HOTAS Interface Voltage Drop Circuit Reduces Wire Complexity

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Solution Overview

Problem

Existing manual human interface systems for aircraft and other electronic control systems face a tradeoff between complexity and cost, particularly in adding additional control inputs which often require increased wire paths and connector interfaces, making them costly and complex, especially in constrained environments like military aircraft.

Innovation Solution

A Hands On Throttle-And-Stick (HOTAS) interface design that uses a circuit with dedicated signal conductors and a common ground conductor to enable multiple control inputs with unique voltage drops, reducing the number of required electrical connections and allowing additional control inputs without additional wire paths, while maintaining backward compatibility with existing systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If additional control inputs are added to HOTAS interface, then control functionality is improved, but wire complexity and cost increase

Engineering Contradiction:
Improvecontrol functionalityVSAvoidwire complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple control inputs share a common ground conductor, merging multiple wire paths into a single shared resource. This allows additional control inputs to be added without proportionally increasing wire complexity, as each new input reuses the existing common ground conductor rather than requiring a dedicated wire for each function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The common ground conductor serves multiple control inputs simultaneously, making it a universal resource that supports various control functions. This multi-functionality allows the same wire infrastructure to accommodate different control inputs (buttons, switches, triggers) without requiring separate wiring for each control element.

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

2Device complexity

If traditional wiring with dedicated conductors is used for each control input, then signal identification is simplified, but the number of electrical connections increases

Engineering Contradiction:
Improvenumber of electrical connectionsVSAvoidsignal identification
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system uses voltage drop as a distinguishing parameter to identify different control inputs. Each control input creates a unique voltage drop characteristic when activated, allowing the system to differentiate between multiple control inputs sharing the same ground conductor based on electrical parameter measurements rather than requiring separate physical conductors.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/wire-based identification system with an electrical measurement system. Instead of using separate physical wire paths to identify control inputs, the system uses voltage drop measurements to detect and identify which control input is activated, substituting physical separation with electrical sensing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 design reduces the number of electrical connections needed, lowers development and implementation costs, and enhances reliability and sensitivity of control operations, while maintaining compatibility with existing systems, thus improving pilot control and situational awareness without increasing wire complexity.

Implementation Method 1

Each signal path has a unique voltage drop within a predetermined range to identify the selected control signal being provided

Methodology Applied
Scientific EffectVoltage drop: Ohm's Law

Data Source

PatentEP2129577B1Aircraft control system and method using a HOTAS interface
Publication Date: 2015.10.14 RAYTHEON CO
  • EP2129577B1 patent drawingFigure 1A~1C
  • EP2129577B1 patent drawingFigure 2

AI summary

In accordance with one embodiment of the present disclosure, a method for controlling an aircraft by a hands on throttle-and- stick (HOTAS) includes selectively connecting, by the HOTAS, two interfaces of a controller for the aircraft. The selective connection is made through one of a plurality of possible paths. Each path has an expected respective voltage drop within a predetermined range. The selected one of the possible paths connecting the two interfaces is determined by determining an actual voltage drop associated with the selected path. A control operation for the aircraft is effected by the controller based on the determined selected path. The method reduces the number of required electrical connections.