Method and apparatus for reducing magnetic tracking error due to floor distortion

US11976921B2 · kind B2 · utility

Assignee

• Penumbra, Inc. · US

Inventors

• Michael D. Collins · Portland, US
• Alejandro Santiago Diaz · San Francisco, US
• Oded Zur · Kochav Yair Tzur Yigal, IL
• Cameron Mahon · Georgetown, CA
• Branislav Vasilijevic · Oakville, CA
• Amir Rubin · Kiryat Ono, IL

Key dates

• Filing date: Jun 7, 2022
• Grant date: May 7, 2024
• Expiry date: Jun 7, 2042

Classification

• Technology area (CPC G): Physics
• CPC primary: G07F17/3239
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and apparatus for reducing magnetic tracking error in the position and orientation determined in a magnetic tracking system having a magnetic field generator. In some embodiments, the measured position and orientation of a sensor is compared to an expected theoretical position and orientation. Any error is assumed to be from “floor distortion,” i.e., eddy currents in the floor caused by the magnetic field generated by the magnetic field transmitter. The floor distortion is modeled as being caused by eddy currents caused by a second magnetic field transmitter that is a reflection of the actual transmitter. An algorithm iteratively searches over a parameter space to minimize the difference between the measured position and orientation and the theoretical position and orientation, and applies a correction to the measured position and orientation. The measurements and corrections of the position and orientation run in real-time with no additional hardware or calibration required.