A Methodology for Dynamic Parameters Identification of 3-DOF Parallel Robots in Terms of Relevant Parameters

TL;DR

This paper introduces a methodology for identifying relevant dynamic parameters in 3-DOF parallel robots, improving model accuracy by focusing on impactful parameters and validating the approach through experimental tests.

Contribution

It proposes a systematic strategy for dynamic parameter identification in parallel robots using model simplification, statistical reduction, and experimental validation.

Findings

The identified models' inverse and forward dynamics match experimental results.

The methodology effectively reduces parameters while maintaining physical feasibility.

Experimental validation on two different robot configurations confirms the approach's effectiveness.

Abstract

The identification of dynamic parameters in mechanical systems is important for improving model-based control as well as for performing realistic dynamic simulations. Generally, when identification techniques are applied only a subset of so-called base parameters can be identified. More even, some of these parameters cannot be identified properly given that they have a small contribution to the robot dynamics and hence in the presence of noise in measurements and discrepancy in modeling, their quality of being identifiable decreases. For this reason, a strategy for dynamic parameter identification of fully parallel robots in terms of a subset called relevant parameters is put forward. The objective of the proposed methodology is to start from a full dynamic model, then simplification concerning the geometry of each link and, the symmetry due to legs of fully parallel robots, are carried out. After that, the identification is done by Weighted Least Squares. Then, with statistical considerations the model is reduced until the physical feasibility conditions are met. The application of the propose strategy has been experimentally tested on two difierent configurations of actual 3-DOF parallel robots. The response of the inverse and forward dynamics of the identified models agrees with experiments. In order to evaluate the forward dynamics response, an approach for obtaining the forward dynamics in terms of the relevant parameters is also proposed.