PTC Shroud Sensor Cover Ice Removal
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Solution Overview
Problem
Extreme temperatures and environmental conditions, such as ice buildup, can impair sensor performance in outdoor imaging systems by blocking light and obscuring the field of view.
Innovation Solution
An imaging system incorporating a positive temperature coefficient (PTC) shroud on the sensor cover, electrically coupled with an active cooler and blower, which heats or cools the cover to remove debris and ice by controlling heat radiation based on temperature, thereby maintaining sensor clarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the sensor is exposed to outdoor environment for imaging, then imaging capability is improved, but ice buildup blocks light and obscures imaging
Solution Approach 1:
The PTC shroud changes its electrical resistance based on temperature, which controls the amount of heat generated. At low temperatures, the shroud generates heat to prevent ice buildup. As temperature rises and resistance increases, heat generation decreases, preventing overheating and protecting the sensor from thermal damage.
Solution Approach 2:
The system utilizes phase transition of ice to water by heating the cover through the PTC shroud. When temperature reaches melting point, ice transitions to liquid water and is then blown away by the cooling fan, clearing the cover surface and restoring light transmission.
2Object-affected harmful factors
If active cooling is used to remove debris, then sensor clarity is improved, but sensor temperature may drop too low causing ice buildup
Solution Approach 1:
The PTC shroud acts as a temperature-dependent feedback mechanism. When the cooling fan operates and cover temperature drops, the PTC shroud's resistance decreases, allowing more current and heat generation to warm the cover. This automatic feedback prevents temperature from dropping too low and forming ice.
Solution Approach 2:
The PTC shroud provides preliminary heating action before ice can form on the cover. By continuously monitoring temperature through its resistance changes and providing preemptive heat, the system prevents ice buildup rather than reacting after ice forms, working in coordination with the cooling fan.
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
The system effectively clears debris and ice from the sensor cover, enhancing imaging capability by regulating temperature-dependent heat radiation, thus improving sensor performance in varying environmental conditions.
Implementation Method 1
a positive temperature coefficient (PTC) shroud on the sensor cover... controlling heat radiation based on temperature
Implementation Method 2
controlling heat radiation based on temperature
Data Source
AI summary
A sensor and a system using the sensor are described. The sensor may comprise: a cover; and a positive temperature coefficient (PTC) shroud located at a periphery of the cover. The system may include one or more such sensors in a passage of a housing. The system further may comprise a blower that moves air through the passage and across at least a portion of the sensor(s).