Active Fault-tolerant Control of Auxiliary Power Unit Based on Analytical Redundancy and Heterogeneous Redundancy Design

With the rising complexity of aero-engine control system, active fault-tolerant control has attracted increasingly more attention due to the demands of high security and reliability. Sensors are extremely prone to be disturbed and faulted triggered by bad working conditions. So an adaptive turning particle filter (ATPF) is used as fault-tolerant filter to estimate the state parameters of engine and downgrade dependency on specific sensor by analytical redundancy technique in the fault-tolerant control. For an auxiliary power unit (APU) where the exhaust temperature is taken as a closed control variable in starting process, a novel control schedule design method based on the acceleration is proposed, the details of which is revealed hereby, and is used to design and optimize the reconstruction control law which will be switched to when the exhaust temperature sensor fails. The testing results show that the transient response is stable, and static and dynamic characteristics is good when switched to the designed fault-tolerant controller.