Rotatable Tool Holder Sensor Feedback for Grinding Compliance

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Solution Overview

Problem

Existing grinding processes are labor-intensive and require complex, costly active impedance control systems to adapt to the irregular surfaces of workpieces, making them difficult to automate.

Innovation Solution

A grinding device with a rotatable tool holder and sensor system, such as a rotary encoder, that converts angular position into a control signal to adjust the multi-axis manipulator, allowing passive compliance with the workpiece contour, reducing complexity and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If active impedance control means (vision, force sensors, torque sensors) are used to achieve active compliance, then the ability to adaptively control the grinding tool path relative to the workpiece is improved, but the device complexity and cost increase significantly

Engineering Contradiction:
Improveactive complianceVSAvoidimpedance control means
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the complex active impedance control means (vision systems, force sensors, torque sensors) from the robotic manipulator, replacing them with a simple passive compliance mechanism through the rotatable tool holder that naturally adapts to workpiece contours without active control

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The tool holder is designed to automatically and passively follow the workpiece contour through its own rotational movement about the pivot axis, without requiring external sensing or active control systems to dictate its position

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If complex impedance control programming is implemented to obtain reasonable compliance, then the adaptability to workpiece irregularities is improved, but the programming complexity and operational difficulty increase

Engineering Contradiction:
ImprovecomplianceVSAvoidprogramming complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system eliminates the need for complex compliance programming by using a mechanically passive tool holder that automatically adapts to workpiece contours through its rotational degree of freedom, making the system as easy to operate as conventional fixed-position grinding

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If the tool holder is made freely rotatable about the pivot axis, then the ability to passively follow workpiece contour is improved, but the control precision of grinding angle may deteriorate

Engineering Contradiction:
Improvepassive complianceVSAvoidgrinding angle control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention introduces a sensor on the rotatable tool holder that provides feedback on the actual grinding angle or tool holder position, allowing the control system to maintain precise grinding angle control while preserving the passive compliance benefit of free rotation

Inventive Principle:
Principle #23Feedback

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

Enables efficient, automated grinding by passively following the workpiece contour with reduced complexity and cost, maintaining a constant grinding angle despite irregularities, thus improving process efficiency.

Implementation Method 1

a sensor for converting at least one parameter indicative of an angular position of the tool holder about the pivot axis into an output signal that can be used for determining a control signal for controlling the multi-axis manipulator

Methodology Applied
Scientific EffectAngular position sensing:

Data Source

PatentEP4106947B1Grinding or polishing device and method for treating of a workpiece
Publication Date: 2026.04.15 TOLLENAAR IND BV
  • EP4106947B1 patent drawingFigure 1
  • EP4106947B1 patent drawingFigure 2~3
  • EP4106947B1 patent drawingFigure 4~6

AI summary

The invention relates to a grinding or polishing device and a method for treating a workpiece, wherein the grinding or polishing device comprises a tool holder for holding a grinding or polishing tool and a mounting head for mounting the tool holder to a multi-axis manipulator, 5 wherein the tool holder is rotatable with respect to the mounting head about a pivot axis, wherein the grinding or polishing device further comprises a sensor for converting at least one parameter indicative of an angular position of the tool holder about the pivot axis into an output signal 10 that can be used for determining a control signal for controlling the multi-axis manipulator.