With the development of electronic technology, the importance of avionics system in the whole aircraft is rapidly increasing. According to statistics, in recent years, the proportion of avionics systems in aircraft factory costs has risen sharply, and the research and development costs of avionics systems have accounted for nearly 30% of the total aircraft development costs, and have maintained a continuous expansion trend. As a vital part of the avionics industry chain, test support runs through the entire life cycle of avionics equipment "R&D-manufacturing-operation". Improving and developing avionics test support technology is a key technology to enhance the competitiveness of my country's avionics industry .
1. What is an avionics system
The avionics system is the aircraft avionics system, which refers to the sum of all electronic systems on the aircraft. Avionics systems include display systems, communication systems, data input and control, flight control systems, navigation systems, radar systems, weapon systems, etc.
In the system integration environment, it is necessary to simulate analog quantities, discrete quantities, synchronizers, frequency quantities, RS232/422/485, 1553B, CAN, ARINC429, 1394B, TCP/UDP, which are cross-linked with non-bus signals of various subsystems of avionics , FC, AFDX, Rapid IO, LVDT/RVDT, LVDS, HB6096 and other status signals to realize the verification of the function, interface and cross-link relationship of each subsystem of the avionics.
2. The necessity of scalable automated testing platform
The traditional avionics system function test equipment is: a set of test equipment only tests one model, and the test software is also specially customized. When there are more and more models, it is finally found that many different types of test equipment are needed, and many developers are also required to develop test software. It is difficult for testers to master all kinds of test equipment and various test software proficiently, and the maintenance and management of test equipment is also quite complicated and cumbersome.
Now it is necessary to build a scalable test platform for avionics systems, including a common hardware platform and a common software platform, which can test almost all types of avionics system equipment.
The general hardware platform adopts the PXI bus interface module, and the general software platform adopts the ATECLOUD intelligent cloud test platform.
ATECLOUD intelligent cloud test platform has a highly open secondary development capability: build a test plan, and flexibly expand test items; control each interface module of PXI, generate excitation signals to the avionics system under test, and then collect the feedback signal of the system under test, Compared with the expected results, the function, interface and performance of the avionics system can be tested and verified.
3. Test principle of an avionics system
DUT: various avionics system equipment with different communication buses, all of which are embedded systems. The peripheral signal interfaces of the avionics system include analog output interface, discrete output interface, frequency output interface, synchronizer output interface, serial bus (RS-422) interface, and HB6096 interface.
Software requirements: with secondary development functions: realize test environment construction, automatic execution of test cases, output control of analog quantity, frequency quantity, synchronizer signal value and switch quantity state, as well as serial bus (RS-422) data packets and HB6096 Sending and receiving of bus data packets, automatic comparison of results, automatic generation of result reports and other functions.
Hardware requirements: use a controller based on the PXI bus, and configure analog output interface boards, discrete output interface boards, frequency output interface boards, synchronizer output interface boards, and serial bus (RS-422) interfaces on this basis board, HB6096 interface board as the hardware main body of the general test platform of the avionics system.
ATECLOUD intelligent cloud test platform is deployed and installed on the PXI controller, which is equivalent to a computer host. The scalable automated test platform system for avionics system consists of PXI equipment, ATECLOUD test platform, disconnection detection interface, signal interface, aviation plug cable and the avionics system under test.
The main configuration of PXI hardware:
✦BST71013 14-slot PXI chassis ✦BST11207 embedded zero-slot controller ✦BST34211 48-channel discrete input and 48-channel discrete output module
✦BST32204 64-channel 16-bit analog voltage output module
✦BST23208 8-channel serial port module
✦BST24080 dual-channel synchronizer module
✦BST32203 8-channel waveform output module
✦CPCI-429-88 8 send 8 receive ARINC429 communication module
4. Execution process of an avionics system test
Using the ATECLOUD intelligent cloud test platform can quickly build a hardware test environment for analog output interfaces, discrete output interfaces, frequency output interfaces, synchronizer output interfaces, serial bus (RS-422) interfaces, and HB6096 interfaces. Cables connect the DUT and various modules. Then use the ATECLOUD intelligent cloud test platform to build a test project, configure parameters, run the test, and finally get the test report.
Figure 4: Example of building an ATECLOUD test plan
Figure 5: Example of ATECLOUD run test
Figure 6: ATECLOUD test data insight interface
ATECLOUD is a domestic industrial automation test software platform, based on which the development and deployment of system test software can be completed. This product is a domestic self-controllable 0-code test and development platform first launched in the industry by Namisoft, which effectively breaks the long-term monopoly of imported software LabView and other products in this field in China. ATECLOUD can be widely used in the research and development of test tooling, test instruments and other equipment in various industries such as aerospace, weaponry, industrial control, automotive electronics, and instrumentation. It has the characteristics of wide application range, strong real-time performance, high development efficiency, simple use, easy expansion, domestic independence, etc. It supports deployment schemes of various domestic CPU + domestic operating systems, and is compatible with Windows, linux, Mac and other operating systems.
The ATECLOUD automated testing platform is used to quickly build a test plan, and when the requirements change, it can be quickly expanded on the basis of the original plan. At the same time, ATECLOUD can automatically generate test reports that meet user needs, which greatly reduces the overall time consumption of the project. Let the testers be freed from the testing work, and concentrate on activities such as meaningful test design.
Automated testing ensures the reliability and robustness of the software, and at the same time reduces testing costs, improves testing efficiency, and enhances the market competitiveness of enterprises. For the iterative development model of continuous delivery and continuous integration, automated testing is crucial.