Sonic Sensor User Presence Detection Using Background Data
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Solution Overview
Problem
Existing range sensors, such as ultrasonic sensors, often erroneously detect stationary objects as human bodies, leading to incorrect determination of user presence or absence around electronic devices like printers, due to reflections from objects other than human bodies.
Innovation Solution
An information processing apparatus equipped with a sonic sensor that outputs and receives sonic waves, using distance data and pre-prepared background data to differentiate between human body reflections and stationary object reflections, allowing accurate detection of user presence or absence by analyzing intensity patterns over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an ultrasonic sensor is used to detect human bodies by measuring reflected waves, then the ability to detect user presence is improved, but erroneous detection of stationary objects as human bodies occurs
Solution Approach 1:
The system performs preliminary measurement during a learning period to capture background reflected wave data from stationary objects before actual user detection begins. This preliminary action stores the stationary object patterns in memory, enabling the subsequent detection process to distinguish between stationary objects and moving human bodies by comparing real-time measurements against the stored background data
Solution Approach 2:
The patent introduces background reflected wave data as an intermediary element that mediates between the raw sensor output and the final detection decision. By storing and comparing against this intermediate background representation, the system can filter out stationary object reflections and isolate genuine human body detection signals
2Productivity
If the ultrasonic sensor continuously monitors the detection area, then user presence detection capability is enhanced, but false alarms from stationary objects increase
Solution Approach 1:
The system extracts and separates the stationary object component from the total reflected wave signal by comparing current measurements against stored background data. This extraction process isolates the moving object component, which represents actual human bodies, thereby eliminating false alarms from stationary objects while maintaining continuous monitoring capability
Solution Approach 2:
The system implements feedback by continuously comparing real-time reflected wave measurements against the stored background data and adjusting the detection decision based on the difference. This feedback mechanism enables the system to maintain high responsiveness while filtering out stationary object interference through continuous comparison and adaptation
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 effectively prevents erroneous detection by distinguishing between moving human bodies and stationary objects, ensuring accurate user detection even when stationary objects are present in the detection area.
Implementation Method 1
The ultrasonic sensor is a sensor that detects an object by radiating an ultrasonic wave and receiving a reflected wave that returns
Implementation Method 2
By measuring the elapsed time between the ultrasonic wave being output and the reflected wave from the object being received, the distance to the object is calculated
Data Source
AI summary
An information processing apparatus including: a sonic sensor that outputs a sonic wave and receives a reflected wave of the output sonic wave; and a control unit configured to determine whether a person exists on a periphery of the information processing apparatus based on distance data and background data, wherein the distance data indicates intensity of a reflected wave in fixed time units received by the sonic sensor during a predetermined period of time after a sonic wave is output from the sonic sensor, the fixed time units being obtained by dividing the predetermined period of time, and the background data is past distance data prepared in advance.