Detailed Explanation of Temperature Control Technology in Automotive Air Conditioning System Sensor Networks
1. Core Sensor Configuration
Evaporator Temperature Monitoring
Using an NTC temperature sensor with a B value of 3950K, installed in the middle of the evaporator fins
Detection accuracy ±0.1℃ (at 25℃), response time < 3 seconds
Frost prevention control: Immediately shut down the compressor when the temperature approaches 0℃
Multi-zone Temperature Sensing
4-6 environmental temperature sensors arranged inside the vehicle (front/rear/left/right/top)
Using a 10kΩ NTC in series with a 10kΩ fixed resistor in a voltage divider circuit (3.3V power supply)
The temperature field reconstruction algorithm achieves a spatial resolution of 0.5℃
2. Intelligent Control System
Dual-mode Control Strategy
PID Control: Basic temperature adjustment (proportional coefficient 0.8, integral time 2 min)
Fuzzy Neural Network: Handles nonlinear operating conditions (rule base contains 128 control rules)
Outlet Temperature Stability: ±1℃ (traditional systems ±3℃)
Precise Control of the Compressor
Variable displacement compressor control response time < 2 seconds
PWM duty cycle adjustment based on evaporator temperature (1% resolution)
Cooling efficiency improved by 30% (compared to traditional switch control)
3. System Optimization Technology
Dynamic Calibration Mechanism
Automatic zero-point calibration every 24 hours (performed when the compressor is off)
Three-point temperature calibration (0/25/80℃ ice water bath calibration)
Pressure sensor five-segment linear compensation (0-5MPa range)
Energy Consumption Optimization Plan
Advance control based on load prediction (reducing energy consumption by 15%)
Humidity sensor linked control (dew point accuracy ±2℃)
Intelligent sleep strategy used in models like Tesla (standby power consumption < 5W)
4. Typical Fault Protection
Response to Sensor Failure
Triple redundancy design (main backup + thermal backup sensors)
Automatically switch to safe mode during failure (fixed 22℃ air supply)
CAN bus transmission calibration coefficient (compliant with ISO 11898-2)
Handling Abnormal Operating Conditions
Fault Type
Countermeasures
Recovery Time
Sensor Drift
Enable self-calibration mode
<30 seconds
Communication Interruption
Switch to local closed-loop control
Immediate effect
Extreme Temperature
Gradient limit protection
Adjust at 1℃/min
Note: Modern high-end models collect sensor signals through a 24-bit ADC, combined with a Kalman filtering algorithm, can reduce temperature control fluctuations to ±0.5℃. For new energy vehicles, special attention should be paid to the temperature compensation design of the 7MPa high-pressure sensor to ensure 0.5% FS accuracy across the full temperature range of -40~125℃.