Vehicle Intake Air Heater Coil Resistance Control
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Solution Overview
Problem
Existing intake air heating systems for internal combustion engines face challenges in efficiently controlling the temperature of the heater coil, leading to potential over-temperature conditions and increased wear, especially when the engine is started from a warm condition, as they do not accurately account for the air heater's initial temperature and ambient conditions.
Innovation Solution
The system employs a control circuit that measures the resistance of the heater coil to infer its temperature, calculates a desired resistance based on a target temperature, and modulates the current to maintain the desired resistance, using a combination of voltage and current measurements and pulse-width modulation to perform closed-loop control, while also accounting for connection resistance and ambient temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed time-out control is used for the air heater, then the heater is guaranteed to cool down before warm restart, but the heater may overheat when the engine is started from a warm condition
Solution Approach 1:
The patent implements feedback control by measuring the resistance of the heater coil to determine its temperature, then using this information to modulate the electrical switching device and adjust current flow accordingly. This closed-loop feedback mechanism prevents both overheating and unnecessary heating by continuously monitoring and adjusting based on actual heater state.
Solution Approach 2:
The system transitions from static fixed time-out control to dynamic control that adapts to real-time conditions. The electrical switching device is modulated based on measured resistance values, allowing the heater operation to dynamically respond to varying thermal conditions, ambient temperature, and engine state.
2Speed
If full current is continuously supplied to the heater coil, then the heater reaches target temperature faster, but energy consumption increases and wear increases
Solution Approach 1:
The system uses periodic modulation of the electrical switching device rather than continuous full current supply. By pulsing current based on measured resistance and thermal state, the heater achieves necessary temperature while reducing overall energy consumption and wear compared to continuous full-power operation.
Solution Approach 2:
The control system changes the current parameter dynamically based on measured resistance values. Current magnitude and duration are adjusted according to the heater's actual thermal state, transitioning from fixed parameter control to variable parameter control that optimizes energy efficiency while maintaining heating effectiveness.
3Reliability
If the heater operates for extended periods to ensure warm condition, then ignition reliability improves, but the system complexity increases
Solution Approach 1:
The patent replaces complex mechanical temperature sensing and control mechanisms with electrical resistance measurement. By using the heater coil's own resistance as a temperature indicator, the system achieves accurate thermal monitoring without additional mechanical sensors or complex control hardware, simplifying the overall system while maintaining ignition reliability.
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 effectively prevents over-temperature conditions by accurately controlling the heater coil temperature, reducing wear and energy consumption, and allowing for faster engine starts while minimizing emissions.
Implementation Method 1
an electrical switching device configured to selectively connect a battery of the vehicle to a heater coil in contact with intake air of the vehicle
Implementation Method 2
The control circuit is configured to measure a resistance of the heater coil indicative of a temperature of the heater coil
Data Source
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AI summary
An intake air heating system for a vehicle includes an electrical switching device configured to selectively connect a battery of the vehicle to a heater coil in contact with intake air of the vehicle. The intake air heating system includes a control circuit configured to, in response to an enable signal from an engine controller, drive the electrical switching device to connect the battery to the heater coil at full current. The control circuit is configured to measure a resistance of the heater coil indicative of a temperature of the heater coil. The control circuit is configured to, in response to the temperature of the heater coil exceeding a desired temperature value, modulate the electrical switching device to reduce current from the battery of the vehicle to the heater coil.