نوشته دانلود ترجمه مقاله الگوریتم بهینه سازی انفجار بزرگ مه بانگ برای پخش بار اقتصادی با تاثیر نقطه-سوپاپ – 2010 اولین بار در ترجمه فا پدیدار شد.

• فهرست مطالب:

 چکیده
۱ مقدمه
۲ اصل اساسی سیستم VVT الکتروهیدرو لیک
۲ ۱ ساختارVVT
۲ ۲ تشخیص زمان بندی سوپاپ
۲ ۳ کنترل زمان بندی سوپاپ
۲ ۴روش تجربی
۳ برای کنترلر
۱ ۳ مدل سازی سیستم
۳ ۲ کنترل حذف اختشاش فعال
۳ ۳ کنترل مصرف سوخت
۳ ۴ مرحله تنظیم چرخه
۴ اعتبارسنجی
۴ ۱ آزمون پایداری
۴ ۲ ‌آزمون توانایی حذف اغتشاش
۵ نتیجه گیری

• بخشی از ترجمه:

در این مقاله،  استراتژی HDRC  برای سیستم زمان بندی متغیر سوپاپ با مکانیزم هیدرولیک مغناطیسی ارائه شده است.تأثیر فشار سوخت و درجه حرارت بر رفتار پاسخ VVT از یک مدل ایستا و ساده بوده که براساس آن یک کنترل سوخت به جلو را برای اطمینان از پاسخ سریع طراحی کرده است. همه تردیدهای باقی مانده و پویایی , بیش از حد,  دشواری را در مدل نشان می دهد. آنها تخمین زده شده اند و در زمان واقعی توسط یک کنترل LADC مرتبه اول , لغو شده اند واین نشان می دهد که توانایی حذف اغتشاش وجود دارد . HDRC , متغیر بوده با یک کنترل دستی مورد مقایسه قرار گرفت که نتایج نشان داد که یک مزیت قابل توجه در سرعت پاسخ و نیرومندی فشار روغن و تغییرات سرعت موتور وجود دارد . به همین ترتیب , توانایی حذف اغتشاش نیز نشان داده شده است و با استفاده از جبران اختلال درADRC بوده و آن برای حل مشکلات کنترل VVT امیدوار کننده است. 

• بخشی از مقاله انگلیسی:

Introduction Timing for the opening and closing of valves in gasoline engines, determined by the relative angle of the crankshaft and camshaft, is essential for the gas exchange process. For optimal fuel efficiency and engine performance, valve timing must vary as engine rotational speed varies. The traditional fixed valve timing system is unable to provide appropriate matching between the valve train and the engine at different operation conditions. This phenomenon leads to unwanted pumping loss, resulting in deteriorated fuel economy. To alleviate this problem, electro-hydraulic variable valve timing (VVT) optimizes the gas-exchange process providing about 3–5% fuel-saving potential for traditional sparkignited (SI) gasoline engines [1]. Further improvements to fuel economy can be achieved if homogenous charge compression ignition (HCCI), a new concept in combustion, can be realized by VVT, reducing the amount of pumping loss caused by low intake manifold pressure [2]. To improve SI combustion and make HCCI realizable, the valve timing fluctuation should be 711 in crankshaft angle (1CA) [3] even in the face of disturbances such as speed and oil pressure variations. Electro-hydraulic VVT is challenging to control because of the low sampling rate which is limited by the engine speed. A pair of position sensors, one for the crankshaft and one for the camshaft, measures the valve timing when the engine runs. Constrained by the practical sensors in production engines, the valve timing can only be fed back between one and eight times per engine cycle. Thus, the resulting sample rate can fall below 5 Hz at low engine speed, and varies with engine speed. Also challenging to control are the strong disturbances that exist in the VVT system in production engines, which are difficult to measure or model. The pressure difference between two oil chambers, supplied by the crankshaft driven oil pump, results in an engine speed-related driven force. Although the pressure difference can be controlled by a proportional solenoid, the response varies with the battery voltage leading to a time-variant actuator dynamic. Likewise, the frequent inverse force from the valve spring significantly disturbs valve timing [4]. The time delay and nonlinear characteristics of the hydraulic system also present control challenges to VVT control. Various solutions to the aforementioned problems have been reported for VVT control. To deal with the disturbance from oil pressure variation caused by engine speed fluctuation, gainscheduling PID according to engine speed is investigated. However, it was found that there are times, such as when the oil temperature is low, when the engine is cold, slow response or oscillation could take place [5] using this solution. This is because the oil flow resistance varies with oil temperature, changing the oil pressure difference inside the cam phaser, i.e., the driving force of valve timing. Consequently, the controller gain becomes inappropriate under varied system dynamics. To compensate for this influence from oil temperature, an estimation algorithm for pressure difference inside the cam phaser is designed, based on which PID gain-scheduling is adopted. However, utilizing this algorithm, the controller stability could be poor in steady state condition if the controller gain is set very large to improve the response in the transient state [6]. Accordingly, a PID gainswitching solution based on steady and transient state detection is proposed [6]. Although these kinds of controllers can compensate for the disturbances, such as the engine speed, oil pressure, as well as oil temperature, they usually require time-consuming parameter optimization. Another possible choice is to use feedforward control based on various kinds of models such as the neural network model [7], the discrete nonlinear model [8], and the power-oriented graphs (POG) model [9]. However, these models are usually too complex for an engine control unit (ECU) application due to the computational burden upon the processor. To summarize, the dilemma is between the strong disturbances, the low sampling rate, and the limited disturbance rejection ability of existing PI controllers. Gain-scheduling PI control and dynamic model based feed-forward control can alleviate the dilemma, but suffer from time-consuming parameter optimization limiting their appeal for practical application.

نوشته دانلود ترجمه مقاله کنترل حذف شرایط اختشاش ترکیبی برای سیستم زمان بندی متغیر سوپاپ – مجله الزویر اولین بار در ترجمه فا پدیدار شد.

• فهرست مطالب:

 چکیده
۱ مقدمه
۱ ۱موتور
۲ روش عددی
۳ نتایج
۳ ۱ تجزیه و تحلیل جریان ثابت
۳ ۲ تجزیه و تحلیل عملکرد
۳ ۳ تجزیه وتحلیل سیلندر
۱ ۳ ۳ تجزیه وتحلیل گاز
۲ ۳ ۳ تجزیه وتحلیل چرخش متغیر
۳ ۳ ۳ تجزیه وتحلیل احتراق
۴ نتیجه گیری

• بخشی از ترجمه:

بهبود در اقتصاد سوخت، با سيستم جرقه زني كوچك در موتر است كه ناشي از اتخاذ يك زمان بندي متغير در سوپاپ با فشار كنترل شده است كه با استفاده از شبيه سازي عددي يك بعدي و سه بعدي مورد تجزيه و تحليل قرار گرفت. نتايج به دست امده در مورد اين آزمايش، اطلاعاتي را ارئه نمايد. در اين مقاله توضيح داده شد كه موتور تحت مطالعه با فناوري ساده VVT است كه عمدتا جهت بهبود راندمان موتور در قسمت بار مي باشد. بنابراين ، مصرف و فرايندهاي يهينه سازي شده و اتخاذ چنين ويژگي هاي خاص در چرخه ي معكوس ميلر و چرخش داخلEGR وجود دارد. جزئيات حركت در درون سيلندر، با باقيمانده توزيع جرم گاز و مصرف و سوپاپ و پورت است كه در ايجاد حركت سالزمان يافته بسيار بوده است كه در موتور مورد تجزيه و تحليل قرار گرفت. روند محاسبه تعداد چرخش بايد مدنظر باشد. حركت چرخش ضعيف توليد شده و توسط پورت مصرفي در حركت به سوي بالا بوده است. در خالي كه يك چرخش بزرگ توسط جريان برگشتي اگزوز كامل پوشانده شده و دريچه تخليه در حالت كم مي باشد. اين يك نتيجه جالب است. زماني كه نرخ EGR موجود در نقاط موجود شير ، بالا باشد، اين مي تواند براي هردو شكل گاز خروجي و كنترل بار مطلوب باشد، اما نرخ احتراق كاهش يافته و بازده حرارتي موتور در حالي كه شكل  گيري Co و H3 مي تواند بدتر شود. 

• بخشی از مقاله انگلیسی:

Introduction The European Union has recently signed the Kyoto protocol. Thus, the control of green-house gas emissions has begun to add to the numerous constraints that vehicle manufacturers have to satisfy. The reduction of engine fuel consumption becomes a primary requirement as well as meeting current and future emission legislations. Naturally, talking about reduction of engine fuel consumption means to keep unvaried, sometimes improved, the performance level of current engine production. Dealing with engine topics exclusively, improving fuel economy to reduce CO2 emissions means improving the engine thermal efficiency. As it is usual in engine management, this target can be met following different routes, each of them could be an effective way with different cost-to-benefit ratio. Often, it could be observed, it is helpful to adopt numerous solutions contemporaneously. As an example, fast combustion, lean burn, variable valve timing and actuation, gasoline direct injection and so long may be reminded. During most of its average life, a road engine is run under low load and low speed conditions. It is known that load reduction in spark-ignition engines is traditionally realized by introducing additional losses during the intake stroke by means of a throttle valve. In these operating points, the engine efficiency decreases from the peak values (already not very high) to values dramatically lower. The optimization of intake and exhaust valve timing can provide significant reductions in pumping losses at part load operation [1–3]. In this paper, the benefit of engine load control performed by using a simple variable cam phaser has been analyzed and the influence of the VVT strategy on the combustion process and engine performance has been evaluated. 1.1. The engine The engine under study (Table 1) derives from a small displacement (1.4 l), 2 valves per cylinder, MPI engine developed in late 1980s. The objective of this paper is to contribute to the development of an up-to-date version pursuing, among others, the target of improving engine fuel economy. To this aim, the adoption of a continuous variable valve timing (VVT) system, able to optimize engine torque and efficiency, has been considered [4]. In particular, the VVT technology here proposed is mainly aimed to the load control and the generation of internal exhaust gas recycle (EGR) rather than to the volumetric efficiency optimization. Due to economic constraints, the engine architecture with a single camshaft for the valve actuation has been kept. A continuously variable cam phaser (CVCP), able to shift the overhead camshaft to retarded positions at constant overlap [5] (Fig. 1), has been chosen. This simple and economic system allows a load control shared between CVCP and throttle. Delaying all valve events, an intensive backflow at the intake end occurs (reverse miller cycle) and a large amount of exhaust gas comes back into the cylinder (internal EGR). Combining reverse miller cycle and internal EGR a significantly high de-throttling effect can be achieved, thus reducing the pumping losses at part load and improving the fuel economy in many driving conditions. Obviously, the engine load control by means of the CVCP system at fully un-throttled operation is limited by the EGR tolerance of the engine. In order to improve this engine characteristic at medium and low loads, when the engine is operated at high EGR rate, a particular exhaust port geometry, able to generate a variable swirl motion of recirculated exhaust gases, has been designed. In detail, an exhaust valve masking has been adopted in order to generate an intensive swirl motion of the re-aspirated exhaust at low valve lifts. Combining this effect with the swirl motion generated during the late intake process allows obtaining a high turbulence level at part load, improving the combustion quality and making tolerable high charge dilutions. (in Fig. 2, some details of the prototype engine are illustrated). Thus, optimized port-valve designs could provide high turbulence levels and high volumetric effi- ciency in order to achieve both satisfying fuel economy at part load and appreciable full load performance. 2. Numerical approach CFD modeling has been utilized in order to both understand the engine in-cylinder phenomena and provide guide lines for the experimental tests aimed to find the optimal solutions. Preliminary analyzes have been carried out to estimate the behaviour of the baseline engine using the CVCP system.

نوشته دانلود ترجمه مقاله بهبود اقتصادی سوخت در موتور کوچک با زمان بندی متغیر سوپاپ – مجله الزویر اولین بار در ترجمه فا پدیدار شد.