Dryer Time Estimation Using Exhaust and Ambient Humidity Sensors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current laundry appliances inaccurately estimate the remaining drying time due to variations in load size, relying solely on moisture sensors, which often result in longer than displayed times for both standalone and combination machines.

Innovation Solution

A system utilizing exhaust temperature, exhaust humidity, and ambient humidity sensors, combined with a trained recurrent neural network and post-processing block, to accurately predict the estimated time remaining by calculating the difference between exhaust and ambient humidity ratios and elapsed time, while ignoring outlying predictions for improved accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a moisture sensor is used to calculate estimated time remaining, then the system is simple to operate, but the measurement precision is insufficient leading to inaccurate time estimation

Engineering Contradiction:
Improveestimated time remaining accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the humidity measurement function into two separate sensors: an exhaust humidity sensor for measuring humidity in the exhaust air and an ambient humidity sensor for measuring environmental humidity. This segmentation allows each sensor to be optimized for its specific measurement environment, improving overall measurement precision while maintaining system simplicity through dedicated functional separation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces the ambient humidity sensor as an intermediary that measures environmental humidity conditions. This intermediary measurement is then used by the controller to compensate for environmental variations in the estimated time remaining calculation, thereby improving accuracy without requiring direct measurement of all affecting factors.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple sensors are used to improve estimation accuracy, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improveestimated time remaining accuracyVSAvoidsensor and processing system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The controller performs multiple functions using the sensor data: it calculates estimated time remaining, displays the information to the user, and potentially adjusts drying parameters. By making the controller multi-functional, the patent avoids adding separate dedicated devices for each function, thereby improving measurement precision through multiple sensors while limiting the increase in overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the exhaust humidity sensor, ambient humidity sensor, and controller into an integrated system where the controller processes data from both sensors to generate the estimated time remaining. This merging consolidates multiple components into a unified system, improving measurement precision through combined sensor input while managing complexity through integration rather than separate standalone units.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If a recurrent neural network with post-processing is used, then estimation accuracy improves, but device complexity and processing requirements increase

Engineering Contradiction:
Improveprediction reliabilityVSAvoidprocessing system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The recurrent neural network is trained in advance with historical drying data to learn the complex relationships between humidity, temperature, load size, and drying time. This preliminary training action allows the network to make accurate predictions during operation without requiring complex real-time calculations, thereby improving prediction reliability while managing processing complexity through pre-computed knowledge.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The post-processing block implements a feedback mechanism where the estimated time remaining is continuously monitored and adjusted based on actual drying progress. This feedback loop allows the system to learn from actual performance and refine its predictions over time, improving accuracy while using relatively simple comparison logic rather than complex real-time optimization algorithms.

Inventive Principle:
Principle #23Feedback

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

The system provides a more accurate estimation of the remaining drying time, accounting for load size variations and improving prediction reliability by using machine learning to analyze humidity and temperature data, ensuring precise timing and user convenience.

Implementation Method 1

an exhaust temperature sensor disposed in the exhaust vent generating an exhaust temperature signal

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 2

an exhaust humidity sensor disposed in the exhaust vent generating an exhaust humidity signal

Methodology Applied
Scientific EffectHumidity sensing:

Implementation Method 3

an ambient humidity sensor generating an ambient humidity signal

Methodology Applied
Scientific EffectHumidity sensing:

Data Source

PatentUS20240352638A1Method and system for determining and estimated time remaining for a dryer system
Publication Date: 2024.10.24 WHIRLPOOL CORP
  • US20240352638A1 patent drawing
  • US20240352638A1 patent drawing
  • US20240352638A1 patent drawing

AI summary

A laundry appliance includes a cabinet having a laundry compartment located inside said cabinet, an exhaust vent extending from the laundry compartment, an exhaust temperature sensor disposed in the exhaust vent generating an exhaust temperature signal, an exhaust humidity sensor disposed in the exhaust vent generating an exhaust humidity signal and an ambient humidity sensor generating an ambient humidity signal. The appliance further includes a display and a controller coupled to the exhaust temperature sensor, the exhaust humidity sensor and the ambient humidity sensor. The controller determines an estimated time remaining for a drying cycle based on the exhaust temperature signal, the exhaust humidity signal and the ambient humidity signal and causes the display to display the estimated time remaining.