Strain Monitoring and Applied Load Estimation for the Development of Intelligent Tires Using a Single Wireless CCD Camera

Abstract

From a traffic safety point of view, there is an urgent need for intelligent tires which can optimize braking control by estimating the slip ratio and friction coefficient between a road surface and an automobile tire. The present study develops concurrent monitoring of frictional and vertical loads applied to the tires from the inner tire strain data for estimating the road/tire friction coefficient, which enables optimization of vehicle control and implementation of a road condition warning system. The tire strain is obtained using a three-dimensional digital image correlation method with a single wireless CCD camera attached to the wheel rim inside the tire. The procedures of the applied load estimation decompose the measured strain into the frictional and vertical strain components using their symmetrical and anti-symmetrical characteristics. Static tire rotation tests were carried out, and the applied loads were estimated from the inner tire surface strain distribution. Compared with the actual applied loads measured from strain gages attached to the experimental apparatus, it was confirmed that the vertical and frictional loads can be estimated independently with adequate accuracy.

Measurement of friction coefficient between a tire and grounding surface with the deformation of inner of the tread

“…タイヤと路面間の摩擦係数などを測定することを提案している (Yilmazoglu et al, 2001)．Sergio (Sergio et al, 2006) や，Matsuzaki (Matsuzaki et al, 2006 (Matsuzaki et al, 2008)．また，Hiraoka (Hiraoka et al, 2009)，Matsuzaki (Matsuzaki et al, 2010(Matsuzaki et al, , 2012 Experimental apparatus composed of a tire rotating device, a force plate and a parallel mechanism. The parallel mechanism can apply high vertical and horizontal loads to the tire.…”

A Multisensing Setup for the Intelligent Tire Monitoring

“…Another related project is based on image processing [32] and has been developed by the Department of Mechanical Engineering of the University of Science in Tokyo. The system relies on the estimation of vertical and frictional loads at the contact interface and uses a CCD camera that monitors the deformation of the internal tire carcass, on which a series of rubber blocks are attached accordingly to a specific pattern.…”

“…Works of Audisio [30], Morinaga [31] and Hannah [14] are more focused on a widespread industrial application of smart tire and employ commercial sensors, while others [8,13,15,25,32] use prototypal devices to study the nature of the phenomena involving the tire rolling.…”

Addressed Fiber Bragg Structures in Load-Sensing Wheel Hub Bearings

“…Theoretically, every component of the vehicle transferring the loads from the tire contact patch to the vehicle body can be used to estimate the wheel loads. Thus, four main categories of wheel force determination methods can be distinguished in accordance with the vehicle components they are based on: tire-based methods (including the ones that use piezoelectric [5][6][7], fiber-optic [8][9][10], or optical [11][12][13] sensors; electrical resistance strain gauges [14,15]; or accelerometers [16]); wheel disc-based methods (primarily used in testing equipment [7]); suspension-based methods (including strain measurement of suspension bushings [17], displacement measurement of knuckle [18]), and wheel hub bearing based methods (load-sensing bearings) [19][20][21][22][23][24]. Wheel force measurements based on load-sensing hub bearings have a number of advantages in comparison with the other approaches.…”