Drive an electric car for a long vacation, and you will be on fire

Produced by Tiger Sniff Car Group

Author|Li Wenbo

Head Image|Network

In the movie "The Wandering Earth" released in 2019, there is such a popular line:

There are thousands of roads, safety first.

Although these ten words sound unpretentious, they have profound brainwashing skills. So deep that every time you get into the driver's seat, fasten your seatbelt, hold the steering wheel, and get ready to go, this phrase will involuntarily ring in your ears.

Yes, driving on the road, nothing matters more than the word "safety".

How can you maximize the safety of driving, especially on the long and time-consuming holiday home?

It is necessary to start from two aspects: first, the human level, that is, the driver starts from himself and is the first responsible person for driving safety; Secondly, at the level of vehicles, with the increasing number of new energy vehicles running on highways, elevated, provincial highways, county roads and rural roads at all levels in China, whether it is safer to drive a fuel vehicle home, or it is safer to drive a new energy vehicle back, has become a widely discussed social topic.

After all, in the past six months, news of various new energy vehicle collisions, fires, and spontaneous combustion has been common.

According to the statistics of the emergency management department, in the first quarter of 2023 alone, the spontaneous combustion rate of new energy vehicles increased by 32%, and an average of 8 new energy vehicles had fires (including spontaneous combustion) every day.

This means that a total of 720 new energy vehicles caught fire in the first quarter, and according to the 1.586 million new energy vehicle sales in China in the first quarter, the proportion of new energy vehicles in the first quarter of 2023 was as high as 0.45%.

Is it the safety factor of traditional fuel vehicles that have been tested by various consumers for a long time and have a "taste of antiques" is higher, or are new energy vehicles that have subverted the bad habit of building cars for a century and are full of epic innovative black technology safer?

To answer this question, we must first figure out what is going on in the automotive safety evaluation system.

First must be passive

I believe that people who have slightly participated in the evolution of China's automobile consumption will not be unfamiliar with the following already coated divine map:

A large group of sales stood on the front door of a Volkswagen, trying to convey the idea of "this car, more advanced".

Although this picture was repeatedly ridiculed by the group at the time, in fact, it did show a facet of passive safety in the safety performance of a car.

According to the traditional theoretical system, automobile safety is simply divided into two dimensions: "active safety" and "passive safety": among them, "active safety" focuses on preventing as much as possible before an accident; "Passive safety" is concerned with minimizing the damage to people, vehicles and the surrounding environment after an accident.

At a finer granularity, "active safety" is divided into four branches: driving safety, environmental safety, sensory safety, and operational safety.

Driving safety focuses on vehicle performance itself, such as improving handling and raising the possibility of saving vehicles in extreme conditions; Improve the rigidity of the body and reduce the intrusion of external forces into the passenger compartment in the event of a collision;

Environmental safety focuses on reducing the psychological pressure of drivers during driving, such as ambient lights, fragrance systems, automatic air conditioning, etc.;

Feeling safe aims to improve the driver's awareness of the surrounding environment during driving, such as the front windshield with a better sense of openness, and the vehicle approaching a reflector that can be alerted by lights. In the era of smart electric vehicles, the burden of feeling safe is shared by sensors such as cameras, millimeter-wave radar, and lidar.

Operational safety is best understood, that is, make full use of ergonomics in the cockpit, reduce the driver's line of sight during driving, such as the current smart electric vehicle likes to use voice control, gesture control to replace traditional physical buttons, the purpose is to "open the mouth without hands".

"Passive safety" also has its own more granular division: external security and internal security.

The goal of external security is to protect traffic actors who are not present in the cockpit, such as pedestrians, bicycles, battery cars. The most well-known external safety measure is the active pop-up engine compartment cover - when the front of the car hits a pedestrian, the part of the engine compartment cover close to the front windshield bounces up, preventing the pedestrian from hitting the glass due to the impact force, reducing the probability of secondary injury.

Interior safety is best understood – ensuring the safety of every occupant in the cabin, whether in the front, rear or third row. Common measures are seat belts and airbags, which are "life-saving artifacts" in emergencies.

Whether it is a traditional fuel vehicle or a new energy vehicle, if you want to achieve the high safety of the final vehicle, you must start from the two core dimensions of "active safety" and "passive safety".

In terms of the current situation of automotive safety technology, new energy vehicles, especially pure electric vehicles running on the road with large battery packs, do have a certain gap in safety and traditional fuel vehicles.

The reason is that a pure electric car that is safe enough = a frame that is safe enough + a very safe battery pack.

To make the frame safe, the difficulty itself is very high, plus a "naturally delicate, unstable personality, fire when touched" battery pack, the difficulty is even higher.

Battery safety is a complex system engineering, which mainly consists of four projects:

Mechanical safety, that is, whether the battery pack can ensure structural safety under the action of external forces such as vibration, impact, impact, and extrusion;

Circuit safety, insulation safety between high-voltage components, to ensure that the entire battery pack will not suffer due to short circuit;

Heat-resistant and safe, this is a good understanding, when the battery overheats for various reasons, can it explain the external pressure leakage to ensure that the battery pack does not catch fire;

Wading safety, test the waterproof performance of the battery pack, when passing through water, the inside will not cause short circuit due to water seepage.

We know that building a car is throwing money, but this money is down, at least a few cars can be seen driving down the production line. But to do battery safety, many times, money down, is thrown into the water, battery safety improvement effect, extremely limited. The most effective path is "no cost, no return", but such a "foolish" path obviously goes against the original intention of the vast majority of automobile companies to "make money".

Moreover, the batteries are bought from the supplier, and from the root, this research and development fund should also be paid for the battery.

Taking the initiative is the nirvana

In terms of passive safety, new energy vehicles are indeed trapped by batteries, and they have distanced themselves from old fuel vehicles. But this distance, new energy vehicles rely on the advanced nature of active safety to make up for it.

After the collision, traditional fuel vehicles may be safer. But, is there a possibility that this car could not have been hit?

On a 100,000 yuan Chinese brand new energy vehicle, you can see a variety of full driving assistance functions, and even support high-speed NOA functions covering the whole country. But on traditional fuel vehicles at the same price, the highest-level intelligent driving function you can find is lane keeping that is not yet standard.

The reason behind this is that the electronic and electrical architecture of new energy vehicles and traditional fuel vehicles has a version iteration gap.

Most of the traditional fuel vehicles use distributed electronic and electrical architecture, and the suppliers package the functions and hardware, sell them to car companies in the form of black boxes, and assemble them in the corresponding positions to perform fixed functions.

Each ECU is responsible for controlling a single functional unit, common such as engine controller (ECM), driveline controller (TCM), brake controller (BCM), battery management system (BMS), etc.

If you want to add a function, it is very troublesome, first add an ECU, add a wiring harness, and finally, find its place in the already crowded space.

Even with the help of the CAN bus in the later stage, the electronic and electrical architecture of the whole vehicle has been streamlined, it still cannot undertake the large number and cumbersome intelligent functions of the intelligent car era. The number of ECUs in non-intelligent vehicles is only dozens, but the number of ECUs in smart cars can easily exceed hundreds, and the length of the wiring harness connecting the ECUs becomes longer, and the weight also increases, resulting in increased vehicle costs and low assembly automation rates.

Moreover, the distributed architecture makes each function in the car can only be an information island, car companies are highly dependent on suppliers, want to upgrade functions, need a supplier, a supplier communication docking.

To take the simplest example, for example, after a car company launched a new car, it received a large number of complaints from users about the granularity of the speed adjustment of the wipers, and the car company hopes to modify it. However, post-listing modification is equal to secondary development, and it is necessary to mobilize suppliers at all levels of the chain, re-do the calibration and verification at all levels, spend money, take a long time, and when the modification is finally released, users may have sold the car.

This kind of hardware-based development system process obviously cannot meet the needs of anxious users in the era of intelligent cars.

New energy vehicles using centralized electronic and electrical architecture just solve these troubles: a small number of high-performance computing units replace a large number of ECUs in the past, and small sensors scattered everywhere are integrated into a single sensor with more powerful functions, first integrated into functional domains: power domain, chassis domain, body domain, cockpit domain, automatic driving domain, and then centralized and simplified into three functional domains: automatic driving domain, intelligent cockpit domain, and vehicle control domain.

Source: Zosi Automotive Research Institute "2023 Intelligent Vehicle E/E Architecture Research Report"

The resulting decoupling of software and hardware makes rapid iteration of functions a reality, and any function can be implemented OTA as long as the hardware supports it.

This makes the active safety of the car, no longer relying on the "native family" to live a life like passive safety, but a growth function with infinite possibilities and can keep pace with the times.

Traditional fuel vehicles, if the lane keeping function is not realized when leaving the factory, then basically to the day of scrapping, users will not enjoy it. But smart electric vehicles, there is no function when leaving the factory, users still have at least a trace of imagination, this time OTA does not, the next OTA does not, the next time may have.

Write at the end

If you only watch the news, you will feel that new energy vehicles are catching fire, spontaneous combustion, and explosion all the time. In fact, the maturity of new energy vehicles in safety is indeed not comparable to fuel vehicles, at least at this stage, electric vehicles are still a long way from being truly safe.

But we cannot ignore that fuel vehicles have also developed after a hundred years of development and learned lessons from blood and tears from various accidents to the ultimate state of "foolproof" today. This is like letting the little immortals who have only practiced for 10 years engage in actual combat confrontation with the ancient primordial gods who have been cultivating for thousands of years, which is somewhat "bullying".

For new energy vehicles, we can be more patient, just like when we wait for charging in front of the highway charging pile.