Cam-Based Cabin Door Load Simulation for Multi-Load Accuracy

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Solution Overview

Problem

Existing load simulation designs for aircraft cabin door actuation systems fail to accurately simulate multiple loads such as gravity, friction, inertia, and gust wind disturbances, failing to meet the actual use needs of aircraft cabin doors.

Innovation Solution

A cam-type load simulator comprising n cam sets, an input shaft, and a friction disk, connected through couplings, with each cam set including gravity, inertia, and wind load simulators, and adjustable actuators to simulate these loads simultaneously.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple load simulation mechanisms are integrated into a single device, then simulation accuracy and versatility are improved, but device complexity increases

Engineering Contradiction:
Improveload simulation capabilityVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The load simulation device is divided into multiple independent cam sets, with each cam set responsible for simulating specific load types (gravity load, inertia load, wind load). Each cam set includes dedicated components such as gravity cam simulators with gravity weights, inertia cam simulators with inertia weights, and wind load cam simulators with spring mechanisms. This segmentation allows each module to be optimized independently while collectively providing comprehensive load simulation capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple cam sets are connected in series through a common input shaft and coupling mechanism, merging them into a single integrated load simulation device. The friction disk is connected to the tail ends of all cam sets through couplings, creating a unified structure that simultaneously simulates multiple load types. This merging approach consolidates what would otherwise be separate simulation devices into one coherent system.

Inventive Principle:
Principle #5Merging (Combining)

2Area of stationary object

If cam sets are connected in series through input shaft and couplings, then space requirements are reduced, but coupling complexity increases

Engineering Contradiction:
Improvedevice footprintVSAvoidcoupling structure
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

Multiple cam sets are connected in series through a common input shaft and coupling mechanism, merging them into a single integrated load simulation device. The friction disk is connected to the tail ends of all cam sets through couplings, creating a unified structure that simultaneously simulates multiple load types. This merging approach consolidates what would otherwise be separate simulation devices into one coherent system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cam sets are arranged in a nested configuration where each cam set is positioned within the spatial envelope of the overall device. The input shaft serves as a common backbone that accommodates multiple cam sets, and the couplings are integrated into the existing structural framework rather than adding external complexity. This nesting approach minimizes the overall footprint while maintaining modular functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Measurement precision

If friction disk is added to simulate friction load, then load simulation accuracy is improved, but device complexity increases

Engineering Contradiction:
Improveload simulation accuracyVSAvoidcomponent quantity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The friction disk serves multiple functions within the load simulation system. It is integrated into the series connection of cam sets and can simulate friction loads in addition to working in conjunction with the cam sets to simulate gravity, inertia, and wind loads. This multi-functionality reduces the need for separate dedicated friction simulation mechanisms, thereby limiting the increase in device complexity while improving simulation accuracy.

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

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

The simulator effectively reduces space requirements, allows adjustable load simulation, and can simulate sudden wind disturbances, providing accurate load simulation for aircraft cabin doors under various conditions.

Implementation Method 1

the gravity weight is connected to an outer circumferential side wall of the gravity cam with a steel wire rope, a corresponding torque is generated by a self-weight of the gravity weight

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

the inertia weight is connected to an outer circumferential side wall of the inertia cam with a steel wire rope, a corresponding torque is generated by a self-weight of the inertia weight

Methodology Applied
Scientific EffectInertia: Inertia

Implementation Method 3

a friction load is simulated by applying friction resistance on a disk surface of the friction disk

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

the wind load weight is connected to an outer circumferential side wall of the wind load cam through the spring

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP4202398B1CAM type airplane cabin door load simulation device and simulation method
Publication Date: 2025.11.05 BEIJING RES INST OF PRECISE MECHATRONICS CONTROLS
  • EP4202398B1 patent drawingFigure 1~2
  • EP4202398B1 patent drawingFigure 3~4
  • EP4202398B1 patent drawingFigure 5~6

AI summary

A cam type airplane cabin door load simulation device and simulation method. The device comprises n cam groups, an input shaft (7), 3n couplers (8), and a friction disc (41) load device; the n cam groups and the friction disc (41) load device are connected in series by means of the input shaft (7); 3n couplers (8) are provided on the input shaft (7); each cam group comprises a gravity cam simulation device (1), an inertia cam simulation device (2), and a wind load cam simulation device (3); and in each cam group, the gravity cam simulation device (1), the inertia cam simulation device (2), and the wind load cam simulation device (3) are sequentially connected in series by means of the input shaft (7), and the tail ends of the n cam groups are connected in series with the friction disc (41) load device by means of a coupler (8). According to the device, an airplane cabin door bears various loads such as a gravity load, an inertia load, a friction load, and a gust disturbance load at the same time