Li Wenhai

Design of Interface Module for LXI Class B Based on MCU

The precise clock synchronization technique based on IEEE1588 protocol is one of the key techniques of LXI. This technique is used in LXI class B device. First, the development trend of LXI is introduced in this paper. Then the basic principle of precise clock synchronization technique is analyzed, precise clock synchronization based on MCU platform is designed and the LXI class B module is designed. In order to improve the precision of clock synchronization, FPGA is used in the system to stamp time label for Ethernet data.

Implementing parallel test in traditional serial framework ATS

The research described in this paper attacks the difficult problem of parallel testing of automatic test systems built on a serial architecture. Several key technologies, such as the control of test resources, the sharing of test resources and test data, and software development are investigated. Memory mapping, messaging, TCP/IP and the centralized control of testing resources by the resource management kernel are proposed to resolve the problem of test resources and test data sharing between multi-process. The benefits of adopting specific engineering practices for improving the parallel test for the automatic system of serial framework are discussed.

Research on prognostic for switch power based on HMM

The fault prediction technique plays a vital role in enhancing security, reducing the life cycle cost and improving maintenance support efficiency for equipment. The hidden Markov model is one of fault prediction techniques to solve the prognostic problem on buck Switch Power. The health degeneration process is analyzed in detail, and the output ripple voltage, inductance current and output power are selected as monitoring parameters. Each state of sample series is used to train HMM, and then the observation sequences of signals to be measured are tested by the model above. So we can get the likelihood possibility of signals to be measured. Experimental results show that this method can accurately predict switching power supply condition.

Research on health assessment based on Hidden Markov Model

The health assessment is an important part of Prognostic and Health Management. Since the early fault signals are difficult to detect, we argue to convert them into the information that easily observed by using Hidden Markov Model (HMM), evaluate current state that deviation from the normal state and estimate the health status for the maintenance decision of Condition Based Maintenance. In this paper, we describe the basic theory, discuss the implementation methods of HMM in detail, and give an example for validation. Experimental results show that the method can effectively assess the health status of equipment.

Research on Integrated Grounds Health Management for aviation gyroscope

The Prognostic and Health Management (PHM) technology plays an important role in improving the security of aviation equipment, decreasing the life cycle cost and improving the logistics efficiency. According to the technique characteristics and the requirements on logistics of certain aviation gyroscope, we put forward to setting up the Integrated Grounds Health Management(IGHM) system for Aviation equipment using the historical failure information, current status information and current environmental information on the basis of integrated logistics information system in existence. On the basis of analyzing PHM technology, the system structure and key technologies to realize IGHM system are discussed in detail. Research shows that the IGHM system is open and universal, which is easy to upgrade and to apply on other logistics systems.