Global Kalman filter approaches to estimate absolute angles of lower limb segments

[Background] In this paper we propose the use of global Kalman filters (KFs) to estimate absolute angles of lower limb segments. Standard approaches adopt KFs to improve the performance of inertial sensors based on individual link configurations. In consequence, for a multi-body system like a lower...

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Bibliographic Details
Authors: Nogueira, Samuel L., Lambrecht, Stefan, Inoue, Roberto S., Bortole, Magdo, Montagnoli, Arlindo N., Moreno, Juan Camilo, Rocón, Eduardo, Terra, Marco H., Siqueira, Adriano A. G., Pons Rovira, José Luis
Format: article
Status:Published version
Publication Date:2017
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/150052
Online Access:http://hdl.handle.net/10261/150052
Access Level:Open access
Keyword:Exoskeleton
Inertial sensors
Kalman filter
Markovian jump systems
Wearable robots
Description
Summary:[Background] In this paper we propose the use of global Kalman filters (KFs) to estimate absolute angles of lower limb segments. Standard approaches adopt KFs to improve the performance of inertial sensors based on individual link configurations. In consequence, for a multi-body system like a lower limb exoskeleton, the inertial measurements of one link (e.g., the shank) are not taken into account in other link angle estimations (e.g., foot). Global KF approaches, on the other hand, correlate the collective contribution of all signals from lower limb segments observed in the state-space model through the filtering process. We present a novel global KF (matricial global KF) relying only on inertial sensor data, and validate both this KF and a previously presented global KF (Markov Jump Linear Systems, MJLS-based KF), which fuses data from inertial sensors and encoders from an exoskeleton. We furthermore compare both methods to the commonly used local KF.