wheel numeric and different versions of mobility numbers are important models for predicting the rolling resistance. in this study, data related to the rolling resistance of cross ply and radial ply tires were compared with the resultant values from several models. also, the preciseness of models in rolling resistance prediction was evaluated. for this purpose f test and 1-1 line method (p≥ 0.0...

Wheel numeric and different versions of mobility numbers are important models for predicting the rolling resistance. In this study, data related to the rolling resistance of cross ply and radial ply tires were compared with the resultant values from several models. Also, the preciseness of models in rolling resistance prediction was evaluated. For this purpose F test and 1-1 line method (p≥ 0.0...

The purpose of this study was to evaluate a technique of pushing a wheelchair at the level of the handle bars as a method for measuring rolling resistance of wheelchair-user systems under different field conditions. Under standardized conditions on a motor driven treadmill, rolling resistance was determined using a 2D strain gauge-based push technique at the level of the handle bars and a commo...

The objective of this study was to compare the rolling resistance of four common manual wheelchair tires (two pneumatic and two airless solid) and the solid tires used on a commercially available force- and moment-sensing wheel. Coast-down tests were performed with a wheelchair positioned on a two-drum dynamometer. Within each of three load conditions, tire type had a significant effect on roll...

The hysteresis loss theory of rolling resistance is developed for solid rubber wheelchair tires. The analysis is used to correlate test data for a clay-filled natural rubber and a polyurethane tire material. A discussion of tire rolling work, hysteresis loss factor measurement, and rolling loss measurement is presented. An example calculation of rolling resistance for a polyurethane tire is giv...

rolling-based seismic isolation systems, in which rollers of circular or non-circular section are used, are less expensive and easier to manufacture. however, this type of isolation suffers from either lack of restoring or re-centering capability, or weakness against uplift forces. to resolve the first shortcoming the use of elliptical as well as pillow-shape rolling parts has been suggested, a...

Numerous studies have associated increased stomatal resistance with response to water deficit in cereals. However, consideration of change in leaf form seems to have been neglected. The response of adaxial and abaxial stomatal resistance and leaf rolling in rice to decreasing leaf water potential was investigated. Two rice cultivars were subjected to control and water stress treatments in a dee...

Cold rolling of steel is one of the most important metal forming processes so an accurate control of its parameters during the process is necessary. In this paper, the friction coefficient has been proposed as a function of cold rolling parameters such as forward slip, forward and backward tensile stresses ,strip thickness, static deformation, resistance of strip before and after rolling ,strip...

Power Assist Wheelchair (PAW) has being developed for users and caregivers in current high aging society. As a human-machine system, it is important for PAW to sense the human force and operation. In this paper, a Disturbance Observer (DOB) based force estimator is applied to PAW to estimate external forces including the human force, the rolling resistance and the sliding resistance. The rollin...

A balance platform setup was defined for use in the determination of the center of gravity in the sagittal plane for a wheelchair and patient. Using the center of gravity information, measurements from the wheelchair and patient (weight, tire coefficients of friction), and various assumptions (constant speed, level-concrete surface, patient-wheelchair system is a rigid body), a method for estim...