Vehicle Air Conditioner Passenger Detection Using Single IR Sensor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle air conditioner control systems that use multiple infrared (IR) sensors to detect passengers on rear seats increase costs and energy consumption by unnecessarily discharging air when no passengers are present, as they require separate sensors to measure passenger and reference temperatures.
Innovation Solution
A system that uses an IR sensor to sense the surface temperature of the passenger sitting part and estimates the reference temperature of the passenger non-sitting part through heat transfer and solar radiation changes, allowing for precise judgment of passenger presence and adjusting air conditioner output accordingly, reducing the need for additional sensors and optimizing energy use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple IR sensors are used to detect passengers on rear seats, then passenger presence detection accuracy is improved, but system cost and device complexity increase
Solution Approach 1:
The patent uses a single IR sensor to detect temperature at one location, then creates a virtual copy of this temperature reading and applies heat transfer mathematical models to estimate temperatures at other locations where additional sensors would be placed. This allows the system to achieve multi-point detection accuracy using only one physical sensor, thereby reducing device complexity while maintaining measurement precision.
Solution Approach 2:
The patent replaces the mechanical approach of using multiple physical IR sensors with a computational approach using heat transfer mathematical models. Instead of physically placing sensors at multiple locations to detect temperature, the system uses a single sensor combined with mathematical modeling to calculate and predict temperatures at multiple locations, substituting physical hardware with computational methods.
2Ease of operation
If air is discharged toward second and third row seats, then passenger comfort is improved, but energy consumption increases when no passengers are present
Solution Approach 1:
The system uses the temperature detection capability to automatically determine whether rear seats are occupied, and then self-adjusts the air discharge volume and temperature accordingly. When no passengers are detected, the system automatically reduces or stops air discharge to those areas, eliminating unnecessary energy consumption while maintaining comfort when passengers are present.
Solution Approach 2:
The patent dynamically adjusts air discharge parameters (volume and temperature) based on real-time passenger presence detection. The system continuously monitors temperature changes to determine occupancy status and adapts the air conditioning output in real-time, switching between different operational modes to optimize both comfort and energy efficiency.
3Measurement precision
If IR sensors measure both passenger temperature and reference temperature separately, then detection accuracy is improved, but cost and weight increase
Solution Approach 1:
The patent creates virtual temperature measurements at multiple locations by mathematically modeling heat transfer, rather than placing physical sensors at each location. The single IR sensor's measurement is copied and processed through heat transfer equations to generate estimated temperature readings at multiple points, achieving comprehensive temperature monitoring without additional sensor weight.
Solution Approach 2:
The single IR sensor serves multiple functions: it directly measures passenger seat temperature, provides reference data for heat transfer modeling, and enables indirect measurement of multiple other locations through mathematical calculation. This multi-functionality allows one sensor to replace what would traditionally require multiple sensors, reducing overall system weight.
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 allows for precise detection of passenger presence on rear seats without additional hardware, reducing energy consumption and costs by optimizing air discharge volume and temperature, thereby improving fuel efficiency.
Implementation Method 1
a sensor configured to sense surface temperature of a passenger sitting part of a rear seat of a vehicle
Implementation Method 2
estimate surface temperature of the passenger non-sitting part of the rear seat as a reference temperature using temperature change due to heat transfer through convection of indoor air
Data Source
AI summary
A system for controlling an air conditioner for vehicles may include a sensor configured to sense surface temperature of a passenger sitting part of a rear seat of a vehicle, a reference temperature estimation device configured to estimate surface temperature of the passenger non-sitting part of the rear seat as a reference temperature, a passenger boarding recognition device configured to compare the surface temperature of the passenger sitting part sensed by the sensor, with the reference temperature estimated by the reference temperature estimation device and to judge that a passenger is seated on the rear seat when a difference between the surface temperature of the passenger sitting part and the reference temperature exceeds a critical value, and an air conditioner operation controller configured to differently control volume and temperature of air discharged from the air conditioner according to whether or not a passenger is seated on the rear seat.