Thermostat Occupancy Prediction Correction for HVAC Setpoint Control

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Solution Overview

Problem

Existing HVAC systems lack the capability to determine whether a user is present or away without user input, leading to inefficiencies in energy consumption and wear on components, as they cannot automatically adjust set point temperatures without this information.

Innovation Solution

Employing machine learning to predict user behavior and preferences by collecting data from user devices, interactions, and network connections to generate a predicted occupancy schedule, allowing the HVAC system to adjust temperatures for energy savings and reduce wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the HVAC system automatically adjusts set point temperatures without user input, then energy consumption is reduced and component wear is minimized, but the user's comfort level may be affected when the user is actually present

Engineering Contradiction:
Improveenergy consumptionVSAvoiduser comfort
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The system performs preliminary actions by adjusting temperatures in advance based on predicted occupancy. The machine learning model predicts when users will be away, and the HVAC system proactively adjusts temperatures before the user leaves, ensuring energy savings are achieved without compromising comfort when users are actually present.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by continuously monitoring actual occupancy data and comparing it with predicted occupancy. When discrepancies are detected (e.g., user is present but predicted as away), the system learns from this feedback and corrects its predictions, thereby improving both energy efficiency and user comfort over time.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If the HVAC system requires user input for scheduling information, then accurate occupancy data is obtained, but users may never provide this information leading to system inefficiency

Engineering Contradiction:
Improveoccupancy data accuracyVSAvoiduser input requirement
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system practices self-service by automatically collecting occupancy data from various sources (mobile device locations, network connections, smart home devices) without requiring explicit user input. The machine learning model processes this collected data to generate accurate occupancy predictions, making the system both easy to operate and data-accurate.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses intermediary data sources such as mobile device locations, network connection types, and interactions with other smart home devices to indirectly determine occupancy status. These intermediaries provide the occupancy information needed for accurate temperature adjustment without requiring direct user input about their schedules.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If the HVAC system makes conservative temperature adjustments, then user comfort is maintained, but energy saving benefits are reduced

Engineering Contradiction:
Improveenergy saving benefitsVSAvoidtemperature adjustment flexibility
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The system dynamically adjusts temperature set points based on the confidence level of occupancy predictions. When the machine learning model is highly confident that users are away, the system makes aggressive temperature adjustments for maximum energy savings. When confidence is lower or occupancy is uncertain, the system makes conservative adjustments to maintain comfort, thereby adapting its flexibility to the situation.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS12078366B2Error correction for predictive schedules for a thermostat
Publication Date: 2024.09.03 LENNOX IND INC
  • US12078366B2 patent drawing
  • US12078366B2 patent drawing
  • US12078366B2 patent drawing

AI summary

A heating, ventilation, and air conditioning (HVAC) control device is configured to record a plurality of actual occupancy statuses, to determine a plurality of corresponding predicted occupancy statuses, and to compare the plurality of predicted occupancy statuses to the plurality of actual occupancy statuses. The device is further configured to identify conflicting occupancy statuses based on the comparison. A conflicting occupancy status indicates a difference between an actual occupancy status and a corresponding predicted occupancy status. The device is further configured to identify timestamps corresponding with the conflicting occupancy statuses, to identify historical occupancy statuses corresponding with the identified timestamps, and to update the conflicting occupancy statuses in the predicted occupancy schedule with the historical occupancy statuses.