【机械类毕业论文中英文对照文献翻译】马自达公司的速度感应四轮转向系统
【机械类毕业论文中英文对照文献翻译】马自达公司的速度感应四轮转向系统,机械类毕业论文中英文对照文献翻译,机械类,毕业论文,中英文,对照,对比,比照,文献,翻译,马自达,公司,速度,感应,轮转,系统
编号无锡太湖学院 毕业设计(论文)相关资料题目: 基于横摆率反馈的四轮 转向系统的仿真研究 信机 系 机械工程及自动化专业学 号: 0923201学生姓名: 孙建国 指导教师: 陈炎冬 (职称:讲师 ) (职称: )2013年5月25日目 录一、毕业设计(论文)开题报告二、毕业设计(论文)外文资料翻译及原文三、学生“毕业论文(论文)计划、进度、检查及落实表”四、实习鉴定表无锡太湖学院毕业设计(论文)开题报告题目: 基于横摆率反馈的四轮 转向系统的仿真研究 信机 系 机械工程及自动化 专业学 号: 0923201 学生姓名: 孙建国 指导教师: 陈炎冬 (职称:讲师 ) (职称: )2012年11月12日 课题来源 实际应用 科学依据(1)课题科学意义 四轮转向(Four-wheel steering, 4WS)作为一种有效改善车辆操纵性能的技术,近期在高档车中应用正受到更多重视,有在中低档车上应用的趋势。使用4WS 技术的主要目的有:减少车辆质心侧偏角;减少车辆横摆率与车辆横向加速度之间的相差;增加轮胎横向力的裕度,使其远离饱和状态。从驾驶的观点看,4WS车辆低速时有较小的转弯半径,这增强了车辆的低速性能,如更加灵活或和方便于泊车;高速时4WS 车辆由于由较小的角和相差,高速变道将更加平滑,操纵控制更容易,乘客感觉更加舒适;高速紧急避让时,车体较少甩尾,减少了车体扫过的包线面积,从而减少了碰撞的可能性。(2)四轮转向的研究状况及其发展前景 国内外主要研究的方法中主要有如下:定前后轮转向比四轮转向系统;前后轮转向比是车速函数的四轮转向系统;具有一阶滞后的四轮转向系统;前后轮转向比是前轮转角函数的四轮转向系统;具有反相特性的四轮转向系统;前轮转向角比例前馈加横摆角速度比例反馈;具有自学习、自适应能力的四轮转向系统。国内方面主要侧重于对于二自由度的研究,目前还处于理论阶段。国外学者开始将现代控制理论与智能控制理论应用于四轮转向汽车。 经过不断的研究,目前已有许多研究成果,对于其发展前景如下: (1)四轮转向汽车将出现新型的后轮转向执行机构和后轮转向传动机构,这样可以提高转向时的操纵轻便性、灵活性和转向角度的准确性。 (2)高性能、高精度、高灵敏度的传感器的应用于4WS系统,以便于正确地检测汽车的运动信号。(3)更加深入的研究转向过程中轮胎的瞬态特性 ( 4)将先进的控制理论与控制方法应用于4WS控制器的研究中。 (5)从主观评价出发,考虑闭环综合性能指标,将“人车路”看成一个系统。 (6)基于新控制理论的全主动四轮转向系统。 把4WS技术与其它主动安全技术(如4WD、ABS、ASR、ASC、DYC等)相结合,实现汽车主动底盘技术的综合控制,这是主动控制4WS系统研究的长期目标。 研究内容 熟悉4WS技术的发展历程,特别是近十几年来的发展; 熟练掌握4WS汽车动力学的原理以及其模型建立的分析; 掌握前轮转角比例前馈汽车的研究的传递函数的推导以及动态、稳态、瞬态分析; 掌握前轮转向角比例反馈加横摆角速度比例反馈的4WS系统模型分析; 能够熟练使用MATLAB仿真。针对三幅典型的灰度图像,采用基于4WS模型其编码,用客观标准和主观标准综合评价重建图像的质量; 熟练使用MATLAB提供的Simulink工具。拟采取的研究方法、技术路线、实验方案及可行性分析(1)实验方案 对二轮系统和四轮系统进行建立模型,着重研究横摆率跟踪控制的四轮转向系统,然后应用Matlab画出模型图,输入原始参数,控制好变量,编好程序,进行仿真。(2)研究方法 在同一图形下,分析两个图形的差别; 在不同的参条件下,对同一个图像做不同的量化,分析两者的区别。研究计划及预期成果研究计划:2012年11月12日-2012年12月25日:按照任务书要求查阅论文相关参考资料,填写毕业设计开题报告书。2013年1月11日-2013年3月5日:填写毕业实习报告。2013年3月8日-2013年3月14日:按照要求修改毕业设计开题报告。2013年3月15日-2013年3月21日:学习并翻译一篇与毕业设计相关的英文材料。2013年3月22日-2013年4月11日:4WS模型的建立与相关推导。2013年4月12日-2013年4月25日:MATLAB程序设计。2013年4月26日-2013年5月21日:毕业论文撰写和修改工作。预期成果:达到预期的实验结论:通过前轮转角比例前馈汽车的仿真分析得到4WS比2WS有更加好的性能以及稳定性;通过前轮转向角比例反馈加横摆角速度比例反馈的4WS系统的仿真分析,得到比2WS有更好的性能以及稳定性,同时与前轮转角比例前馈汽车的仿真比较,有更好的性能以及稳定性。特色或创新之处 使用MATLAB编程仿真,效果明显,方便改变参量,能够直观判断实验结果。 采用固定某些参量、改变某些参量来研究问题的方法,思路清晰,简洁明了,行之有效。已具备的条件和尚需解决的问题 实验方案思路已经非常明确,已经具备使用MATLAB编程仿真的能力和图像处理方面的知识。 使用MATLAB编程的能力尚需加强。指导教师意见 指导教师签名:年 月 日教研室(学科组、研究所)意见 教研室主任签名: 年 月 日系意见 主管领导签名: 年 月 日英文全文 The Mazda Speed Sensing Computerised 4-Wheel Steering System. the Mazda Speed Sensing Computerised 4-Wheel SteeringThe Mazda Speed SensingComputerised 4-Wheel Steering System.Three and a half decades ago,well-calculated conclusion that presentation Conference,at the October 26,two young Mazda designers arrived at a far-sighted and was quite revolutionary for the time. In their technical 1962 Japanese Automotive Engineers Society Technical Dr Tadashi Okada concerning vehicle dynamics as and engineer Toshiaki summarised their arduous research follows. 1 The basic difference in the characteristics of oversteer and understeer lies in themagnitude of time delay and response. 2.a vehicle that is stable under high speed must possess understeer characteristics 3.the rear wheel tyre reflects heavily on the stability and a major improvement on control and stability may be anticipated by means of the automatic rear wheel steering system. The conclusions and formulations presented by these two engineers established thefoundation for Mazdas present-day reputed suspension technology. Over years of dedicatedresearch and development expertise, their original discoveries and theories have contributed to some of the most significant achievements within the recent history of automotive chassis engineering, incorporated by Mazda within its series production products. These developments include the twin trapezoidal link rear suspension, first employed in the original front-wheel drive Mazda 323 (1980) and the Mazda 626 (1982, and then perfected within the updated Mazd 626; the award winning Dynamic Tracking Suspension System of the second generation Mazda RX-7 (1985); and the elaborate E-link rear suspension of the new Mazda 929 (1987). While various external forces and loads are exerted to the rear wheels of a vehicle as itcombats the elements of the law of motion as defined by Sir Isaac Newton, these new suspension systems convert those forces into 4WS effects which positively aid in vehicle stability and agility. the Mazda designers and engineers ultimate goal was still a positive measure to generateforces for positive controls; a Four-Wheel Steering system. In 1983, Mazda astonished the automotive world with the introduction of an engineeringconcept car, the MX-02, exhibited at the Tokyo Motor Show. This four-door Sedan, withgenerous passenger accommodation on an unusually long wheelbase, incorporated among itsnumerous advanced features a true 4WS system that aided high-speed stability as well as itslow-speed manoeuvring. The degree of rear wheel steering was determined by themeasurement of both front wheel steering angle and vehicle speed, by means of a centralcomputer unit. The MX-02 was followed by another exciting concept car; the MX-03, first exhibited at theFrankfurt Motor Show in September 1985. This sleek four seat futuristic coupe of the 1990scombined a refined electronically-controlled 4WS system with a continually varying torque-split, four-wheel drive system and a powerful three-rotary engine. Mazda Electronically一Controlled Four-Wheel Steering System: A Beneficial Technology Mazdas electronically-controlled, vehicle-speed-sensing Four-Wheel Steering System (4WSsteers the rear wheels in a direction and to a degree most suited to a corresponding vehicle speed range. The system is mechanically and hydraulically actuated, producing greatly enhanced stability, and within certain parameters, agility. The driver of a Mazda 4W5-equipped car derives five strategic benefits, over and above theconventional vehicle chassis. 1.Superior cornering stability 2.Improved steering responsiveness and precision 3.High-speed straightline stability 4.Notable improvement in rapid lane-changing manoeuvres 5.Smaller turning radius and tight-space manoeuvrability at low vehicle speed range The most outstanding advantage of the Mazda 4WS is that it contributes to a notable reduction in driver fatigue over high-speed and extended travelling. This is achieved by optimally: 1 .reducing the response delay to steering input and action and 2. eliminating the vehicles excessive reaction to steering input In essence, by providing the optimum solution to the phenomena researched by the two youngMazda engineers in the early sixties一by the method advocated by them一the 4WS system hasemerged as a fully beneficial technology. Strategic ConstructionThe Mazda 4WS consists of a rack-and-pinion front steering system that is hydraulically assisted by a twin-tandem pump main power source, with an overall steering ratio of 14.2:1. The rear wheel steering mechanism is also hydraulically assisted by the main pump andelectronically controlled一according to the front steering angle and vehicle speed. The rearsteering shaft extends from the rack bar of the front steering gear assembly to the rearsteering-phase control unit. The rear steering system is comprised of the input end of the rear steering shaft, vehicle speedsensors, a steering-phase control unit determining direction and degree), a power cylinder andan output rod. A centering lock spring is incorporated, which locks the rear system in a neutral(straightforward position in the event of hydraulic failure. Additionally, a solenoid valve thatdisengages hydraulic assist (thereby activating the centering lock spring in case of anelectrical failure is ineluded. The 4WS system varies the phase and ratio of the rear-wheel steering to the front wheels,according to the vehicle speed. It steers the rear wheels toward the opposite phase (directionof the front wheel during speeds less than 35kmlh (22mph for a tighter turn and neutralizesthem (to a straightforward direction, as in a conventional two-wheel steering principle at35kmlh (22mph. Above that speed, the system steers toward the same phase-direction as thefront wheels, thereby generating an increased cornering force for stability. The maximunsteering angle of the rear wheels extends 5 degrees to either left or right, a measurement th敏Mazda has determined to be optimally effective and natural to human sensitivity. Primary Components 1. Vehicle speed sensors Interpret speedometer shelf revolutions and send signal to the electronic computer unit. two sensors, one within the speedometer and the other at the transmission output, are used to crosscheck the other for accuracy and failsafe measures. 2. Steering phase control unit Conveys to the power steering cylinder booster valve thedirection and stroke of rear wheel steering by the combined movement of the control yoke angle and bevel gear revolutions. 3.Electric stepper motor Performs altering of the yoke angle and bevel gear phasing 4.Rear steering shaft Transmits front wheel steering angle by turning the small bevelgear in the steering phase control unit, which rotates the main bevel gear in the assembly. 5.Control valve Feeds hydraulic pressure to the steering actuator, according to thephase and stroke required for appropriate rear wheel steering. 6.Hydraulic power cylinder Operates the output rod by hydraulic pressure and steersthe rear wheels. It locks the rear wheels in a neutral (straightforward) position withthe centering lock spring, which is activated by a solenoid valve in case of failure toensure a normal 2WS function for the vehicle. 7.Hydraulic pump. Provides hydraulic pressure to both the front and rear steeringSystems. Details of Steering Phase Control Unit The steering phase control unit alters the direction and degree of rear wheel steering. Itconsists of a stepper motor that controls the rear steering ratio, a control yoke, a swing arm, amain bevel gear engaged to the rear steering shaft via a small bevel gear, and a control rodconnected to the control valve. It operates: a. Opposite phase (direction) steering under 35kmlh (22mph) 1.Control Yoke is at an angle activated by the stepper motor 2.Front wheels are steered to the right. The small bevel gear is rotated in direction X bythe rotation of the rear steering shaft. The small bevel gear, in turn, rotates the mainbevel gear. 3.Rotation of the main bevel gear causes movement of the control rod toward the control valve. 4.Input rod of the control valve is pushed to the right, according to the degree of the control rods movement (determined by the disposition of the swing arm, which is positioned to move in an upward direction, to the right. The rear wheels are thus steered to the left, in an opposite direction to the front wheels 5.As the angle of the control yoke is increased in direction A as vehicle speeddecreases, the rear-to-front steering ratio proportionately increases and the vehiclessteering lock tightens. b. Same phase (direction over 35kmlh (22mph) The operation of this phase is the reverse of the opposite phase one, because the control yokeis angled toward positive in this vehicle speed range, as illustrated. The phasing of the swingarm, yoke rod and bevel gear steers the rear wheels toward the right-the same direction as thefront wheels. c. Neutral phase, at 35kmlh (22mph The control yokes angle is horizontal (neutral). Thus, theinput rod is not affected, even if the control rod is moved with the rotation of the bevel gear unitAs a result, the rear wheels are not steered in this mode. Power Cylinder The movement of the input rod of the control valve unit is transmitted to the power cylindersspool. The spools displacement to the sleeve causes a pressure difference between the right and left side chambers in the hydraulic power cylinder. The pressure difference overcomes the output shaft load and initiates sleeve movement. The sleeve-power rod assembly is moved in the direction of the input rod by a proportionate degree. The output rod transmits steering action to the tie rod on either end of the rear wheel steering control-mechanism unit, thereby steering the rear wheels.Fai-Safe Measures The system automatically counteracts possible causes of failure, both electronic and hydraulic.In either case, the centering lock spring housed in the steering system unit returns the outputrods in the neutral straightforward position, essentially alternating the entire steering systemto a conventional 2WS principle. Specifically, if a hydraulic defect should render a reduction in pressure level (by a movementmalfunction or a broken driving belt), the rear wheel steering mechanism is automaticallylocked in a neutral position, activating a low-level warning light. In the event of an electrical failure, such would be detected by a self-diagnostic circuitintegrated within the 4WS control unit, which stimulates a solenoid valve and then neutralizeshydraulic pressure and return lines, thereby alternating the system again to that of a 2WSprinciple. Henceforth, the warning light referencing the 4WS system within the main instrumentdisplay is activated, indicating a system failure.中文译文马自达公司的速度感应四轮转向系统 三十五年前,两个马自达设计师提出了个远见的、有计算认为是相当革命性的结论。 他们在1902年1 0月26日日本汽车工程师学会技术会议上Tadashi 0 kada博士和Toshiak,工程师总结了他们关于车辆动力学的辛勤研究如下: 1.琴本特性差别在于过度转向与不足转向的和时间上的延迟和pn应 2.汽车在局速状态卜应具备不足转向特点。 3.后方的稳定很人程度上反映出车轮和轮胎口 4.控制:稳定的一大进步,可预期的方式自动引导系统后车轮 这种结论和提法被这两个工程师提出并为良好悬架技术的研制成立了华金会多年来致力于研究和开发,原有的理论有定的作用,些最重要的成就在近代历史上汽车底盘工程,将在马自达的系列产品的生产.这些发展包括双斜后方的联系巾断,首先采用原第一轮驱动323K(1980),马自达6X(1982,然后在更新完善马自达626.获奖的动态跟踪系统中断的第二代发票RC7(1985);并制定电了后方联系中断新马自达929(i987. 而与此同时各种外部压力和负荷作用,J汽车后方的车轮,因为它违背斗顿的运动学原理,这些新系统中断将这些力量纳入”4ws效应积极帮助稳定车辆和机敏。 马自达的设计师和土程师们的最终目标仍是积极的方法产生积极的控制措施;四轮转向体系。 1983年马自达将举世震惊的概念引入工程车MX-02中,并在东京会展上亮相。这辆四门私家轿车在不寻常的长轴距上布置了宽敞的乘客空间,它汇聚许多先进的特点具有高速稳定和低速操控性能的真正意义的4WS系统。后方轮的量取决于前力双轮的角度和汽车的速度,而这此是由中央计算机单元控制的。 MX-02之后另个令人振奋的概念车;MX-03于1985年9月第次在法兰克福展出。这辆豪华的四座双门未来派轿车装配了90年代精确电子控制的4WS系统和不同扭矩均分系统,四轮驱动和强劲的三旋轮发动机。 马白达电子控制四轮转向系统:有利的技术马自达的电子控制、汽车速度感应四轮转向系统(4ws)驱动双后轮在定方向和量上是最适合汽车的速度范围的。这种系统是机械和液压系统驱动,伴随着生产稳定提高,并在某些参数上反应敏捷。 马自达4WS装备车来自五个战略利益的驱动,超过了传统的底盘。 1优秀的转弯稳定性。 2.改良的驾驶响应时间和精度控制。 3.高速直线稳定性。 4急速换道的机动性大大改观。 5更小的转弯半径和低速范围狭小空间的可操纵性。 马自达最显著的优势在于4WS系统能显著降低高速疲劳驾驶和长期驾驶,这是最优化后取得的。 1降低对驾驶输入和动作的反应延迟。 2.消除汽车对驾驶输入的过度响应。 从根本上说,在60年代初两位年轻的马自达工程师通过提供这个最佳解决现象的方法,一以这种方法他们提倡一4WS系统已经作为一项完全有利的技术出现。战略性建设 马自达4WS齿条副转向系统系统由两个串联泵来提供主要的动力来源的液压辅助的前置式齿轮该转向系的总的传动比为14.2: 1。后面的车轮的转向依然是靠全泵提供动力的液压辅助驱动和根据前轮转角和汽车行驶速度来实现电子控制的装置。后轮的转向轴从前转向器的转向齿条延伸到转向控制单元。 后而的转向系统包括转向轴后的输入端,车辆速度传感器,转向控制单元(确定方向和角度),一个动力气缸和一个输入轴。为了以防液1.+:故障转向系统卜面装了一个中央锁弹簧,它将系统锁止在中间位置,另外一旦发生电类的故障作用在螺旋管阀液体压力将消失(因此此时将中央锁弹簧将被开启)。依据车速的不同变化“4 W S”系统因应前轮的变化不断改变后轮的状态和比率。当汽车在急转弯时如果速度小于35km I h C 22mplz )将使汽车的后轮与前轮的状态相反且35km l h ( 22mph)在使它们失效直到笔直向前,按照传统的两轮转向原理)。当速度高于35km1 h ( 22mph)时系统将于前轮保持同相转动,因此增加了转弯时的稳定力。将转向后车轮的最大转角无论同左或足同右都增加了50 a马自达已经确定了使人感觉到自然和保持人类灵敏性的测量方法。 主要组成部分 1.车辆速度传感器解析速度计架子的旋转并把这种信号传递到打字计算机单元。有两个传感器,个在速度计内部另个在传输的输出端,用这样两个传感器是为了使它们两个相互求证和失效保险。2.转向状态控制单元通过控制扼角度和锥形齿轮的配合运动将方向和行程传递给转向后轮。3.步进电机执行扼角度的改变和锥形齿轮定相。 4.后轮驱动轴通过控制那些小锥形齿轮来传递前轮转向角,旋转在组件里的主要锥形齿轮。 5.控制阀将液压传递给转向执行机构,根据状态和行程要求引导合适的后轮转向。 6.液压动力气缸以液压驱动输出轴和后轮转向,一个中央锁止弹簧将后转向轮锁在中间位置,如果在不能确保其对正常的2 W S车辆起作用时该锁将被开启。 7.液压泵,给前面两个提供液压和后驱动轮。车专向状态控制的细节转向控制单元改变转向后轮的度和方向。已有控制转向后轮转向系传动比的步进电机,一个控制扼,一只摆动臂,一个通过小锥齿轮连接在后轮转向轴上的锥齿轮,和一个操纵杆连接控制阀。它操作: a.转向状态(方向)少于35km I h /22mph)的转向。 1控制扼在步进电机作有一个角度。 2前轮被转向右边。小的锥形齿轮由于转向后轮轴的旋转而沿X方向旋转,小的锥形齿轮依次旋转主要的锥形齿轮。 3.主要锥形齿轮的旋转引起控制阀操纵杆的运动。 4.控制阀的输入杆被推到右边,根据操纵杆的运动的度(通过摆动臂的安排确定),被确定位置进入一个方向,朝右边。后车轮在左侧被如此使得转向后轮对转向前轮有个相反的转向。 5.随着车辆速度的减少控制扼的角度增加,由后到前的转向系传动比也要成比例增加而转向锁收紧。这个阶段的操纵与第一个阶段的操作相反,这是因为在一定的速度范围控制扼的转动角度趋向明显,如同说明的那样。摆动臂,扼杆和锥形齿轮与前转向轮保持相同。 b.转向状态(方向)多于35km I h/ 22mph)的转向。 这个阶段的操纵与第一个阶段的操作相反,这是因为在一定的速度范围控制扼的转动角度趋向明显,如同说明的那样。摆动臂,扼杆和锥形齿轮与前转向轮保持相同。的状态。c.中间状态,以35km l h /(22mph)控制扼的角度是水平的(中间位置)。因此,这根输入杆没有被影响,即使这个操纵杆为锥形齿轮单元所带动。因此后转向轮没有被这种方式所驱动。动力气缸控制阀单元的输入轴的运动被传递给气缸线轴。由于线轴相对与套管的位移使得液压动力气缸的左右壁室的形成一个压力差。压力差克服输出轴的负荷并使轴套运动。轴套动力轴总成被以相同的比例传递到输入。输出轴将转向运动传递到后轮的任一转向控制单元。由此驱动后转向轮。故障安全保障 系统能自动消除电子和液压可能存在的问题,无论发生哪种情况,封装在转向系统里面的中央锁止弹簧返回给输出轴并确保其在中间的位置。本质上是使整个转向系统符合一个传统的2WS准则。尤其是一个液压的缺陷使得压力水平的降低(一个错误的操作或者是安全带的断裂),后轮转向装置被锁止在中间位置,并气动一盏低级的警告灯,如果是一个电子元件的错误,那么这个错误将被集成在4WS控制单元里面的自诊断回路所探测到,这将促使一个螺线管阀门的开启然后使液压无效并且返回到回路里面,因此再次使该系统符合2WS准则。从今以后,4WS系统在主要仪器内展示的警告灯开动,就表明一个系统故障。
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