Precision motion and energy exchange control on robot’s leg interaction with soft surface

Nowadays, various ideas have been presented in developing bio-inspired robot such as legged, flying, swimming and other crawling mechanisms. Generally legged robot development and control covered beyond manipulation issues in which stability of the overall system need to be catered as well. Stable l...

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Main Author:	Wan Mohd Nafis, Wan Lezaini
Format:	Thesis
Language:	English
Published:	2019
Subjects:	TJ Mechanical engineering and machinery TK Electrical engineering. Electronics Nuclear engineering
Online Access:	http://umpir.ump.edu.my/id/eprint/28004/ http://umpir.ump.edu.my/id/eprint/28004/1/Precision%20motion%20and%20energy%20exchange%20control%20on%20robot%E2%80%99s%20leg%20interaction.pdf

id	ump-28004
recordtype	eprints
spelling	ump-280042020-02-27T03:46:11Z http://umpir.ump.edu.my/id/eprint/28004/ Precision motion and energy exchange control on robot’s leg interaction with soft surface Wan Mohd Nafis, Wan Lezaini TJ Mechanical engineering and machinery TK Electrical engineering. Electronics Nuclear engineering Nowadays, various ideas have been presented in developing bio-inspired robot such as legged, flying, swimming and other crawling mechanisms. Generally legged robot development and control covered beyond manipulation issues in which stability of the overall system need to be catered as well. Stable leg manipulation for a legged robot becomes a priority to guarantee the whole system stability. One of the challenges in legged robot manipulation control is to sustain the leg’s joint angular motion precision. As the number of degrees of freedom for a leg is increased, the demand for robust control becomes higher since it requires precise coordination in foot workspace. Besides that, the nonlinearity factor in robot’s leg motion also need to be tackled to ensure the overall stability of a legged robot especially during walking on uneven terrain. Popular method such as impedance control has been extensively used by understanding dynamic interaction between leg tips and the environment. Most of the researched had emphasized on dynamic control that is able to reposition robot’s foot placement during walking on the unstructured terrain with hard surfaces. This method may not be suitable for soft surface that required robot’s leg to withstand the ground medium while pushing its body although repositioning was done. As a result, the overturning may happen to the robot since the robot’s foot will slip due to the low energy to adapt with environment surface stiffness. Here, there are two problem statements which are implication of imprecision of leg joint motion and uncontrollable energy exchange in foot dynamic motion. Therefore, this study has taken initiative to propose two solutions for the aforementioned issues which are hybrid Proportional Integral-Antiwindup-Fuzzy Logic Control-Derivative (PIA-FLC-D) and impedance control respectively. PIA-FLC-D is proposed to overcome leg’s joint precision affected by nonlinear gravitational factor. On the other hand, impedance control is derived to cater the velocity shaping as indirectly controlling the energy exchange of the leg specifically at leg dragging period. A bio-inspired robot named Hexapod-to-Quadruped (Hexaquad) robot is used as the targeted platform for verification and validation. The proposed PIA-FLC-D was verified and the results were compared with the predecessor controllers. The results show that PIA-FLC-D performs fast response with only 0.1s delay compared to its predecessor controller with 0.25s delay during trajectory tracking. For the case of the impedance control, the results show that Hexaquad’s leg velocity increases with the contact force on vertical position in which resulting energy increased on the leg while maintaining the overall leg motion shape. The same Hexaquad’s leg that applied the proposed impedance controller also tested completing the walking motion on the soft surface medium (dry sand) while bearing the robot’s body weight. The results showed that during drag sequence, by using the proposed controller, each joint of Hexaquad’s leg manage to follow the reference motion precisely compared to without using the proposed controller. 2019-03 Thesis NonPeerReviewed pdf en http://umpir.ump.edu.my/id/eprint/28004/1/Precision%20motion%20and%20energy%20exchange%20control%20on%20robot%E2%80%99s%20leg%20interaction.pdf Wan Mohd Nafis, Wan Lezaini (2019) Precision motion and energy exchange control on robot’s leg interaction with soft surface. Masters thesis, Universiti Malaysia Pahang.
repository_type	Digital Repository
institution_category	Local University
institution	Universiti Malaysia Pahang
building	UMP Institutional Repository
collection	Online Access
language	English
topic	TJ Mechanical engineering and machinery TK Electrical engineering. Electronics Nuclear engineering
spellingShingle	TJ Mechanical engineering and machinery TK Electrical engineering. Electronics Nuclear engineering Wan Mohd Nafis, Wan Lezaini Precision motion and energy exchange control on robot’s leg interaction with soft surface
description	Nowadays, various ideas have been presented in developing bio-inspired robot such as legged, flying, swimming and other crawling mechanisms. Generally legged robot development and control covered beyond manipulation issues in which stability of the overall system need to be catered as well. Stable leg manipulation for a legged robot becomes a priority to guarantee the whole system stability. One of the challenges in legged robot manipulation control is to sustain the leg’s joint angular motion precision. As the number of degrees of freedom for a leg is increased, the demand for robust control becomes higher since it requires precise coordination in foot workspace. Besides that, the nonlinearity factor in robot’s leg motion also need to be tackled to ensure the overall stability of a legged robot especially during walking on uneven terrain. Popular method such as impedance control has been extensively used by understanding dynamic interaction between leg tips and the environment. Most of the researched had emphasized on dynamic control that is able to reposition robot’s foot placement during walking on the unstructured terrain with hard surfaces. This method may not be suitable for soft surface that required robot’s leg to withstand the ground medium while pushing its body although repositioning was done. As a result, the overturning may happen to the robot since the robot’s foot will slip due to the low energy to adapt with environment surface stiffness. Here, there are two problem statements which are implication of imprecision of leg joint motion and uncontrollable energy exchange in foot dynamic motion. Therefore, this study has taken initiative to propose two solutions for the aforementioned issues which are hybrid Proportional Integral-Antiwindup-Fuzzy Logic Control-Derivative (PIA-FLC-D) and impedance control respectively. PIA-FLC-D is proposed to overcome leg’s joint precision affected by nonlinear gravitational factor. On the other hand, impedance control is derived to cater the velocity shaping as indirectly controlling the energy exchange of the leg specifically at leg dragging period. A bio-inspired robot named Hexapod-to-Quadruped (Hexaquad) robot is used as the targeted platform for verification and validation. The proposed PIA-FLC-D was verified and the results were compared with the predecessor controllers. The results show that PIA-FLC-D performs fast response with only 0.1s delay compared to its predecessor controller with 0.25s delay during trajectory tracking. For the case of the impedance control, the results show that Hexaquad’s leg velocity increases with the contact force on vertical position in which resulting energy increased on the leg while maintaining the overall leg motion shape. The same Hexaquad’s leg that applied the proposed impedance controller also tested completing the walking motion on the soft surface medium (dry sand) while bearing the robot’s body weight. The results showed that during drag sequence, by using the proposed controller, each joint of Hexaquad’s leg manage to follow the reference motion precisely compared to without using the proposed controller.
format	Thesis
author	Wan Mohd Nafis, Wan Lezaini
author_facet	Wan Mohd Nafis, Wan Lezaini
author_sort	Wan Mohd Nafis, Wan Lezaini
title	Precision motion and energy exchange control on robot’s leg interaction with soft surface
title_short	Precision motion and energy exchange control on robot’s leg interaction with soft surface
title_full	Precision motion and energy exchange control on robot’s leg interaction with soft surface
title_fullStr	Precision motion and energy exchange control on robot’s leg interaction with soft surface
title_full_unstemmed	Precision motion and energy exchange control on robot’s leg interaction with soft surface
title_sort	precision motion and energy exchange control on robot’s leg interaction with soft surface
publishDate	2019
url	http://umpir.ump.edu.my/id/eprint/28004/ http://umpir.ump.edu.my/id/eprint/28004/1/Precision%20motion%20and%20energy%20exchange%20control%20on%20robot%E2%80%99s%20leg%20interaction.pdf
first_indexed	2023-09-18T22:43:55Z
last_indexed	2023-09-18T22:43:55Z
_version_	1777417097907798016

Precision motion and energy exchange control on robot’s leg interaction with soft surface

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