Groundless Robotic Interface Alignment Through Decoupled Motion Control

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Solution Overview

Problem

Existing hyperdexterous robotic systems face challenges in aligning master control devices with slave systems when operated in free space, leading to misalignment issues that affect the precision and ease of use during surgical procedures, as they lack the physical constraints of grounded devices which force specific orientations and positions.

Innovation Solution

The system employs groundless user interface devices (UIDs) that allow operators to control robotic tools from any position, with features like decoupling and scaling of motion components, anisotropic scaling, and a defined center of workspace to maintain alignment and orientation, enabling the slave control to follow the master even when misaligned, and transforming natural operator movements into specific robotic tool movements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If groundless user interface devices are used to allow free-space operation, then operator flexibility and comfort are improved, but alignment and orientation between master control and slave system deteriorate

Engineering Contradiction:
Improveoperator flexibilityVSAvoidalignment precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system continuously tracks the position and orientation of both the groundless UID and the robotic tool, comparing their coordinate frames in real-time. This feedback mechanism allows the system to detect misalignment and apply corrective transformations to maintain proper correspondence between master control movements and slave system responses.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts transformation parameters including translation vectors and rotation matrices to compensate for misalignment. By modifying these coordinate frame parameters in real-time, the system maintains accurate mapping between the UID frame and tool frame even when the operator moves freely in space.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If motion components are decoupled and processed independently, then control precision is improved, but system complexity increases

Engineering Contradiction:
Improvecontrol precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The motion control is segmented into independent degree of freedom components, with each DOF processed separately through its own transformation and scaling operations. This segmentation allows precise control of each motion component while using modular processing blocks that manage complexity through systematic decomposition.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies dynamic scaling factors to different motion components based on the current operational state. Anisotropic scaling adjusts the magnitude of motion in different directions independently, allowing adaptive control precision without requiring complex static structures.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If anisotropic scaling is applied to motion components, then operational precision is improved, but computational requirements increase

Engineering Contradiction:
Improveoperational precisionVSAvoidcomputational power
Core Design Contradiction:
Manufacturing precisionVSPower

Solution Approach 1:

Anisotropic scaling applies different scaling factors to different spatial directions (local qualities) based on the specific operational context. Rather than uniform scaling, the system adjusts scaling along each axis independently according to the current pose and task requirements, optimizing precision where needed while reducing computational overhead elsewhere.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3262469B1Hyperdexterous system user interface
Publication Date: 2023.11.22 SRI INTERNATIONAL
  • EP3262469B1 patent drawingFigure 1
  • EP3262469B1 patent drawingFigure 2
  • EP3262469B1 patent drawingFigure 3

AI summary

Systems and methods for embodiments of a hyperdexterous robotic system using groundless user input devices (UIDs). In some embodiments, the hyperdexterous system allows for the slave control to follow the master control even when the two are misaligned. The motion of the master control occurring in multiple degrees of freedom may be decoupled into its component parts and processed differently. Each degree of freedom may be processed independently and scaled differently. For example, in some embodiments, only the roll motion of the groundless user interface device is transferred, in some embodiments, the master slave control is only allowed when the master and slave are within a certain region of each other.