Sensor assembly, actuator, control system, electrically adjustable piece of furniture and method for operating an electrically adjustable piece of furniture
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Solution Overview
Problem
Existing electrically adjustable furniture systems face challenges in accurately detecting low-force collisions or deformations without triggering false alarms, which can lead to injuries or damage.
Innovation Solution
A sensor assembly using a light transmitter, receiver, and a movable aperture element that adjusts the light path to maintain a constant light quantity received, allowing for precise detection of deformations or movements, which are then evaluated for collision detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If strain gauges or piezo-based force transducers are used to detect collision forces, then force detection capability is improved, but measurement precision deteriorates at very low forces and deformations
Solution Approach 1:
The patent replaces mechanical force transducers (strain gauges, piezo-based sensors) with an optical measurement system. A light transmitter emits light through a light path to a light receiver, and an aperture element moves into the light path in response to deformations, modulating the light quantity received. This optical substitution enables detection of very low forces and deformations without the minimum detection threshold limitations of mechanical sensors.
Solution Approach 2:
The patent changes the measurement parameter from direct force measurement to light quantity modulation. The aperture element's position, which changes in response to deformation, modulates the amount of light reaching the receiver. A control system adjusts the light transmitter output to maintain constant received light, and the manipulation variable serves as a deformation signal. This parameter transformation enables high-precision detection of minute deformations.
2Object-affected harmful factors
If sensitive force detection is implemented to detect low-force collisions, then safety is improved, but false triggers increase
Solution Approach 1:
The patent implements a control system that continuously monitors the light quantity received by the light receiver and adjusts the light transmitter output accordingly to maintain a constant received light level. This feedback mechanism filters out noise and transient disturbances, ensuring that only genuine deformations trigger collision detection. The system evaluates changes in the manipulation variable over time, distinguishing between accidental disturbances and real collision events.
3Measurement precision
If mechanical aperture elements are used to modulate light quantity, then measurement sensitivity is improved, but device complexity increases
Solution Approach 1:
The patent merges the aperture element with the existing structural components of the adjustable furniture. The aperture element is integrated into the furniture structure itself, eliminating the need for separate mechanical transducer assemblies. This integration reduces device complexity while maintaining the optical measurement functionality and high sensitivity to deformation.
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 enables accurate detection of low-force collisions and deformations in electrically adjustable furniture, preventing injuries and damage while minimizing false triggers.
Implementation Method 1
a light transmitter and a light receiver, which are coupled to each other via an optical light path. The light receiver is configured to provide a reception signal based on a received amount of light
Data Source
AI summary
A sensor assembly for an electrically adjustable piece of furniture having at least one actuator for adjusting a component and a control for the actuator comprises a light transmitter and a light receiver which are coupled to one another via an optical light path. An aperture element which is configured to at least partially cover the light path and which is mounted in a movable manner with respect to the light path in such a way that a change in a position of the aperture element results in a change in the covering of the light path. An evaluation circuit regulates a light quantity emitted by the light transmitter to a reference quantity by means of a control signal and generates a deformation signal based on the control signal or on a signal derived from the control signal. The aperture element converts a deformation or movement of the component into a change of position of the aperture element relative to the light path.