1、柴油机电控燃油动力系统外文文献翻译中英文翻译外文翻译柴油机电控燃油动力系统设计1 EUP控制方法燃料喷射时时控制系统最重要的是发动机操控单元，它保障控制精度来达到能量消耗最少的要求。传感器的信号是来自对凸轮轴位置的检测，信号是对曲轴测量参数，即喷油量和喷油时间的关系。微型调速器(MCU)是由计时器结构模块(CTM)和定时处理部件(TPU)控制的。当计时器结构模块被凸轮轴触发器中断，控制部件将为燃料供给系统作出相应的反应，集中维护模块中的曲轴信号连接定时处理部件(TPU），集中维护模块检测出一个脉冲和齿数。如果存才Z个齿，那么跨度就是。脉冲式控制器由PSP和PMM相结合发出的，PSP有两种工作方
2、式，角角、角时间，在角角工作模式中，上升沿和下降沿的输出脉冲与两者没有关系。在角时间工作模式中，下降沿的输出脉冲取决于上升沿，其控制参数是ANGLE1开始角和ANGLE1结束角。喷油时间是由EUP的两个参数控制。喷射时间取决于以上两个参数的位置结合。我们使用的是角角工作模式来对发动机工作的控制。图1-1 逻辑控制电路控制喷射量和喷射时间图对于喷油量和喷油时间的计算方法是保证提前角的控制精度，角度应是个整数，并且与十六进制成比例。例如：一个距离是，那么结果就是。关于合适的燃料喷射系统，通常用下面公式表示：2 EUP的研究2.1 喷射时间的延迟一个燃料喷射延迟的开始位置是由EUP发出的驱动信号来控
3、制的，燃料的喷射在一个短期内的倍增称之为喷射延迟。EUP是一个复杂的控制系统，由电子单元、液压、机械部件组成，所以这个延迟是三元化的。这意味着控制系统的设计是由驱动脉冲延迟部分来对喷射量进行有效控制，延迟是由一个压电晶体传感器来控制的，它位于高压油管上，例如图2-1，燃油喷射时间由喷射器控制，延迟在不同的发动机转速下进行试验，用延迟角表示。发动机在较高的转速下运转时则是一条非线性的曲线，发动机在低速时的曲线斜率较大。图2-1 喷射延迟波形2.2 喷油量和发动机转速在一定的时间内，喷射到气缸的燃油取决于压力变化和燃料的比率。因为后者燃料的回收取决于泄压阀和公式2-1： （2-1）是燃油回流系数，
4、是表面积，是在出口或在出口之前的输出压力，是燃料在装有可调节弹簧的空值杆上的作用力。当发动机转速上升到较高的压力时，监测口处的德操纵杆上的力是静止不变的，它以较高的比率反馈到燃料模块上，另一项重要的就是压差数值是管内的压力滞后，这个时间间隔会使发动机长时间地高速运转，从而使燃油回流增加，在图2-2中，燃料喷射量的增加同燃料供给角、高转速的最低位置的计算、燃料喷射持续时间成线性关系，并且大于对低速的要求。是每个喷射循环的喷油量。图2-2 发动机转速与喷射量图2.3 喷油定时喷油定时的作用是控制发动机燃料经济性和动力性的关键，有效的喷油时间就是燃料时间滞后一个供给角，单位压力燃油泵的变化率可以表示
5、为式2-2： （2-2）为燃料弹性模量，为喷油量的增量，为燃油管的体积和横截面，等式中如果全部的参数是唯一不变的，喷油量的上升速度会影响压力的变化。使用一个斜率为常数的凸轮轴作为驱动轮，燃料供给角的增加量则开始线性变化。从图2-3中可以得到燃料喷射量是线性增加的，这条曲线在不同的喷射时间下不会改变。 图2-3 喷油时间与喷油量3 实验研究测试工作已经在一个四气缸的涡轮增压柴油机上完成了。众所周知，超高压喷射系统的EUP可以满足欧洲II排放标准，有的甚至可以满足欧洲III排放标准。对喷射系统EUP的校准工作是非常重要的，其关键部分是喷油时间，即燃料的经济性和动力性，在1300r/min, 32N
6、/m的工况下进行试验得到了这些数据，从喷射角开始，在燃油经济性和排气温度变化很小的情况下检测检测NO的浓度是否增加，减少NO的浓度是一个趋势，而且喷射起始角越小，燃料燃烧效果就越好。反之，尾气排放、燃油经济性和排气温度就会越差。根据这种规律我们绘制出了燃油喷射图（图3-1）。图中表示了发动机转速升高时，喷射角开始增加，所以混和气控制装置的工作时间也会增加，当负荷减少时，喷射角则相应减小，发动机转速下降到1400r1800r/min时，这种图谱则适应重型柴油机的燃料喷射规律。 图3-1 燃油喷射图工作的第一步是绘制出载荷曲线，我们发现喷射脉冲与供给角呈线性关系，功率在喷射时间上可以自由控制，根据
7、此种规律绘制出了满载负荷时和极限功率曲线图3-2图3-2 满载负荷时和极限功率曲线图考虑到速度稳定性，首先让硅油离合器停止工作，使燃油经济性达到，甚至超过这个数值。高压持续喷射时间相应减少，在此我们可以得到极限角的额定点，喷射延迟性是对高速柴油机包括重负载柴油机在内都是有很大帮助的。时时校准工具CUCSA对额定功率曲线、燃油速度的调节、扭矩储备系数都可以自由地控制，因为不同的工作状况都是适用的。在不同的燃料喷射时间内都是可以人为控制。总之，发动机控制系统可以在不同的速度范围内进行控制。4 结论以上的研究是以下面三个条件为基础进行研究的。1，根据柴油机EUP来设计发动机燃油喷射量进行实时控制，按
8、照发动机动力装置传递，控制系统中的诸多参数。2，燃油喷射时间图谱和发动机功率峰值性能曲线的完成，可以精确的控制曲柄转角达到Electronic Unit Pump Diesel Engine Control Unit Design forIntegrated Powertrain SystemAn integrated powertrain system means that the engine and the transmission should be treated as a wholeBoth design method and control system deve1opment
9、should be organized together. Generally，the best engine working points are chosen as the gearshift moment for either vehicle fuel economy or power performance On the other hand，some researches have focused on active engine control during gear shifting. In this paper a powertrain composed of an elect
10、ronic unit pump(EUP) diesel engine and an electronic automatic transmission(EAT) is studiedThe controller of both the power unit and the transmission wil1 be developed and calibrated to make the engine and the transmission work rightlyTo implement the operation mentioned above，as a power unit the EU
11、P diesel engine is suitable because its injection quantity and timing are freely controllableBased on these，some properties of the engine can be user-defined，such as the peak power curve，speed regulate mode， torque reserve coefficient etcwhich is quite useful for the integrated contro1 1. EUP Contro
12、l Method The fuel injection quantity and timing control are the most important aspects to engine control unitWhile the control precision is guaranteed， the resource of the system shouldnt be expended much The sensor mounted on the camshaft is used for stroke judgementThe signal from crankshaft is th
13、e measure reference mark of both fuel quantity and timingConfigurable timer module (CTM)and time processor unit(TPU)of the micro-controller unit (MCU)are utilizedWhen a CTM interrupt is triggered by the camshaft，it means that the compress stroke will come and the control unit should prepare for fuel
14、 supplyThe crankshaft signal is connected to a channel of TPU that uses the PMM functionThe PMM function detects a missing transition and marks the teeth numberIf there exists z teeth，the span is obviously The control pulse is generated by PSP function combining with PMMThe PSP has two operating mod
15、es: angle-angle and angle-time. In angle-anglemode，the rising and failing edges of the output pulse are determined independently of each otherIn angle-time mode，the failing edge of the output pulse is determined in reference to the rising edgeThe control parameters are ANGLE1 (start angle)， RATIO1(m
16、ultiple ratio1). The injection duration is decided by the last two parameters combined with the former partWe use angle-angle mode that is similar to the engine working process The algorithm of injection quantity and timing is the best technique to guarantee the control accuracyThe angle number is a
17、n integer and the ratio is the proportion of 080(hexadecima1)For example，if the span is 10CAthe resolution will be 0.1CA，which is good enough for fuel injection systemThe detailed deduction could be expressed as: 2 EUP Properties Research21 Injection Time DelayThere exists a time delay of fuel injec
18、tionAt the point of start of injection(SOI)，a drive signal is imposed on the EUPThe fue1 wil1 be injected after a short period Td that is called delayAs the EUP is a compound system，which is composed of electric，hydraulic and mechanical components，so that the delay also has those three elements3. Th
19、is is quite meaningful for control system design for the drive pulse minus the delay part is effective for fuel quantity contro1We get the delay by means of a piezocrystal sensot, which is mounted on the high-pressure fuel pipe near the injectorAs shown in Fig.2, in the wave-form of pipe vibration t
20、here is a saltation point, at that time the fuel has been delivered to the injector. We test the delay at different engine speeds, which has clearly shown the relationship of delay angle vs engine speed. It is a nonlinear curve that the slope is big at lower engine speed and is getting small as the
21、engine goes to a higher speed 22 Fuel Quantity and Engine Speed 22 Fuel Quantity and Engine SpeedIn a definitely period of time， the fuel quantity delivered to the cylinder is decided by both the pressure change rate and the backward fuel mass rateFor the latter the fuel return is treated assembly a
22、s a pressure relief valve and we have where is the flow coefficient of the return orifice； is its section area；Po is the pressure before the orifice or we call it upstream pressure；Pc is the fuelreturn control pressure by which the backward fuel flow rate through a spring is controllable When the en
23、gine speed goes higher the pressure before orifice increases while the return control pressure is still changelessThis will make the backward fuel mass rate higherThe other important thing is that the phenomenon of pressure hysteresis which is the pressure drop in the pipe costs timeThe time span ev
24、en will go longer as the engine speed goes up，which also makes the return fuel increase Here we meter the fuel by the crank angle，so we have the test results in Fig.3In Fig.3 the fuel quantity increases linearly with the fuel supply angle and the high speed one in the low position means for the same
25、 fuel injection duration the fuel mass under lower speed is more than that under higher speed refers to the fuel quantities per cycle. 23 Injection TimingInjection timing is critical for engine control considering that it affects both the fuel economy and emission performanceWe also investigate the
26、effect of injection timing on the fuel quantity under the same supply angleThe pressure change rate of the unit plunge pump is expressed as 5. where is the isothermal elastic modulus of the fuel； is the lift of the plunge while V and are their volume and cross section area From the equation we can t
27、ell that if the mass change rate is invariable only the plunge lift speed will affect the pressure change rateHere we use a constant slope profiled camshaft as the driveSo as the fuel supply angle increases the fuel quantity will change linearly and fuel injection timing will have no effect on the f
28、uel quantity for no matter where injection startsWe got this in Fig.4 from which it is clearly shown that the fuel quantity is linearly increased and different injection time curves cannot change this trend As a result, such a kind of camshaft will make the control unit design easierMeanwhile to mee
29、t the more stringent emission regulations，the cam profile maybe need some change for good injection rate shapingThis is still in researching3 Experiment Research Experiment research has been done on a fourcylinder turbocharged diesel engine It is known that the super high pressure injection systemEU
30、P has a potential to satisfy EURO emission standard and even to meet EURO The calibration work of the system is important So at first，an injection timing map is made point by pointconsidering both fuel economy and emission propertyA certain working state(1400r/mm，320N/m)is selected to sample thisThe
31、 angle of start injection is added step by step and it is found that NO emits more while fuel economy and exhaust temperature change less. That will decrease the emission to the opposite trend，but the angle could not be too small that will make the fuel burning after the TDC. If this happened both t
32、he fuel economy and exhaust temperature will be worseAccording to this rule we make a fuel injection timing mapFig5 shows that the start injection angle will increase when the engine speed goes up；this is just because the mixture preparation and burning time will be longThe loads have less effect compared with the speed and we only suspend the angle in middle load area and 1400-1800 rmin engine
