Vehicle Air Conditioning Control via Dynamic Pressure Loss Evaluation

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Solution Overview

Problem

Multi-zone air conditioning systems in vehicles face inefficiencies in control speed, noise development, and climate distribution, particularly when managing individual climate zones with limited fans or blowers, leading to complex control and suboptimal energy and noise regulation.

Innovation Solution

A control method that evaluates setting-specific air mass values for individual air ducts, determines the air duct with the greatest pressure loss, and adjusts fan output and throttle valve positions to match the required admission pressure, enabling faster and more efficient climate control with reduced noise and improved adjustment options.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the fan output is increased to improve climate control performance across multiple zones, then the climate distribution improves, but the energy consumption and noise increase

Engineering Contradiction:
Improveclimate control performanceVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The fan output is dynamically adjusted based on real-time pressure loss measurements from individual air ducts. The control system continuously monitors pressure differential across each duct and modulates fan speed to maintain optimal airflow without excessive energy consumption, transitioning from static to dynamic control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters by measuring pressure loss in each air duct and using this data to optimize fan output settings. By monitoring pressure differential and adjusting fan speed accordingly, the system achieves efficient energy utilization while maintaining effective climate distribution across all zones.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the fan output is increased to improve climate control performance, then the climate distribution improves, but the noise development increases

Engineering Contradiction:
Improveclimate control performanceVSAvoidnoise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The fan operates dynamically at variable speeds based on actual airflow requirements determined by pressure loss measurements. This dynamic adjustment allows the system to maintain effective climate control while operating at lower fan speeds when possible, thereby reducing noise generation from the fan motor and airflow turbulence.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system optimizes the operational parameters of the fan by adjusting speed and output based on measured pressure differential across air ducts. This parameter optimization enables the fan to operate efficiently at lower power levels, reducing both energy consumption and noise emission while maintaining adequate climate distribution.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the control system regulates all air ducts simultaneously, then the climate distribution is optimized, but the control speed decreases

Engineering Contradiction:
Improveclimate distribution optimizationVSAvoidcontrol speed
Core Design Contradiction:
ProductivityVSSpeed

Solution Approach 1:

The control system segments the air distribution network by measuring and identifying individual pressure loss characteristics for each air duct. By treating each duct as a separate controlled entity with its own pressure profile, the system can make targeted control decisions rather than regulating all ducts uniformly, improving response speed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary measurement of pressure differential across each air duct during initialization or idle periods, storing this data for rapid reference during active control. This preliminary characterization of each duct's flow resistance allows the control system to quickly determine optimal fan output without performing complex real-time calculations for all ducts simultaneously.

Inventive Principle:
Principle #10Preliminary action

4Measurement precision

If the system provides detailed control for each air duct to improve climate precision, then the climate control precision improves, but the device complexity increases

Engineering Contradiction:
Improveclimate control precisionVSAvoidcontrol complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control system achieves detailed climate control through self-service measurement of pressure differential across each air duct. By autonomously monitoring and characterizing the flow resistance of individual ducts, the system obtains precise control data without requiring complex external measurement equipment or manual calibration procedures for each duct.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system replaces complex mechanical measurement and control mechanisms with electronic pressure sensing and digital processing. By using electronic pressure differential sensors and microcontroller-based control logic, the system achieves precise individual duct control with simpler and more reliable electronic components rather than complex mechanical adjustment mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 approach results in a faster and more responsive control system, providing efficient and low-noise operation with finer climate control adjustments, and simplifies software implementation by separating vehicle-specific characteristics from air conditioning system characteristics.

Implementation Method 1

a fan, preferably a blower, for example an axial or radial fan; an air distribution system for distributing the air mass flow caused by the fan or the blower

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

several motor-adjustable throttle flaps to influence the flow resistance in the air ducts

Methodology Applied
Scientific EffectFlow resistance:

Implementation Method 3

a temperature control device for temperature control of the air flowing into the fan or blower and/or out of the fan or blower

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP2576253B1Improved air conditioning control
Publication Date: 2014.04.23 PREH GMBH
  • EP2576253B1 patent drawingFigure 1

AI summary

The invention relates to an improved control method for an air conditioner (1) of a vehicle, in particular a motor vehicle, wherein the air conditioner comprises the following: a fan (2); a temperature control device (3) for controlling the temperature of the air in the fan (2) and/or flowing out of the fan (2); an air distribution system (4) for distributing the air mass flow caused by the fan (2) via a plurality of air channels (4a-4d) to associated air discharge openings (9a-9d); a plurality of motorized adjustable throttle flaps (5a-5d) for influencing the flow resistance in the air channels (4a-4d); and control electronics (6) having a user interface (11), wherein the method comprises the following: analyzing the setting of the user interface (11) for providing air mass values specific to the adjustment for the individual air channels (4a-4d) and selecting particular air channels (4a-4d) as a function of the adjustment; determining which air channel (4a-4d) has the greatest pressure loss in the unthrottled setting of the associated motorized adjustable throttle valve (5a-5d) out of the selected air channels (4a-4d); determining a required system pressure for the particular air channel (4a-4d) having the greatest unthrottled pressure loss; controlling the fan power as a function of the required system pressure and as a function of the sum of the air mass values of the selected air channels (4a-4d); determining the throttle flap settings of the selected air channels (4a-4d) using the air mass values specific to the settings, such that the required system pressure is achieved, wherein the throttle flap settings of said air channel (4a-4d) out of the selected air channels having the greatest unthrottled pressure loss are the unthrottled setting; setting the throttle flaps (5a-5d) to the associated, previously determined throttle flap settings.