1. Accident review: the extreme challenges of autonomous driving
On the night of March 29, a Xiaomi SU7 was involved in a serious traffic accident on the highway, resulting in a fire in the vehicle, and a total of three drivers and passengers were killed. Draw a lesson from a bitter experience! The accident sparked extensive discussions about autonomous driving systems (NOAs), battery safety, and vehicle design. New energy vehicles, autonomous driving and other industry hotspots in full swing seem to collectively cool down, stop, and think about what more urgent and priority things the industry has to do in the face of life safety!
Xiaomi provided a timeline of the accident today (April 1), showing that NOA had issued multiple warnings before the accident, but the driver took over only 0.4 seconds before and failed to avoid danger. This detail also exposes the difficulty of interacting intelligent driving systems with human drivers in emergency situations.
22:44:24 NOA issues a risk warning "Please be aware of obstacles ahead", sends a request to slow down, and starts to slow down
22:44:25 NOA is taken over, entering the driving state, the steering wheel turns to the left angle 22.0625 degrees, and the brake pedal opening is 31%
22:44:26 Steering wheel turns 1.0625 degrees to the right, brake pedal opening 38%
Between 22:44:26-28 Vehicle collides with concrete guardrail
22:44:28 Ecall triggers on the vehicle side
2. Deficiencies of NOA system: early warning mechanism and human-computer interaction optimization
The core challenge of the NOA system is how to get the driver to take over the vehicle in a timely manner at a critical moment. Research from Stanford University shows that it usually takes 2.3 seconds for a driver to switch from assisted driving mode to full control, while the NOA of the Xiaomi SU7 is only 0.4 seconds before the driver takes over, leaving little room for reaction.
Short warning time: Should the NOA warn the driver at an earlier stage, especially in difficult road conditions?
Lane Change Strategy: Is it possible to optimize the NOA's lane change decisions to take a more conservative approach when faced with unknown obstacles?
Automatic Brake Optimization: Should the NOA enable a stricter brake protection mechanism by default to reduce the impact of accidents?
Although Xiaomi's NOA is similar to Tesla's FSD, Huawei's ADS and other systems, such accidents show that the existing autonomous driving system still does not fully solve the reliability problem of human-computer interaction.
Pictured: Xiaomi SU7 accident killed 3 people
3. Battery safety: technical analysis of collision and fire
After the accident, the vehicle caught fire in a short period of time, which raised concerns about the safety of lithium iron phosphate batteries. According to data from the New Energy Vehicle Research Center of Tsinghua University, the probability of electric vehicles catching fire after a collision is about 3.7 times that of fuel vehicles, but this data still needs to be analyzed in combination with the specific collision environment.
Is the battery structure optimized? Lithium iron phosphate batteries have a lower risk of thermal runaway than ternary lithium batteries, but if the battery pack structure and anti-collision design of the vehicle are insufficient, it may still cause short circuit or thermal runaway due to mechanical shock.
Is there a safer battery protection design? Some companies in the industry, such as BYD, use "blade batteries" to strengthen the structure to reduce collision damage, can Xiaomi learn from such designs?
Is it possible to add thermal runaway detection? Can the existing BMS (Battery Management System) prevent the spread of fires through faster temperature monitoring and isolation mechanisms?
4. Locked car door controversy: Is the emergency escape mechanism perfect enough?
The family of the owner questioned that the door of the Xiaomi SU7 could not be opened after the accident, making it difficult for passengers to escape. Many modern electric vehicles use electronic door lock systems, but in the event of a power outage, are there enough clear escape instructions and redundant design?
Is the escape mechanic intuitive? Modern electric vehicles are often equipped with mechanical emergency unlocking devices, but in an emergency, can passengers quickly find and use them?
How reliable is the door opening in the event of a power outage? In 2024, 17 electric vehicles have been recalled due to the problem of door lock failure after power failure, does the Xiaomi SU7 also have similar design flaws?
This issue requires car companies to provide more clear technical explanations, while optimizing escape mechanisms in future product designs.
5. Data Transparency and Corporate Responsibility: How to Balance Investigation and Public Trust?
Xiaomi has released a timeline of the accident, but some members of the public are still skeptical about transparency. In contrast, after Tesla had a similar accident in 2018, Musk responded directly and provided detailed technical analysis.
Should companies proactively provide complete driving data? To the extent permitted by regulatory authorities, open incident data can increase public trust.
What is the difference between domestic and foreign brands in crisis PR? Tesla tends to respond directly to consumers, while domestic automakers usually focus more on technical explanations, should this strategy be adjusted?
6. Future improvement direction: the safety boundary of intelligent driving
The accident exposed multiple problems in the safety and human-computer interaction of smart electric vehicles. In the future, Xiaomi and other car companies can consider:
Optimize the NOA system:
Enhance early warning time to avoid sudden takeover challenges.
Adjust autonomous driving strategies in complex road conditions to reduce high-risk lane change behaviors.
The automatic braking logic is further optimized to reduce accident damage.
Improving battery safety:
More advanced anti-collision structures are used, such as BYD's "blade battery" or CATL's CTP technology.
Strengthen the real-time monitoring of BMS to improve the thermal runaway protection capability of the battery.
Improved Escape Design:
Enhance the mechanical emergency unlocking design to ensure that the door can be opened quickly in the event of an accident.
Provide more intuitive escape guidance in the car to improve user awareness.
Improving corporate transparency:
After the accident, proactively provide more detailed technical analysis and improvement plans.
Combined with the experience of international crisis public relations, enhance consumer communication and improve brand trust.
7. Conclusion: Technological progress needs to move forward cautiously
The Xiaomi SU7 accident reminds us that intelligent driving technology is still in the development stage, and safety challenges cannot be ignored. Although the NOA system can theoretically improve driving convenience, in practice, it is still necessary to optimize human-computer interaction, improve battery safety, optimize vehicle design, and enhance corporate responsibility.
In the future, the smart electric vehicle industry should find a better balance between innovation and safety to ensure that user safety is always the core of technological development.
