Article A Study on the Influence of Tire Speed and Pressure on Measurement Parameters Obtained from High-Speed Tire Uniformity Testing Meng Du 1,2, Pengfei Sun 1,3,*, Shuiting Zhou 1,2, Hongwu Huang 1,3 and Jie Zhu 4 1 Collaborative Innovation Center for R&D of Coach and Special Vehicle, Xiamen University of Technology, Xiamen 361024, China; [email protected] (M.D.); [email protected] (S.Z.); [email protected] (H.H.) 2 School of Mechanical & Automotive Engineering, Xiamen University of Technology, Xiamen 361024, China 3 School of Aerospace Engineering, Xiamen University, Xiamen 361102, China 4 Testing Center, Wanli Tire Co., Ltd., Guangzhou 510940, China; [email protected] * Correspondence: [email protected] Received: 15 July 2020; Accepted: 18 August 2020; Published: 8 September 2020 Abstract: In order to improve the test conditions of the tire uniformity test and the effect of the speed and tire pressure on the uniformity parameters, the uniformity test of the tire under different speeds and tire pressure was carried out by a high-speed uniformity test machine, and the experimental data were analyzed and fitted by the regression analysis method. This paper introduces the definition of uniformity and the uniformity parameters of automotive tires; the working principle of a high-speed uniformity testing machine is briefly described, a mathematical model of the uniformity testing machine is established, and the signal acquisition process of the tire uniformity parameters and the calculation method of the uniformity parameters are described. The test result indicates: As the speed increases, the radial force fluctuation, lateral force fluctuation, tangential force fluctuation, and turning torque fluctuation of the tire increase, and the positive torque fluctuation first increases and then decreases; with the increase of tire pressure, the radial force fluctuation and the tangential force fluctuation of the tire increase, and the lateral force fluctuation, the turning torque fluctuation, and the returning moment fluctuation are all reduced. Compared to the low speed uniformity test, the high speed uniformity test can better reflect the uniformity of the tire, reducing the speed of the vehicle can reduce the radial runout and lateral sway of the tire; increasing the tire pressure can reduce the left and right swing of the vehicle. Keywords: speed; pressure; high-speed uniformity testing; uniformity parameters 1. Introduction With the rapid development of the automotive industry, the performance of cars in the past no longer meets the needs of drivers in the present; vehicles are constantly improving in their handling and comfort. As the only part of the vehicle in contact with the road surface, the performance of the tires directly affects the performance of the whole vehicle. Therefore, the automotive industry pays attention to and cooperates with the tire industry as part of its efforts to improve the performance of vehicles, so that vehicle stability and comfort are further enhanced. A tire will deform irregularly when driven at high speed, resulting in fluctuations in radial, lateral, and tangential forces, reflecting variation in the circumferential forces of the tire, known as tire nonuniformity. Due to the unevenness of the tire, the forces acting on the rotating shaft during the rolling process cause the vehicle to vibrate, which reduces the maneuverability, ride, and comfort of the car, and can seriously damage some of the car’s components. Tire uniformity testing is a major Vehicles 2020, 2, 559–573; doi:10.3390/vehicles2030031 www.mdpi.com/journal/vehicles Vehicles 2020, 2 560 Vehicles 2020, 2, FOR PEER REVIEW 2 of 14 part of tire tire quality testing. For For ne newlywly produced produced tires, tires, uniformity uniformity testin testingg is is required required to to make make sure sure that that thethe actual actual measurement measurement uniformity uniformity parameter parameter error error is is within within the the allowable allowable tolerance tolerance range, range, ensuring ensuring thethe tire tire quality quality assurance assurance during during use use [1]. [1]. The The high-s high-speedpeed uniformity uniformity testing testing machine machine is is a a device device that that detectsdetects the the fluctuation fluctuation of of the the circumferential circumferential forces of the tire tire by by driving driving a a drum drum to to rotate rotate the the tire tire and and applyingapplying a a certain certain load load to to the the tire tire and and can can accurate accuratelyly measure measure the the tire tire uniformity uniformity parameters, parameters, thereby thereby beingbeing able able to to characterize characterize the performance of the vehicle. TheThe high-speed uniformityuniformity testing testing machine machine is is a semi-automatica semi-automatic testing testing device device for measuringfor measuring tires tiresunder under different different speeds, speeds, loads, andloads, pressures. and pressures. The uniformity The uniformity parameters paramete of the testrs of include the test radial include force radialfluctuation, force fluctuation, lateral force lateral fluctuation, force tangentialfluctuation, force tangential fluctuation, force radialfluctuation, force harmonics, radial force lateral harmonics, forces lateralharmonics, forces tangential harmonics, force tangential harmonics, force positive harmonic torques, fluctuations,positive torque rollover fluctuations, torque fluctuations, rollover torque taper fluctuations,effects, and angle taper e ffeffects,ects [2 ].and According angle effects to the [2]. measured According test to data, the measured not only can test the data, quality not only of the can tire the be qualityjudged, of but the also tire the be performance judged, but ofalso the the tire perfor can bemance improved of the by tire using can the be uniformity improved parametersby using the to uniformityimprove the parameters performance to improve of the vehicle. the performance of the vehicle. InIn the the past, past, many scholars mostly mostly used used the lo low-speedw-speed uniformity testing testing machine machine to to study study the the uniformityuniformity parameters parameters of of tires, tires, and and used used it it as as the the standard standard for for tire tire quality quality evaluation evaluation [3]. [3]. At At present, present, thethe speedspeed ofof vehicles vehicles on on the the highway highway is about is about 120 km 120/h, km/h, and the and test the results test of results the low-speed of the low-speed uniformity uniformitytester cannot tester accurately cannot reflectaccurately the forces reflect of the the forces tire when of the it tire is rolling when atit is high rolling speed; at high some speed; parameters some parametersthat are neglected that are in neglected the low-speed in the uniformitylow-speed testunif mayormity be test important may be reference important factors reference in high-speed factors in high-speeduniformity uniformity tests, such tests, as tangential such as tangential force fluctuations, force fluctuations, positive-torque positive-torque fluctuations, fluctuations, and roll-over and roll-overtorque fluctuations. torque fluctuations. The accuracy The ac ofcuracy the sensors of the sensors of the low-speedof the low-speed uniformity uniformity tester tester does notdoes meet not meetthe test the requirements test requirements of these of parameters, these paramete and doesrs, notand fully does reflect not thefully uniformity reflect the characteristics uniformity characteristicsof the tires; these of the parameters tires; these can parameters be used tocan characterize be used to thecharacterize uniformity the ofuniformity the tires atof highthe tires speed. at highIn a tirespeed. uniformity In a tire uniformity test, there aretest, many there factorsare many that factors affect that the unevennessaffect the unev ofenness the tire, of such the tire, as speed, such asload, speed, and load, pressure, and pressure, which should which be should examined be examin in ordered toin study order theto study change the of change forces andof forces moments and momentswhen the tirewhen is rolling the tire at is high rolling speed. at high In this speed. paper, In a th high-speedis paper, a uniformity high-speed tester uniformity is used totester measure is used the tochange measure of forces the change and moments of forces of and a tire moments under di offf erenta tire speedsunder different and different speeds pressures, and different and the pressures, influence andof speed the influence and pressure of speed on tire and uniformity pressure parameters on tire uniformity is analyzed. parameters Additionally, is analyzed. the relationship Additionally, between the relationshiptire uniformity between parameters tire uniformity and vehicle parameters performance and is brieflyvehicle described, performance providing is briefly a reference described, for providingimproving a the reference production for improving level of tires the and prod vehicleuction design.level of tires and vehicle design. 2.2. Tire Tire Uniformity Uniformity 2.1.2.1. Tire Tire Uniformity Uniformity Definition Definition AA tiretire isis an an annular annular elastic elastic body body made made of various of various materials materials such assuch rubber, as rubber, steel cord, steel and cord, polyester. and polyester.Its quality, Its size, quality, and size, rigidity and are rigidity uneven are duringuneven the during structural the structural design anddesign