Robot Cleaner Multi-Sensor Lifting Detection to Reduce User Injury
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Solution Overview
Problem
Existing robot cleaners struggle to accurately detect when they are lifted from the floor surface, leading to potential user injuries and erroneous operation states.
Innovation Solution
A robot cleaner equipped with a sensor part that includes a tilt sensor module, a distance sensor module, and a light amount sensor module, which work in conjunction with a controller to calculate operation information and determine whether the robot cleaner is lifted, thereby controlling the power module accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring-connected wheel structure is used to detect lifting, then the robot can detect whether it is lifted, but the structure cannot be applied to robot cleaners that drive by mop rotation without separate wheels
Solution Approach 1:
The patent replaces the mechanical spring-connected wheel detection system with an optical sensing system. A light source emits light toward the floor, and a sensor detects the reflected light amount. When the robot is lifted, the light reflection pattern changes, providing electrical signals that indicate lifting state without requiring mechanical contact components like wheels or springs.
Solution Approach 2:
The patent introduces light as an intermediary medium between the robot body and the floor surface. Instead of direct mechanical contact detection, the light reflects off the floor surface and carries information about the robot's position and lifting state to the sensor, enabling indirect detection that works with the mop-driven structure.
2Measurement precision
If a cliff sensor is used to detect distance from the floor surface, then the robot can determine lifting state, but shaking during start/stop or foreign matter between mop and floor causes erroneous detection
Solution Approach 1:
The patent employs feedback mechanisms where the sensor continuously monitors light reflection patterns and the controller compares current readings with reference values. When the robot shakes or foreign matter is detected, the system can identify these as transient anomalies rather than true lifting events by analyzing the consistency and duration of the signal changes, reducing false positives.
Solution Approach 2:
The patent changes the detection parameter from direct distance measurement (which is sensitive to shaking) to light reflection amount analysis. By measuring the intensity and pattern of reflected light rather than physical distance, the system becomes less sensitive to transient vibrations and more reliable in distinguishing actual lifting from normal operation variations.
3Productivity
If the robot continues to rotate the mop when lifted, then the unified driving and cleaning operation is maintained, but user injury may occur from rotating mops
Solution Approach 1:
The patent implements preliminary anti-action by detecting the lifting state before the rotating mop can cause injury. The optical sensor and controller continuously monitor for lifting conditions, and when detected, immediately send stop commands to the power module, preventing the harmful effect of rotating mops contacting user skin before the injury can occur.
Solution Approach 2:
The system takes preliminary action by establishing a detection-control loop that identifies lifting events and triggers mop rotation cessation in advance of any potential harm. The controller is pre-programmed to recognize lifting patterns and automatically execute the safety stop sequence, preventing the need for user intervention.
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 solution significantly improves the accuracy of detecting when the robot cleaner is lifted, reducing the risk of user injury and preventing erroneous operation states.
Implementation Method 1
a tilt sensor module configured to detect tilt information of the body part
Implementation Method 2
a distance sensor module configured to detect distance information from a floor surface on which the body part drives
Implementation Method 3
a light amount sensor module configured to detect light amount information reflected from the floor surface
Data Source
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AI summary
A robot cleaner and a control method thereof are disclosed. A robot cleaner, according to an embodiment of the present invention, comprises: a tilt sensor module; a distance sensor module; and a light amount sensor module. Each piece of sensed information is transmitted to a lifting information calculation module. The lifting information calculation module calculates information on whether the robot cleaner is lifted, by using each piece of the transmitted information. If it is calculated that the robot cleaner is lifted off a floor, a power module is stopped. In addition, if it is calculated that the robot cleaner is not lifted off the floor, the power module is driven. Accordingly, when a user lifts the robot cleaner, injuries to the user caused by operation of a drive module can be prevented.