Capacitive Bed Frame Perimeter Sensing for Pinch Point Detection
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Solution Overview
Problem
Traditional presence-sensing technologies for automated bedding systems are prone to inaccuracies and practical issues, such as sensor misplacement and sensitivity problems, which can lead to false readings or failure to detect a person's presence, making them unreliable for preventing 'pinch points' and other safety concerns.
Innovation Solution
The integration of capacitive wire sensing technology around the perimeter of an adjustable bed, using conductive wires and capacitive components to detect presence through changes in capacitance, which are monitored by a processor to determine presence or absence, thereby enabling reliable presence detection and preventing unintended bed articulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional presence-sensing switches are routed around the perimeter of a mattress, then presence detection function is provided, but the switches may shift or bend during bed articulation causing inaccurate readings and misplacement
Solution Approach 1:
The patent replaces traditional mechanical presence-sensing switches with capacitive sensing technology. The capacitive sensor detects presence through electrical field changes rather than mechanical contact, eliminating the problems of switching misplacement and bending during bed articulation. The sensor remains fixed while detecting changes in capacitance caused by proximity of conductive materials.
Solution Approach 2:
The patent introduces capacitive sensing as an intermediary detection method between the bed structure and the presence detection function. Instead of directly mounting switches that can shift, the system uses capacitive fields that can detect presence without physical contact or rigid mounting requirements.
2Reliability
If pressure pads and switches are used for presence detection, then presence sensing is achieved, but the switches may fail to be triggered or may be too sensitive causing false activation
Solution Approach 1:
The patent changes the detection parameter from mechanical pressure (in traditional switches) to electrical capacitance. This allows for adjustable sensitivity thresholds in the capacitive sensing system, enabling precise control over when presence is detected. The system can be calibrated to detect specific capacitance changes without being overly sensitive to minor variations.
3Reliability
If traditional presence-sensing switches are used, then presence detection is provided, but additional analog components such as sensors and oscillators are required increasing device complexity
Solution Approach 1:
The patent extracts and eliminates unnecessary analog components from traditional presence-sensing systems. By using capacitive sensing integrated with digital processing, the system removes the need for separate sensors, oscillators, and complex analog circuitry, simplifying the overall device architecture while maintaining detection capability.
4Strength
If upholstery is pulled too tight during application, then secure covering is achieved, but presence-sensing switches may already be compressed causing inaccurate readings
Solution Approach 1:
The patent replaces mechanical switches that are susceptible to compression from tight upholstery with capacitive sensors. The capacitive sensing mechanism is not affected by mechanical compression in the same way, as it detects presence through electrical field changes rather than requiring precise mechanical switch actuation.
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 provides a reliable and accurate method for detecting presence, reducing the risk of safety issues like 'pinch points' by effectively monitoring changes in capacitance to control bed functions and prevent unsafe movements.
Implementation Method 1
A capacitive wire or other capacitive component is adapted to have a voltage based on proximity of a person or body to the capacitive wire or component.
Data Source
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AI summary
A system and method for incorporating presence- sensing technology into furniture is provided. More particularly, the invention relates to detecting presence using a metal, adjustable bed frame. The bed frame is pulsed with a voltage to provide a charge, against which capacitance is measured. A controller determines the corresponding response based on presence detection by the frame. Conductive bushings may also be used to measure capacitance using the bed frame. In further embodiments, capacitance is measured by a foil tape surrounding a perimeter of the adjustable bed. The foil tape has a voltage based on proximity of an object to the tape, and may be embedded with a capacitive wire. A processor receives information regarding changes in capacitance and determines when a change in voltage satisfies a threshold. Based on a determination of presence, or lack of presence, a variety of corresponding features of the adjustable bed may be activated.