Design And Realization Of Equivalent Equipment For Telemetry External System

Telemetry system is an important component of various telemeter missiles and launch vehicles, and is a main way of gaining the credible and comprehensive flight information, which provides reliable basis for rocket system's performance evaluation, fault analysis and the improvement of design and production technique. Based on current domestic and foreign research and development trend of test system, by simulating all control and measurement parameters, a design proposal of the equivalent test platform is put forward, aiming at examining the functions and performances of the telemetry system efficiently.Adopting stack structure design and based on the design mode of foundation test plus expansion test, the design of hardware modulation, connection standardization, functional software as well as test procedure visualization are realized. Making use of the standard computer USB communication interface, depending upon the high program control ability of FPGA and the high flexibility and the ultra strong hardware descriptive power of VHDL, the task about downloading simulation signal sources and real-time gathering, memorizing, analyzing, processing and demonstrating measured signals is accomplished. The design scheme not only saves system development cost and shortens development cycle, but also improves reliability, maintainability, reconfigurability, and environmental adaptability of the system. Additionally it can determine working status of telemetry system and fault diagnosis at any time.Key technologies are explained in detail,such as USB and LVDS bus technology, digital frequency synthesis technology as well as anti-electromagnetic interference technology. Unifying technical specifications and parameter requests of each equality module, taking advantage of GPIF transmission mode in EZ-USB FX2 singlechip, high speed data correspondence between host computer and testing hardware platform is realized; test data transmission with telemetry system is accomplished through LVDS, RS422 etc. Moreover, the design project of the whole system, the realization principle of each functional module, as well as various problems encountered in designing process and the corresponding steps are analyzed and discussed thoroughly. The feasibility, validity, reliability and versatility of design proposal are verified in light of the actual test results.