introduction
The number and complexity of electronic systems in automobiles are continuously increasing. If the cost of electronic systems in the total production cost of automobiles is used as an indicator, the share of electronic systems has accounted for one-third of the total production cost in 2010. Increased trend. At present, about 90% of the innovations in new cars are based on electronic products. These innovations enable automakers to better meet customers' requirements for high performance, comfort, communication and entertainment, in order to integrate these large-scale growth needs into today's In the electronic system, today's cars are equipped with a large number of sensors, actuators, control modules and distributed systems. Faced with this situation, auto manufacturers need a set of test platforms that can meet these ever-changing test requirements. Moreover, due to product cycle considerations, test platforms need to have higher test efficiency and higher flexibility.
In this context, Beijing Fanhua Hengxing Technology Co., Ltd. combined more than 10 years of experience in automotive electronics testing, introduced a new automotive electronic test platform eCAR? (AUTOMOTIVE ELECTRONICS TEST SYSTEM), the platform is developed for automotive electronic testing needs Comprehensive test platform, through scalable architecture and modular design, can provide a package solution for automotive electronic testing, and can quickly change to complete a new test task.
eCAR ​​platform
The eCAR? automotive electronics test platform uses modular hardware and general-purpose software. The platform can be divided into independent functional modules. The architecture of the platform is shown in Figure 1.
The test platform has the following features:
1. Open hybrid bus architecture: The platform is based on the PXI platform to ensure the high efficiency of test and control. At the same time, it integrates Ethernet, GPIB, RS232, CAN, K-Line, FlexRay, and other buses. This open hybrid bus architecture makes various instruments possible. Resources are optimized for use under this platform.
2, test environment simulation technology: Accurately build a test environment from design to diagnosis, strict incentive response control, independent resources and parallel processing capabilities, while meeting the requirements of signal simulation and reliable measurement.
3, high-efficiency switch: The platform can effectively monitor the working status of the pin of the DUT under the condition of access load through the combination of programmable load and matrix. Through the cooperation of matrix units and measuring instruments, complex tests can be completed efficiently;
4. Reliable General Electric System: The platform utilizes the GE system to meet the requirements of automatic testing of production line final inspection equipment, and has the ability to control cylinders, motors and other operations, read external status, and control electrical safety.
In order to meet the actual test requirements of different test items, the eCAR? automotive electronic test platform is based on the common architecture, with different hardware components, to meet the needs of different test projects. The main hardware modules are as follows, and each type of module contains multiple model.
1, rack: to prevent measuring instruments, loads, etc.
2, power distribution: power supply for the equipment;
3, PXI chassis: used to install PXI controllers, PXI boards, optional 8-slot, 14-slot, 18-slot chassis;
4, digital I / O: for the amount of reading and control;
5, Bus communication: Bus copper to be tested, optional CAN, K-Line, Flexray bus;
6, analog I / O: analog output part includes static analog output, PWM signal output, waveform generator, resistor signal output signal generation module; analog input part includes digitizer, multimeter, analog voltage acquisition module;
7, switch module: including multiplex switch, matrix switch, according to the use of optional RF switch, power switch, low frequency signal switch;
8, load box: to provide load for the DUT, optional multiple load and load parameters;
9, General Electric: status input for signal input of proximity switches and optical sensors; execution output for pneumatic valve body, pilot light and other controls; safety control, for security grating, emergency stop button status detection, hardware level Responsively cut off power supply, origin, etc.
10, programming power: According to the different requirements of the power supply to be tested, a variety of power supply is optional;
eCAR? Automotive electronic test platform software function module design adopts modular and plug-in design concept, basically covers all the functions of the final inspection equipment of the production line, including: English interface, user management, parameter configuration, sample model, product Mode, engineer mode, database storage, report generation, data browsing, MSA analysis, etc. For different users, the test function can be easily matched. Has the following characteristics: a rich hardware driver library, hardware resources can be configured, the test process can be edited, a professional set of test parameters and test function optional. Platform software has the following features:
1, custom test sequence / process: eCAR? automotive test platform software through ATLAS language parser, customers can easily customize the test sequence / process, improve the test system scalability.
2, rich hardware drive and bus communication library: Taking into account the automotive electronics testing involves a large number of devices and protocols, automotive electronics test platform software provides mainstream instrument driver functions, and supports customer-defined instrument drivers.
3, industry experts algorithm library: for different types of applications, providing a professional industry expert algorithm library, through a variety of signal analysis methods, combined with digital signal processing technology to restore the most authentic signal characteristics, characteristics of the measured object.
4. Intelligent management of interchangeable instrument technology and hardware resources: Taking into account the future upgrade and replacement requirements of the test system, the software of the test system has good compatibility with various instruments. When the system is replaced with the instrument model, even the supplier's At that time, the software platform can be seamlessly changed.
According to the different testing requirements of automotive electronics products, selecting a corresponding hardware module and collocation platform software, a new test system can be designed. The following case is designed based on the eCARTM automotive electronics test platform.
Engine Controller LTT Test System
In automotive electronics, the engine controller is one of the most complex electronic devices. The role of the engine controller includes ignition control, fuel injection control, launch control, turbocharger maintained boost level control, and other peripheral control. Implementing these controls requires acquiring a large number of sensor signals, such as MAP sensor signals, accelerator pedal sensor signals, throttle position sensor signals, oxygen sensor signals, and temperature sensor signals. Typically, the number of pins on the engine controller is between 100 and 200. This requires the test system to provide a variety of simulation signals, such as resistance signals, switching signals, PWM signals, sine signals, static analog signals, etc., and provide the controller with up to 30 more load channels.
In addition, since the LTT test of the engine controller requires continuous operation (up to 24 days) in different environments (high temperature environment, low temperature environment, vibration environment, high humidity environment, etc.), the test system needs to provide independent instrument resources. , load resources and power supply system.
The engine controller LTT test system is built using the eCARTM automotive electronics test platform. The modular hardware used in the test system is shown in 1:
Test system block diagram shown in Figure 2:
The test system adopts the structure of the upper computer and multiple lower computers. The upper computer is an industrial control computer, the lower computer is TestUnit, and the industrial computer and the TestUnit are connected through a switch and communicate using the TCP/IP protocol. TestUnit contains independent instrument resources, load resources, and power supply system. Each TestUnit corresponds to an engine controller. Multiple TestUnits can work independently in parallel and correspond to different test environments. The test system can expand up to 20 TestUnits, corresponding to 20 controllers simultaneously tested in different environments.
TestUnit's system block diagram is shown in Figure 3. TestUnit has the following features:
1, Abundant instrument resources: including 110 digital I/O channels, 32 channels of 16-bit resolution analog input channels (shared 250kS/s sampling rate), and 4 channels of 16-bit resolution analog output channels;
2, powerful communication capabilities: high-speed (1Mbit / s) CAN bus, K-Line bus, scalable LIN, Flexray bus;
3, up to 64 programmable analog load channels;
4, quick connection: through a 150-pin Harting connector to connect with the engine controller;
5, convenient debugging interface: auxiliary Harting interface, used for manual monitoring of the instrument's working status during the test;
6, The modular design of the card type is convenient for maintenance and upgrade. When the model of the engine controller changes, the definition of the pin, the test environment and other changes, there is no need to replace the expensive instrument resources of the TestUnit, just replace the programming resistor card, Signal conditioning card, analog load card, switch card can be. ,
TestUnit appearance as shown in Figure 4:
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The appearance of the engine controller LTT test system is shown in Figure 5, using a 42U standard cabinet:
The software of the engine controller LTT test system is built using the software of the eCARTM automotive electronics test platform. The main software interface is shown in Figure 6.
The test system software includes the basic functions of the eCARTM platform software such as custom test sequences/procedures, instrument management, bus communication, and expert algorithm library.
summary
The testing of automotive electronics products requires a transition from simple qualification to multiple performance testing. For these changes, the eCARTM automotive test platform can provide standards with flexible hardware configurations and a portable software platform for automotive electronics testing. Provides an efficient solution.