Sanitary Sensor ToF Switching for Presence Detection

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Solution Overview

Problem

Existing monitoring devices for sanitary facilities often lead to incorrect operating sequences due to reliance on intensity-based distance measurement, resulting in inefficient power consumption and potential water wastage, as they struggle to accurately detect user presence with varying object reflectivities and distances.

Innovation Solution

A monitoring device comprising a first ToF sensor for precise distance measurement and a second sensor for broader area detection, with a control unit switching the ToF sensor between stand-by and operating modes based on user presence, reducing power consumption and preventing false triggers by using a combination of Time of Flight technology and a motion detector.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a presence sensor with long range is used to detect user presence from a distance, then the reception range is improved, but false triggering occurs due to incorrect distance measurement with varying object reflectivities

Engineering Contradiction:
Improvereception rangeVSAvoiddetection accuracy
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The spatial detection area is divided into two segments: a first spatial area monitored by a first sensor for close-range detection, and a second spatial area monitored by a second sensor for far-range detection. This segmentation allows each sensor to operate in its optimal range, preventing false triggers from distant objects with varying reflectivities while maintaining broad coverage.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If the first sensor operates continuously in operating mode to ensure accurate detection, then detection accuracy is improved, but power consumption increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The first sensor alternates between operating mode and stand-by mode based on detection needs. The second sensor continuously monitors the second spatial area and triggers the first sensor to switch to operating mode only when a user is detected in the second spatial area, creating a periodic activation pattern that reduces power consumption while maintaining detection accuracy when needed.

Inventive Principle:
Principle #19Periodic action

3Use of energy by moving object

If the first sensor is switched to stand-by mode to save energy, then power consumption is reduced, but detection response time increases

Engineering Contradiction:
Improvepower consumptionVSAvoiddetection response time
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The second sensor performs preliminary detection in the second spatial area (broader area) continuously or at intervals, identifying potential users before they enter the first spatial area. This preliminary action allows the first sensor to be activated in advance of actual need, reducing the effective response time when a user actually requires detection while still maintaining energy savings during stand-by periods.

Inventive Principle:
Principle #10Preliminary action

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

Ensures reliable operation, reduces energy consumption, and minimizes water wastage by accurately detecting user presence and adjusting the sanitary facility's operation accordingly, preventing incorrect triggering and optimizing power usage.

Implementation Method 1

A ToF sensor can, for example, work according to the principle that a light signal is emitted onto which a modulation signal that is comparatively low in frequency compared to the light frequency is modulated. There are also variants of the ToF sensor in which a short light pulse is emitted, the transit time of which can be determined immediately.

Methodology Applied
Scientific EffectTime of Flight: Time of Flight

Implementation Method 2

the second sensor is basically used to check whether there are people in the further vicinity of the sanitary fitting

Methodology Applied
Scientific EffectThermal Radiation: Thermal Radiation

Data Source

PatentEP3312351B1Monitoring device for a sanitary installation
Publication Date: 2020.04.15 AQUIS SANITAR
  • EP3312351B1 patent drawingFigure 1
  • EP3312351B1 patent drawingFigure 2
  • EP3312351B1 patent drawingFigure 3

AI summary

A monitoring device (M) for a sanitary installation (1) is proposed, comprising a first sensor (8) for monitoring the presence of persons in a first spatial area (9, 10) in the vicinity of the sanitary installation (1) and a second sensor (13, 14) for monitoring a second spatial area (R) in the vicinity of the sanitary installation (1). The first sensor (8) has an operating mode and a standby mode, and the second sensor (13, 14) is configured to switch the first sensor (8) from a standby mode to an operating mode upon a predetermined detection. To avoid errors in the operating sequence, the first sensor (8) is configured as a distance sensor, in particular as a time-of-flight (TOF) sensor.