Vehicle Camera Heater Control for Dew-Point Defogging
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Solution Overview
Problem
Existing heater control devices for vehicles do not effectively prevent fogging in the image capturing transparent region of window glass without wasting energy, as they lack consideration for dew-point temperature and require a temperature sensor, increasing manufacturing costs.
Innovation Solution
A heater control device that estimates the dew-point temperature based on inside temperature and humidity, and controls the camera heater's energization using a correlation between outside temperature, vehicle speed, and energization electric power to maintain the image capturing transparent region's temperature above the dew-point, preventing fogging while minimizing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the heater is energized continuously to prevent fogging, then the fogging prevention reliability is improved, but the energy consumption increases
Solution Approach 1:
The heater control system dynamically adjusts the heater's operation state based on real-time temperature and humidity sensor data. The control unit calculates the dew-point temperature and compares it with the actual glass temperature to determine whether heating is needed, transitioning the system from static continuous heating to dynamic conditional heating, thereby preventing fogging while reducing unnecessary energy consumption.
Solution Approach 2:
The system incorporates temperature and humidity sensors that continuously monitor the image capturing transparent region's conditions. The control unit receives this feedback, calculates the dew-point temperature, and adjusts the heater's energization accordingly. This closed-loop feedback mechanism ensures the heater operates only when necessary to maintain the glass temperature above the dew-point, optimizing both fogging prevention and energy efficiency.
2Measurement precision
If a temperature sensor is added to detect glass temperature for precise control, then the control precision is improved, but the manufacturing cost increases
Solution Approach 1:
The system utilizes the vehicle's existing temperature and humidity sensors (already present for cabin environmental control) to calculate the dew-point temperature and determine heating requirements. Instead of adding dedicated glass temperature sensors, the system makes the existing sensors serve dual purposes: cabin comfort monitoring and fogging prevention control, thereby achieving precise control without increasing manufacturing cost.
Solution Approach 2:
The system transforms the control approach from direct glass temperature measurement to indirect dew-point temperature calculation using the relationship between temperature and humidity parameters. By calculating dew-point from existing temperature and humidity sensor data and comparing it with actual temperature, the system achieves equivalent control precision without the need for additional expensive glass temperature sensors.
3Reliability
If the heater energization is increased to ensure fogging removal, then the fogging removal effectiveness is improved, but the energy wastage increases
Solution Approach 1:
The system applies partial heating action only when and where needed by comparing the actual glass temperature with the calculated dew-point temperature. Instead of excessive continuous heating of the entire window, the system provides targeted heating to the image capturing transparent region only when the temperature approaches the dew-point, achieving effective fogging prevention while minimizing energy wastage through proportionate heating action.
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
Accurately prevents fogging in the image capturing transparent region without the need for a temperature sensor, reducing energy wastage and manufacturing costs by maintaining the region's temperature above the dew-point without excessive heating.
Implementation Method 1
a camera heater (24) configured to generate heat by being energized, and to heat the image capturing transparent region with the generated heat
Data Source
AI summary
A heater control device includes a camera sensor configured to capture an image of an outside of a vehicle through an image capturing transparent region of a window glass, and a camera heater configured to heat the image capturing transparent region. The heater control device is configured to: apply, to a correlation which is set in advance between an outside temperature, a vehicle speed, and energization electric power, and a temperature of the image capturing transparent region corresponding to the outside temperature, the vehicle speed, and the energization electric power, the outside temperature at a current time, the vehicle speed at the current time, and a target temperature equal to or higher than a dew-point temperature, to thereby determine defogging electric power so that the temperature of the image capturing transparent region is prevented from falling below the dew-point temperature.