Design And Implementation Of Equivalent Equipment For A Telemetry System

Telemetry system is an important way to obtain the flying parameters and working status of the aircraft system,so its own reliability has an important influence on the design and production of the aircraft.In order to test telemetry system in the laboratory environment,an equivalent equipment for the telemetry system is designed,which is used to simulate the control and interface signals of the telemetry system,providing multiple analog and digital signals needed for the telemetry system self-test.The equipment is mainly composed of the test computer and the test device.At the normal mode,the test computer communicates with the test device by the Ethernet interface,and sends the command,finally controls the test equipment to produce the required signal.According to the classification of the excitation signals,the modular design idea is adopted,and the functional modules are concentrated on the corresponding board,which improves the reliability of the design and makes the equipment easy to debug and more extensible.Each board of the test device using FPGA as the central control unit,combined with peripheral hardware circuit,can generate multiple time command signals,continuous adjustable DC signals,sine wave signals,RS422 serial digital signals and isolated voltage signals,besides,the equipment can receive the command signal and display its real-time status.This paper introduces the technical requirements and overall design of the equivalent equipment for the telemetry system,and expounds the selection basis of the communication interface and the design of the system communication protocol.The design of the main control board of the test device is studied,the design of hardware circuit and corresponding FPGA control logic of each function module are introduced.Finally,the test platform is built,the equivalent equipment is tested,and the test results are analyzed.The actual test result shows that the output signals of the equivalent system are stable,which can meet the requirements of the task and has strong practicability.