Robotic Cleaner Line Array Sensor for Low-Cost Obstacle Detection

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Solution Overview

Problem

Existing robotic vacuum cleaners rely on expensive 3D sensors like time-of-flight cameras for navigation and obstacle detection, which increases costs and limits affordability.

Innovation Solution

A robotic cleaning device equipped with a combination of a close-range wide light source, a long-range narrow light source, and a low-resolution line array sensor, using these light sources to detect objects and navigate surfaces by emitting light beams and measuring their reflections to compute object positions and generate 3D representations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If advanced 3D sensors such as time-of-flight cameras are used for navigation and obstacle detection, then navigation accuracy and obstacle detection capability are improved, but device cost increases significantly

Engineering Contradiction:

Improveobstacle detection capabilityVSAvoiddevice cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent divides the sensing function into multiple segments: a first light source (LED) for close-range wide-area detection, a second light source (laser) for long-range narrow-beam detection, and a line array sensor for depth measurement. This segmentation allows each component to be optimized for its specific function, replacing the need for expensive 3D sensors while maintaining overall system performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent combines multiple light sources with different characteristics (LED for wide coverage, laser for precision) with a line array sensor to create a composite sensing system. This merging of simple, inexpensive components achieves the functional equivalence of complex 3D sensors at a lower cost.

Inventive Principle:

Principle #5Merging (Combining)

2Ease of manufacture

If a low-resolution line array sensor is used instead of a 3D sensor, then device cost is reduced, but measurement precision and navigation accuracy deteriorate

Engineering Contradiction:

Improvedevice costVSAvoidnavigation accuracy

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent introduces light sources as intermediaries between the robot and the environment. By actively illuminating the scene with structured light patterns (wide beam from LED, narrow beam from laser) and using the line array sensor to capture reflected light, the system creates artificial depth cues that compensate for the sensor's low resolution, enabling accurate navigation without requiring high-resolution hardware.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system uses periodic emission of light from multiple sources with different temporal characteristics. The LED provides continuous wide illumination while the laser emits periodic narrow beams, creating a temporal pattern that the line array sensor can distinguish. This periodic action allows the low-resolution sensor to capture sufficient information for accurate depth measurement and navigation.

Inventive Principle:

Principle #19Periodic action

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

Enables effective navigation and obstacle detection while reducing costs by using a lower-resolution sensor array, allowing for affordable and efficient object detection and surface mapping.

Implementation Method 1

an array sensor configured to detect light reflected from one or more of the light sources to detect illuminated objects from which said light is reflected

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 2

a controller configured to control the light sources to emit light, one light source at a time, and to compute time-of-flight of the light emitted from the respective light source and being reflected onto the array sensor

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Data Source

PatentUS20220299650A1Detecting objects using a line array

Publication Date: 2022.09.22 AB ELECTROLUX

AI summary

A robotic cleaning device configured to detect objects as the robotic cleaning device moves over a surface to be cleaned. The robotic cleaning device has a first light source configured to produce a close range wide light beam in front of the robotic cleaning device, a second light source configured to produce a long range vertically-narrow light beam in front of the robotic cleaning device, and an array sensor configured to detect light reflected from one or more of the light sources to detect illuminated objects from which said light is reflected.