Pressure sensors for side crash detection (SAB)

Front and side impact sensor's locations

Impact detection sensors used in cars for safety are generally located at the front of a vehicle, as this is the area where accidents occur most often. These sensors get alerted by a vehicle’s sudden deceleration. They measure collision intensity; if it is determined that airbags need to be released, sends an electric signal to the SRS control system. Side impact sensors also measure the collision intensity, but within the passenger doors on the sides of a car, they measure the pressure changes that occur inside the doors due to external impact.

Infineon's XENSIV™ family of collision detection sensors

Infineon's XENSIV™ family of collision detection sensors for vehicles includes integrated impact pressure sensors that are long-lasting, accurate, and versatile, equipped with PSI5 peripheral interfaces that convert and send electric signals from sensors to ECUs. Our car crash detection sensors operate with cutting-edge safety systems that increase the protection of car occupants and pedestrians in the event of a collision. Pedestrian protection and impact pressure sensors meet the highest quality and accuracy standards, fully adhering to ISO26262 compliance. Despite needing only two impact detection sensors, Infineon safety crash impact sensors deliver a reliable signal at an industry-leading reaction time.

Front impact sensors in cars

All front impact sensors for a car work in concert with its supplemental restraint system (SRS). The SRS is a passive system which controls the deployment of airbags and seatbelt restraints. When the front impact sensors sense a crash situation of the car, they send electric signals to the SRS. The SRS then compares this data with the car’s yaw rate and, if needed, sends a signal to deploy the necessary airbags via the airbag pressure switch and seatbelt restraints.

Side impact sensors

Crash detection sensors in the side of a vehicle, XENSIV™ KP 200/204, react to pressure changes that occur in the doors. One left front side impact sensor is located inside the driver door and one right front impact sensor in the passenger door. Similarly, the left and right rear side impact sensor locations are inside the rear doors. When a vehicle sustains lateral impact, these sensors in the affected door(s) observe the change of pressure inside. Within these sensors, a microprocessor analyzes the pressure information and determines whether to send a collision signal to the SRS. If and when that signal reaches the SRS system, the SRS determines which door(s) to deploy airbags from and sends the appropriate signal. 

XENSIV™ front impact sensors for pedestrian protection

The benefits of these front-facing impact sensors in a car are clear. They are instant, accurate, and durable; the Infineon XENSIV KP 201 sensor, for example, is specially designed to withstand high engine heat by being operational in temperatures up to 125 degrees Celsius. However, they do not present a catch-all solution to passenger or pedestrian safety. Auto manufacturers’ mounting need to address an increase in lateral accidents has brought about innovations in side-impact safety technology and equipment. More than ever before, it is now becoming standard that cars be fitted with right and left rear side impact sensor locations, in addition to front sensors.