Fault-tolerant flight profile simulator for launch vehicle applications

A simple, rugged and accurate Flight Profile Simulator (FPS) for launch vehicle hardware and software real-time testing is proposed in this paper. The launch vehicle onboard system is a MIL-STD-1553B based configuration with Onboard Computer (OBC) as Bus Controller (BC) and Navigation, Sequencing and Control subsystems as Remote Terminals (RT). The simulator acts as another RT on the 1553B bus and emulates input RT's like Inertial Navigation Sensor (INS) interface module and rate gyro package module. It simulates the analog pressures required for pnuemo-hydraulic algorithm as well as the fuel flow, oxidizer flow and temperatures required for onboard Mixture Ratio Control (MRC) algorithm. The proposed simulator is augmented using a fault-tolerant scheme that ensures all onboard elements are protected in case of any failure in any simulator hardware/ software elements. The flight simulator has been used for real-time testing of launch vehicle avionics systems and close match is seen between test results and predicted reference.