Gripper Sequence Planning for Irregular Case Depalletizing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional grippers struggle to depalletize transfer cases with irregularly stacked orientations due to the inability to access the top surface, leading to unpredictable gripping sequences and failure in picking up cases.

Innovation Solution

A method for determining a gripping sequence that involves obtaining finger geometry and case layout, detecting overlaps with neighbor cases, and selecting a pickable case based on these overlaps to allow the gripper to successively depalletize the case stack.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the gripper attempts to grip transfer cases with irregular stacking orientations, then the gripper may be able to access more cases, but the gripping sequence becomes unpredictable and gripping fails

Engineering Contradiction:

Improvegripper access capabilityVSAvoidgripping success rate

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system performs preliminary analysis of the case layer layout and finger geometry to determine grip areas and detect overlaps before the gripping operation. This advance planning identifies pickable cases and establishes a reliable gripping sequence, ensuring the gripper can successfully access cases with irregular orientations without unpredictable failures

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The method enables the system to automatically determine the gripping sequence by analyzing the layout and detecting overlaps independently. The system self-adapts to irregular case orientations by computing which cases are pickable based on finger geometry and overlap detection, making the gripping process reliable without external intervention

Inventive Principle:

Principle #25Self-service

2Ease of operation

If the gripper needs to access sidewalls of cases for gripping, then the grip area must be sufficiently wide, but this increases the complexity of determining pickable cases

Engineering Contradiction:

Improvegripper access to sidewallsVSAvoidgrip area determination complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The method segments the case layer into individual cases and determines grip areas for each case separately based on finger geometry. By analyzing each case's grip area independently and detecting overlaps with neighbor cases, the system simplifies the determination of pickable cases while ensuring sufficient access to sidewalls

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The concept of grip area serves as an intermediary between the gripper's physical constraints and the case layout. By introducing this intermediate representation and detecting overlaps, the system translates the complexity of sidewall access requirements into a manageable analysis of pickable cases based on geometric relationships

Inventive Principle:

Principle #24Intermediary (Mediator)

3Quantity of substance

If cases are irregularly placed in the case layer, then more cases can be stacked, but the gripping sequence determination becomes more difficult

Engineering Contradiction:

Improvenumber of cases in case layerVSAvoidgripping sequence determination difficulty

Core Design Contradiction:

Quantity of substanceVSDifficulty of detecting and measuring

Solution Approach 1:

The system automatically adapts to irregular case placements by analyzing the actual layout and finger geometry to determine grip areas and detect overlaps. This self-service approach computes the gripping sequence directly from the given configuration without requiring cases to be in standard positions, making the process straightforward regardless of case quantity or arrangement

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The method changes the analysis parameters from assuming fixed case orientations to analyzing actual case positions and orientations in the layout. By computing grip areas based on finger geometry and detecting overlaps with neighbor cases, the system determines pickable cases based on actual geometric relationships rather than predetermined patterns

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20260001230A1Method for determining gripping sequence controller, and computer readable storage medium

Publication Date: 2026.01.01 ABB (SCHWEIZ) AG

AI summary

Embodiments of present disclosure relate to a method of determining a gripping sequence of cases in a case stack for a gripper. The method includes obtaining at least one finger geometry of the plurality of fingers. The method includes determining a layout for a case layer of the case stack. The method includes determining a grip area for each case in the case layer and based on the layout and the at least one finger geometry. The grip area is dimensioned to allow the plurality of fingers to grip the sidewalls in the grip area; detecting overlaps of the grip area of each case with neighbor cases of each case. The method includes determining the gripping sequence for the case layer based on the detected overlaps. In this way, the gripping sequence can be automatically determined to allow the gripper to depalletize the case stack successively.