Search Results

The operating environment of aircraft causes accumulation and build-up of contamination on both the narrowest passages of the ECS (Environmental Control System) i.e: the heat exchangers. Accumulated contamination may lead to reduction of performance over time, and in some case to failures causing AOG (Aircraft on Ground), customer dissatisfaction and elevated repair costs. Airframers/airlines eschew fixed maintenance cleaning intervals because of the high cost of removing and cleaning these devices preferring instead to rely on on-condition maintenance. In addition, on-wing cleaning is t impractical because of installation constrains. Hence, it is desirable to have a contamination monitoring that could alert the maintenance crew in advance to prepare and minimize disruption when contamination levels exceed acceptable thresholds. Two methods are proposed to achieve this task, The effectiveness of these methods are demonstrated using analytical and computational tools.

A non-dynamic motor inverse model is used to achieve torque control of the motor in an automotive electric power steering system. Variations of the motor parameters directly impart inaccuracies in the motor control. Parameter estimation schemes based on the non-dynamic motor inverse model have been investigated in the past. This paper proposes an improved adaptive control scheme by approximating motor electrical dynamics and correcting for the back EMF compensation error caused by the velocity sampling delay. Comparison of simulations confirms a lower bound of error of the estimated parameter and faster adaptation with the proposed scheme compared to previously employed methods.