title: A new crank arm-based load cell for the 3D analysis of the force applied by a cyclist.
abstract: This report describes a new crank arm-based force platform designed to evaluate the three-dimensional force applied to the pedals by cyclists in real conditions. The force platform was designed to be fitted on a conventional competition bicycle crankset while data is transmitted wirelessly through a Bluetooth™ module and also stored on a SD card. A 3D solid model is created in the SolidWorks (Dassault Systèmes SOLIDWORKS Corp.) to analyze the static and dynamic characteristics of the crank arm by using the finite elements technique. Each crankset arm is used as a load cell based on strain gauges configured as three Wheatstone bridges. The signals are conditioned on a printed circuit board attached directly to the structure. The load cell showed a maximum nonlinearity error between 0.36% and 0.61% and a maximum uncertainty of 2.3% referred to the sensitivity of each channel. A roller trainer equipped with an optical encoder was also developed, allowing the measurement of the wheel's instantaneous velocity.
authors.affiliation: Electrical Engineering, Instrumentation Laboratory, Federal University of Rio Grande do Sul, Avenue Osvaldo Aranha 103, Porto Alegre 90035-190, Brazil. alexandre.balbinot@ufrgs.br.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Balbinot
authors.affiliation: Electrical Engineering, Instrumentation Laboratory, Federal University of Rio Grande do Sul, Avenue Osvaldo Aranha 103, Porto Alegre 90035-190, Brazil. cleiton_milani@hotmail.com.
authors.forename: Cleiton
authors.initials: C
authors.lastname: Milani
authors.affiliation: Electrical Engineering, Instrumentation Laboratory, Federal University of Rio Grande do Sul, Avenue Osvaldo Aranha 103, Porto Alegre 90035-190, Brazil. jussan.sbn@gmail.com.
authors.forename: Jussan da Silva Bahia
authors.initials: Jda S
authors.lastname: Nascimento
mesh_terms: D001642:Bicycling / Q000502:physiology*; D017076:Computer-Aided Design; D003217:Conductometry / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005080:Exercise Test / Q000295:instrumentation*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D016247:Information Storage and Retrieval; D005082:Physical Exertion / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D013314:Stress, Mechanical; D014160:Transducers, Pressure; D059015:Wireless Technology / Q000295:instrumentation*