Airbags are one of the most essential safety features in modern cars, but they also pose some risks if they are not designed, tested, and deployed properly. In this article, you will learn about the most important safety standards for airbag systems, how they are regulated, and what you can do to ensure your airbag system is safe and effective.
An airbag system consists of several components that work together to inflate and deflate the airbags in case of a crash. The main components are the sensors, the control unit, the inflator, and the airbag itself. The sensors detect the impact and send a signal to the control unit, which determines if and when to deploy the airbags. The inflator generates gas to fill the airbag, which is made of a fabric material that can withstand high pressure and heat. The airbag then cushions the occupants from hitting the interior of the car.
I agree. Most of the recent vehicles will have driver's advanced airbag system which includes component such as SPS sensor (seat position sensor). SPS determines the distance of the driver from the airbag. Based on information from SPS and the severity of the impact, the advanced airbag system determines the optimal deployment of the driver's airbag to protect driver in the event of crash. In case of front passenger's, the advanced airbag system has weight sensors and this system automatically turns off the passenger’s airbag once it detects that the weight of the front passenger weighing approximately 65lbs or less, which is normally the case when a child of age 12 or less rides in the front passenger seat.
It should be noted that airbags are the supplemental restraint, whereas the most important part of the restraints system is the seatbelt system to couple the occupants to the seats and the vehicle as a whole. The complete restraints system comprises of components that: 1. Sense the crash event in order to detect and deploy the restraints as per design. 2. Detect the occupants, their type and position, as well as whether they are wearing seat belts. 3. The algorithm and firing control logic which takes the inputs of (1) & (2) to deploy the restraints with respect to the crash type and severity to provide optimal protection, and in some cases suppression (child seat usage) The rest of the vehicle also contributes to occupant protection.
From a safety perspective, airbags should be treated like the explosives they are. Related documentation, training, and proper tools must be used to ensure safe practices are followed and upheld.
There are various standards and regulations that govern the design, performance, and testing of airbag systems. The Federal Motor Vehicle Safety Standard (FMVSS 208) defines the requirements for occupant crash protection, including airbags, seat belts, and child restraints. Additionally, the International Standard for Functional Safety of Road Vehicles (ISO 26262) covers the entire life cycle of electronic and electrical systems, including airbag systems. Moreover, the Society of Automotive Engineers Standard for Performance Requirements for Inflatable Airbag Modules (SAE J2909) establishes the minimum performance requirements for airbag modules. All of these standards are essential in ensuring the reliability and integrity of airbag systems.
From my experience an airbag item in most of the cases will be rated ASIL D according the ISO26262 standard. knowing the severity of harm that could occur in case of this item elements failures, applying the recommended ISO26262 ASIL D methods and requirements by the development team is crucial. moreover, during the development lifecycle, functional safety assessment should be performed by a sufficiently independent and knowledgeable person/team, and the findings shall be taking seriously in order to avoid surprises in the roads.
The are three categories of standards which we design restraints systems (airbags & seatbelts): 1. Legal mandates such as FMVSS 208 (frontal occupant protection), 214 (side impact occupant protection) 2. Due care best practices such as TWG for side airbag systems which aren’t as thoroughly covered by (1). ISO26262 for the electrical & electronics robust design. Etc. 3. Consumer tests such as USNCAP & IIHS which target optimal occupant protection as a metric that can be measured and published so that consumers can make informed choices on their vehicle purchases.
The performance requirements of the SRS system should document and follow standards that all manufacturers must abide by. Functionality standards help prevent variablities that can risk safety standards.
To ensure that airbag systems meet the standards and regulations, they undergo rigorous testing and validation processes. Static testing involves testing the airbag system components in a laboratory setting, using equipment that simulates crash conditions and measures the performance parameters of the airbag system. Dynamic testing involves testing the airbag system in a real or simulated vehicle, using dummies or human volunteers that represent the occupants. Additionally, field testing involves testing the airbag system in actual road conditions, using vehicles that are equipped with sensors and cameras that monitor the airbag system performance and behavior. All of these methods are essential for ensuring that airbag systems meet safety standards and regulations.
Typically the general public isn’t aware of the magnitude of testing that is performed on restraints systems. These fall under the categories of: 1. Component testing not just at ambient temperatures, but also at extreme temperatures (typically-35C and +85C) to ensure robust design in the real world. 2. System testing of the airbag and the surrounding components (interior trim, seats etc), again across a similar range of temperatures as (1). The purpose of these tests are to ensure that as the airbags deploy, the components that they interact with don’t present additional risks to the occupants. 3. Vehicle level sled & crash tests to ensure optimal restraints positioning, coverage and restraining performance across a wide variety of tests.
Airbag systems come with a variety of benefits and advantages, however, they also pose certain risks and challenges. Unintended deployment can occur when the system deploys without a crash or in a minor crash, potentially causing injury or distraction to the occupants or other road users. Inadequate deployment may happen if the system fails to deploy or deploys too late or too slowly in a severe crash, leading to insufficient protection or increased injury. Additionally, inappropriate deployment can occur if the system deploys in an unsuitable way for the occupant's position, size, or condition, resulting in harm or discomfort. Lastly, defective components can compromise the functionality and safety of the airbag system.
Airbag System Risks can be categorised by: 1. Unintended deployment during a crash event or non-crash event (mitigated by robust misuse testing for calibration) 2. Unintended deployment during service (mitigated by service procedures and training) 3. Defective components such as airbag inflator housing ruptures (mitigated by lot acceptance testing) 4. Out of position occupants (mitigated by airbag performance testing and firing control logic suppression) 5. In correct deployment (no fire/late fire), mitigated by a robust sensing and algorithm development program.
I agree. Additionally, if any inadequate deployments happen during a severe crash could be fatal leading to occupant’s death. Vehicle manufacturers study reliability testing of airbag deployments at all worst possible combinations to avoid the cases of inadequate deployments keeping occupants safety as priority.
It is essential to maintain and inspect your airbag system regularly and properly in order to prevent or reduce the risks and challenges associated with airbag systems. Be sure to follow the manufacturer's instructions and recommendations for servicing and replacing components, especially the inflator, which can deteriorate over time and lead to malfunction or explosion. Additionally, check the warning light on your dashboard, which indicates if there is a problem or fault with your airbag system. If the light is on, take your vehicle to a qualified technician immediately. Furthermore, you should avoid modifying or tampering with your airbag system, as this can affect its performance and safety. It is also important to adjust your seat and seat belt properly, keeping a safe distance from the steering wheel and dashboard where the airbags are located. Do not place any objects or passengers between you and the airbags, as it could interfere with their deployment or cause injury.
Additionally, it is important to avoid putting an add on seat trim cover for the seat that is installed with side airbag as it could prevent an adequate deployment of the side airbag through add on cover. This could lead causing an injury to the seat occupant. It is always best to follow vehicle manufacturer instructions.