Redundant Current-Sum Feedback Actuator Control

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Solution Overview

Problem

Electrical non-optimality in actuator systems of aircraft flight control surfaces can cause un-commanded movements and structural anomalies, leading to deviations from intended flight paths and potential damage, which existing technologies fail to adequately suppress without complex monitoring and tuning.

Innovation Solution

A redundant current-sum feedback control system that uses actuation coil current sensors to measure the total coil current and control actuation coils based on the difference between commanded and measured currents, effectively suppressing electrical non-optimality through inner and outer feedback loops, regardless of its origin or characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If redundant control loops are implemented to suppress electrical non-optimality, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvefault suppression capabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple coil current measurements into a single sum signal that represents the total actuator current. This merged signal is then fed back to all controller channels, allowing redundant control loops to suppress electrical non-optimality without requiring complex individual monitoring of each coil. The summation approach simplifies the feedback architecture while maintaining reliability through redundancy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The current sum feedback signal serves multiple functions simultaneously: it provides fault detection capability, enables active suppression of electrical non-optimality across all controller channels, and maintains compatibility with existing actuator architectures. This multi-functional approach improves reliability without proportionally increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If elaborate monitoring and tuning systems are implemented to detect electrical non-optimality, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvenon-optimality detection accuracyVSAvoidmonitoring system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential information needed for fault detection by summing all coil currents into a single representative signal. This extracted sum contains the critical information about total current consumption and anomalies, eliminating the need for complex individual coil monitoring while maintaining measurement precision for detecting electrical non-optimality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The current sum is fed back to all controller channels to enable active suppression of electrical non-optimality. This feedback mechanism automatically corrects detected anomalies without requiring elaborate tuning systems, as the redundant controllers naturally adjust their output based on the shared sum feedback signal.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If custom analysis and tuning of monitors are performed, then measurement precision is improved, but loss of time increases

Engineering Contradiction:
Improvefault detection accuracyVSAvoidcertification and scheduling time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The redundant control architecture with current sum feedback enables self-diagnosis and self-correction of electrical non-optimality. Each controller channel independently monitors the sum feedback and automatically adjusts its output to suppress anomalies, eliminating the need for extensive custom analysis and tuning during certification while maintaining high measurement precision for fault detection.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly reduces the effects of electrical non-optimality to negligible levels, eliminating the need for elaborate monitoring and tuning, and allows for the use of less costly devices while ensuring near-perfect fault suppression in actuator systems.

Implementation Method 1

receiving a magnetic flux from the sensor coils in a magnetic core

Methodology Applied
Scientific EffectMagnetic flux: Electromagnetic Induction

Implementation Method 2

Electric current flows through a coil (or coils) and is converted to a magnetically induced useable force to actuate the actuator

Methodology Applied
Scientific EffectElectromagnetic effect: Electromagnetic Induction

Data Source

PatentEP2840021B1Redundant current -sum feedback actuator
Publication Date: 2019.01.02 THE BOEING CO
  • EP2840021B1 patent drawingFigure 1~2
  • EP2840021B1 patent drawingFigure 3
  • EP2840021B1 patent drawingFigure 4

AI summary

A system and methods for redundant current-sum feedback control of an actuator system is presented. An actuator comprises actuation coils configured to actuate the actuator, and an actuation coil current sensor senses a measured total coil current comprising a sum of coil currents of each of the actuation coils. Actuator coil controllers control the actuation coils based on a commanded total coil current and the measured total coil current.