【正文】 1dimensional codes are linked in this manner in order to create a plete model of engine performance (including gas dynamics), coolant system and control system.為進(jìn)行這樣研究，真正的聯(lián)合仿真是在不同的軟件代碼間編寫代碼來連接各子模型，并在規(guī)定的時(shí)間步長內(nèi)將子模型并聯(lián)在一起，并相互溝通。Firstly, MATLAB174。 is used to model the control of the coolant system. It is also used as the code that produces the links to the other software codes, manages the information flow between the submodels, and controls the timestep of the simulation. The engine performance model, which includes the effects of gas dynamics in the engine and EGR system, is modeled using Ricardo’s mercially available software WAVE. In fact a link between MATLAB174。 and WAVE has existed for some time, as it is often used to control the engine and run multiple WAVE simulations, and is included in the WAVE package as supplied. Finally, the coolant system is modeled using FLOWMASTER174。 Simulink174。作為產(chǎn)生鏈接到其他軟件代碼的代碼，它也可以用來管理子模型之間的信息流，并控制仿真的時(shí)間步長。事實(shí)上，MATLAB174。和WAVE之間的聯(lián)系已經(jīng)存在一段時(shí)間了，因?yàn)樗怯脕砜刂瓢l(fā)動(dòng)機(jī)和運(yùn)行多個(gè)WAVE仿真，并包含它所提供的WAVE組件。Figure 4. CoSimulation Architecture amp。 provides a link to MATLAB174。 but this is only done by using FLOWMASTER174。目前，F(xiàn)LOWMASTER174。 Simulink174。的信息和鏈接管理器。MATLAB174。 LINK In conjunction with FLOWMASTER, Ricardo have developed a script in MATLAB174。 that will initiate the FLOWMASTER174。 Simulink174。. The cosimulation is controlled from Simulink174。到FLOWMASTER174。 Simulink174。求解器模塊和提供與它的通信。 Simulink174。之間進(jìn)行通信的軟件平臺(tái)DCOM軟件技術(shù)。協(xié)同仿真控制是通過一個(gè)M文件的S函數(shù)實(shí)現(xiàn)的。 treats the SFunction as a transfer function, such that it gives the transfer function an input, and follows the required directions (denoted by the script in the SFunction) to receive an output. The rest of the simulation subsequently acts on this output. In the case of this cosimulation, the Sfunction structure is actually used to handle the exchange of information with a client program (here FLOWMASTER174。 only monitors the states, which represent a small subset of possible model states that FLOWMASTER174。它可能包含了被用來計(jì)算該系統(tǒng)的狀態(tài)和輸出的其他方程和其導(dǎo)數(shù)的集合。把S函數(shù)當(dāng)作傳遞函數(shù)，這樣，它給出傳遞函數(shù)的輸入，并如所要求的方向(以S函數(shù)的腳本表示)接收輸出。在協(xié)同仿真的情況下，S函數(shù)的的結(jié)構(gòu)實(shí)際上是用于處理與客戶端程序(此處FLOWMASTER174?？蛻舳顺绦蛱幚淼囊惑w化和其他計(jì)算所需的先進(jìn)仿真。的輸入、輸出和狀態(tài)，雖然Simulink174。SAMPLE TIMES The cosimulation operates by synchronizing the two simulations, and for proper synchronization needs to have FLOWMASTER174。 executes at sec, the SFunction needs to execute at sec, sec, sec, etc.采樣時(shí)間：協(xié)同仿真通過同步的兩個(gè)模擬操作，為了能正確的同步，需要由FLOWMASTER174。例如，如果FLOWMASTER174。 system should be an integer multiple of the system sample time specified in the Simulation/Parameter dialog box. The current configuration of the cosimulation SFunction inherits the fastest sample time of the entire Simulink174。系統(tǒng)中所有模擬/參數(shù)模塊的采樣時(shí)間是對(duì)話框中指定的系統(tǒng)采樣時(shí)間的整數(shù)倍。整個(gè)系統(tǒng)的最快采樣時(shí)間。For the cosimulation and control system development, FLOWMASTER174。 at sec (inherited from Simulation Parameters). This gives reasonable results for the long (1000 seconds) test files.對(duì)于協(xié)同仿真和控制系統(tǒng)開發(fā)，F(xiàn)LOWMASTER174。(從模擬參數(shù)繼承)內(nèi)運(yùn)行。COSIMULATION MODEL仿真模型SIMULATION CONTROL amp。. The primary function of these blocks is to transport data from one system model, whether in Simulink174。模塊中進(jìn)行?；蚱渌a。從圖4可以看出信息流的傳遞過程。在實(shí)際應(yīng)用中，這些數(shù)據(jù)將被發(fā)送到電子控制模塊。The physical data is purely required for the modeling purposes. This data describes the interaction between the engine and coolant system. This data is primarily related to the heat rejection to coolant within the engine and the EGR cooler. Strictly speaking the pump speed in the mechanical pump circuits is also physical data but as the control system looks after the pump speed in the other two circuits it was decided to do so in all instances. In Figure 4 this data is represented as passing through the dotted Simulink174。此數(shù)據(jù)描述了發(fā)動(dòng)機(jī)和冷卻劑系統(tǒng)之間的相互作用。嚴(yán)格的來說，在機(jī)械泵電路中的泵的速度也是物理數(shù)據(jù)，但作為控制系統(tǒng)來看在其他兩個(gè)電路后泵的轉(zhuǎn)速，在所有情況下都會(huì)這樣決定。發(fā)動(dòng)機(jī)型號(hào)：發(fā)動(dòng)機(jī)型號(hào)包括進(jìn)排氣歧管的定義，包括廢氣再循環(huán)(EGR)系統(tǒng)，并允許用于控制發(fā)動(dòng)機(jī)的各種參數(shù)，如EGR效率、發(fā)動(dòng)機(jī)轉(zhuǎn)速、燃料體積等。 Simulink174。發(fā)動(dòng)機(jī)的性能模型是在曲軸轉(zhuǎn)角的基礎(chǔ)上運(yùn)行的，輸出的結(jié)果是每完成一個(gè)周期后的周期平均值。很顯然，在這個(gè)時(shí)間步長內(nèi)運(yùn)行其余的模型，這將意味著需要更高的處理能力水平。COOLANT SYSTEM MODEL – This study will investigate four possible concepts for the design of a coolant system, as illustrated in Figurse 6a to 6d. They illustrate a progression from a simple mechanical system which is cheap, tried and tested, up to a more plex electrically controlled system. Obviously, the choice of system is best considered on a case by case basis.冷卻液系統(tǒng)模型：本研究將探討冷卻系統(tǒng)的四個(gè)可能的設(shè)計(jì)概念，如圖6a至圖6d所示。顯然，系統(tǒng)的選擇最好是考慮在某個(gè)案例的基礎(chǔ)上進(jìn)行。從泵的出口被分為兩個(gè)，類似與從汽缸體相鄰的泵，或直接從滾動(dòng)泵殼體的出口。這將確保通過冷卻器的最大壓力的壓降可以得到實(shí)現(xiàn)。In the second coolant circuit a solenoid activated control valve (EV) is fitted to the cooler circuit, while the rest of the circuit remains the same. The addition of the control valve allows for some variation in the restriction through the cooler leg of the system and thus will help regulate flow through it.在第二個(gè)冷卻劑回路，一個(gè)電磁控制閥(EV)被裝配到冷卻器的回路中，而該回路的其余部分仍然是相同的。Figure 6c. Simple Electric Coolant Pump CircuitThe third circuit utilizes an electrically motored coolant pump, as well as the control valve, to regulate flow. The other parts of the circuit are as the first circuit, purely mechanical.第三個(gè)回路運(yùn)用了一個(gè)電動(dòng)冷卻液泵以及控制閥，以調(diào)節(jié)流量。Figure 6d. Complex Electrically Controlled Coolant CircuitThe final circuit, Figure 6d, shows a high level of plexity that offers a significant amount of flexibility. The electrically motored coolant pump and an electrically controlled valve (EV1) allows for full control over the flow of coolant through the engine and EGR cooler. Also, the second electrically controlled threeway valve (EV2) can be used to control flow through the radiator and, thus control the coolant temperature, regulated using the temperature sensor (TS). This is used to raise the coolant temperature at low loads and speeds and thus improve radiator performance.如圖6d所示的最后一種回路，顯示出了高度的復(fù)雜性和可供大量的靈活性。此外，第二個(gè)二位三通電控閥可以用來控制流經(jīng)散熱器，此外，使用溫度傳感器(TS)調(diào)節(jié)控制冷卻液溫度。CONTROL SYSTEM MODEL – The control models can be split into two categories, engine and coolant system. The control of the engine is done via mon parameters such as fueling, engine speed and EGR valve