Automotive safety electronics are the airbag control units, braking systems and steering motors in a car, together with their sensors. These are safety systems. They must act within milliseconds, every time, for the whole life of the car.
Each system has the same shape. Sensors measure something. A control unit decides. An actuator, a part that moves when a computer tells it to, then acts. In an airbag system, crash sensors measure the sudden slowing of the car. The airbag control unit decides whether the crash is serious. It then fires the airbag's gas charge. The whole sequence takes a few tens of milliseconds, before the passenger's body has moved far.
Take, for example, a hatchback that hits a road divider at 50 km/h on a highway near Nagpur. The sensors in the front of the car detect a sharp slowing within 2 milliseconds. The control unit compares it with its stored crash patterns and decides that the crash is serious. It fires the front airbags within about 20 milliseconds. A pothole or a hard brake should not fire them, so the decision must be exactly right.
The braking system has electronics of its own. The anti-lock braking system (ABS) stops the wheels from locking when the driver brakes hard on a wet road. Electronic stability control brakes one wheel at a time to correct a skid. Both use wheel-speed sensors and a control unit that decides many times every second.
In India, the Bharat NCAP programme crash-tests cars and gives them a star rating. Buyers now look at these stars, so carmakers fit more safety electronics.
Because lives depend on them, these systems follow strict rules of safety certification. Their code is checked with tools described under static analysis for safety-critical code. Their sensors, such as pressure and position sensors, are close relatives of industrial sensors.
The braking system also takes orders from driver assistance, which can request an emergency stop. The systems report their status over the vehicle E/E architecture. They are made by Tier 1 suppliers, in the group described under Tier 1 and Tier 2 suppliers.