ZHMT101 In-Vehicle Life Presence Sensor Module: High-Reliability Multi-Modal Sensing Core

Nexisense ZHMT101 series is specially developed for automotive aftermarket and OEM life safety applications, adopting a multi-modal architecture of infrared passive micro-motion detection (PIR + precision optical lens) combined with electrochemical CO gas sensor and auxiliary temperature and humidity monitoring. Through the internal MCU, it realizes real-time signal acquisition, noise suppression, breathing/heartbeat micro-motion feature extraction, and environmental risk assessment, ultimately outputting life presence status (present/absent), CO concentration (ppm), temperature (℃), and graded alarm flags.

Typical detection range covers the main areas inside a standard 5-seat passenger cabin (rear seats, trunk), with micro-motion detection sensitivity reaching sub-millimeter level (breathing motion), CO detection range 0～1000 ppm (resolution 1 ppm, accuracy ±5% FS). The module supports wide-temperature operation -40℃～85℃, complies with AEC-Q100 Grade 2 automotive electronics reliability requirements, low-power design (average<100 mW) adapts to long-term standby monitoring after vehicle shutdown.

Typical Application Scenarios and System Integration Value

Child and Infant Left-Behind Protection System ZHMT101 is integrated into the whole vehicle BMS or domain controller. After vehicle shutdown, when life signs (micro-motion + heartbeat features) are detected in the rear row and temperature >35℃ or CO >50 ppm, it triggers graded alarms: first in-cabin buzzer + mobile phone push, then remote air conditioning activation or window lowering. It has been implemented in multiple new energy vehicle models to achieve Euro NCAP Child Presence Detection compliance, supporting false-alarm-free standby monitoring for more than 15 minutes.

Pet Left-Behind and Animal Welfare Monitoring For pet transportation or daily carrying scenarios, the module distinguishes human/animal breathing patterns through micro-motion signals, combined with CO and temperature data to avoid high-temperature asphyxiation risks. Actual cases include multiple pet-friendly SUV aftermarket solutions, linked with vehicle T-Box to achieve remote real-time status query and ventilation control.

In-Cabin Environmental Risk Comprehensive Early Warning The sensor CO channel monitors concentration rise caused by exhaust leakage or air conditioning system failure in real time, combined with temperature anomalies to determine potential heatstroke risks. In projects, it is often fused with in-cabin air quality systems to form a closed-loop safety strategy: life presence + high-risk environment → forced ventilation + alarm.

Selection Guide and System Integration Notes

Key Parameter Selection Reference

Integration Notes

1. Installation Position: Preferably in the rear overhead light area or above the seat backrest, avoid direct sunlight and obstruction; optical window facing the main monitoring area.

2. LIN Bus Integration: Follow LIN protocol specification 2.2A, define dedicated node address and signal frames (life status, CO value, temperature, fault codes); recommend adding termination resistor (if it is a sub-node).

3. Power Management: Enter low-power mode after shutdown (<50 μA), support remote wake-up; recommend adding TVS and filtering circuit to suppress transient interference.

4. Algorithm Tuning: Factory preset multi-scenario thresholds, system side can adjust sensitivity and alarm grading (Level 1～3) through LIN configuration frames.

5. EMC and Reliability: The module has passed CISPR 25 Class 3 radiated emission and immunity tests; install away from high-power antennas and motors during installation.

6. Function Self-Check: Automatically perform sensor health check after power-on, output DTC code in case of abnormality, convenient for OTA diagnosis.

OEM Customization and Bulk Supply Advantages

Nexisense provides end-to-end support for the automotive supply chain:

• Interface protocol customization (extended CAN FD bridging, custom signal definitions, diagnostic services).

• Shape and installation optimization (different size housings, angle adjustment brackets, concealed installation solutions).

• Algorithm scenario adaptation (detection field adjustment for SUV/MPV cabin layout).

• Consistency assurance: inter-batch micro-motion sensitivity deviation<10%, CO zero drift <2 ppm/year, provide CoC and AEC-Q100 test reports.

• Supply capability: support annual production scale of 200,000+ pieces, suitable for platform model introduction and global market expansion.

These advantages help Tier1 suppliers and OEMs quickly pass regulatory certification and achieve differentiated safety functions.

Frequently Asked Questions FAQ

1. What diagnostic services does the ZHMT101 LIN output protocol support?
   Supports UDS diagnostics (ISO 14229), including reading DTC, life status query, CO concentration real-time value, and sensor self-test results, convenient for whole vehicle OBD system access.

2. How does the module distinguish micro-motion signals of children/adults/pets?
   Distinguish through signal amplitude, frequency characteristics, and persistence algorithm: children/pets have higher breathing frequency (0.2～0.5 Hz) and smaller amplitude; system side can configure thresholds for further subdivision.

3. How is the false alarm rate controlled in strong sunlight or car window reflection environments?
   Adopts narrow-band infrared filter and dynamic background suppression algorithm, effectively filters environmental light interference; typical direct sunlight scenario false alarm<0.5%.

4. Does ZHMT101 support long-term standby monitoring after vehicle shutdown?
   Supported, enters ultra-low power mode after shutdown (<50 μA), battery life can reach several weeks; can be activated through door control signal or remote wake-up.

5. How does the CO sensor channel suppress cross-interference (such as ethanol, formaldehyde)?
   Electrochemical sensor selects high-selectivity electrodes, combined with algorithm compensation, cross-response to common in-cabin VOC<10%; system level can add threshold filtering.

6. How to adjust detection sensitivity and alarm grading through LIN configuration?
   The master node sends configuration frames (specific ID + data bytes), supports 3-level sensitivity and 4-level alarm threshold settings, power-down preservation.

7. Does bulk supply provide performance traceability reports for each batch?
   Yes, provides batch reports including micro-motion sensitivity, CO linearity, temperature compensation coefficients, and consistency statistics, supporting IATF 16949 audits.

8. How to perform on-site functional verification after module installation?
   Send self-test command through LIN diagnostic tool, module returns status code; standard breathing simulator or CO calibration gas can be used for end-to-end testing.

9. Does ZHMT101 comply with Euro NCAP Child Presence Detection test protocol?
   The design meets the protocol's rear-row life detection requirements (>99% detection rate,<1% false alarm), and actual projects have been verified by multiple third-party laboratories.

10. Does Nexisense provide reference integration code and debugging tools?
    Provides LIN protocol stack examples, configuration tools, and log parsing software, supporting rapid prototype verification and joint debugging during mass production introduction.

Conclusion

Nexisense ZHMT101 in-vehicle life presence sensor module meets the core requirements of modern intelligent vehicles for life safety and environmental risk monitoring with multi-modal fusion perception, LIN compatible interface, and automotive-grade reliability. Whether it is front-mounted child left-behind protection, pet safety extension, or comprehensive in-cabin early warning system, this series can provide stable and precise data and control foundation.

If you are developing related ADAS/safety domain functions, evaluating life detection sensor solutions, or planning bulk mass production introduction, welcome to contact the Nexisense engineering team. We can provide detailed specification sheets, prototype verification support, and joint integration debugging services to jointly explore the technical path and regulatory compliance strategy most suitable for your project.