Gravity Compensation Device for Robot End Effector Flange

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Solution Overview

Problem

Existing automated handling systems with gravity-compensating devices face challenges in efficiently moving heavy loads without interfering with the robot's movement, as the large interfering contours of the object holder and gravity compensation device require redesign for each task, limiting the robot's ability to perform standard tasks without adjustments.

Innovation Solution

The system attaches the load body to a load-body holding means connected to the robot's end effector flange, with the gravity-compensation device acting on the robot's end effector flange, allowing the robot to maneuver the load body in six degrees of freedom while minimizing interfering contours, and using a mechanical articulated arrangement with passive movement to compensate for gravity and dynamic forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the gravity compensation device is directly connected to the load body, then the robot arm can be relieved of the load weight, but the large interfering contours of the object holder and gravity compensation device require redesign for each task

Engineering Contradiction:
Improveload weightVSAvoidsystem configuration
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary connection structure where the gravity compensation device connects to the robot's end effector flange rather than directly to the load body. This intermediary connection point (the flange) allows the gravity compensation to function while minimizing interfering contours, as the connection is made at the robot's existing interface rather than requiring a separate object holder structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Speed

If the gravity compensation device is coupled to a limb of the robot, then the load body can be moved with reduced dynamics, but the limbs and joints between the connection member and load body must support the load weight and inertial forces

Engineering Contradiction:
Improvemovement speedVSAvoidforce on limbs
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The patent extracts the gravity compensation function from the robot's limb structure and places it at the end effector flange. This separation allows the gravity compensation device to counteract the load weight independently, so the robot limbs only need to handle inertial forces and positioning, not the full load weight, enabling faster movement with reduced force requirements on the limbs.

Inventive Principle:
Principle #2Taking out (Extraction)

3Weight of moving object

If the robot is designed to carry heavy loads completely, then the load body can be moved without external assistance, but the robot's payload capacity and speed are reduced

Engineering Contradiction:
Improveload carrying capacityVSAvoidrobot movement speed
Core Design Contradiction:
Weight of moving objectVSSpeed

Solution Approach 1:

The patent employs an anti-weight mechanism through the gravity compensation device that actively counteracts the load weight by applying an opposing force. This allows the robot to move heavy loads at higher speeds because the robot arm only needs to overcome inertial forces and positioning requirements, not the full gravitational force, effectively decoupling payload capacity from movement speed.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

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

This configuration enables the robot to move heavy loads with reduced dynamics, supporting standard tasks without needing adjustments, while minimizing collision risks and maintaining flexibility in movement options, thus enhancing the robot's ability to handle various assembly tasks efficiently.

Implementation Method 1

the gravity-compensating device is provided with a connection member on the load side... the gravity-compensation device then being attached to the robot... the load body is carried predominantly, in particular at least largely or completely, by the gravity compensation device

Methodology Applied
Scientific EffectGravity compensation: Gravitation

Data Source

PatentEP2508308B1Method and handling system for automated movement of a gravity-compensated load
Publication Date: 2015.08.26 KUKA DEUT GMBH
  • EP2508308B1 patent drawingFigure 1
  • EP2508308B1 patent drawingFigure 2
  • EP2508308B1 patent drawingFigure 3

AI summary

The invention relates to a method for the automated movement of a gravity-compensated load body (6), in which the load body (6) is supported by a load body holding device (3) which is connected to an end effector flange (2) of a robot (1) for the automated movement of the load body (6), wherein a gravity compensation device (9) is provided which has a connecting element (17) which engages a link (7, 7a) or the end effector flange (2) of the robot (1) for gravity compensation of the load body (6).The invention also relates to an automated handling system comprising a gravity compensation device (9) for a load body (6), which is provided on the load side with a connecting element (17), a load body holding means (3) and a robot (1) for automatically moving the gravity-compensated load body (6), which robot (1) has an end effector flange (2), wherein the connecting element (17) of the gravity compensation device (9) is connected by means of a joint coupling (21) to a link (7, 7a) or the end effector flange (2) of the robot (1).