A Robotic System with a Hybrid Motion Cueing Controller for Inertia Tensor Approximation in Micro-Manipulations

Umar Asif,Javaid Iqbal

doi:10.5772/45702

Abstract

This paper summarizes the development of a robotic system for the approximation of inertia tensor of micro-sized rigid bodies. We described the design and computer-based simulation of a 6-DOF motion platform in our earlier work [ 32 ] that benefits from an anthropological serial manipulator design. In [ 32 ] we emphasized that, in contrast to a standard configuration based on linear actuators, a mechanism with actuator design inspired from an anthropological kinematic structure offers relatively a larger motion envelope and higher dexterity making it a viable motion platform for micromanipulations. After having described the basic design and kinematic analysis of our motion platform in [ 32 ], we now aim to propose an advanced motion cueing algorithm for facilitating the identification of inertial parameters at micron-level. The motion cueing algorithm for achieving high fidelity dynamic simulation is described in this paper using a hybrid force-position-based controller. The inertia tensor identification is done by generating a controlled motion on the specimen and measuring the resultant forces and moments to approximate the inertia tensor using rigid body dynamics equations. The paper evaluates the performance of the controller using closed-loop dynamic simulations and validates the significance of the proposed method through experimental results.

Highlights

This paper summarizes the development of a robotic system for the approximation of inertia tensor of micro‐sized rigid bodies
In the field of motion dynamics, the identification and measurement of inertial parameters like center of mass and inertia tensor are generally accomplished through CAD models with the increase in complexity of the system, these standard methods suffer from uncertainty [1, 2 & 3]
In this paper and its companion [32], we presented a study on the design and practical implementation of a six‐DOF motion platform inspired from an anthropological serial manipulator design in facilitating the identification of inertial parameters of micro‐sized rigid bodies

Summary

Introduction

In the field of motion dynamics, the identification and measurement of inertial parameters like center of mass and inertia tensor are generally accomplished through CAD models with the increase in complexity of the system, these standard methods suffer from uncertainty [1, 2 & 3]. Methods based on frequency response functions and high rotational speed experiments are conducted to identify the centre of mass and inertia tensor of rigid bodies [5]. These experiments require positioning and orientation of the. 235 Int J Adv Robotic Sy, 2011, Vol 8, No 4, 235-247 www.intechweb.org www.intechopen.com body/assembly at high speed that may damage certain sophisticated assemblies or micro‐sized components and the problem of devising a robust solution to identify the inertial parameters of micro‐sized objects is still under investigation. The motivation of this paper is inspired from the work presented in [44] which delivers an excellent study with appreciable experimental results on the identification of inertial parameters of rigid bodies using a Stewart platform. A parameter identification procedure [9] can further be used to eventually determine the inertia tensor of the desired object using rigid body dynamics equations

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Conclusion