slope estimation during normal walking using a shank-mounted inertial sensor斜率估计使用shank-mounted惯性传感器在正常行走.pdf

Sensors 2012, 12, 11910-11921; doi:10.3390/s120911910 OPEN ACCESS sensors ISSN 1424-8220 /journal/sensors Article Slope Estimation during Normal Walking Using a Shank-Mounted Inertial Sensor Antonio M. López *, Diego Álvarez, Rafael C. González and Juan C. Álvarez Multisensor Systems and Robotics Laboratory, University of Oviedo, Campus de Viesques, ed. 2, 33204, Gijón, Asturias, Spain; E-Mails: dalvarez@uniovi.es (D.A.); rcgonzalez@uniovi.es (R.C.G.); juan@uniovi.es (J.C.A.) * Author to whom correspondence should be addressed; E-Mail: amlopez@uniovi.es; Tel.: +34-985-181-994; Fax: +34-985-182-068. Received: 7 June 2012; in revised form: 16 August 2012 / Accepted: 24 August 2012 / Published: 29 August 2012 Abstract: In this paper we propose an approach for the estimation of the slope of the walking surface during normal walking using a body-worn sensor composed of a biaxial accelerometer and a uniaxial gyroscope attached to the shank. It builds upon a state of the art technique that was successfully used to estimate the walking velocity from walking stride data, but did not work when used to estimate the slope of the walking surface. As claimed by the authors, the reason was that it did not take into account the actual inclination of the shank of the stance leg at the beginning of the stride (mid stance). In this paper, inspired by the biomechanical characteristics of human walking, we propose to solve this issu