Zhang Fujun

Gasoline engine idle speed control system development based on PID algorithm

One of the often-running modes for a gasoline engine is idling, and idle speed stability is one of the key aspects to evaluate a vehicles performance when it is equipped with a gasoline engine. Therefore, it is very important to control the idle speed stability and to keep the idle speed constant in spite of the various engine load disturbances. In order to reach this goal, usually the closed loop control is applied. Among various control algorithms, traditional PID algorithm has been used successfully for many applications. The key advantages of PID control are its simplicity and practicality. Its control parameters can be tuned on line; the flexibility of its software development makes it easier to get a better control result. In this paper, based on PID control algorithm, an idle speed control system for 462Q electronic controlled gasoline engine is developed. The hardware design of this system, the design of the digital PID controller, the selection of the sample interval and the method for tuning the control parameters are introduced in detail.

Electronic Control Unit Development for Unit Pump Diesel Engine

Electronic unit pump (EUP) fuel injection system has prospective application in medium or heavy diesel engine. Developing an ECU of EUP diesel engine is necessary to meet emission regulations and economic requirements. The structure and working principle of EUP fuel injection system was studied. An ECU was developed, which consists of digital circuit, power supply module, driving circuit and sensor signal processing circuit. A diesel engine management system named micro real time kernel was also designed to run the control program. The control strategies of injection timing and injection quantity were put forward. Experimental research on diesel engine verified the availability of the ECU system.

A micro-processor based adaptive ignition control system

An adaptive ignition control system can adjust ignition angle automatically, so the power of the SI engine is improved while preventing it from knock. This paper describes an ignition control system, whose core is a micro-processor (80C552). The inputs include intake manifold pressure sensor, throttle position sensor, water temperature sensor, crankshaft position (speed) sensor, synchronization sensor and knock sensor. The software of the system includes main flow program and several interruption programs. The article describes how the knock signal acquisition, knock condition judgment, ignition-signal, etc. are controlled by the software. The peak-value of the knock signal is recorded in a circuit during one cycle, and accordingly this value of the knock is detected. A new two-parameter ignition angle adjusting method is used, which is according to the peak-value of knock signal during one cycle and the mean value of several cycle peak-values. This method effectively resolved the contrast of the high response and small cycle fluctuation of ignition angle control. The experiments on 368Q engine shows that the design of the system hard-and-software is feasible and the engine is prevented from knock effectively, the torque of the engine is improved.

Database Design of a PDM System for Research Institutions

On the background of developing the Product Data Management(PDM) system for vehicle powertrain integrated design, we found three problems to solve. The first is product and its technical parameters need to customize freely. It’s solved by defining code fields for product database table and parameter table. Second, the technical parameters of different levels overlap each other or the cause and effect relationship exists. The solution is storing one parameter in structured format and others in unstructured format. Third, design task needs to be dynamicly associated with its input parameters, output parameters, knowledge, tools, and the solution is introducing the Design Function as the carrier of data package. Base the database design, one PDM system was developed which provides a better tool for designing activity of the research institutions. In the paper, the relational database design scheme offer a new way of thinking for the database design of PDM system.

An Integrated Analysis Approach for Dynamic Energy Distribution of Off-Road Vehicle Powertrain

A transient model of off-road vehicle powertrain has been established according to the basic laws of thermodynamics and heat transfer. With the utilization of distributed simulation system based on high level architecture (HLA), the transient simulation of powertrain has been executed. A cycle experiment on a off-road vehicle has been designed and conducted, and the models have been verified by the experiment data. Using the method founded, the conditions of energy distribution and engine heat statistics have been discussed. Other additional mechanical loads (i.e. fan, pump etc.) were taken into account in this model as well. The analyzed results show that the model can reflect the dynamic characteristic of the powertrain more accurately. Furthermore, it is approved that the integrated approach is available for off-road vehicle powertrain simulation.

Design of a PDM System for Research Institutions

On the background of developing the design platform for vehicle power train integrated design, we found the problem that for the design activities of research institutions, design object and its technical parameters need to be able to customize freely, the design activities are around design tasks such as the design parameters, knowledge, tools, methods are all need to be dynamic configured for each design task, which can not be satisfied by the mature Product Data Management(PDM) softwares, so we developed a PDM system for research institutions which called Power train Integrated Design System(PIDS). In this paper, Unified Modeling Language(UML) is used to represent a visual and unambiguous system functions. Four Use Case Diagrams of actors including Leaders, Designer, Reviewer, and Administrator are designed. The design task life cycle is established using an Activity Diagram with embeding lanes. The concepts of Technical Parameters Table, Data Package, Design Function, Product Code are proposed to support the design process. The innovative solution proposed is also useful for the development of design platform for other research institutions, and its a new way of thinking for the improvement of enterprise-oriented PDM softwares.

Simulation of vehicular emission features in terms of engine emission performance

The paper presents a new vehicular emission simulation method, aiming to improve the prediction of the overall vehicular emission in terms of engine emission performance characteristic of the early design stage. The method helps to optimize the matching performance of the vehicle and the engine by reducing the number of parameters to fewer engine running points.