Tissue Dispenser Level Sensing for Waste-Aware Refills
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Solution Overview
Problem
Current solutions for monitoring consumable levels in washroom dispensers often result in material waste due to over-refilling or inappropriate dispensing amounts, and lack cost-effective and energy-efficient methods for determining product levels and types accurately.
Innovation Solution
A tissue dispenser equipped with a detection system featuring two sensor elements with light sources and detectors, which transmit and detect light to determine the level of tissue products, providing accurate, reproducible, and flexible monitoring, and communicating this information wirelessly to a central server for timely refills.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If janitors refill dispensers on regular service intervals, then consumables are continuously available, but material is wasted when dispensers are refilled before complete depletion
Solution Approach 1:
The sensor detects consumable levels in advance and communicates them to janitors, enabling them to plan refills based on actual needs rather than fixed schedules. This preliminary detection prevents premature refilling and reduces material waste while ensuring availability.
Solution Approach 2:
The system provides real-time feedback on consumable levels through sensors and communication interfaces, allowing janitors to adjust their refilling actions based on actual consumption patterns. This feedback loop eliminates the need for conservative over-refilling and optimizes material usage.
2Measurement precision
If automatic dispensing is implemented, then consumable levels are tracked accurately, but material is wasted due to pre-defined dispensing amounts that are not appropriate for each guest
Solution Approach 1:
The system transitions from static pre-defined dispensing amounts to dynamic, sensor-based level detection. The sensor continuously monitors actual consumption and communicates real levels, allowing dispensing amounts to be adapted to actual needs rather than following fixed predetermined patterns.
Solution Approach 2:
The sensor system enables the dispenser to self-monitor its own consumable levels and communicate this information autonomously. This self-service capability eliminates the need for manual tracking and prevents waste by providing accurate real-time data on actual consumption versus remaining stock.
3Loss of substance
If manual level checking is performed, then material waste is reduced by refilling only when necessary, but labor time and service frequency increase
Solution Approach 1:
The system replaces manual mechanical level checking with automated optical or electromagnetic sensors. These sensors continuously detect consumable levels without requiring janitor intervention, eliminating the time loss associated with manual checking while maintaining accurate tracking to prevent waste.
Solution Approach 2:
The dispenser performs self-monitoring of consumable levels through integrated sensors, eliminating the need for external manual inspection. This self-service capability reduces labor time while maintaining the ability to identify when refilling is actually needed, preventing both waste and unnecessary service visits.
4Productivity
If sensors are added to detect consumable levels, then refill timing is optimized, but device complexity and cost increase
Solution Approach 1:
The sensor function is extracted as a separate, modular component that can be independently implemented. This allows the core level-detection capability to be added without fundamentally redesigning the entire dispenser system, reducing the complexity burden while maintaining refill optimization benefits.
Solution Approach 2:
The sensor system is designed to perform multiple functions: detecting consumable levels, determining when refilling is needed, and communicating this information to both janitors and automated systems. This multi-functionality justifies the added complexity by delivering comprehensive productivity improvements across multiple operational aspects.
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 reduces material waste by providing precise level detection and flexible dispensing, allowing for optimal refill timing and minimizing unnecessary service visits, while being cost-effective and energy-efficient.
Implementation Method 1
The detection device is arranged to transmit light from the light source and detect reflected light in the light detector
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
The present invention relates to a solution for detecting level of a consumable tissue product (201, 301) in a tissue dispenser (103, 106) located in a washroom. This is provided in a number of aspects such as a tissue dispenser, a method, system, and a sensor unit utilizing two sensor elements (420, 430) each arranged to measure light reflected from a reflection field located on the tissue product, reflected directly from the tissue product, or measure the absence of the tissue product. Data from the sensor elements are wirelessly transmitted to a server for further handling, such as for instance notification to a janitor in charge of service of the washroom.