Hexapod Motion Simulator with Supplementary Roll Pitch Actuation

Solution Overview

Problem

Motion simulators face a trade-off between achieving large excursion in rotational degrees of freedom and maintaining stiffness and cost-effectiveness, as longer actuators increase expense and decrease stiffness, making them unsuitable for applications requiring high movement in roll and pitch degrees of freedom.

Innovation Solution

A motion simulator design that incorporates a hexapod for global six degrees of freedom movement, supplemented by a supplementary actuation assembly with universal joints and parallel manipulators to enhance movement range and stiffness, using shorter actuators to reduce cost and maintain stiffness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If longer hexapod actuators are used to achieve larger platform excursion, then the workspace is improved, but the cost increases significantly and stiffness decreases

Engineering Contradiction:

ImproveworkspaceVSAvoidstiffness

Core Design Contradiction:

Volume of moving objectVSStrength

Solution Approach 1:

The motion simulator is divided into two functional segments: a hexapod base providing six degrees of freedom with standard-length actuators, and a supplementary actuation assembly providing additional rotational degrees of freedom. This segmentation allows each component to use appropriately sized actuators, avoiding the need for excessively long hexapod actuators while maintaining stiffness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An intermediate platform is introduced between the hexapod and the final motion platform. The hexapod moves this intermediate platform, which then serves as a base for the supplementary actuation assembly. This intermediary structure enables the system to achieve large excursions through the supplementary assembly rather than requiring long hexapod actuators.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Volume of moving object

If longer hexapod actuators are used to achieve larger platform excursion, then the workspace is improved, but the cost increases significantly

Engineering Contradiction:

ImproveworkspaceVSAvoidcost

Core Design Contradiction:

Volume of moving objectVSEase of manufacture

Solution Approach 1:

The motion simulator is divided into two functional segments: a hexapod base providing six degrees of freedom with standard-length actuators, and a supplementary actuation assembly providing additional rotational degrees of freedom. This segmentation allows each component to use appropriately sized actuators, avoiding the need for excessively long hexapod actuators while maintaining stiffness.

Inventive Principle:

Principle #1Segmentation

3Length of moving object

If a hexapod is designed for large excursion in roll and pitch, then the movement range is improved, but the device complexity increases due to requiring longer actuators

Engineering Contradiction:

Improvemovement rangeVSAvoidactuator configuration

Core Design Contradiction:

Length of moving objectVSDevice complexity

Solution Approach 1:

The motion simulator is divided into two functional segments: a hexapod base providing six degrees of freedom with standard-length actuators, and a supplementary actuation assembly providing additional rotational degrees of freedom. This segmentation allows each component to use appropriately sized actuators, avoiding the need for excessively long hexapod actuators while maintaining stiffness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The supplementary actuation assembly uses universal joints that can accommodate multiple rotational degrees of freedom (roll and pitch) with a single joint mechanism. This multi-functionality reduces the overall complexity compared to using six long actuators in the hexapod to achieve the same effect.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10699591B2Motion simulator

Publication Date: 2020.06.30 MOOG BV

AI summary

A motion simulator is constructed from a base driving an intermediate member via a 6 DOF hexapod, and a platform driven by a 2 DOF simulator is provided on the intermediate member to supplement pitch and roll.