机载任务设备控制模块自适应BIT检测电路设计

Design of Adaptive BIT Detection Circuit for Airborne Mission Load Control Module

作为系统测试和故障诊断与隔离的一种手段,BIT(built in test)技术被广泛应用于航空电子设备可靠性、维护性、测试性与安全性设计中;文中针对某型无人机机载任务设备的BIT检测功能以及资源分配指标要求,给出了任务设备控制模块的电路组成;通过分析BIT检测信号类型,介绍了基于A/D转换器单端口多状态电压的BIT检测常规设计方法与电路特点,并针对该电路存在的诸多不足,提出了利用二级管单向导电特性所具备的电子开关功能,设计出可筛选分离不同电压、自动识别单端口多状态电压的自适应BIT检测电路,仿真与飞行验证表明,该电路设计满足了节省资源、减小体积、节能降耗、降低成本以及高可靠性的指标要求,并成功应用于多型无人机的同类产品及其他电子产品中。

As a means of system testing and fault diagnosis and isolation,BIT(Built In Test)technology is widely used in the design of reliability,maintainability,testability and security of the avionics.In this paper,according to BIT test function and resource allocation index requirements of a certain UAV airborne mission load,the circuit composition of mission equipment control module is given.By analyzing the type of BIT detection signal,the conventional design method and circuit characteristics of BIT detection based on single port multi state voltage of A/D converter are introduced.Aiming at the shortcomings of the circuit,the electronic switch function of the diode unidirectional conductivity is proposed,and the adaptive BIT detection Circuit which can screen and separate different voltages and automatically identify single port multi state voltage is designed,simulation and flight verification show that the circuit designed meets the requirements of resource saving,volume reduction,energy saving and consumption reduction,cost reduction and high reliability,and has been successfully applied to the similar products of multi-type UAV and other electronic products.