Link Hub Posture Control Without Convergence Calculations

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing link actuation devices face difficulties in intuitive manipulation due to the need to transform rectangular coordinates into angular coordinates for controlling the posture of the link hub, requiring convergence operations that are time-consuming and complex.

Innovation Solution

A manipulating device that acquires the distal end posture in an angular coordinate system by projecting the spherical link center onto a two-dimensional rectangular coordinate system, allowing for easy teaching of a target posture and input transformation without convergence operations, using a posture acquirer to calculate bending and turning angles from projected coordinates and setting relay points to facilitate smooth and high-speed movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If rectangular coordinates are used for teaching target posture, then intuitive manipulation is improved, but transformation to angular coordinates requires time-consuming convergence operations

Engineering Contradiction:

Improveintuitive manipulationVSAvoidcalculation time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

Instead of transforming from rectangular coordinates to angular coordinates through convergence operations, the patent inverts the approach by directly calculating angular coordinates (bending angle and turning angle) from the rectangular coordinates of the spherical link center projection. This eliminates the need for iterative convergence operations while maintaining intuitive rectangular coordinate input.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces the mechanical convergence operation system with a direct mathematical calculation system. By projecting the spherical link center onto a two-dimensional rectangular coordinate system and directly computing the angular coordinates from the projection coordinates, the time-consuming iterative mechanical process is substituted with efficient mathematical computation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If convergence operations are used for coordinate transformation, then accurate posture control is achieved, but calculation complexity and time increase

Engineering Contradiction:

Improveposture control accuracyVSAvoidcalculation complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential geometric relationship from the complex convergence operation process. By focusing on the projection of the spherical link center onto the two-dimensional rectangular coordinate system and directly calculating the angular coordinates from this projection, the patent removes the unnecessary complexity of iterative convergence operations while preserving the accuracy of posture control.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the computational parameters from iterative convergence operations to direct mathematical calculation parameters. By using the rectangular coordinates of the spherical link center projection as input parameters and directly computing the bending angle and turning angle through mathematical formulas, the patent simplifies the calculation process while maintaining precision.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If direct angular coordinate input is required, then control precision is maintained, but ease of operation decreases due to transformation requirements

Engineering Contradiction:

Improvecontrol precisionVSAvoidoperation simplicity

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent introduces the projection of the spherical link center onto the two-dimensional rectangular coordinate system as an intermediary. This intermediary allows operators to input intuitive rectangular coordinates while the system automatically computes the required angular coordinates, thus maintaining control precision without requiring operators to directly manipulate angular coordinates.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11154983B2Link actuation device manipulating device and link actuation system

Publication Date: 2021.10.26 NTN CORP

AI summary

In a link actuation device, a distal end side link hub is coupled to a proximal end side link hub via three or more link mechanisms such that a posture of the distal end side link hub can be changed relative to the proximal end side link hub, and a posture of the distal end side link hub relative to the proximal end side link hub is arbitrarily changed by actuators provided to two or more link mechanisms. The manipulating device includes a posture acquirer for acquiring a distal end posture represented by a bending angle and a turning angle, from a coordinate position at which a distal end side spherical link center is projected onto a two-dimensional rectangular coordinate system that has an origin located on an extension of an axis of the proximal end side link hub and is orthogonal to the extension of the axis.