The Design Of Communication Software And Signal Synchronization In The Analog Signal Source System Of The Flight Test Platform

Airbus and Boeing have been playing the role of leading enterprises in the international civil aviation market and they have dominated the field of large civil aircraft for decades. With the booming economy of our country and the fast development of the technology, in order to break the monopoly of the market and win a place in the field of aerospace manufacturing, our government assigned the Large Civil Aircraft Project as one of the 16 major science and technology projects in 2007.Flight test is an essential part in the process of a new type of aircraft’s development and it is also the most central part in the flight test of the airborne test system. Airborne test system is the equipment used to obtain test data in flight tests and it plays an important role in troubleshooting and technical upgrading. Flight test verification platform is a comprehensive ground verification system which integrates various testing methods and techniques. It is used to test whether the performance of the airborne test system meets the requirement of airborne flight tests. In addition to provide test vectors for the key technical parameters of the airborne test system, the test flight verification system can also simulate the working condition of the aircraft in some special flight tasks. The ground verification platform is one of the main means for estimating the performance of airborne testing system. The analog signal source system, which is an important subsystem of the ground verification platform, is used to simulate the output signal of all kinds of airborne sensors. It provides the excitation input for the sensor signal acquisition channel of the airborne test system so that we can verify the airborne test system’s ability of collecting, transmitting and processing the data from sensors.Based on the specific engineering project and the actual functional design requirements, the function realization of the analog signal source system of airborne testing system is discussed from three aspects in this paper: communication system, signal synchronization and system application software’s design. The function realization of communication system is divided into three levels: the response from client software to user’s operation, the communication between the host computer and the slave computer, which needs both the hardware communication network and a set of complete and efficient communication orders. The design of the output signal from the analog signal source board driven by the lower computer; The realization of analog signal synchronous output function can be divided into the synchronization of system clocks between PXI chassis and the signal synchronization of multiple analog signal output channels from a chassis. The clock synchronization scheme provided in this paper has improved the accuracy of the system clock from the level of the microsecond to nanosecond by using IEEE1588 clock synchronization technology and combining NI clock synchronization boards and low loss clock signal transmission cable. In the design of analog signal synchronization output, in order to ensure the synchronization precision of the output signal, we not only completed the analog signal board DA clock’s synchronization, but also designed a high performance of the synchronous trigger signal transmission network. In the design of the software application, we have developed a set of software application including the client software and the lower computer driving software in the LabVIEW development environment. The architecture design of the software is emphatically introduced in this paper.