Proximity Sensor Modulated Signal Anti-Fall Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current self-propelled cleaning robots face issues with misjudging falling events due to interference from ground colors and ambient light sources, leading to malfunctions, especially when moving on black floors, as their anti-falling detection systems rely on infrared sensing and complex amplifying filter circuits.
Innovation Solution
A proximity sensing method and apparatus that involves transmitting an encoded signal and an interference signal, which interferes with the encoded signal to generate an interfered signal, allowing the system to determine whether the received signal matches the encoded signal, and outputting a proximity signal to control movement when a mismatch is detected, thereby preventing falls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If infrared sensing is used for anti-falling detection, then the robot can detect ground surfaces, but the detection accuracy deteriorates due to interference from ground colors and ambient light sources
Solution Approach 1:
The patent introduces a modulated infrared signal as an intermediary carrier to transmit depth information. Instead of directly detecting ambient infrared radiation which is affected by ground color and lighting, the system uses a transmitted modulated signal that reflects off the ground and returns to the sensor. The modulation acts as a mediator that allows the system to distinguish the reflected signal from ambient interference, thereby maintaining detection reliability while improving measurement precision.
Solution Approach 2:
The patent changes the parameter of the infrared signal from passive detection of ambient radiation to active transmission of modulated signals with specific frequency characteristics. By modulating the transmitted infrared signal at a known frequency and detecting the phase or frequency of the reflected signal, the system can filter out ambient light interference and ground color variations, thus improving sensing accuracy while maintaining reliable anti-falling detection.
2Reliability
If circuit parameters are adjusted to counteract environmental effects, then detection reliability improves, but device complexity increases due to complex amplifying filter circuits
Solution Approach 1:
The patent replaces complex analog circuit-based interference cancellation methods with a digital signal processing approach. Instead of using complex amplifying and filtering circuits to counteract environmental effects, the system transmits modulated infrared signals and uses digital correlation or phase-detection algorithms to extract depth information while automatically rejecting ambient light interference. This substitution of mechanical/electrical circuit complexity with signal processing simplicity reduces device complexity while maintaining or improving reliability.
3Adaptability or versatility
If the robot uses infrared sensing for proximity detection, then it can navigate environments, but the measurement precision deteriorates due to interference from ambient light sources
Solution Approach 1:
The patent employs periodic modulation of the transmitted infrared signal at a specific frequency. By transmitting the infrared signal in a periodic modulated manner and detecting the phase or frequency characteristics of the reflected signal, the system can distinguish the reflected modulated signal from ambient light sources. This periodic action allows the robot to maintain environmental navigation capability while significantly improving proximity sensing accuracy by filtering out non-modulated ambient light interference.
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 solution enhances the accuracy of proximity sensing, reducing the impact of environmental factors like light and surface colors, and simplifies the signal processing circuit, preventing robot malfunctions and falls by accurately detecting obstacles and maintaining distance from hazards.
Implementation Method 1
The interference signal transmission unit transmits an interference signal. The interference signal interferes with the encoded signal to generate an interfered signal.
Data Source
AI summary
A proximity sensing apparatus is provided. The proximity sensing apparatus includes an encoded signal transmission unit, an interference signal transmission unit and a reception unit. The encoded signal transmission unit transmits an encoded signal, and the interference signal transmission unit transmits an interference signal. The interference signal interferes with the encoded signal to generate an interfered signal. The reception unit receives a sensing signal and outputs the sensing signal to a signal processing unit. The sensing signal is either the interfered signal or the encoded signal. The signal processing unit is electrically connected to the reception unit, and determines whether the sensing signal matches the encoded signal. The signal processing unit further outputs a proximity signal when the sensing signal does not match the encoded signal.