Vehicle Auxiliary Heating Control for Air Temperature Stability
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Solution Overview
Problem
Existing electric auxiliary heating systems for motor vehicles struggle to maintain consistent air temperature due to inertia effects in heating elements, leading to insufficient heating during acceleration and excessive heating during deceleration, causing discomfort and draught issues.
Innovation Solution
The system adjusts the temperature of the air discharged by the auxiliary heating unit based on vehicle speed, using a control unit to vary the heating power and decouple air flow rate from speed changes, while considering cold air temperature and external parameters, to maintain comfortable temperatures in the passenger compartment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the air current volume is increased during acceleration phase, then the heating coverage is improved, but the heating element cannot provide sufficient heating power due to inertia
Solution Approach 1:
The control unit anticipates the need for heating power adjustment by detecting vehicle acceleration and proactively increasing heating power before the temperature deficit occurs. This preliminary action compensates for the thermal inertia of the heating element, ensuring adequate heating power is available when air current volume increases during acceleration.
Solution Approach 2:
The system continuously monitors temperature at the discharge opening and uses this feedback to dynamically adjust heating power. When temperature drops due to increased air flow during acceleration, the feedback loop detects this and increases heating power accordingly, maintaining temperature stability despite the inertia of the heating element.
2Stability of the object's composition
If the heating power is maintained constant during deceleration, then the heating stability is improved, but excessive heating occurs due to reduced air current volume
Solution Approach 1:
The system transitions from static constant heating power to dynamic heating power adjustment based on vehicle speed and air current volume. During deceleration, when air flow decreases, the control unit automatically reduces heating power to prevent excessive temperature buildup, making the heating system adaptive rather than fixed.
Solution Approach 2:
Temperature monitoring at the discharge opening provides continuous feedback that enables the control unit to detect when discharged air temperature becomes excessive during deceleration. The feedback loop then reduces heating power accordingly, maintaining temperature within acceptable ranges despite changing air flow conditions.
3Temperature
If the blower and heating power are both controlled to adapt air current intensity, then the temperature stability is improved, but the device complexity increases
Solution Approach 1:
The invention extracts the temperature control function from the complex dual-control system (blower + heating power) and implements it through a simplified approach that primarily adjusts heating power based on vehicle speed and temperature feedback. This separation simplifies the control architecture while maintaining temperature stability.
Solution Approach 2:
The system changes the control parameter from dual-control (blower speed and heating power) to primarily heating power adjustment based on vehicle speed and temperature feedback. This parameter change simplifies the control system while achieving the same temperature stability objective through more direct control of the heating element.
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 ensures consistent and comfortable air temperatures in the passenger compartment by adapting heating power to vehicle speed and external conditions, reducing temperature fluctuations and enhancing passenger comfort.
Implementation Method 1
at least one PTC heating element (3) which heats the air (2) flowing through the auxiliary heating (1)
Data Source
AI summary
An electric auxiliary heating unit for a motor vehicle reliably avoids temperature overshoots of the heated air, especially during acceleration phases of the vehicle. The temperature of adjustment the discharged hot air is adjusted in dependence upon the vehicle speed. This is preferably done via a stored characteristic field via which a plurality of vehicle parameters, such as the vehicle speed, the opening condition of the convertible top, the outside temperature, etc., can easily be taken into account. The temperature of the incoming air can also be derived from temperature values which are already available in the vehicle. This heating can preferably be used locally in the vehicle, e.g. in the vehicle seat or in the rear of the passenger compartment. Temperature fluctuations in the heated air can be avoided reliably and easily even in the case of dynamically varying operating conditions of the motor vehicle.