Distributed adaptive control of a multi-zone HVAC system

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Solution Overview

Problem

HVAC systems in buildings face inefficiencies in regulating temperature across multiple zones due to complexities in system dynamics, human activity, and environmental factors, leading to increased energy consumption and equipment wear.

Innovation Solution

A distributed adaptive control system is implemented, where each zone has a controller that uses a combination of sensors to measure temperature and adjust supply air temperature and volume flow rate based on estimated adaptive control laws, minimizing the effects of surroundings and activity, and allowing for online estimation of controller parameters without requiring knowledge of system dynamics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a distributed adaptive control system is implemented, then temperature tracking accuracy and energy efficiency are improved, but system complexity and implementation difficulty increase

Engineering Contradiction:
Improvetemperature tracking accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control system is divided into multiple independent zone controllers, each managing a specific building zone. Each controller operates autonomously with its own sensors and actuators, allowing distributed decision-making while maintaining overall system coordination. This segmentation reduces the complexity burden on any single controller and enables parallel operation across zones.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each zone controller automatically adapts its own parameters through online estimation algorithms without requiring external intervention or centralized coordination. The controllers self-tune their gain parameters and adapt to changing conditions (occupancy, weather, equipment degradation) autonomously, eliminating the need for manual calibration or system-wide reconfiguration.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If adaptive control laws with online parameter estimation are used, then system adaptability and energy savings are improved, but computational requirements and processing time increase

Engineering Contradiction:
Improvesystem adaptabilityVSAvoidcomputational processing time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The adaptive algorithm focuses computational effort only on estimating the critical gain parameters that most significantly affect control performance, rather than attempting to model the entire system dynamics. This partial estimation approach achieves sufficient adaptability with reduced computational burden, avoiding the need for complete system identification.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

Parameter estimation and adaptation occur at discrete time intervals rather than continuously, allowing the system to update its parameters periodically based on accumulated data. This periodic updating reduces real-time computational requirements while maintaining adaptability to changing conditions over time.

Inventive Principle:
Principle #19Periodic action

3Measurement precision

If multiple sensors and controllers are deployed in each zone, then measurement accuracy and control precision are improved, but system cost and installation complexity increase

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidinstallation ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

Each zone controller is designed as a multi-functional unit that integrates temperature sensing, humidity sensing, control computation, and actuator control capabilities. This universal controller design consolidates multiple functions into a single device, reducing the number of separate components that need to be installed and wired, while maintaining high measurement and control precision.

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

Data Source

PatentUS12072114B2Distributed adaptive control of a multi-zone HVAC system
Publication Date: 2024.08.27 UNIV OF SOUTHERN CALIFORNIA
  • US12072114B2 patent drawing
  • US12072114B2 patent drawing
  • US12072114B2 patent drawing

AI summary

A distributive adaptive control system for HVAC control and a method for controlling the temperature in a building with one or more zones is disclosed. The control system and method are based on a design that may accommodate buildings with multiple interconnected thermal zones. The system includes a controller for each zone of the building. Each controller is designed to regulate temperature while attenuating the effect of directly neighboring zones, wall temperature, weather conditions and heat gains. The control mechanism does not require any prior accurate knowledge of system parameters but instead calibrates itself to meet the needs of each thermal zone. An appropriate adaptive law may be used for learning the building and HVAC system parameters and auto-calibrating the controller. The proposed system and method can extend the life of the HVAC by compensating for a wide range of tear and wear and other defects in the equipment.