Ranging System Combining Stereo Parallax and Laser Radar

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Solution Overview

Problem

Conventional stereo ranging technologies combined with laser radar struggle to achieve high spatial resolution when scanning an entire capturing area, requiring low spatial resolution for the laser radar to scan within a frame cycle, which limits accurate distance calculation to ranging objects.

Innovation Solution

A ranging system that includes a stereo imaging unit and a laser radar ranging unit, where the laser radar determines a specific scanning area based on information processing, allowing it to measure distances with high spatial resolution by emitting pulsed laser light and adjusting its scanning area dynamically to coincide with the imaging unit's capturing area, thereby enhancing accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the laser radar scans the entire capturing area within a frame cycle, then the scanning coverage is complete, but the spatial resolution must be set low

Engineering Contradiction:
Improvescanning coverage areaVSAvoidspatial resolution
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The system performs preliminary actions by using the stereo imaging unit to capture images and calculate parallax distance information before the laser radar scanning. This preliminary distance information is used to generate distance map information that guides the laser radar to scan only specific regions of interest, thereby achieving high spatial resolution without requiring the laser radar to scan the entire capturing area within a frame cycle.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by making different parts of the scanning area have different functions. Instead of uniformly scanning the entire capturing area, the system identifies specific regions (such as regions with ranging objects or regions requiring high accuracy) and concentrates laser radar scanning resources on these local areas. This allows high spatial resolution to be achieved in critical regions while reducing overall scanning time and maintaining complete coverage of important areas.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If the laser radar spatial resolution is set high, then the distance measurement accuracy is improved, but the scanning time exceeds the frame cycle of the imaging unit

Engineering Contradiction:
Improvedistance measurement accuracyVSAvoidscanning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary parallax calculation using stereo images to obtain distance information before laser radar scanning. This preliminary action provides a foundation that reduces the need for the laser radar to scan all areas at high resolution, thereby reducing total scanning time while maintaining accuracy in critical regions through selective high-resolution scanning guided by the distance map.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies partial action by having the laser radar scan only specific regions of interest rather than the entire capturing area. The scanning regions are determined based on distance map information generated from stereo images, allowing the system to achieve high distance measurement accuracy in relevant areas without the time cost of scanning the complete area at the same resolution.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If the laser radar scans only specific regions, then the spatial resolution is high, but the scanning coverage may be incomplete

Engineering Contradiction:
Improvespatial resolutionVSAvoidscanning coverage
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The system performs preliminary scanning using the stereo imaging unit to capture images of the entire capturing area and calculate parallax distance information. This preliminary action ensures complete coverage of the capturing area is achieved through imaging, while the laser radar then focuses on specific regions with high spatial resolution based on the generated distance map, combining the benefits of both complete coverage and high resolution.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges the functions of the stereo imaging unit and the laser radar ranging unit. The stereo imaging unit provides complete area coverage through image capture, while the laser radar provides high-resolution distance measurement for specific regions. By combining the distance information from both sources and generating comprehensive ranging information, the system achieves both complete scanning coverage and high spatial resolution in critical areas.

Inventive Principle:
Principle #5Merging (Combining)

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

The system generates ranging information with high spatial resolution by combining parallax calculation distance information from stereo images with laser distance information, effectively improving distance measurement accuracy, especially for challenging areas like road surfaces covered with snow or shadows.

Implementation Method 1

a laser radar ranging unit (120) that measures a distance to a ranging object by emitting pulsed laser light

Methodology Applied
Scientific EffectTime of Flight: Time of Flight

Implementation Method 2

laser radar ranging technology

Methodology Applied
Scientific EffectLIDAR: LIDAR

Implementation Method 3

captured images (stereo images) captured by using plural imaging units

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2927710B1Ranging system, information processing method and program thereof
Publication Date: 2019.06.12 RICOH CO LTD
  • EP2927710B1 patent drawingFigure 1
  • EP2927710B1 patent drawingFigure 2A~2B
  • EP2927710B1 patent drawingFigure 3

AI summary

A ranging system for measuring a distance to an object imaged on a captured image, includes a region extraction unit configured to extract a first region and a second region other than the first region from the captured image, on the first region a first object being imaged and on the second region a second object being imaged; a first measurement unit configured to measure a distance to the first object based on a reflected electromagnetic wave reflected at the first object; and a second measurement unit configured to measure a distance to the second object by performing a parallax calculation based on an imaged position of the second object in the captured image.