Magnetometer-free Realtime Inertial Motion Tracking by Exploitation of Kinematic Constraints in 2-DoF Joints

Laidig D, Lehmann D, Begin MA, Seel T (2019)

Publication Type: Conference contribution

Publication year: 2019

Journal

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society IEEE Engineering in Medicine and Biology Society

Publisher: Institute of Electrical and Electronics Engineers Inc.

Pages Range: 1233-1238

Conference Proceedings Title: Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS

Event location: Berlin DE

ISBN: 9781538613115

DOI: 10.1109/EMBC.2019.8857535

Abstract

Inertial Measurement Units (IMUs) are used to track the motion of kinematic chains in a wide variety of robotic and biomedical applications. However, inertial motion tracking is severely limited by the fact that magnetic fields are inhomogeneous in indoor environments and near electronic devices. Methods that use only accelerations and angular rates for orientation estimation yield no absolute heading information and suffer from heading drift. To overcome this limitation, we propose a novel method that exploits an orientation-based kinematic constraint in joints with two degrees of freedom (DoF), such as cardan joints, saddle joints, the human wrists, elbow or ankles. The method determines the relative heading of the joint segments in real time by minimization of a nonlinear cost function. A filter for singularity treatment ensures accurate tracking during motion phases for which the cost function minimum is ambiguous. We experimentally validate the method in metacarpophalangeal (MCP) joints between the palm and the fingers. Accurate relative orientation tracking is achieved continuously despite several singular motion phases and even though the heading components of the 6D orientations drift by more than 360 degrees within ten minutes. The proposed method overcomes a major limitation of inertial motion tracking and thereby facilitates the use of this technology in robotic and biomechanical applications.

Authors with CRIS profile

Thomas Seel

Involved external institutions

Technische Universität Berlin DE Germany (DE) Massachusetts Institute of Technology (MIT) US United States (USA) (US)

How to cite

APA:

Laidig, D., Lehmann, D., Begin, M.A., & Seel, T. (2019). Magnetometer-free Realtime Inertial Motion Tracking by Exploitation of Kinematic Constraints in 2-DoF Joints. In Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS (pp. 1233-1238). Berlin, DE: Institute of Electrical and Electronics Engineers Inc..

MLA:

Laidig, Daniel, et al. "Magnetometer-free Realtime Inertial Motion Tracking by Exploitation of Kinematic Constraints in 2-DoF Joints." Proceedings of the 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019, Berlin Institute of Electrical and Electronics Engineers Inc., 2019. 1233-1238.

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