The development trend of automotive electronics-automotive safety integration

In the past 20 years, manufacturers have fierce and benign competition in the field of automobile safety, which has greatly improved the safety performance of automobiles. How automobile safety ratings meet or exceed national or international standards has become a marketing tool for automobile manufacturers. Innovation and advanced technology have become the core of the safety system. According to traffic safety data over the years, passive and active safety systems have been developed and improved in recent years, which has played a positive and effective role in reducing traffic accidents.

Figure ACC

Although automobile safety has been greatly improved, it is still an important challenge that needs to be further improved. Traffic data in 2007 showed that there were 41,000 fatal accidents and more than 2.4 million injuries across the United States caused by motor vehicle collisions. Passive safety systems such as seat belts, structural extruded belts and airbags have become rigid requirements and necessary components of automotive design. The purpose of developing these systems is to cushion the impact forces (ie, contact pressure, squeezing force, and acceleration) that passengers experience when they collide or brake suddenly. The branch of engineering specializing in this kind of technology is generally called "crash resistance research".

The safety measures used to protect passengers against crashes mainly focus on the following topics: car body structure design concepts (such as car front crash energy absorption devices, body steel plate hardness, etc.), advanced material development (such as high strength / weight ratio materials, composite Materials, reinforced pressure-resistant materials, etc.), as well as the design of specific safety systems composed of materials, structures, and other advanced components (such as seat belts, airbags, folding steering columns, side impact protection, etc.).

Although crash resistance measures help to improve the safety of cars, research shows that most crashes are caused by driver errors and illegal operations. There are various reasons for these situations, such as drunk driving, inattention, fatigued driving, and lack of control of the car. The US Department of Transportation ’s Highway Traffic Safety Administration (NHTSA) estimates that nearly 42% of traffic fatalities in the US each year are caused by drinking or driving under the influence of drugs. This is one of the most common criminal offences in the United States. Every year, one-third of Americans are involved in such charges, and an average of 167 people are arrested every hour. In the United States, every 39 minutes, one person dies due to drunk driving (the average alcohol concentration in the driver ’s blood is 0.08). On average, there are 37 people a day, and more than 16,000 people die every year.

Advanced vehicle control technologies, driver assistance systems, collision warning systems, and collision prevention systems are all designed to reduce driver errors and violations, and improve vehicle safety. With the continuous improvement of computing performance and the emergence of embedded systems, sensors, automatic control and communication technologies, automotive safety systems known as "active" safety systems have emerged and improved over the past 10 years. Many "active safety" concepts were born in the automotive and R & D industries as early as the 1970s. By the 1990s, with the advent of cheaper, smaller, and more portable electronic devices, sensors, and central processors, these concepts were reborn. Unlike passive safety systems that are responsive anti-collision measures, active systems generally use sensing (using cameras, radar, etc.) and actuation (ie, control functions) to actively reduce the potential collision risk or risk. These systems are designed to predict possible driving accidents by sensing cars, drivers, and the surrounding environment, and proactively circumvent to prevent dangerous events, or activate safety systems in advance to reduce passenger injuries at the critical moment of a collision. Based on the active concept, automotive equipment manufacturers provide various anti-collision and early warning strategies to provide additional safety and comfort for driving.

Many new vehicles on the market are equipped with active safety systems, such as ESP (Electrical Body Stability System-from 2012, all vehicles in the United States must be equipped with this system), ACC or ICC (Adaptive Cruise Control or Intelligent Cruise Control). ESP will detect the traction force, steering angle and slip conditions of the car, and automatically adjust the distribution of braking force and intervene in the acceleration of the driven wheels (ie selective braking or wheel drive) to keep the vehicle stable and not deviate from the lane. The working principle of ACC is very similar to that of conventional cruise control, but it can automatically maintain the distance to the vehicle or obstacle in front; most ACC systems will use more than 95% of the braking force to stop, and enable the driver to make a final stop by starting the early warning system. instruction. ACC may use radar, close-range or other types of sensors to detect long-range and close-range obstacles, and perform advanced sensor processing algorithms to distinguish between fixed guardrails on curved road sections and vehicles or faults on the road ahead.

Figure ESP

Active safety systems can be classified according to their degree of interaction with the driver or intervention in driving control. For example, some active systems start automatically (such as the ESC electronic stability system), while others provide information or warnings to the driver and act as a driver assistance system. In detail, the automatic control function, that is, the control function related to vehicle dynamics, the driver may not feel their existence-just like the automatic transmission car automatically performs the manual gear shift task for the driver. ESC is an automatic stability control system that does not require driver intervention. The information providing function is a pure information system, which only provides useful information to the driver, thereby improving the driver's situational awareness, such as weather assistant, icy road conditions and other information. Between the two are various safety and comfort systems with varying degrees of intervention. These systems may warn the driver, provide corrective suggestions, or perform partial (such as tactile) control (ie, such as auxiliary braking). For example, the lane departure warning system recently introduced by multiple manufacturers can warn the driver when the car departs from the lane. Generally speaking, the camera installed behind the rearview mirror scans the lane markings on the road ahead, and a visual information processing unit determines whether the car crosses the line, and is only activated when the driver does not show the intention to change lanes through the turn signal A beep or visual warning system is used. Many driver assistance systems are ways for drivers to provide information and warning signals, and they can freely choose whether to enable them.