DEFINITION:

Engine control includes two branches:

1. Engine modelling. It consists:

• in identifying a mathematical model with the engine actual operating data: such mathematical model is necessary to define the control strategy and loops of the engine during its operations.
• in defining the control algorithms that will be implemented in the control loops.

2. Engine control system architecture and its related equipment (sensors and actuators).

• Engine control systems include all sensors, actuators, and regulators or/and computers that determine the operating parameters of the operating engine.
• Sensors are temperature, pressure, rpm,?; actuators are variable surface (vanes, blade angle settling) control actuators , fuel pumps and metering units; digital computers or hydro-mechanical regulators may be used to build up the control loops.
• System architecture is influenced by engine architecture and mission profile, by the thermal and dynamic environment created in and around the engine, and available equipment technology.

(Source: ACARE Domain 307)

SUBDOMAINS:

1. Engine modelling is evolving fast with the increase of on-board computing capability: these allow more sophisticated and efficient control strategies by implementation of model based schemes, with identification of model parameters on actual engine operating status, in order to set up operating points based on performance computed parameters instead of single sensor signals. Such innovative strategy allows to reduce operating margins coming from engine to engine dispersion, or ageing, or component wear, and therefore contributes to the increase of engine performance and/or life increase. This is possible thanks to the best advanced mathematics such as fuzzy logic, neuronal networks, Kalman filtering, genetic algorithms,…

2. Engine control systems are influenced by advances in electronics , sensor and actuator technologies:

• high temperature ( more than 200C°) electronics allows to incorporate intelligence in the harsh environment of an operating engine, giving the way to smart sensors and actuators, and distributed architecture
• power electronics allows to shift from hydraulic to electrical actuation with better reliability and maintainability as a benefit for the aircraft operator: more electrical systems allows easier health monitoring, and trouble shooting.