3D Fork Slot Position Estimation for Tilted Forklift Cameras

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing forklift systems face inaccuracies in inserting forks into pallet slots due to camera tilt, leading to improper positioning.

Innovation Solution

An information processing apparatus that includes a detection unit to identify fork insertion slots and forks, an acquisition unit to capture depth information, a correction unit to refine depth data, and a position estimation unit to accurately estimate three-dimensional positions using edge detection and depth images.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a camera is mounted on the forklift to detect pallet position, then the forklift can operate autonomously, but the position detection accuracy deteriorates when the camera is tilted

Engineering Contradiction:
Improveautonomous operationVSAvoidpallet position detection accuracy
Core Design Contradiction:
Extent of automationVSMeasurement precision

Solution Approach 1:

The system changes the parameter representation from 2D image coordinates to 3D spatial coordinates by incorporating depth information. The conversion unit transforms the detected 2D pallet position into 3D position data, accounting for camera tilt and depth variations, thereby maintaining measurement precision regardless of camera mounting orientation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention transitions from two-dimensional image plane detection to three-dimensional spatial position detection. By adding the depth dimension through depth image processing and coordinate transformation, the system accurately determines pallet position in 3D space even when the camera is tilted, resolving the contradiction between autonomous operation capability and position detection accuracy

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If only two-dimensional images are used for position detection, then the system complexity is reduced, but the three-dimensional position estimation accuracy deteriorates

Engineering Contradiction:
Improvedetection system complexityVSAvoidthree-dimensional position estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system merges 2D image data from the camera with 3D depth data from the depth sensor to create accurate three-dimensional position estimates. The conversion unit integrates information from both 2D images and depth images, combining the simplicity of 2D detection with the accuracy of 3D measurement without requiring complex standalone 3D detection hardware

Inventive Principle:
Principle #5Merging (Combining)

3Loss of time

If depth information is not corrected, then the processing time is reduced, but the shape recognition accuracy in depth images deteriorates

Engineering Contradiction:
Improveprocessing timeVSAvoidshape recognition accuracy
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The system performs preliminary correction of depth information using the detected 2D shape data before final 3D position estimation. The conversion unit pre-adjusts the depth values based on the known 2D shape characteristics, so that when depth images are displayed or processed further, the shapes are already recognized with high accuracy, reducing the need for additional complex processing steps

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS12493974B2Information processing apparatus, three-dimensional position estimation method, and a non-transitory computer-readable medium
Publication Date: 2025.12.09 NEC CORP
  • US12493974B2 patent drawing
  • US12493974B2 patent drawing
  • US12493974B2 patent drawing

AI summary

An information processing apparatus (10) includes: a detection unit (11) configured to detect, using an image and forks for supporting the transport pallet are captured, a shape of fork insertion slots into which the forks are inserted and a shape of the forks; an acquisition unit (12) configured to acquire a depth image showing depth information of the fork insertion slots and depth information of the forks in the image; a correction unit (13) configured to correct, using the shape of the fork insertion slots and the shape of the forks that are detected, the depth information so that the shape of the fork insertion slots and the shape of the forks can be recognized in the depth image; and a position estimation unit (14) configured to estimate three-dimensional positions of the fork insertion slots and three-dimensional positions of the forks based on the depth information.