Retrospective Cost Adaptive Control of Generic Transport ModelrnUnder Uncertainty and Failure

摘要

This paper presents a case study on the application of retrospective cost adaptive control to the NASA generic transport model under conditions of uncertainty and failure. To apply retrospective cost adaptive control to the generic transport model, a collection of control architectures is defined, where each architecture has a decentralized adaptation structure in the sense that a performance (error) variable is assigned to each control channel for online decentralized adaptation. Sensor signals may be shared among the channels to account for channel coupling. Then, a series of cases that examine the performance of retrospective cost adaptive control under various conditions is considered, including trim finding, startup, unknown time-varying aircraft dynamics (such as icing and mass variation), unknown flight envelope (including the possibility of conflicting commands), known sensing constraints (a failed air data system), known actuation constraints (requiring differential thrust), unknown sensor failure (stuck and biased airspeed measurement), and unknownactuator failure (severe stroke and rate saturation, dead zone, and jam). For each case, a range of scenarios is considered that captures various commands and performance objectives. Disturbance rejection is included in the form of unknown wind shear.