Virtual Instruments and Virtual Experiment Technology in the Automobile Industry

lengyan

Virtual Instruments and Virtual Experiment Technology in the Automobile Industry [Copy link]

Abstract:

Virtual instrument technology is a new generation of instrument technology developed in recent years. It completely changes the shortcomings of previous instruments, such as low flexibility and high cost. It combines the rapidly developing computer technology, electronic technology, communication technology and testing technology, and becomes a revolution in the instrument industry.
Virtual testing is a simulation test system developed based on software engineering. With the help of interactive technology and test analysis technology, designers can evaluate or experience the operating performance of products during the design stage.
With the vigorous development of the modern automobile industry, especially the rapid development of automotive electrical technology, the use of virtual technology can not only simulate the electrical instruments and nodes of various new models to reduce R&D costs and improve work efficiency, but also develop a flexible detection system suitable for its own characteristics in the detection of the vehicle electrical system.

Keywords: virtual instrument, virtual experiment.

I. Virtual Instrument Technology
1. Introduction to
Virtual Instrument Technology Virtual Instrument was first proposed by National Instrument in the 1980s. It is a computer-based hardware and software testing platform and the product of the deep integration of computer technology and modern instrument technology. In a virtual instrument system, hardware is the physical platform on which the entire system works, used to establish the connection channel between the signal and the computer and form the I/O interface of the computer. Software is the soul of the entire virtual instrument hardware system. Users can communicate with the virtual instrument hardware system through the interface generated by software design, and the data acquisition, analysis, processing and display functions of the virtual instrument can only be realized through software. Virtual instruments combine general computers with instrument hardware through application programs, and combine computer resources with the measurement and control capabilities of instrument hardware in a transparent way. Through software, data analysis and processing are realized, expressed and displayed in a friendly graphical interface. The emergence of virtual instruments is hailed as a revolutionary new era in the instrument industry.
2. Design and development of virtual instruments
Since application software realizes the communication between virtual instruments and users, it can provide a friendly user interface and powerful data acquisition and processing functions. It is a key factor in realizing the functions of virtual instruments. Therefore, whether it is convenient to design a user-friendly and powerful virtual instrument software is directly related to the realization of instrument functions and the performance of the instrument. At present, the development of virtual instruments mostly uses Lab Windows CVI, LabVIEW, etc. launched by NI. They use the most popular graphical programming environment, which includes both general user interface attributes such as menus and headers, as well as instrument application interface attributes such as switches, sliders, and digital display windows.
The design method and implementation steps of virtual instruments are basically the same as those of general software, except that the hardware part must be considered when designing virtual instruments. The design method of virtual instruments mainly includes the following three parts:
(1) Design of IO interface instrument driver;
(2) Design of instrument panel;
(3) Design of instrument function algorithm.
3. Virtual instrument technology in automotive engineering
With the vigorous development of the automotive industry, more and more automotive electrical equipment are used, from engine control to transmission system control, from driving, braking, and steering system control to safety assurance system and instrument alarm system, from power management to various efforts to improve comfort, making the automotive electrical system a complex large system. Modern cars have gradually evolved into a mobile PC network system. By using virtual instrument technology, we can easily simulate various automotive electrical equipment and develop various automotive electronic control units. By using this technology, we do not have to design the hardware directly, but can develop the hardware functions in principle through virtual technology before. In this way, we can not only shorten the development time, but also reduce the development cost. On the other hand, the electrical system of modern automobiles is becoming more and more complicated. If traditional hardware measurement equipment is used, it will not only increase the number of equipment and increase the workload of inspection, but also the flexibility of each hardware equipment is not strong and the cost is too high. By using virtual instrument technology, we can integrate various data acquisition devices into the computer, realize various data reading and signal analysis and processing through software, and finally display the results. In this way, the workload of detection can be greatly reduced, the cost can be reduced, and the detection function integration suitable for its own vehicle model can be flexibly developed.

II. Virtual Test Technology
1. Introduction to Virtual Test Technology
The combination of scientific experiments and theoretical research is a prominent feature of modern science and technology. Theory needs to be tested and verified by experiments, and experiments need the guidance of theories. The two are interdependent and complementary. Any theory can only be established after being confirmed by scientific experiments. In engineering technology, any successful product is the product of the combination of design and experiment. The design process is the test process, and the test runs through the entire design work. Any design idea and theoretical calculation must be tested by experiments. In many complex engineering and technical problems, experiments are often an effective way to solve problems.
In a broad sense, any method and technology that does not use or partially use actual hardware to construct the test environment and complete actual physical experiments can be called virtual experiments. Virtual experiments can be defined as experiments conducted in a virtual environment. The virtual test environment is a simulation test system developed based on software engineering. It allows designers to install virtual prototypes on it for testing. With the help of interactive technology and test analysis technology, designers can evaluate or experience the operating performance of the product during the design stage. Or virtual experiment is to use software to replace part or all of the hardware in the computer system to build various virtual test environments, so that the experimenter can complete various predetermined test items as if in a real environment, so that the test results are close to or equal to those obtained in the real environment.
Computer simulation has opened up a new solution for scientific experiments. Computer simulation is an experimental method that uses computers to simulate the mathematical model of the test object to obtain the regularity of the physical prototype system. It has brought virtual experiments into the digital stage. The simulation test process conducted by the computer is all calculation and logical judgment. However, due to the advantages of computers in memory capacity and computing speed, computer simulation experiments can handle some complex systems and nonlinear system experiments. The powerful information processing ability and powerful computing power of computers have gradually shifted the scope of virtual experiments from simple research to complex research, and from qualitative research to quantitative research.
The further development of computer simulation is virtual reality test (VR). Virtual reality is a computer system that artificially creates and experiences a virtual world. It has three important characteristics: high immersion, credibility and interactivity. By using virtual reality technology, a virtual test environment can be easily created on the computer to conduct various performance tests and inspections on the tested products; through the human vision, hearing, touch and other senses, people can feel as if they are in the real environment, so that the tester can complete various predetermined test items as if they were in the real environment. The
virtual test system can not only serve as the preliminary preparation for the real test, but also replace the traditional test to a certain extent. Compared with the traditional test, it has the following advantages:
(1) It can greatly reduce the number of prototype manufacturing tests, shorten the new product test cycle, and at the same time reduce the actual test cost.
(2) The application of virtual test technology in the development of complex products can realize the mutual feedback of information between designers and product users during the design stage, so that designers can fully absorb and adopt suggestions for new products.
(3) Virtual test technology replaces the actual test, realizing that the test is not limited by the venue, time and number of times, and the test process can be replayed, reproduced and repeated.
2. Application of virtual test technology in the automotive industry
The continuous development of computer technology and the continuous improvement of hardware performance have promoted the application of virtual testing in vehicle engineering. In 1972, General Motors of the United States first developed the general prediction program GPSIM for vehicle power and fuel economy. This program can simulate the instantaneous fuel consumption, cumulative fuel consumption, driving time and distance of a car under any driving condition, and predict the impact of changes in car design parameters such as mass, transmission ratio, air resistance coefficient, etc. on car performance. The Virtual Environment Laboratory of the University of North Carolina in the United States has carried out research on the virtual environment of vehicle drivers, which has strong engineering applicability. The ADAMS software developed by MDI in the United States is a good platform for constructing virtual prototypes of products. The CAR module is a complete vehicle virtual software package developed by MDI in cooperation with Audi, BMW, Renault and Volvo, integrating their experience in automobile design and development. With this module, engineers can quickly build high-precision virtual prototypes of the whole vehicle (including body, suspension, transmission system, engine, steering mechanism, braking system, etc.) and simulate them. Through high-speed animation, the dynamic response of the whole vehicle under various test conditions (such as weather, road conditions, driver experience) is intuitively displayed, and the characteristic parameters of Peugeot's handling stability, braking, ride comfort and safety are output, thereby reducing dependence on physical prototypes. The VTL (Virtual Test Lab) system is a virtual test system developed by the American MTS (Mechanical Test System). The system installs virtual sensors on products or components and installs virtual prototypes in different test environments. Once the virtual model is determined, it can be tested repeatedly and the design can be repeatedly modified according to the results of the virtual test to obtain the best design solution.
Compared with developed Western countries, domestic research units in virtual testing are mainly concentrated in colleges and universities. The State Key Laboratory of Vehicle Dynamic Simulation of Jilin University conducted a systematic analysis of the hybrid simulation test bench of the vehicle anti-lock braking system (ABS), established vehicle models, tire models, road simulations and ABS hydraulic system models for hardware-in-the-loop simulation, and conducted hardware-in-the-loop simulation tests. It embeds actual ABS components into the software environment for hybrid simulation, greatly expanding the functionality of software simulation and providing development tools and test platforms for ABS product development.

III. Conclusion
Modern automobiles have developed into an intelligent network computing platform. The automobile network runs through the control system, information system, driving system and sensor execution system of the whole vehicle. With the continuous development of the automotive electronics industry, the automotive industry is no longer a single mechanical manufacturing. According to relevant data, in the future automobile manufacturing, electronic products will account for nearly 50% of the process and cost. The development and testing of related electronic products will also develop rapidly. Virtual instrument technology and virtual test technology will play an increasingly important role in automotive engineering with its low cost, high efficiency, flexibility and reliability.