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DISTRIBUTED CONTROL SERVO MODULE HARDWARE IMPLEMENTATION

IP.com Disclosure Number: IPCOM000240267D
Publication Date: 2015-Jan-20
Document File: 8 page(s) / 93K

Publishing Venue

The IP.com Prior Art Database

Abstract

This invention relates to a new design for distributed control modules used for implementing an aircraft engine control system.

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This is the abbreviated version, containing approximately 27% of the total text.

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DISTRIBUTED CONTROL SERVO MODULE HARDWARE IMPLEMENTATION

TECHNICAL FIELD

    This invention relates to a new design for distributed control modules used for implementing an aircraft engine control system.

BACKGROUND

    Some known aircraft engines employ a Full Authority Digital Engine Control System (FADEC) made up an Electronic Engine Control (EEC), actuators, sensors, electrical harnesses and related accessories. The EEC is comprised of a digital computer, associated engine control software, power supply and analog and digital interface electronics. The EEC receives multiple input variables of the current engine operating and aircraft flight condition including, but not limited to, air density, throttle lever position, engine temperatures, engine pressures, and current values of other engine parameters. The inputs are analyzed and engine operating parameters such as fuel flow, stator vane position, bleed valve position, and other parameters are computed from this data and applied as appropriate to provide optimum engine operation for a given current flight condition.

    In a FADEC control system all of the engine control functions are centrally located in the EEC. In contrast, distributed engine control architectures have some of the control system functionality distributed around the engine to smart sensors and smart actuators. Distributed controls systems have the potential to reduce overall system weight, improve sensor and control accuracy and improve system life cycle cost. Distributing some of the ECC functions reduces the size and weight of the ECC and the size and weight of electrical harnesses providing significant system weight reductions. Locating the interface electronics in the sensors and actuators


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provides for local device specific calibration providing increased sensor accuracy and improved actuator control. Locating the interface electronics in the remote sensors and actuators improves fault isolation and improves system life cycle costs.

    In a FADEC engine control system the EEC uses a microprocessor to analyze sensor inputs and compute new controls system values. While a microprocessor could be used to implement a smart sensor or actuator it is has significant drawbacks. Microcontrollers and microprocessors are expensive, have limited performance capabilities, and operate over a limited temperature range. Due to the large number and type of smart sensors and smart actuators in a distributed control system they must be low cost, and capable of operating in high temperature locations. Therefore, a higher performance, high temperature, and less expensive method of implementation is desirable.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a block diagram of a potential module.

DETAILED DESCRIPTION

    A module for use in a distributed system controlling a gas turbine engine is generally provided. The module closes a servo loop using an algorithm implemented by a state machine. The features of the module include a...