動力轉向系統參數對汽車操縱穩定性影響的研究外文文獻翻譯、中英文翻譯

動力轉向系統參數對汽車操縱穩定性影響的研究外文文獻翻譯、中英文翻譯,動力,轉向,系統,參數,汽車,操縱,穩定性,影響,研究,外文,文獻,翻譯,中英文 THIS DOCUMENT IS PROTECTED BY U.S. AND INTERNATIONAL COPYRIGHTIt may not be reproduced, stored in a retrieval system, distributed or transmitted, in whole or in part, in any form or by any means.Downloaded from SAE International by Guangxi University of Tech, Sunday, March 10, 2013 10:41:20 PM 2.2 英文原文 Research of the Impact of Power Steering SystemParameters on the Vehicle Handling Stability ShuHua Liao and Caihong YangGuangxi University of Technology2012-01-0256Published04/16/2012ABSTRACTThe characteristic of steering system is extraordinary criticalto vehicle handling and stability, and the coulomb friction,which consist of steering gear coulomb friction and kingpincoulomb friction, are usually neglected in the many previoussteering system model. In the paper, the dynamic model ofhydraulic power steering system (HPS) including 9 rotationaldegree-of-freedom (DOF) and 1 translational DOF ispresented, taking into account coulomb friction of steeringsystem, and the 2-DOF mathematical model is establishedbased on the manipulation of dynamical theory. Thensimulation of vehicle handling stability is developed using themodel, a goal of investigation of effects of steering ration,stiffness coefficients and moment of inertia of parts on signsof handling and stability involving yaw rate, slip-angle ofcenter of gravity and lateral acceleration. All the work laygood groundwork for designing and selecting of theparameters of steering system.Keywords2-DOF vehicle dynamics model, hydraulic power steeringsystem model, vehicle handling and stability, simulation,effectINTRODUCTIONHandling and Stability is one of key indicators for estimatingthe vehicle performance, which is the ability that car canfollow the direction of the road the driver applied thoughsteering system and steering wheel, even when encounteredoutside interference, the car can resist interference and keepstable driving 1. Automobile chassis is the main componentsof affecting the control stability, and the steering systemwhich is specially handling driving directions has the closestrelations with handling and stability. Therefore, buildingCopyright 2012 SAE Internationaldoi:10.4271/2012-01-0256fairly precise steering system dynamic equation is the key toresearch manipulation stability. In paper, the hydraulic powersteering system model concerning sticky damper, dry frictionand clearance of steering system is deduced; the relationbetween steering system characteristic parameters and vehiclesteering stability is analyzed.1. REPRESENTATION OF THEHYDRAULIC POWER STEERINGSYSTEMSteering system consists of a series of drive components,force or torque applied by drivers through steering wheel,steering gear, steering horizontal bars and steering knucklearm to turn the wheels to achieve the purpose of steering thevehicle2. After years development, automobile steeringsystem has experienced several stages such as puremechanical steer, hydraulic power steer, electric-hydraulicpower steer, electric power steer and steer by-wire. Atpresent, hydraulic power steering system is mostly adoptedon the commercial vehicle 3.Device of the typical rack-pinion steering system is shown infigure 1.1.Hydraulic pump is directly driven by the enginewith a belt, distributing valve and oil pump combine, steeringcontrol valve, power cylinder and steering gear are assembledtogether by means of pipelines. The turn signal applied bydriver with hand power flows past steering, control valve,power cylinder and steering linkage, then a amplifying forcegained on the front roadwheel through hydraulic system.Meanwhile, the resistance coming from road is deduced bysteering gear, and the steering wheel gain a feedback throughcontrol valve to form the “road sense” on driver hands 2.THIS DOCUMENT IS PROTECTED BY U.S. AND INTERNATIONAL COPYRIGHTIt may not be reproduced, stored in a retrieval system, distributed or transmitted, in whole or in part, in any form or by any means.Downloaded from SAE International by Guangxi University of Tech, Sunday, March 10, 2013 10:41:20 PMAccording to the working principle, the system is simplifiedto the model in figure 1.2, which also shows the direction ofthe torque. Each symbol meaning is displayed as follows.Fig 1.1. diagram of hydraulic power steering systemFig 1.2. diagram of power steering system and torquetransfer TSW-torque of steering wheel ISW-moment of Inertia of steering wheel IFW1-moment of inertia of left roadwheel IFW2-moment of inertia of right roadwheel MR-rack mass TP-torque of torsion bar TK1-torque of left king pin TK2-torque of right king pin AT1-aligning torque of left roadwheel AT2-aligning torque of right roadwheel FPS-aUxiliary force of power steering system CFGR-friction of steering gear CFKP1-friction of left roadwheel around king pin CFKP2-friction of right roadwheel around king pin CSW-damping coefficient of steering column CGR-damping coefficient of steering gear CKP1-damping coefficient of left king pin CKP2- damping coefficient of right king pin KSC-rotational stiffness of steering column KT-rotational stiffness of torsion bar KKP1-rotational stiffness of left king pin KKP2-rotational stiffness of right king pin NL1-transmission ratio between rack and left roadwheel NL2- transmission ratio between rack and right roadwheel SW-angle displacement of steering wheel SC-angle displacement of steering column G-angle displacement of pinion YR-Translation displacement of rack SLU1, SLU2-angle displacement of steering arm aroundking pin SLL1, SLL2-angle displacement of knuckle arm aroundtheir king pin FW1-angle displacement of left roadwheel FW2-angle displacement of right roadwheel RG-pitch radius of pinion SFP-clearance of steering system2. ESTABLISHING OF POWERSTEERING SYSTEM DIFFERENTIALEQUATIONSThe model in figure 1.1 is divided into four lumped-mass androtation mass system including revolving quality of steeringwheel and column, rotation mass of left and right frontroadwheel around their king pin, the rack mass. The wholemodel is described with nine rotation movement and a totalvariable. These variables are respectively steering wheelangle displacement SW, the steering column angleTHIS DOCUMENT IS PROTECTED BY U.S. AND INTERNATIONAL COPYRIGHTIt may not be reproduced, stored in a retrieval system, distributed or transmitted, in whole or in part, in any form or by any means.Downloaded from SAE International by Guangxi University of Tech, Sunday, March 10, 2013 10:41:20 PMdisplacement SC, pinion angle displacement G, angledisplacement of left and right steering arms around theircorresponding king pin SLU1 and SLU2, left and rightsteering knuckle arm angle SLL1 and SLL2, front roadwheelsteering angle FW1 and FW2 and rack linear displacementYR.Fig 2.2. diagram of rack and pinion2.1. THE STEERING WHEEL AND THESTEERING COLUMN MOTIONEQUATIONSThe stress of this component is analyzed in figure 2.1, theestablishment of differential equations are developed.(2-5)Fig 2.1. diagram of steering wheel and steering column(2-1)The torque delivered by steering column is presented as:(2-2)The transferring torque of torsion bar in control valve is:(2-3)The force is balanced on both ends of the torsion bar,therefore,(2-4)2.2. MOTION EQUATIONS OF RACKAND PINOIN STEERING GEARStress of steering gear is shown in figure 2.2, assuming thatrack is driven to turn right by pinion, the kinematicsdifferential equations are written as:Transferring torque of king pin in the curse of steering is:(2-6)According to the kinematic relation between the rack andpinion, the following equation is can be gotten.(2-7)Because the translation movement of the rack is can beconverted into the rotary motion of steering knuckle armaround king pin by the horizontal bar, the equations aretranslated into:(2-8)2.3. EQUATIONS OF LEFT AND RIGHTFRONT ROADWHEELThe left front roadwheel stress is revealed in figure 2.3,consequently, the kinematics differential equations aredisplayed as:Fig 2.3. diagram of left front roadwheelTHIS DOCUMENT IS PROTECTED BY U.S. AND INTERNATIONAL COPYRIGHTIt may not be reproduced, stored in a retrieval system, distributed or transmitted, in whole or in part, in any form or by any means.Downloaded from SAE International by Guangxi University of Tech, Sunday, March 10, 2013 10:41:20 PMHere, GP mean relaxation angle of steering gear. FGP0, FGP1,(2-9)Similarly, the right front roadwheel equations are obtained.(2-10)When ignoring front road wheel additional steering anglebecause of body rolling, the equation will turn to thefollowing formulas.(2-11)2.4. DRY FRICTION MODEL OFSTEERING SYSTEMAll components of Steering system have certain frictioncalled dry friction of steering system in the process ofsteering. It can affect the drivers “the road feeling”information if the friction is too large. To the contrary, smallfriction will increase the impact of rough road to the steeringwheel. Generally, the dry friction mainly include king pinfriction and steering gear friction.2.4.1. Model of the king pin frictionThe friction torque formula proposed by Guo KH4 professoris adopted to describe the friction characteristics of king pin.(2-12)(2-13)Where, S is relaxation angle. FKP0, FKP1, FKP2 display thecoefficient of friction with the change of angle, which aredetermined by test, FKP0=15.654, FKP1=5.6, FKP2=1.77.2.4.2. Model of the steering gear frictionThe model of steering gear friction is described as:(2-14)(2-15)FGP2 indicate the coefficient of friction determined by thetest, FGP0=0.99675, FGP1=0.00268, FGP2=3.8058e-4.Figure 2.4 is the result of simulation and experimentalproving the validity of the model.Fig 2.4. diagram of steering gear friction simulationresult2.5. DESCRIPTION OF STEERINGSYSTEM CLEARANCEIn order to consider the influence of the steering systemclearance, we assume the clearance SFP is in the scope of. In that way, the torque transferred bytorsion bar can be displayed as:If(2-16)Or2.6. MODEL OF HYDRAULIC POWERSYSTEMThe power produced by power steering system FPS isexpressed as multiplier of cylinder pressure difference andpower cylinder piston area, that is:(2-17)Where, AP is area of power cylinder piston, Pb meanspressure difference of power cylinder piston, so the powermodel is shown as follows5 6.THIS DOCUMENT IS PROTECTED BY U.S. AND INTERNATIONAL COPYRIGHTIt may not be reproduced, stored in a retrieval system, distributed or transmitted, in whole or in part, in any form or by any means.Downloaded from SAE International by Guangxi University of Tech, Sunday, March 10, 2013 10:41:20 PMTable 1. simulation parameters(2-18)Here, PC is increased pressure to meet the design requirementof steering control valve, it can be offered by designdepartment.Pb acts the actual increased pressure force. Tbdisplays time constant reflecting hydraulic system lag.Usually, Tb takes 0.0015s, and efficiency of steering geartakes 1.0. Figure 2.5 reveals the contrast figure of simulationand test that fit each other very well.Fig 2.5. diagram of power steering system3. MODEL VERIFICATIONIn this chapter, vehicle dynamics model of two degree-of-freedom including yaw-rate and lateral acceleration isestablished.(3-1)(3-2)Where(3-3)Aligning torque is calculated by pneumatic trail and lateralforce, that is(3-4)The all parameters are summarized in table 1.From all the formulas mentioned above, the simulation modelis built and the response of the yaw rate, sideslip angle andlateral acceleration are deduced, as shown in figure 3.1,figure 3.2, figure 3.3. The simulation result is compared tothe test result of double lane change.Fig 3.1. vehicle yaw rate curveFig 3.2. vehicle sideslip angle curveTHIS DOCUMENT IS PROTECTED BY U.S. AND INTERNATIONAL COPYRIGHTIt may not be reproduced, stored in a retrieval system, distributed or transmitted, in whole or in part, in any form or by any means.Downloaded from SAE International by Guangxi University of Tech, Sunday, March 10, 2013 10:41:20 PMFig 3.3. vehicle lateral acceleration curveFig 4.1. effect of transmission ratio on yaw rateAs the figures show, simulation value of yaw rate and lateralacceleration fit experimental value perfectly. Whereassideslip angle has certain difference because tires haveappeared nonlinear area at high speed of 22.5 m/s. In theprocess of simulation, linear tire model is adopted lead to thedifference of simulation and experiment.4. EFFECT OF STEERING SYSTEMPARAMETERS ON VEHICLEHANDLING AND STABILITYIn order to explore the relationship between steering systemand vehicle control stability, some parameters have beenchanged to research modification of yaw rate, sideslip angleand lateral acceleration.4.1. THE INFLUENCE OF THETRANSMISSION RATIOThe steering system angle ratio is formed by steering gearratio and steering linkage transmission ratio 7, the steeringgear ratio is expressed as, where, YR is rackdisplacement and FW represents steering wheel angle.Steering truss transmission ratio is shown as, sothe steering system ratio is developed as.Figure 4.1, figure 4.2, figure 4.3 shows the simulation resultsthat before and after steering system transmission ratio ischanged. The solid line is a result of using the data in table 1in the paper. the dotted line presents steering gear ratio iCranges from 0.00877m/rad to 0.01077m/rad which isequivalent to steering system transmission ratio i reduces, thespotted line indicates that steering linkageFig 4.2. effect of transmission ratio on sideslip angleFig 4.3. effect of transmission ratio on lateralaccelerationtransmission ratio iL varies from 0.14388 m/rad to 0.15388m/rad which is equal to steering system transmission ratio irises.From the figures, we can find out that when steering gearratio iC mounts, amplitude of vehicle yaw rate r, side-slipangle and lateral acceleration ay fall respectively 1.53%,3.7% and 2.63%, and overshoots reduce respectively 14.3%,19.18% and 32.23%. Otherwise, maximum value of vehicleyaw rate r, side-slip angle and lateral acceleration ay growrespectivelyrespectivelyshortened.THIS DOCUMENT IS PROTECTED BY U.S. AND INTERNATIONAL COPYRIGHTIt may not be reproduced, stored in a retrieval system, distributed or transmitted, in whole or in part, in any form or by any means.Downloaded from SAE International by Guangxi University of Tech, Sunday, March 10, 2013 10:41:20 PM, but overshoot reduce, the reaction time isFrom the above analysis, we learned that the change of stemtransmission ratio iL has the bigger effect on the vehiclesteering stability, especially to yaw rate and lateralacceleration. In contrast, peak value of side-slip angle changefurther as steering gear ratio of iC ranges.4.2. THE EFFECT OF STIFFNESSCHARACTERSteering system stiffness properties include steering columnrigidity, torsion bar stiffness, and steering king pininflexibility8, whose changing results to vehicle steeringstability is shown as 4.4, 4.5, 4.6 figures. The solid line growsout of introducing the data in table 1, the dotted line showsthe simulation results that the torsion bar rigidity Kt reducesfrom 108.617 N-m/rad to 88.617 N-m/rad, the spotted linesreveals that steering columnFig 4.4. influence of stiffness on yaw rateFig 4.5. influence of stiffness on sideslip angleFig 4.6. influence of stiffness on lateral accelerationstiffness Ksc varies from 840.694N-m/rad 1204.694N-m/rad,and the dash-dotted line is a consequence that king pintorsion rigidity KCKP changes by 49939.5214 N-m/rad to69939.521 N-m/rad.The graphs show that when torsion bar stiffness changes, theyaw rate r, center of gravity sideslip angle and the lateralacceleration ay almost stay their previous level; the reasonmaybe is that the hydraulic power system itself has biggishstiffness which can compensate the drop of torsion barrigidity. Because the torsion distortion diminishes followingthe steering column stiffness KSC increases, series-woundstiffness of torsion and column is equal to its primary rigiditythat is why the vehicle yaw rate r, sideslip angle and thelateral acceleration ay also almost have no change. But theyaw rate r, sideslip angle and the lateral acceleration ayvalue were rising 4.06%, 4.08% and 4.06% respectivelyalong with king pin stiffness increases.4.3. THE IMPACT OF DRY FRICTIONCHARACTERISTICSSteering system friction characteristics consists of mainlysteering gear friction character and king pin friction feature.Friction should be in the reasonable scope, neither too big nortoo small, which ensure the driver to have a good “roadsense” and make steering wheel impact force not overlarge8.Figure 4.7, figure 4.8, figure 4.9 show the results that frictionmaximum of steering system components is changed. Thesolid line expresses the simulation results of adopting the datain table 1, the dotted line displays the results that the steeringgear friction amplitude CFGR reduces from 0.9968 N-m to0.6968 N-m with the steering gear angle is zero, the spottedlines reveals king pin friction peak value CFKP varies from15.654 N-m to 9.654N-m.THIS DOCUMENT IS PROTECTED BY U.S. AND INTERNATIONAL COPYRIGHTIt may not be reproduced, stored in a retrieval system, distributed or transmitted, in whole or in part, in any form or by any means.Downloaded from SAE International by Guangxi University of Tech, Sunday, March 10, 2013 10:41:20 PMAs the figures demonstrate, the peak value of yaw rate r,sideslip angle and the lateral acceleration ay ascend,reaction timeFig 4.7. effect of friction maximum value on yaw rateFig 4.8. effect of friction maximum value on sideslipangleFig 4.9. effect of friction maximum value on lateralaccelerationis shortened, and overshoot has declined when amplitudevalue of steering gear friction and king pin friction decrease.And that, the simulation curves are nearly identical, alongwith steering gear friction falls less than the king pin.Consequently, steering gear friction has greater influence onhandling and stability than the king pin friction. When kingpin stiffness KCKP increases, amplitude of yaw rate r, side-slip angle and the lateral acceleration ay are rising.4.4. THE INFLUENCE OF STEERINGSYSTEM PARTS QUALITY ANDINERTIAThe steering system is divided into four lumped-mass androtating mass parts which contain steering wheel rot