Our company provide the services consisting the repair and activation of the airbag system drivers. Every airbag activation (e.g. after the car accident) is recorded and cannot be exploit second time in this car. However, during the repair, we modify the software and introduce the airbag data prior the accident. It is a safe operation involving only the reprogramming of integrated circuits which allows you to reuse the same driver without high expenditures. Of course you cannot put the Airbag driver back to the car and all the reparation are undertake due to demonstration purposes.
CONSTRUCTION OF THE AIRBAG SYSTEMS
In relation to the history, the SRS Airbag systems appeared in the early 80s in luxury vehicles. Therefore, the development of the technology, cost reduction and simplicity of the automotive technical solution entail the airbag popularity in the middle and low class vehicles. The security and comfort solutions have become the determinants that maintain the manufactures’ competitive advantage.
The development directions of the SRS systems aim to ensure the maximum safety in both, emergency situation as well as normal car utilization. In order to increase the safety conditions during car accident, the manufacturers develops modern and complex pillows that protect different parts of human body. Additionally, the systems are also evolving in the way to increase its reliability – and avoid unwanted pillows’ activation.
The main features of the system:
- the decision to detonate airbags and seat belt tensors (during accident)
- auxiliary functions – unlocking central locking, cutting off fuel and power from the battery, the notification systems
- constant monitoring of the airbag systems (tensors, sensors and pillows)
- management of the control system
- communication with the diagnostic device
The airbag is a vehicle safety device that consist of the gas generator and flexible envelope. The shape and size of the airbag depends on its purpose – protection of the driver, passenger (greater one), or a side airbag. The load in the gas generator is electrically initiated by overheating the fiber fuse. In fact, the gas that fills the bag is not an air but pure nitrogen. The main chemical constituents in the airbag are: sodium azide – NaN3 and KNO3; potassium nitrate and silicon dioxide SiO2. The gas generator that mixture these components is initiated electrically by warming pulse which entails slow detonation known as ‘deflagration’. That reaction triggers a certain amount of nitrogen and fills the pillow by successive chemical components. Each airbag is part of a single use system, and after the first launch should be removed from the vehicle and scrapped.
SYSTEM’S DRIVERS – SENSORS
We have noticed a new (Bosch) brand airbag’s driver on the market. The advanced system of this airbag ensure the reliability, precision and safety during potential car accident. At the basis of two sensor, located on the front engine compartment, the system detects and analyzes the strength of a frontal collision in the early stage. The information from the central crash sensor secure the appropriate airbag activation. Depending on the course of the collision, the passenger security systems can be activated by one or two phases.
However, the low-quality airbags available on the market are sometimes unable to define the strength of external impact force and launch the pillows after 50 milliseconds after first stage of accident. On the other hand, the new airbag system is equipped with two acceleration sensors placed directly in the crumple zone. Frontal collision sensors transmit electronic that precisely calculate the absorption of the energy and car deformation (depending on the vehicle’s speed) after about 15 milliseconds after accident. These sensors immediately detect whether it is only the soft flap (no need to activate the airbags) or a serious collision – necessary to activate safety systems.
Moreover, the side collisions are detected based on the four side impact sensors which transmit the electronic signal to the central sensor in the driver airbag. This system design provides an early activation of side airbags and sufficient protect of the driver’s head and chest. This solution is also invented to optimally protect passengers against external side impact.