Abstract

The goal of this research is to develop the tire test method and mobile tire test rig. The test rig enables measurement of tire properties as stiffness and viscous damping in vertical direction, and tire–ground characteristics on the asphalt rigid surface. The tire-ground characteristics are measured by force and a torque measurement hub. The design, calibration and the algorithm for calculating the forces in the wheel center are also developed in this work. The mobile tire test rig is based upon the idea of a quarter-vehicle. The vertical stiffness and viscous damping are measured by two methods. The test by free oscillation where the tire rolls over an obstacle and the test of random vibration where the tire is excited by road unevenness are used to measure the tire’s properties for large and small excitation amplitudes respectively. The third method surveys tire–ground interactions in lateral direction in a test called step response of lateral force. The aim of this test is to measure the tire’s capability for transmitting suddenly appearing transient lateral forces. During this test the forces are plotted over the wheel slip angle. The three test methods confirmed that it is possible to measure tire parameters and tire-ground characteristics with one mobile tire test rig. The significant achievements of this work are: force measuring hub, excitation ramp instead of beam in test by free oscillation, accuracy definition in the test by random vibration.

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