柴油机电控燃油动力系统设计外文文献翻译、中英文翻译、外文翻译

1 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 360 /o z 。  脉冲式控制器由 PSP 和 PMM 相结合发出的， PSP 有两种工作方式，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 010CA ，那么结果就是 00.1CA 。关于合适的燃料喷射系统，通常用下面公式表示 ：  12223 6 0 /( ) / ( 1 )( ) / ( 1 2 8 )( ) / ( 1 )( ) / ( 1 2 8 )iiiididtzN t D tr t D t tN t D tr t D N t t 2 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：   002dCm C A P P                      （ 2-1）  dC是燃油回流系数，0A是表面积，0P是在出口或在出口之前的输出压力，CP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。fcm是每个喷射循环的喷油量。   3 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为式 2-2：  1TPd m d hpAV d t d t            （ 2-2）  T为燃料弹性模量， h 为喷油量的增量，PA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 4 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/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 1400r 1800r/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10 /g kw h ，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 5 到极限角 030CA 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 01CA   6 Electronic Unit Pump Diesel Engine Control Unit Design forIntegrated Powertrain System An integrated powertrain system means that the engine and the transmission should be treated as a whole Both design method and control system deve1opment 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 electronic unit pump(EUP) diesel engine and an electronic automatic transmission(EAT) is studied The controller of both the power unit and the transmission wil1 be developed and calibrated to make the engine and the transmission work rightly  To implement the operation mentioned above， as a power unit the EUP diesel engine is suitable because its injection quantity and timing are freely controllable Based on these， some properties of the engine can be user-defined， such as the peak power curve， speed regulate mode，  torque reserve coefficient etc which is quite useful for the integrated contro1  1.  EUP Control Method The fuel injection quantity and timing control are the most important aspects to engine control unit While the control precision is guaranteed，  the resource of the system shouldnt be expended much  The sensor mounted on the camshaft is used for stroke judgement The signal from crankshaft is the measure reference mark of both fuel quantity and timing Configurable timer module (CTM)and time processor unit(TPU)of the micro-controller unit (MCU)are utilized When a CTM interrupt is triggered by the camshaft， it means that the compress stroke will come and the control unit should prepare for fuel supply The crankshaft signal is connected to a channel of TPU that uses the PMM function The PMM function detects a missing transition and marks the teeth number If there exists z teeth， the span is obviously 360 /o z  The control pulse is generated by PSP function combining with PMM The PSP has two operating modes: angle-angle and angle-time. In angle-angle  7 mode， the rising and failing edges of the output pulse are determined independently of each other In angle-time mode， the failing edge of the output pulse is determined in reference to the rising edge The control parameters are ANGLE1 (start angle)，  RATIO1(multiple ratio1). The injection duration is decided by the last two parameters combined with the former part We 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 accuracy The angle number is an integer and the ratio is the proportion of 080(hexadecima1) For example， if the span is 10 CA the resolution will be 0.1 CA， which is good enough for fuel injection system The detailed deduction could be expressed as: 12223 6 0 /( ) / ( 1 )( ) / ( 1 2 8 )( ) / ( 1 )( ) / ( 1 2 8 )iiiididtzN t D tr t D t tN t D tr t D N t t 2 EUP Properties Research 2 1 Injection Time Delay There exists a time delay of fuel injection At the point of start of injection(SOI)， a drive signal is imposed on the EUP The fue1 wil1 be injected after a short period Td that is called delay As the EUP is a compound system， which is composed of electric， hydraulic and mechanical components， so that the delay also has those three elements3. This is quite meaningful for control system design for the  8 drive pulse minus the delay part is effective for fuel quantity contro1 We get the delay by means of a piezocrystal  sensot, which is mounted on the high-pressure fuel pipe near the injector As shown in Fig.2, in the wave-form of pipe vibration there 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 engine goes to a higher speed  2 2 Fuel Quantity and Engine Speed 2 2 Fuel Quantity and Engine Speed In 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 rate For the latter the fuel return is treated assembly as a pressure relief valve and we have where dCis the flow coefficient of the return orifice；0Ais its section area； Po is the pressure before the orifice or we call it upstream pressure； Pc is the fuel return control pressure by which the backward fuel flow rate through a spring is controllable  When the engine speed goes higher the pressure before orifice increases while the return control pressure is still changeless This will make the backward fuel mass rate higher The other important thing is that the phenomenon of pressure hysteresis which is the pressure drop in the pipe costs time The time span even 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.3 In Fig.3 the  9 fuel quantity increases linearly with the fuel supply angle and the high speed one in the low position means for the same fuel injection duration the fuel mass under lower speed is more than that under higher speedfcmrefers to the fuel quantities per cycle. 2 3 Injection Timing Injection timing is critical for engine control considering that it affects both the fuel economy and emission performance We also investigate the effect of injection timing on the fuel quantity under the same supply angle The pressure change rate of the unit plunge pump is expressed as 5. where T  is the isothermal elastic modulus of the fuel； h  is the lift of the plunge while V and pAare their volume and cross section area  From the equation we can tell that if the mass change rate is invariable only the plunge lift speed will affect the pressure change rate Here we use a constant slope profiled camshaft as the drive So as the fuel supply angle increases the fuel quantity will change linearly and fuel injection timing will have no effect on the fuel quantity for no matter where injection starts We got this in Fig.4 from which it is  10 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 easier Meanwhile to meet the more stringent emission regulations， the cam profile maybe need some change for good injection rate shaping This is still in researching  3 Experiment Research Experiment research has been done on a fourcylinder turbocharged diesel engine  It is known that the super high pressure injection system EUP 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 point considering both fuel economy and emission property A certain working state(1400r/mm， 320N/m)is selected to sample this The 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 the fuel economy and exhaust temperature will be worse  According to this rule we make a fuel injection timing map Fig 5 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 long The loads have less effect compared with the speed and we only suspend the angle in middle load area and 1400-1800 rmin engine speed This is so called common use area of heavy diesel engine in  11 EURO II test procedure  First we work some part load curves out We find that the injection pulse is linear with the supply angle and the power equably while the injection timing angle can be operated freely Finally we make the full load or the peak power curves in Fig.6 For the speed stabilization consideration we invalidate the fan silicon clutch，  which will make the fuel economy 10g (kwh) more than the actual value The high pressure makes the injection duration less We can see the maximum angle is 30 CA of the rated point including injection delay that property is beneficia1 to future high speed and heavy duty diesel engine By the online calibration tool-CUCAS (common used calibration system) we have developed the rated power curve， the slop of speed regulate， the torque reserve coefficient can be defined freely for different purposes of use For the fuel injection timing can be controlled， as you want at any points， all this make the integrated control meaningfu1 In other words，the active control of engine during transmission period promotes the quality of gearshift itself   12 4 Conclusions Based on all the research work mentioned above， we have the following conclusions 1 Mounting the EUP on the diesel engine would make the engines fuel quantity and timing contro11able As it is used as the power unit of the integrated powertrain， more parameters can be operated &n