A semi-analytical approach towards determining the largest collision-free sphere in R3 inside the effective regular workspace of a 6-6 Stewart-Gough platform manipulator corresponding to a given orientation workspace
{"title":"A semi-analytical approach towards determining the largest collision-free sphere in R3 inside the effective regular workspace of a 6-6 Stewart-Gough platform manipulator corresponding to a given orientation workspace","authors":"Bibekananda Patra, Nishanth Adithya Chandramouli, Sandipan Bandyopadhyay","doi":"10.1016/j.mechmachtheory.2025.106331","DOIUrl":null,"url":null,"abstract":"<div><div>This article focusses on the problem of interference among the links of a parallel robot, namely, the Stewart-Gough platform manipulator. The geometry of the legs is approximated by <em>capsules</em>, leading to the detection of collision among any pair of legs in terms of tangency of the corresponding capsules. Analytical conditions for the said cases of tangency are derived in closed-form, which manifest geometrically as certain quadrics in space. Through a thorough study and explicit characterisation of these surfaces, novel analytical methods are developed to find the largest spheres in space which are tangent to these surfaces. Such spheres are free of possibilities of link collisions, and they can be derived analytically for a given orientation of the moving platform of the manipulator. The analysis is subsequently extended to the orientation workspace of the manipulator by repeating the above-mentioned computations over a large number of discrete samples. The results obtained are verified numerically by comparing them with those generated from other sources. A parametric study is performed to demonstrate the utility of the proposed analysis in practice.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"220 ","pages":"Article 106331"},"PeriodicalIF":5.9000,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mechanism and Machine Theory","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0094114X25004203","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/1/9 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
This article focusses on the problem of interference among the links of a parallel robot, namely, the Stewart-Gough platform manipulator. The geometry of the legs is approximated by capsules, leading to the detection of collision among any pair of legs in terms of tangency of the corresponding capsules. Analytical conditions for the said cases of tangency are derived in closed-form, which manifest geometrically as certain quadrics in space. Through a thorough study and explicit characterisation of these surfaces, novel analytical methods are developed to find the largest spheres in space which are tangent to these surfaces. Such spheres are free of possibilities of link collisions, and they can be derived analytically for a given orientation of the moving platform of the manipulator. The analysis is subsequently extended to the orientation workspace of the manipulator by repeating the above-mentioned computations over a large number of discrete samples. The results obtained are verified numerically by comparing them with those generated from other sources. A parametric study is performed to demonstrate the utility of the proposed analysis in practice.
期刊介绍:
Mechanism and Machine Theory provides a medium of communication between engineers and scientists engaged in research and development within the fields of knowledge embraced by IFToMM, the International Federation for the Promotion of Mechanism and Machine Science, therefore affiliated with IFToMM as its official research journal.
The main topics are:
Design Theory and Methodology;
Haptics and Human-Machine-Interfaces;
Robotics, Mechatronics and Micro-Machines;
Mechanisms, Mechanical Transmissions and Machines;
Kinematics, Dynamics, and Control of Mechanical Systems;
Applications to Bioengineering and Molecular Chemistry