English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Sensor-to-segment calibration is a crucial step in inertial motion tracking.When two segments are connected by a hinge joint, for example in human knee andfinger joints as well as in many robotic limbs, then the joint axis vector mustbe identified in the intrinsic sensor coordinate systems. There exist methodsthat identify these coordinates by solving an optimization problem that isbased on kinematic joint constraints, which involve either the measuredaccelerations or the measured angular rates. In the current paper wedemonstrate that using only one of these constraints leads to inaccurateestimates at either fast or slow motions. We propose a novel method based on acost function that combines both constraints. The restrictive assumption of ahomogeneous magnetic field is avoided by using only accelerometer and gyroscopereadings. To combine the advantages of both sensor types, the residual weightsare adjusted automatically based on the estimated signal variances and anonlinear weighting of the acceleration norm difference. The method isevaluated using real data from nine different motions of an upper limbexoskeleton. Results show that, unlike previous approaches, the proposed methodyields accurate joint axis estimation after only five seconds for all fast andslow motions.

Joint axis estimation for fast and slow movements using weighted gyroscope and acceleration constraints