International Conference on Computer Systems and Technologies - CompSysTech’ 2006 A Virtual Instrument for Automobiles’ Fuel Consumption Investigation Tsvetozar Georgiev Abstract: A virtual instrument for investigation of automobiles’ fuel consumption is presented in this paper. The purpose of this development is to automate and facilitate the research process in this field. As a development environment is used LabVIEW. The virtual instrument computes and visualizes the automobile’s fuel consumption depending on the time of motion. This virtual instrument can easily be used as a module in more sophisticated systems for automobile investigations. Key words: Virtual instruments, LabVIEW, automobiles INTRODUCTION The tendency in the automobile industry is to pay more attention on the fuel consumption [6]. The determination of this characteristic is a part of the investigation programs of all automobile manufacturers during the process of test of the prototypes or new serial models [5]. It helps them to find the right ways to reduce the fuel consumption. Such tests are also made in service-stations. Some of these experiments include determination of the fuel consumption in dependence on the time of motion of the automobiles. For the implementation of such investigations a microprocessor based system which collects data usually is used. In such case special software for calculations, visualizations and analysis must be used. The main part of existing specialized microprocessor systems includes only basic software which makes specific initializations and calculations. One of the disadvantages of such systems is that they use specific software which is very difficult to program again. Another disadvantage is that their software is difficult to be integrated in more sophisticated systems for automobile investigations. A solution of these problems is to develop and use a computer based virtual instrument for investigation the fuel consumption of automobiles. The advantage of such approach is that using virtual instruments, appropriate hardware and additional software [1] it is possible to create modular systems for measurements, experiments and autoimmunization of processes. If there is a change in the investigated system the virtual instrument can be easily expanded by adding additional functions. This gives an opportunity to create user defined solutions. LAYOUT The appropriate environments for development of virtual instruments are LabVIEW and LabWindows/CVI of the National Instruments Company, USA. Their main purpose is for development of virtual laboratories and to ensure distance experiments with these laboratories via Internet. The programs which are created by LabVIEW are named virtual instruments because their appearances imitate the real devices [1]. The virtual instruments (VI) have an interactive user interface, block diagram of data flow (program code) and icon with connections [2]. VIs can be used as subprograms in other virtual instruments. The interactive user interface of VI is named Front Panel because it looks like the panel of the physical device. The Front Panel may include buttons, sliders, digital indicators, controls, graphical displays, etc. The user can input information manually by the keyboard and/or import information from data files. The results from the execution of the program code can be seen on the Front Panel. The G program language has many functions for processing, working with various file formats, analysis, generation of signals and visualization of data. - IIIB.11-1 -