Stability and control of planar compass gait walking with series-elastic ankle actuation

Download

index.pdf

Date

2017-03-01

Author

KERIMOGLU, Deniz
MORGUL, Omer
Saranlı, Uluç

Metadata

Show full item record

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

Item Usage Stats

191
views

0
downloads

Passive dynamic walking models are capable of capturing basic properties of walking behaviours and can generate stable human-like walking without any actuation on inclined surfaces. The passive compass gait model is among the simplest of such models, consisting of a planar point mass and two stick legs. A number of different actuation methods have been proposed both for this model and its more complex extensions to eliminate the need for a sloped ground, balancing collision losses using gravitational potential energy. In this study, we introduce and investigate an extended model with series-elastic actuation at the ankle towards a similar goal, realizing stable walking on level ground. Our model seeks to capture the basic structure of how humans utilize toe push-off prior to leg liftoff, and is intended to eventually be used for controlling the ankle joint in a lower-body robotic orthosis. We derive hybrid equations of motion for this model, and show numerically through Poincare analysis that it can achieve asymptotically stable walking on level ground for certain choices of system parameters. We then study the bifurcation regimes of period doubling with this model, leading up to chaotic walking patterns. Finally, we show that feedback control on the initial extension of the series ankle spring can be used to improve and extend system stability.

Subject Keywords

Dynamic walking, Passive compass gait, Series-elastic actuation, Ankle actuation, Bifurcation analysis, Feedback control

URI

https://hdl.handle.net/11511/38603

Journal

TRANSACTIONS OF THE INSTITUTE OF MEASUREMENT AND CONTROL

DOI

https://doi.org/10.1177/0142331216663823

Collections

Department of Computer Engineering, Article

Suggestions

OpenMETU
Core

Stability of Planar Compass Gait Walking with Series Elastic Ankle Actuation Kerimoğlu, Deniz; Morgül, Ömer; Saranlı, Uluç (null; 2015-07-24) Passive dynamic walking models capture the natural dynamics of stable human-like walking. The passive compass gait (PCG) model, consisting of a point mass and two rigid legs, is among the simplest of such models. The fully passive nature of these models, however, necessitates a sloped ground to recover the energy lost during the ground collisions [1]. A variety of methods have been proposed to eliminate this requirement through different actuation methods. Among these are impulsive energy injection after fo...
Stability of a Compass Gait Walking Model with Series Elastic Ankle Actuation Kerimoglu, Deniz; Morgul, Omer; Saranlı, Uluç (2015-07-31) Passive dynamic walkers exhibit stable human-like walking on inclined planes. The simplest model of this behavior is the well known passive compass gait (PCG) model, which consists of a point mass at the hip and two stick legs. Due to their passive nature, these systems rely on a sloped ground to recover energy lost to ground collisions. A variety of methods have been proposed to eliminate this requirement by using different actuation methods. In this study, we propose a simple model to investigate how seri...
Feature Detection Performance Based Benchmarking of Motion Deblurring Methods: Applications to Vision for Legged Robots Gultekin, Gokhan Koray; Saranlı, Afşar (Elsevier BV, 2019-02-01) Dexterous legged robots can move on variable terrain at high speeds. The locomotion of these legged platforms on such terrain causes severe oscillations of the robot body depending on the surface and locomotion speed. Camera sensors mounted on such platforms experience the same disturbances, hence resulting in motion blur. This is a particular corruption of the image and results in information loss further resulting in degradation or loss of important image features. Although motion blur is a significant pr...
Dynamic Modeling and Control of Underactuated Planar Bipedal Walking Sovukluk, Sait; Ankaralı, Mustafa Mert; Saranlı, Uluç; Department of Electrical and Electronics Engineering (2022-6-16) This study demonstrates an adaptive model predictive control method for input constrained control of underactuated bipedal walking with a predefined trajectory. Our approach aims to increase the trajectory tracking performance of the system and produce realistic and applicable responses while letting a certain amount of posture change around the predefined trajectory. To do so, we employ whole-body dynamics in our control structure, include weights for the unactuated joint inside the cost function, and defi...
Control of quadruped walking behavior through an embedding of spring loaded inverted pendulum template Yılmaz, Mert Kaan; Saranlı, Uluç; Department of Computer Engineering (2022-8) Legged robots require complex dynamical behaviours in order to achieve stable, sustainable and efficient locomotion. Due to their mobile nature, they can neither afford to provide extensive computational power, nor use anything but the most energy efficient structural designs and algorithms to achieve stability and speed. Consequently, simple and efficient ways to solve the complex set of problems is one of the key points of focus in legged robot locomotion research. This thesis offers a novel method that u...

Citation Formats

D. KERIMOGLU, O. MORGUL, and U. Saranlı, “Stability and control of planar compass gait walking with series-elastic ankle actuation,” TRANSACTIONS OF THE INSTITUTE OF MEASUREMENT AND CONTROL, pp. 312–323, 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/38603.