elasticity and wrapping cam mechanisms,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Mechanical Engineering., Middle East Technical University, 2019.