In the automotive industry, active safety refers to the Advanced Driving Assistance Systems (ADAS) in a vehicle that help drivers reduce the severity of accidents or avoid them entirely by managing steering, braking and propulsion.
Safety has always been of paramount concern in the automotive world. The industry has developed world-class testing protocols related to vehicle safety, and its advances have been highly successful at reducing the number of traffic fatalities. The rate of fatalities per 100 million vehicle miles traveled has decreased dramatically over the last few decades, from 3.35 in 1975 to 1.13 in 2018.
The majority of those gains have come from “passive safety” features – that is, features that only activate when an accident occurs and lessen any injury to the driver and passengers. These include seat belts and airbags, as well as structural improvements such as crumple zones that absorb the energy of a crash. However, the gains from passive safety have started to plateau. Additionally, distracted driving has emerged as an increasing issue, partially as a result of smartphones.
To continue the trend in improving safety and reach the industry’s goal of zero vehicle-related accidents and fatalities, vehicles have to help drivers stop hitting things. That is where active safety comes in.
By using sensors such as radar, cameras and ultrasonic sensors, a vehicle can perceive the world around it. Processors then interpret that information, acting as a second set of eyes for the driver and taking actions if needed.
Active safety demonstrates clear benefits
Relatively simple warning systems such as blind spot detection or forward collision warning have the potential to save lives on their own, but when coupled with a technology that takes action beyond a simple warning to create an active safety system, the results are impressive.
For example, a vehicle could detect if it is approaching an object too quickly, attempt to warn the driver and then apply the brakes automatically if the driver doesn’t respond in time. According to the Insurance Institute for Highway Safety, forward collision warning with automatic emergency braking reduces rear-end collisions by 50%. This technology has become much more common in recent years as rating agencies such as Euro NCAP put active safety technologies on their testing roadmaps. In the United States, 20 automakers, representing 99% of U.S. light vehicle sales, committed to making the technology standard by 2022.
Given that the National Highway Transportation Administration estimates that 94% of all accidents are caused by human error, there are many other opportunities for improvement.
Examples of more advanced active safety systems include features such as automatic lane change, highway assist and traffic jam assist. In these examples, multiple sensors around the vehicle must be integrated through sensor fusion, so that powerful domain controllers running advanced software algorithms can process the information and make driving decisions.
While entry-level active safety systems may take a single action, such as braking, these more advanced systems assist the driver with multiple aspects of controlling the vehicle. For example, they typically will manage steering – to keep the vehicle in a lane or navigate around slower vehicles – while simultaneously managing the vehicle speed to maintain a safe distance from other vehicles and obstacles.