One of the First Learners of Autopilot —— Autopilot Level

Automatic driving classification first appeared in a specification J30 16 of American Society of Automotive Engineers (SAE). This specification first defines that autonomous driving is divided into six levels, which we often hear: L0-L5.

For the first time, L0-L2 is designated as assisted driving in the specification, and it can only be called automatic driving above L3 level. At present, this specification has just updated 202 1. In addition to this standard, it is also stipulated in the national standard GB/T40429 issued in February1year. Although the national standard is not called L0 and L 1, it is called 0 and 1 and so on. Generally speaking, the national standard is basically the same as the latest version J30 16.

1, level 0

Level 0 driving automation corresponds to l 0, which can be understood as mainly including two functions. One is the early warning function, which only provides early warning, but will not interfere with the driver's control of vehicle acceleration, deceleration and steering. Basically, all functions that only include early warning and control are related to the L0 level. The other part is the control function, but this part of the control function has a feature that it will not help you control the vehicle continuously, but will only temporarily intervene in the acceleration and deceleration or steering control of the vehicle under certain conditions.

2, 1 level

1 level driving automation corresponds to L 1, which will help drivers to continuously control lateral or longitudinal movements. And will only continue to control one of them. In other words, L 1 will only help you to continuously control one of the acceleration, deceleration or steering of the vehicle.

Level 3 and level 2

Level 2 driving automation corresponds to l 2. This horizontal function will continue to help the driver provide longitudinal and lateral control, that is, it can control the steering and acceleration and deceleration of the vehicle at the same time for a long time. Usually, the functions of L2 and below mentioned above are also called ADAS (Advanced Driver Assistance System) functions.

These functions are not automatic driving functions, but they can better assist drivers. The theme of driving is still the driver, that is to say, the driver should take full responsibility for the whole driving process. These functions have one thing in common, that is, they cannot go against the driver's intention. For example, the current system is determined to provide the driver with the function of longitudinal acceleration, but the driver thinks that it is necessary to slow down at present and gives a deceleration operation, then the vehicle should immediately stop slowing down and then respond to the driver's operation.

Fourth and third grades

Three-level driving automation corresponds to l 3 and L3, which we call conditional automatic driving. The vehicle can be driven automatically on the premise of meeting the required conditions. When the automatic driving system judges that the automatic driving cannot be completed, it will request the driver to take over the vehicle. The driver needs to take over the vehicle within a certain period of time (generally 10). If the driver does not take over the vehicle, the autopilot system will no longer be responsible for the vehicle once the allowed take-over time is exceeded.

If the driver does not take over the vehicle after making the request, the automatic driving system needs to choose whether to implement the minimum risk strategy according to the situation, so that the vehicle can reach the minimum risk state (generally speaking, it is to pull over or stop in the driveway and light up the double flash).

In J30 16, the part that vehicles need to meet is called ODD (Operation Design Domain), that is, the design operation area. Generally speaking, ODD includes road conditions, weather conditions, geographical fences (such as Shanghai Jiangqiao Toll Station to Overseas Chinese Greenland Avenue Toll Station of Beijing-Shanghai Expressway, excluding the up-and-down ramp area), traffic participants, signal connectivity (RTK-GPS signal) and so on. ).

In China's national standards, the description of the working conditions that vehicles need to meet is ODC (design working conditions), that is, design working conditions. The main difference is that ODC contains odd numbers, and it also requires the driver's state (fatigue, eyes closed, eyes not in the driving area, etc.). ) is added.

It is worth mentioning that the most fundamental difference between L3' s function and L2' s function lies in the attribution of responsibility and sovereignty, rather than the problem of covering more scenes as many friends understand. For example, the function of NOA is much more advanced than the traditional LCC or ICC, but it is essentially the same as LAA or ICC.

The function of L3 launched by Mercedes-Benz in Europe only covers one-way cruise below 60kph, and the function usage scenarios are basically the same as TJA, not as much as NOA, and the daily assistance is not as good as NOA, but this function is still the function of L3. From the perspective of mass production function planning, the idea of covering the scene is more practical than the idea of automatic driving level.

Level 5 and 4

Four-level driving automation corresponds to l 4, also called advanced automatic driving. The definition difference between L4 driving and L3 driving is only whether the driver must take over. L4 When the system cannot complete the driving task, the driver will still be prompted to take over, but the driver may be allowed not to take over the vehicle. At this time, the vehicle will implement the minimum risk strategy to ensure that the vehicle reaches the minimum risk state.

That is, during the whole process of L4 function activation, the automatic driving system always assumes the driving responsibility. At present, the application of L4 mainly focuses on some special scenes, such as unmanned feeder vehicles, unmanned delivery vehicles, unmanned taxis, unmanned buses and unmanned logistics vehicles in the park. This kind of application has the characteristics of * * *, and the use environment is in a scene with little change, whether in a park, in a specific high-speed range or on a specific urban road.

However, at present, the so-called L4 autopilot, which focuses on the concept of propaganda in most vehicles, can not be realized at present, and the following article can explain it in detail. In addition, some car companies have a telescopic steering wheel in the concept car, that is, when the function of L4 is turned on, the steering wheel shrinks, and the steering wheel reappears in the stage of manual driving or driver taking over.

Sixth and fifth grades

Level 5 driving automation corresponds to l 5, also called fully automatic driving. Fully-automatic driving cancels the restriction of ODD on the basis of L4, allowing the whole scene to use the automatic driving system, and the automatic driving system will pay full responsibility.

At present, L5-level autopilot will be considered as an unreachable state for a long time in the future, and it will stay in L4 state for a long time in the future, only expanding the scene coverage in L4 state, and even quite a few people think that L5 will never come.

Judging from the driver's condition, L2 can take off his foot, L3 can take off his hand and L4 can take off his eyes. The corresponding vehicle status L3 and the following functions are generally not allowed to cancel the steering wheel. L4 and above functions allow canceling the steering wheel. From the application point of view, L3 and the following functions are more common in mass-produced vehicles, while L4 functions are more common in operating vehicles in specific scenarios.

However, advanced functions will always be gradually applied to life. When the L4 function is popularized on a large scale, the way of human travel will be greatly changed. A bright future awaits us.