Work

Calibration and Characterization of Electromagnetic Position and Orientation Trackers

Year: 2025

Type: article

Abstract: An electromagnetic position and orientation tracker must be calibrated so that magnetic measurements can be converted into spatial data, and the accuracy must also be characterized to know what accuracy is obtained. We describe a magnetic calibration matrix model which is extensible to the common coil configurations. We detail data representations and discuss successful approaches to the calibration optimization. An accurate positioning device is necessary for both calibration and characterization. We discuss the effect of positioning error on calibration accuracy and some design tradeoffs for positioning. We characterize the calibrated accuracy with two different source coil designs and several calibration variations, with the best configuration achieving 208 μm/0.27° uncertainty, an accuracy exceeding published values for commercial EMTs (tested by other methods). We use local measurement nonlinearity to characterize the expected accuracy across small motions, including the cross-coupling between position and orientation. All software described is open source (Apache License 2.0).

Source: IEEE Sensors Journal

DOI: 10.1109/jsen.2025.3533436

Authors: Robert A. MacLachlan, Claudia Pelle, Ralph L. Hollis, Elena De Momi, Cameron N. Riviere

Institutions: Carnegie Mellon University, Fondazione Politecnico di Milano, Politecnico di Milano

Language: English

Topic: Magnetic Field Sensors Techniques

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: green

Funders: National Institutes of Health, National Heart, Lung, and Blood Institute, National Institute of Biomedical Imaging and Bioengineering

Awards: An Active Handheld Micromanipulator, G3355733772, Multi-Frequency Tracker for Control of Handheld Surgical Robotic Systems, G9000205109