Dual-Sensor User Presence Control for Low-Power PC Reactivation
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Solution Overview
Problem
Existing solutions for automatically reactivating PCs, such as those using infrared Time-of-Flight sensors, have limited field of view and high energy consumption, and often generate false detections due to external light radiation and inanimate objects, making it difficult to accurately discriminate the user's position for enabling advanced functionalities.
Innovation Solution
A control method that utilizes a combination of a proximity sensor and an electric or electrostatic charge variation sensor to detect the user's presence and position, activating the proximity sensor only after initial detection by the charge variation sensor, thereby reducing energy consumption and improving detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If infrared Time-of-Flight sensors are used for automatic PC reactivation, then detection capability is provided, but energy consumption increases due to continuous IR source use
Solution Approach 1:
The optical sensor is activated periodically or on-demand rather than continuously. The control method triggers the optical sensor only when motion is detected by the charge variation sensor, converting continuous operation into periodic or event-driven operation to reduce energy consumption while maintaining detection capability.
Solution Approach 2:
The charge variation sensor performs preliminary detection of user presence before activating the optical sensor. This preliminary action filters out unnecessary optical sensor activations, reducing energy consumption while ensuring the optical sensor is only activated when a user is actually present.
2Measurement precision
If optical sensors have a narrow field of view for precise detection, then measurement precision improves, but the area of detection decreases
Solution Approach 1:
The detection system is segmented into two functional zones: a wide-area initial detection zone covered by the charge variation sensor, and a precise measurement zone covered by the optical sensor. This segmentation allows the system to first identify potential users in a broad area, then focus precise measurement resources only on confirmed targets.
Solution Approach 2:
The charge variation sensor acts as an intermediary that expands the effective detection area. It detects user presence in a wider region and triggers the optical sensor only when appropriate, allowing the system to maintain high measurement precision while effectively covering a larger area through the intermediary's broader detection capability.
3Reliability
If optical sensors are activated continuously for user detection, then detection reliability improves, but energy consumption increases
Solution Approach 1:
The optical sensor operates periodically or on-demand based on triggers from the charge variation sensor rather than continuously. This periodic activation maintains detection reliability for actual user interactions while significantly reducing energy consumption by keeping the optical sensor inactive during periods of no user presence.
Solution Approach 2:
The charge variation sensor serves the optical sensor by providing trigger signals based on its own detection of user presence. This self-service mechanism allows the system to maintain reliable detection without continuous optical sensor operation, as the charge variation sensor autonomously determines when optical detection is necessary.
4Device complexity
If a single sensor type is used for user detection, then device complexity is reduced, but false detections increase
Solution Approach 1:
The system merges two different sensor types (charge variation sensor and optical sensor) with complementary detection capabilities. The charge variation sensor detects electrical field changes from user presence, while the optical sensor detects visual characteristics. Combining these sensors reduces false detections by requiring confirmation from both sensor types while maintaining relatively simple device architecture.
Solution Approach 2:
The charge variation sensor serves as an intermediary that filters and pre-processes detection events before they reach the optical sensor. This intermediary role reduces false detections by ensuring the optical sensor only activates when the charge variation sensor has already confirmed user presence, eliminating the need for complex single-sensor algorithms while keeping device complexity manageable.
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 approach enhances detection effectiveness by limiting optical sensor activation to confirmed user presence, reducing false detections, and allowing for precise user positioning, thus enabling efficient activation of PC functionalities while conserving energy.
Implementation Method 1
a charge variation sensor configured to detect an electric or electrostatic charge variation caused by the presence of the user in a detection region of the charge variation sensor
Implementation Method 2
a proximity sensor configured to detect, when the user is in a field of view of the proximity sensor, a first distance of the user from the proximity sensor correlated to a second distance of the user from the apparatus
Data Source
AI summary
A control method of an apparatus is provided. The apparatus includes a control unit coupled to a proximity sensor to detect a first distance of a user in a field of view, and coupled to a charge variation sensor to detect an electric/electrostatic charge variation caused by the user in a detection region. The control method includes acquiring a charge variation signal and generating charge variation parameters as a function of the charge variation signal. The control method further includes determining whether a condition on charge variation parameters is verified, and if the condition on charge variation parameters is verified, activating the proximity sensor and acquiring a proximity signal. Proximity parameters are generated as a function of the proximity signal. If a condition on proximity parameters is verified, one or more functionalities of the apparatus are activated.