Semi-isotropic design of a Stewart platform through constrained optimization. (May 2017)

• Record Type: Journal Article
• Authors: Halder, Biswajit; Saha, Rana; Sanyal, Dipankar
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 231:Number 10(2017)
• Page Start: 1897
• Page End: 1906
• Publication Date: 2017-05
• Subjects: Stewart platform -- semi-isotropic design -- constrained optimization -- kinematic Jacobian matrix -- characteristic length; Mechanical engineering -- Periodicals; 621.05
• DOI: 10.1177/0954406215623576
• Languages: English
• ISSNs: 0954-4062

Abstract

The isotropic property at home configuration for a semi-regular Stewart platform manipulator with equal leg lengths has been found to be nonachievable by kinematic design optimization study. In this context, a new approach of design optimization has been formulated here for achieving semi-isotropicity through variable transformation that has rendered the constrained optimization over a finite workspace to infinite workspace in the transformed domain. The proposed minimization methodology of a positive definite function for all the angular and translational motion has exhibited strong convergence to zero for values of the design parameters that can be worked out as a closed-form solution only for the cases of linear translation. Finally, the variations of the condition number over the permissible range of all single-degree-of-freedom motions have been carried out. The absence of any other minima in the entire workspace has clearly established the home position as globally optimized.