Ghasem Kahe - Aerospace Research Institute, Tehran, IRAN

The flight control system must meet extremely high levels of functional integrity and availability. The control algorithm is processed by onboard computer (OBC). To meet the reliability requirements for onboard computers, various type of redundancy must be employed. In this paper, we concerned with the triple modular redundancy (TMR) for an onboard computer with aerospace application. In the proposed architecture, control inputs and system states are measured using designated sensors. According to the acquired data, mission scenario and control algorithm are processed by the processing unit. Thereafter, the results are applied to the system by actuators.TMR technology in component level is used to improve the reliability of OBC according to the system requirements. All of the constituent modules of OBC, comprising processing unit, bus interface, sensor, actuators, and IO devices, benefits from triple redundancy. The case study shows that the similar architecture is used for high reliable flight computer of passenger airplanes except that our architecture is based on the available multicore microcontrollers. The reliability of the designed onboard computer is evaluated analytically, which indicates that the proposed OBC can meet the reliability requirements.

Onboard Computer, Triple Modular Redundancy, Reliability