Testability design of spacecraft test equipment based on BIT

In this paper, the requirements of power supply and distribution, measurement and control, control and propulsion and other front-end special equipment in the integrated test system of deep space spacecrafts are analyzed, and the testability design method of built-in-test (BIT) of the equipment is studied. It mainly includes the testability design of the key circuit of the board and the device port signal between board and device. Carry out various design of BIT models of analog input / output and digital input / output signals to realize non-destructive or low-loss real-time monitoring of signals. This paper designs a verification environment for BIT function application, and verifies the correctness of BIT design for standard mode and failure mode. It provides a technical method for real-time health diagnosis and failure warning of space equipment in unattended condition.