Research Of Fault Diagnosis Approaches For Radar Digital Circuit Boards

As a kind of widely used military equipment, modern radar is known as the'eye'of commanders in the military and plays an important role in the field of national defense. With the continuous development of microelectronics technology, the radar becomes much more powerful, but also lead to increased complexity of the radar system. As a consequence, higher requirements for the maintenance and test of the radar equipment are put forward. Along with digital circuits having the advantage of high integrity and strong anti-jamming performance, the percentage of digital circuits in the radar equipment is growing continually. Therefore, the research about fault diagnosis based on ATS (Automatic Test System) for the digital circuits of radar equipment is very necessary.The paper, after analyzing the related resources provided by the ATS, studies the fault diagnosis for radar digital circuit boards, especially these boards containing FPGA, DSP and other large scale integrated chips. Then, the paper provides a fault diagnosis scheme. The main contents are as follows:1. The instruments function library for the ATS is developed successfully after learning the related resources provided by the ATS. Meanwhile, in order to ensure the universality of the ATS, this paper also verifies the interchangeability of the function library through constructing the testing environment.2. The boundary scan test platform is built based on Scan Works, which is developed by ASSET. SPV(Scan Path Verify actions) and interconnect actions are applied during the test of one radar digital circuit board. For the coexistence of boundary-scan devices and non-boundary-scan devices in the digital circuit board, Macro test is studied, which is based on the script language. In some ways, Macro test expands the application fields of boundary scan technology. Finally, in order to develop the TPS(Test Program Set) easier, the boundary scan function is integrated as a method module in the ATS.3. FTA(Fault Tree Analysis) is introduced for the radar digital circuit boards with poor testability. In order to do the qualitative analysis and quantitative analysis of the fault tree, the tradition method and BDD(Binary Decision Diagram) are both implemented based on Matlab. After that, the rule for diagnostic sequence of the components is proposed. Finally, the paper, taking the digital circuit board named serial input/output as an example, applies FTA in the fault diagnosis and finishes the development of the TPS.4. The data processing circuit board is analyzed in detail. After that, a new strategy contains fault tree analysis and boundary scan technology is applied in the fault diagnosis of the UUT(Unit Under Test). Meanwhile, the TPS for the UUT is verified to be feasible by the users.At last, the paper summarizes the work above, raises some problems and advice for future work.