自适应巡航控制系统技术解析 Adaptive cruise control system

自适应巡航控制系统AdaptivecruisecontrolsystemHighspeed,keepagooddistanceisanimportantguaranteetodrivingsafetywhendrivinghighspeedwiththevehicleinfront.Onlyinthisway,canoccurbeforethecarinanemergencybrakingsituation,setasideenoughbrakingdistance.Byusingthistechnique,whencruisedriving,thedriveronlyneedstodoistoturnthesteeringwheelcanbe.Adaptivecruisecontrolsystemisanautomaticcontrolsystemforintelligent,itisevolvedbasedoncruisecontroltechnologyalreadyexistonthe.Intheprocessofvehiclemountedsensordistanceinfrontofthevehicle,thevehicle(radar)continuedtoscantheroadaheadofthevehicle,thewheelspeedsensorsignalacquisitionthespeedatthesametime.Whenthedistancebetweenthevehiclebetweenafterhours,theACCcontrolunitcanbethroughwithantilockbrakingsystem,enginecontrolsystemofcoordinatedaction,maketheappropriatewheelbrake,andtheoutputpoweroftheenginedown,tomakethevehicleandthevehicleinfrontalwayskeepasafedistance.Adaptivecruisecontrolsysteminthecontrolofvehiclebraking,usuallythebrakingdecelerationlimitindoesnotaffectthecomfortabledegree,whentheneedforgreaterspeedreduction,theACCcontrolunitsendsouttheacousto-opticsignaltoinformthedrivertakethebrakeoperation.Whenthedistancebetweenthevehiclebetweenincreasedtoasafedistance,theACCcontrolunittocontrolthevehicleaccordingtothesetspeed.Effectof:bycardistancesensorfeedbacksignal,theACCcontrolunitcanbejudgedaccordingtothemovingspeedoftheroadconditionsnearthevehicleobjects,andcontrolthevehiclerunningstate;throughthefeedbackofaccelerationpedal(Figure3)perceivedthedriverappliedonthepedalforce,aACCcontrolunitcandeterminewhethertheexecutionofcruisecontrol.Inordertoreducethefatigueofthedriver.willplayaroleofadaptivecruisecontrolsystemisgenerallygreaterthan25km/hinspeed,andwhenthespeedisreducedtobelow25km/h,requiresthedriverforartificialcontrol.Throughthesystemsoftwareupgrade,adaptivecruisecontrolsystemcanrealizethe"stop/start"function,tostopandstarttodealwiththesituationincitydriving,frequent.Theadaptivecruisecontrolsystemexpansionfunction,canmakethecarcanalsomaintainasetdistancewiththevehicleinfrontatverylowspeed.Thecurrentvehiclestart,adaptivecruisecontrolsystemwillremindthedriver,thedriverthroughthethrottlepedalorpressthebuttontosendasignal,thevehiclecanstartrunning.adaptivecruisecontrolsystemmakesthevehicleformationdrivingeasier.TheACCcontrolunitcanbesettoautomaticvehicletracking,whenthecarfollowthefrontcar,theACCcontrolunitcanbeadjustedtothesamespeedwiththevehicleinfront,andmaintainthestabilityofthedistance,butthisdistancecanbeselectedbysteeringthesettingsbuttoncontrolroddisconthenearThroughthepresettingadistancebetweenthevehicleinfront,thesystemwillbeinaccordancewiththesettoautomaticcontrolandthecarinfrontoftheposition.Ifmorethanthisdistance,thecarwillautomaticallygiveoilcatchup,ifthedistanceisshortened,so,theon-boardcomputerwillsendabrakecommand.Butifyouhaveenteredasetdistanceis20%,thesystemwillautomaticallyflashontheinstrumentpanellights,andissuedawarningsoundtoremindthedrivertocontrolthevehicle.Coupledwiththetraditionalcruisesystem,theprocessofrunningonthehighwaywillbecomeveryeasy.高速行驶的时候，与前车保持一个良好的车距是保证高速驾驶时行车安全的重要保证。只有这样，才能够在发生前车紧急制动的情况下，留出足够的刹车距离。通过使用这个技术，在巡航驾驶的时候，驾驶者唯一需要做的就是转动方向盘就可以了。自适应巡航控制系统是一种智能化的自动控制系统，它是在早已存在的巡航控制技术的基础上发展而来的。在车辆行驶过程中，安装在车辆前部的车距传感器（雷达）持续扫描车辆前方道路，同时轮速传感器采集车速信号。当与前车之间的距离过小时，ACC控制单元可以通过与制动防抱死系统、发动机控制系统协调动作，使车轮适当制动，并使发动机的输出功率下降，以使车辆与前方车辆始终保持安全距离。自适应巡航控制系统在控制车辆制动时，通常会将制动减速度限制在不影响舒适的程度，当需要更大的减速度时，ACC控制单元会发出声光信号通知驾驶者主动采取制动操作。当与前车之间的距离增加到安全距离时，ACC控制单元控制车辆按照设定的车速行驶。作用:(1)通过车距传感器的反馈信号，ACC控制单元可以根据靠近车辆物体的移动速度判断道路情况，并控制车辆的行驶状态;通过反馈式加速踏板(图3)感知的驾驶者施加在踏板上的力，ACC控制单元可以决定是否执行巡航控制，以减轻驾驶者的疲劳。(2)自适应巡航控制系统一般在车速大于25km/h时才会起作用，而当车速降低到25km/h以下时，就需要驾驶者进行人工控制。通过系统软件的升级，自适应巡航控制系统可以实现“停车/起步”功能，以应对在城市中行驶时频繁的停车和起步情况。自适应巡航控制系统的这种扩展功能，可以使汽车在非常低的车速时也能与前车保持设定的距离。当前方车辆起步后，自适应巡航控制系统会提醒驾驶者，驾驶者通过踩油门踏板或按下按钮发出信号，车辆就可以起步行驶。(3)自适应巡航控制系统使车辆的编队行驶更加轻松。ACC控制单元可以设定自动跟踪的车辆，当本车跟随前车行驶时，ACC控制单元可以将车速调整为与前车相同，