Additional Actuator for Fine Positioning in Low-Accuracy Robot Systems

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Solution Overview

Problem

Current robot systems, especially those with low path accuracy, face challenges in achieving high positioning precision during material processing, limiting their effectiveness in precision machining tasks.

Innovation Solution

A method and device that utilize an additional actuator with higher positioning accuracy at the end link of a kinematic chain, coupled with sensors to record and compensate for deviations from a target trajectory, allowing for precise fine positioning independent of the handling device's path accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a simple robot system with low path accuracy is used, then device complexity and cost are reduced, but positioning accuracy deteriorates

Engineering Contradiction:
Improvecost-effectivenessVSAvoidpositioning accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The positioning system is segmented into two independent parts: a handling device for rough positioning and an additional actuator for fine positioning. This allows the use of a simple, low-cost robot for the rough positioning task while a precise actuator handles the fine positioning, thus resolving the contradiction between cost-effectiveness and positioning accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An additional actuator is introduced as an intermediary between the robot and the tool. This intermediary component compensates for the path inaccuracies of the simple robot system, enabling high positioning accuracy to be achieved despite the low accuracy of the underlying robot system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If additional actuators and sensors are added for fine positioning, then positioning accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsystem complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The additional actuator is designed to perform multiple functions: it provides fine positioning in one or more dimensions, compensates for robot path inaccuracies, and works with existing sensors for trajectory tracking. This multi-functionality justifies the added complexity by delivering comprehensive positioning improvement.

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

Solution Approach 2:

Sensors record the actual trajectory of the end link or tool, and this feedback information is used to calculate deviations from the target trajectory. The additional actuator then compensates for these deviations in real-time, creating a closed-loop control system that achieves high positioning accuracy.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If high path accuracy is required from the handling device, then positioning accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvepath accuracyVSAvoidrobot system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The positioning task is divided into rough positioning (handled by the simple robot) and fine positioning (handled by the additional actuator). This segmentation allows the robot to operate at lower accuracy levels, reducing its complexity and cost, while the additional actuator provides the necessary fine positioning capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention converts the low path accuracy of simple robot systems from a disadvantage into a benefit by using sensors to detect the actual trajectory and using an additional actuator to compensate for deviations. This approach allows the use of simpler, more cost-effective robot systems while achieving high positioning accuracy.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP2091699B1Method and device for fine-positioning a tool having a handling device
Publication Date: 2014.04.16 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP2091699B1 patent drawingFigure 1~9
  • EP2091699B1 patent drawingFigure 2~3
  • EP2091699B1 patent drawingFigure 4~5

AI summary

The present invention relates to a method and a device for machining an object by means of a tool, wherein the tool (2) or the object (18) is guided with a handling device, which has multiple axes of movement for the rough positioning of the tool (2) or object (18) forming a kinematic chain. According to the method, an additional actuator (3) is inserted between an end link (1) of the kinematic chain and the tool (2) or object (18), the actuator having greater actuating accuracy than the other axes of movement in at least one dimension or axis. At least one sensor (5) is used to detect a relative movement of the tool (2) or end link (1) of the kinematic chain to the object (18), and any deviation from a target path of movement is compensated for by means of the additional actuator (3). The method and the associated device enable the use of robots or other handling devices having low path accuracy for applications requiring high precision in guiding the tool.