Vehicle Climate Control During Ambient Sensor Heat Soak

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Solution Overview

Problem

The ambient temperature sensor readings in vehicle climate control systems become inaccurate during heat soak mode, where the vehicle is idling or moving at low speeds, due to heat absorption from the engine and ground, leading to errors in maintaining comfort levels within the occupant compartment.

Innovation Solution

A method and system that compare current ambient temperature readings to stored values prior to entering heat soak mode, controlling the HVAC system using the current temperature if it's lower, and determining heat build-up if it's higher, with the system exiting heat soak mode when heat build-up is eliminated, allowing for accurate temperature measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the ambient temperature sensor is used during heat soak mode, then the sensor provides continuous temperature readings, but the temperature measurements become inaccurate due to heat absorption from engine or ground

Engineering Contradiction:

Improveambient temperature measurement accuracyVSAvoidheat absorption from engine or ground

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary action by detecting heat soak conditions before they significantly corrupt the temperature reading. When heat soak mode is detected (vehicle speed below threshold for predetermined time), the system proactively switches to using stored ambient temperature data rather than relying on the corrupted sensor reading, preventing inaccurate climate control decisions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system introduces an intermediary mechanism by using a stored ambient temperature value as a mediator between the corrupted sensor reading and the climate control system. When heat soak is detected, the stored temperature acts as a temporary substitute, allowing the system to maintain accurate climate control without directly using the heat-affected sensor data.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If a fixed speed threshold is used to exit heat soak mode, then the control logic is simple, but the timing of when to resume using sensor readings is inaccurate because the actual time period should be variable

Engineering Contradiction:

Improvecontrol logic simplicityVSAvoidtemperature reading resumption timing accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The system applies dynamics by transitioning from a static fixed threshold approach to a dynamic variable threshold approach. The exit speed threshold is no longer fixed but varies based on how long the vehicle has been in heat soak mode and the rate of temperature change, allowing the system to adapt to different thermal conditions and accurately determine when sensor readings can be reliably used again.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes parameters by making the exit threshold a variable parameter rather than a constant. The threshold dynamically adjusts based on operational conditions, specifically the duration of heat soak mode and temperature differential, enabling more precise control over when to resume using ambient temperature sensor readings.

Inventive Principle:

Principle #35Parameter changes

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 improves the accuracy of ambient temperature measurement and enhances the HVAC system's ability to maintain comfort levels by distinguishing between actual and heat-soaked temperature readings, ensuring precise control and comfort within the vehicle.

Implementation Method 1

obtaining a current ambient temperature reading outside the vehicle

Methodology Applied

Scientific EffectThermal energy measurement:

Implementation Method 2

providing heating, cooling and ventilation

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 3

providing heating, cooling and ventilation

Methodology Applied

Scientific EffectCooling: Cooling

Implementation Method 4

the outside air temperature associated with the vehicle is affected by absorption of non-ambient heat

Methodology Applied

Scientific EffectHeat absorption: Absorption (physical)

Implementation Method 5

heat absorption from the engine or ground

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS20070033953A1Method and system for controlling a climate control system

Publication Date: 2007.02.15 FCA US LLC

AI summary

A method and system for controlling a climate control system on a vehicle after enering a heat soak mode in which the outside air temperature associated with the vehicle is affected by absorption of non-ambient heat includes an ambient temperature sensor for sensing a current ambient temperature outside the vehicle. A controller coupled to the ambient temperature sensor compares the current ambient temperature to a stored ambient temperature representative of the outside air temperature prior to entering the heat soak mode. The controller controls the climate control system using the current ambient temperature if the current ambient temperature is less than the stored ambient temperature. If the current ambient temperature is greater than the stored ambient temperature, the controller determines a heat build up affecting the current ambient temperature and controls the climate control system using the current ambient temperature only upon elimination of the heat build up.