Robot Cleaner Light Pattern Filtering for Reflection-Free Mapping
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Solution Overview
Problem
Robot cleaners face challenges in distinguishing between light patterns generated by direct projection and those reflected from surfaces, which affects their ability to accurately map and navigate cleaning areas.
Innovation Solution
The robot cleaner employs a pattern projection unit and an image acquisition unit to project light patterns and capture images, using geometrical analysis to differentiate between valid and reflected light patterns, allowing for accurate obstacle detection and navigation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If light is projected to the floor to recognize cleaning area state, then the robot can map the environment, but reflected light creates false patterns that reduce measurement precision
Solution Approach 1:
The patent segments the light pattern detection process into multiple analysis steps: detecting the projected light pattern, identifying reflected light patterns, and separately processing valid versus invalid patterns. This segmentation allows the system to distinguish between direct and reflected light, resolving the measurement precision issue caused by reflection interference.
Solution Approach 2:
The patent introduces geometric relationship analysis as an intermediary mechanism to determine whether detected light patterns are valid or reflected. By analyzing the spatial and geometric characteristics of detected patterns against the known projection geometry, the system can filter out false patterns caused by reflection, thereby improving measurement precision.
2Reliability
If the robot uses camera to photograph light patterns for navigation, then it can detect obstacles, but reflected light patterns cause false obstacle detection
Solution Approach 1:
The patent implements a feedback mechanism where the detected light patterns are validated against geometric constraints before being used for obstacle detection. The system continuously compares detected pattern positions and characteristics with expected geometric relationships, providing feedback to filter out false patterns from reflections, thus improving obstacle detection reliability.
Solution Approach 2:
The patent changes the parameters used for pattern validation by incorporating geometric relationship criteria into the detection process. Instead of relying solely on pattern intensity or position, the system evaluates multiple parameters including angular relationships and spatial consistency, which helps distinguish true obstacle patterns from reflected light patterns, reducing false detections.
3Productivity
If the robot cleaner projects light in a predetermined pattern, then it can map the cleaning area, but materials that reflect light generate additional patterns that complicate analysis
Solution Approach 1:
The patent applies preliminary action by pre-establishing the geometric relationship model between the light source, camera, and expected floor patterns before actual detection begins. This pre-computed geometric framework is then used to quickly validate detected patterns, allowing efficient discrimination between valid and reflected patterns without adding complex real-time analysis, thus maintaining productivity while managing complexity.
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 method enables the robot cleaner to effectively discriminate between direct and reflected light patterns, enhancing its ability to map the environment and avoid obstacles, thereby improving its cleaning efficiency and navigation accuracy.
Implementation Method 1
a pattern projection unit for projecting light in a predetermined pattern toward a floor of an area in front of the main body of the robot cleaner
Implementation Method 2
Since some materials of floors or objects to which light is projected reflect the light, a new light pattern due to reflection can be detected
Data Source
AI summary
A method for controlling a robot cleaner configured to project light of a predetermined pattern to a floor of an area in front thereof in a specific direction and to acquire an image of the area to which the light is projected, according to the present disclosure, includes: (a) acquiring a front view image of the robot cleaner; (b) detecting the pattern from the image acquired in (a); and (c) discriminating a pattern formed by reflected light from a pattern formed by light directly projected from the robot cleaner, from among patterns indicated in the acquired image, on the basis of geometrical characteristics defined by a projection direction of the light and the direction of an optical axis in which the image is acquired when two or more patterns are detected from the image.