Development And Research Of Similar Redundancy Flight Control Computer Based On Microcontroller Unit Arbitration Mechanism

As the working time of UAV(Unmanned Aerial Vehicle) is becoming longer and its functions aremore complex than before, the FCS(Flight Control System) is becoming to face a much higher levelof risks. Higher demands for the reliability of the FCS are needed. As the core component of the FCS,the FCC(Flight Control Computer) plays an important role in reliability promotion of the FCS.Usually the FCC is designed using the redundancy technology. With the multi-redundancy stratergythat based on voting mechanism, now many advanced UAVs achieve this goal through hardwareredundancy. By this mean the reliability of the FCS is promoted greatly. However, this method alsobrings some unavoidable technical problems, such as big volume, heavy weight and cost. Besides, thesystem requires at least three flight control computers, which increases the complexity of software andtime sequence design. In order to solve the problems occur in a multi-redundancy FCC system, amethod that using MCU (Microcontroller Unit) arbitration mechanism in a similar two redundancyFCC is proposed.Firstly, according to researchs of the applications and recent developments of the redundancytechnology in the FCS design, a similar two redundancy FCC sturcture is determined. The detailedand engineering design method is given. A theory analyse and engineering design is made accordingto the vital factors such as weight and volume.Secondly, considering the requirements of the FCC, the hardware resources of PowerPCembedded core and MSC1212arbitration unit are arranged logically. The FCC hardware platform isconstructed in an appropriate way. The functions of the FCC are implemented through C programlanguage, such as self-detection, synchronization, data collection and processing.Thirdly, the redundancy management circuit based on arbitration mechanism plays animportment role in the design. Its structure and functions are designed with emphasis. A reasonablearbitration arithmetic is proposed and realized in MCU. The arbitration unit’s monitor and controlmechanism on the FCC is consummated and its expected functions are implemented,such as signalswitch and redundancy mangement.Finally, a technical and personal test and validation scheme carried on half-physical simulationplatform is made to verify the rationality, logic and validity of the similar two redundancy FCC. Afterthe long time tests of logical functions and fault injections, the former expected results are obtained.Test results show that the key problems are solved efficaciously and the design method is scientific, correct and doable. Performance and technical index of the redundant FCC can well meet the basicrequirements of UAV.