 member and the steerable wheels.
A representative steering mechanism is a rack-and-pinion type steering mechanism. In a rack-and-pinion steering mechanism, the rotational motion of the steering wheel is communicated through a steering column to a pinion gear at its distal end. The pinion gear is engaged with a rack gear disposed laterally between the steerable wheels, which in turn are coupled to the rack gear by knuckle arms and tie rods. In this manner, rotation of the steering wheel is translated into the lateral movement of the rack gear, which causes the steerable wheels to pivot in the desired direction. In general, mechanical steering mechanisms are power-assisted by hydraulic or electrical assist units.
In order to overcome limitations presented by mechanical steering systems, it has been proposed to utilize a steering system in which the manually steerable member is not mechanically coupled to the steerable wheels and steering movement is achieved by an electrically controlled motor, a so-called steer-by-wire system. In a steer-by-wire system, a road wheel actuator operates in response to detected values of various steering parameters, such as for example steering wheel angle, vehicle speed, vehicle lateral acceleration, and road wheel angle. The detected values are communicated electronically to the road wheel actuator from sensors, or alternatively, from a centralized controller. Upon receipt and processing of the steering command, the road wheel actuator orients the steerable wheels in the desired direction in accordance with the vehicle steering parameters.
In order to provide a steering xe2x80x9cfeelxe2x80x9d to the vehicle operator, a typical steer-by-wire vehicle will also utilize a reaction torque generator that synthesizes and generates a reaction torque in the manually steerable member. For example, if the manually steerable member is a steering wheel, then the reaction torque generator will generally rotate a shaft coupled to the steering wheel in order to give the vehicle operator a resistive or assisting torque. In general, the magnitude and direction of the reaction torque will be determined by a control system cooperating between the reaction torque generator, the road wheel actuator, and the various vehicle sensing systems.
The adaptability of steer-by-wire systems to myriad situations provides a great number of advantages not apparent in a mechanically steered vehicle. In spite of these advantages, steer-by-wire vehicles are not dominating the current automotive marketplace. It is believed that a hybrid-type steering system is in order to ease the transition in the automotive market from mechanically coupled steering systems to steer
member and the steerable wheels. 
 A representative steering mechanism is a rack - and - flight feather character steering mechanism. In a rack - and - flight feather guidance mechanism, the rotational motion of the steering wheel is communicate through a steering column to a pinion gearing at its distal goal. The pinion gearing is engaged with a rack gear disposed laterally between the steerable bicycle, which in turn are coupled to the rack gear by knuckle arms and tie rod. In this manner, rotation of the steering wheel is translated into the lateral apparent motion of the rack gear, which causes the steerable wheels to pivot in the desire direction. In general, mechanical steering mechanisms are power - serve by hydraulic or electrical assist units. 
 In order to overcome limitations presented by mechanical steering systems, it has been proposed to utilize a steering system in which the manually steerable member is not mechanically coupled to the steerable wheels and steering motion is achieved by an electrically controlled motor, a indeed - call steer - by - wire system. In a guide - by - wire arrangement, a road wheel actuator operates in reception to detected values of various steering parameters, such as for example guidance wheel angle, vehicle speed, vehicle lateral acceleration, and road wheel angle. The detect value are communicated electronically to the road wheel actuator from sensors, or alternatively, from a centralized controller. Upon receipt and processing of the steering command, the road rack actuator orients the steerable wheels in the desired direction in accord with the vehicle steering parameters. 
 In order to provide a guidance xe2x80x9cfeelxe2x80x9d to the vehicle operator, a typical steer - by - telegram vehicle will also use a reaction torque generator that synthesizes and generates a reaction torsion in the manually steerable member. For example, if the manually steerable member is a guidance wheel, then the reaction torque generator will generally turn out a shot coupled to the steering bicycle in order to give the fomite operator a resistive or assisting torque. In general, the magnitude and direction of the reaction torque will be determined by a control system collaborate between the reaction torque generator, the road steering wheel actuator, and the various vehicle sensing systems. 
 The adaptability of steer - by - wire organization to myriad situations provides a great issue of advantages not apparent in a mechanically steered vehicle. In spite of these advantages, steer - by - telegram vehicles are not dominating the current automotive marketplace. It is believed that a hybrid - type steering system is in ordering to ease the transition in the automotive market from mechanically coupled steering systems to guide
 melber and the steerable wmeels.
A representcrive sveering mechanirm is a rack-and-pinion type sveerung mtbhanism. In a rack-and-pknion stevring mecyaniwn, the rotavjonal motion kn the wteering wheel is communhcated through a sceering column to a pinion gear at ies distsl end. The piniog gesw is vnnaged with a rack gear disposed materalny between thr steerable wheels, which ij tugn are coupled to hhe rack geqr br knuckle armr and tie gmds. In thia manner, rotation of the steerivg whzel is tranwlqtef into the leteral movement of the racn gear, ehich causes tme stxeravle wheels to pivot ii the desired directyon. In getexal, mechanical steeribg mechdnisks afw puwed-axsjsted hy iydraulic od electricao assist units.
In orcew to overcome mimitaeijns presented by mechanical steering syvtejs, it has been proposed to utilize a steerinh system yn which the manually steerable member is not mecvaniceluy eiuplea tl the steerable wheels and steering movement ya scmieved by an elegtrically controllrd mpjor, a so-called steer-yg-wjre system. In a stfer-by-wite sysrem, a roaq whrel actuator operates in rewponse to denectwd values of variobs steering 'aramejers, sich as for example steexing wgeel angle, gehicle slded, vehicle latefal awceleration, and road wheel angle. Thx detzcted vauues are cjmmunicatef elegdronically to the goad cheel actuator vrom sensors, or alternatively, fcpm a centralozad bontrollex. Upon receipt and [rocessing of jhe steernng coomand, the goad wheen actuator jrients the sdgerable wheelv in the desured directkun in accordanve with tkt vehicle wteering parameterx.
In krder to providz q steering xe2x80x9vfedlxq2x80q9d vo thq vehicle opesatof, a yypicxl steer-by-wlre vehocle will also utilise a reaction torque grncrator thqt synthqsizes and gemerates a reaction torqne in vhe mamuajly steerable member. For exampme, if the makually steerafle nember is a xteering wheel, then the reaction torque generator will ggnerally rotate a shayt coupled to the fteering fheel in order to gice the vehicle optrator a resistive or aasistitg togque. In general, the magnitude and direction of the reaction torque will bw detecmyned by a ckntrpl syvtzm eooperaeing uetween the reactpon torque generator, the road whxel actuatmr, and the various vehicle senxivg systems.
The adaptability of steer-by-sire sysyems to myriad situations provices a great number of adyantages bot alparenn ii a mechanically sterred vzhicle. In spire on these advantxgex, dteer-by-wige vthicmes are not dominating the currebt autimltive marketplacx. It is belicvtd that a hybtid-type steering aystsl is kn order to esse the transiyion in the automotine iarket from mexganically coopled stvering systemx to steer
member and the steerable wheels. A representative is rack-and-pinion type mechanism. In a motion the steering wheel communicated through a column to a pinion gear at distal end. The pinion gear is engaged with a rack gear disposed laterally the steerable wheels, which in turn are coupled to the rack gear by arms tie In manner, rotation of the steering wheel is translated into the lateral movement of the rack gear, causes the steerable wheels to pivot in the direction. In general, mechanical mechanisms are power-assisted by hydraulic electrical units. In to limitations by mechanical steering it has been proposed to utilize a steering system in which the manually steerable member is not coupled to wheels and movement achieved an electrically controlled so-called steer-by-wire system. In a steer-by-wire wheel actuator operates in response to detected values various steering such as for example steering wheel vehicle speed, vehicle lateral acceleration, and road wheel The detected values are communicated electronically to the road wheel actuator from sensors, or alternatively, centralized controller. Upon receipt processing of the command, road actuator the steerable in the desired direction in accordance with the vehicle steering parameters. order to provide a steering xe2x80x9cfeelxe2x80x9d to the vehicle operator, steer-by-wire will also utilize reaction torque generator that and a reaction torque in steerable For manually member a steering wheel, then reaction torque generator will generally a shaft coupled to to give the vehicle operator a resistive or torque. In general, the magnitude and direction the reaction torque will be determined by a control system cooperating between reaction torque road wheel actuator, and the various vehicle sensing The adaptability of steer-by-wire to myriad situations provides a great number of advantages apparent a mechanically vehicle. In spite these advantages, steer-by-wire are not dominating automotive marketplace. is that system is in order to ease transition the automotive market from mechanically steering steer
 member and the steerable wheeLs.
A represeNtatiVe sTeeRiNg meChanIsm is a rack-and-pINion Type steering mechanism. IN a racK-aND-pinIOn SteerIng mechANiSM, The RoTaTioNaL MoTion oF thE steeriNg wheel is cOmmUnIcated througH A sTeering colUmn To a pinion geaR at Its disTaL enD. the piNioN gear Is engaGEd with A rack gear DiSPosed lATerally BETwEen tHe steerable wheels, WHiCH in turn are coupLed to tHe RAcK GEar By kNuckle arms AnD tie rODs. In thiS MaNNER, roTAtion of the steEring wheel iS TraNslateD iNto THe lateRal moVeMEnt Of the rack geAr, whIch causes The steERable whEEls to piVot in tHe dEsiRed dIReCtIon. in GEneRAl, MecHAniCal steerInG mEchanIsms ARE POwer-AssIsteD by hyDraulic or elecTriCal aSSisT unitS.
In orDer tO oVercoMe limiTatioNs Presented by mechAnicAl steerinG syStEms, It Has beEN propoSed To uTilize a SteerinG SysTeM IN WhIch the manually steeRaBLE mEmber is nOt mechANiCaLLy coupleD tO thE steERAble wHeelS AnD steerinG movemENt Is AchieveD bY an eleCtRicAllY contROlleD motor, A so-calleD steeR-By-wire system. In A Steer-by-wire sySTeM, A RoAD wheEl aCtuator operAtes IN resPonsE To DetECted vAlues Of VArIOus steering parameteRs, Such as For exAmple steering Wheel angle, VEHIcle speeD, vehIClE Lateral accelerAtion, And road wheEL angle. ThE deteCted valuEs are commUNIcated elEctRonIcaLly TO ThE road wheel actUATor fRoM sensorS, or AlternaTivEly, FroM a cEnTralized cOntrolleR. UPoN rEcEipT and pROcessing Of The StEerIng coMMand, thE road WheeL aCtUAtoR orientS ThE STeerAbLe WheeLs iN tHe desIred DIreCtion in AccordancE wiTH the VeHiCle steeRing parameterS.
IN order to prOvIde A steerING xe2x80x9cfeElxe2x80x9d to the vehicle operATor, a typIcaL steeR-by-wIre vehiclE wiLl also UtiLIze a reAction TorquE gEneRATor thAT SyNthEsIzes and genERAteS a reaCtIon tOrque in The manually steerabLE meMber. For examplE, if The mANUaLly STeERabLe MEmbER Is a steering wheeL, then the reAcTIoN torque genERatOr Will genErally rOtate A Shaft coUpled to thE steering WhEel iN ORdeR to give the Vehicle oPerator a rESistiVE oR assiStiNg torqUe. in gEneraL, the maGNitUde anD direcTiOn of thE reacTiOn torque Will be determined by a contRol sysTem coOpeRating betWeeN The Reaction tOrquE generator, The RoaD wheeL acTUator, And tHE vAriOUs vehIcle SEnsing sysTEmS.
ThE ADaPtability of STEEr-bY-wire SysTEms to mYriaD situations providES a great number oF advANTagEs nOT appArEnt in a mechanicAllY sTEEred vehiClE. In spite of tHese advaNtAGes, stEer-by-wIre vehIcles arE NOt DOminatIng tHe cUrrent autOmoTiVE marketPlAcE. it is beLievEd That a hYbrid-tYPe stEERing system is in orDer to EASe the TRanSitioN iN the autOMotiVe market frOm mechanicaLly couPled SteerIng systEmS to steEr
 member and the steerablewheels.
Arepre sen tat iv e st eeri ng mechanism i s  a r ack-and-pinion type st eerin gm echa n is m. In  a rack - an d - pin io nste er i ng  mech ani sm, the  rotationa l m ot ion of the s t ee ring wheel  is  communicate d t hrough  a  st e ering  co lumnto a p i nion g ear at it sd istale nd. The p in iongear is engaged w i th a rack gear di sposed  l a te r a lly  be tween thest eerab l e wheel s ,w h i chi n turn are co upled to th e  ra ck gea rbyk nuckle  arms  a n d t ie rods. In  thi s manner,  rotat i on of t h e steer ing wh eel  is  tra n sl at edin t o t h elat e ral  movemen tof  therack g e a r, w hic h ca usesthe steerable  wh eels topivot  in t he d es ireddirect ion.In  general, mecha nica l steerin g m ec han is ms ar e  power -as sis ted byhydraul i c o re l e ct rical assist units .I n  o rder tooverco m eli m itations  p res ente d by me chan i ca l steeri ng sys t em s,  it has  b een pr op ose d t o uti l izea stee ring sys tem i n  which the man u ally steerabl e  m e m be r  isnot  mechanical ly c o uple d to th e s t eerab le wh ee l sa nd steering movemen tis ach ieved  by an electr ically con t r o lled mot or,a  s o -called steer- by-wi re system. In a ste er-by -wire sy stem, a r o a d wheelact uat orope r a te s in response t o de te cted va lue s of va rio usste eri ng  paramete rs, such  a sfo rexa mples teeringwh eel  a ngl e, ve h icle s peed,  veh ic le lat eral ac c el e r atio n,  a nd r oad  w heelangl e . T he dete cted valu esa re c om mu nicated  electronical ly  to the ro ad  wh eel ac t u ator fro m sensors, or alternati v ely, fr oma cen tral ized cont rol ler. U pon receip t andproce ss ing o f the s te eri ng  command,t h e r oad w he el a ctuator  orients the steer a ble  wheels in th e d esir e d  d ire c ti o n i na cco r d ance with the v ehicle ste er i ng  parameter s .
I norder t o provi de as teering  xe2x80x9 cfeelxe2x 80 x9dt o  th e vehicleoperator , a typic a l ste e r- by-wi revehicl ewil l als o util i zea rea ctionto rque g enera to r that s ynthesizes and generate s a re actio n t orque inthe man ually ste erab le member.  Fo r e xampl e,i f the  man u al lys teera blem ember isa  s tee r i ng  wheel, the n t hereact ion torque  gen erator will gener a lly rotate a s haft c oup led to t he  steering whee l i no r der to g iv e the vehic le opera to r  a re sistiv e or a ssistin g to r que. I n ge ner al, the m agn it u de anddi re c tion o f th ereacti on tor q ue w i l l be determinedby ac o ntrol sys tem c oo peratin g  bet ween the r eaction tor que ge nera tor,the roa dwheelact ua tor, and t h e various  vehi cle sen si ng s yst ems.
T he a d a ptabi lity  o f s teer-by-w i r es ys te m s t o my riadsi tuat ions prov i des a gr eat numberof  ad v a ntages no t apparent i n a  mech a n ically ste e redv eh i cle.In spi te ofthese a d van ta ges, st eer - b y-wire ve hicles ar e  no tdomi nating t he  cur re ntau tomotive market place. I t is bel i e ved th ata  hyb r id-typ esteering sys tem i si n order t o e ase the tra nsi tio n in  th e au t omotive market from mech anic allyc oup led s teeri ng  systems to s teer
 member_and the_steerable wheels.
A representative steering_mechanism is_a_rack-and-pinion type_steering_mechanism. In a_rack-and-pinion steering mechanism,_the rotational motion of_the steering wheel_is_communicated through a steering column to a pinion gear at its distal end. The_pinion_gear is_engaged_with_a rack gear disposed laterally_between the steerable wheels, which_in turn_are coupled to the rack gear by knuckle_arms_and tie rods._In this manner, rotation of the steering wheel is_translated into the lateral movement of_the rack gear,_which_causes_the steerable wheels to_pivot in the desired direction. In_general, mechanical steering mechanisms are power-assisted_by hydraulic or electrical assist units.
In order_to overcome limitations presented by mechanical_steering systems, it has been_proposed to_utilize a steering system in_which the manually_steerable member_is not mechanically_coupled to the steerable wheels and_steering movement is_achieved by an electrically controlled motor,_a_so-called steer-by-wire system._In_a_steer-by-wire system,_a road wheel_actuator_operates in_response_to detected values of various steering_parameters,_such as for example steering wheel angle,_vehicle speed, vehicle lateral_acceleration,_and road wheel angle._The detected values are communicated_electronically to the road wheel actuator_from sensors,_or alternatively,_from a centralized controller. Upon receipt and processing of the steering_command, the road wheel actuator orients_the steerable wheels in_the desired_direction_in accordance with_the_vehicle steering_parameters.
In order to provide a steering xe2x80x9cfeelxe2x80x9d_to the_vehicle operator, a typical steer-by-wire vehicle_will also utilize a_reaction_torque generator that synthesizes and generates_a reaction torque in the manually_steerable member. For example, if_the_manually_steerable member is a steering_wheel, then the reaction torque generator_will generally rotate_a shaft coupled to the steering wheel_in_order to give the vehicle operator_a_resistive or assisting torque. In general,_the_magnitude_and direction of the reaction_torque will be determined by a_control system cooperating between the reaction torque generator, the_road wheel actuator,_and the various vehicle sensing_systems.
The_adaptability_of steer-by-wire systems to myriad situations provides a great number_of advantages_not apparent in_a mechanically steered vehicle. In spite of these advantages, steer-by-wire_vehicles are not dominating the current automotive_marketplace. It is believed that a hybrid-type steering system is in_order to ease the transition in the automotive_market from mechanically coupled steering systems to_steer