Development of Sensor Attachment Criteria (Immunity) - Side Impact Sensor Mounted on Door Impact Beam 2011-01-1445

The sensor mounted on the door impact beam plays a major role in side impact events. The accelerations of side impact sensors are processed by sensing algorithms to make a decision on the air bag deployment. The sensing signal criterion for the deployable condition is a well understood process. However, the non-deployment sensing signal for the immunity to abuse conditions is a function of sensor attachment stiffness to the base structure. The base structure can be a door inner panel or door impact beam. In one of the production program, the acceleration based sensor attached to the impact beam showed immunity issues in the abusive door slams/opening to objects. Hence, the computer Aided Engineering (CAE) analysis was used to develop the sensor attachment criterion. Based on the CAE analysis and the lessons learned on the production program, the side sensor attachment response criteria, such as acceleration and velocity decay were developed using the frequency response and the transient response analyses, respectively. These criteria have been adopted in several programs in designing the sensor attachment on the door impact beam and validated successfully in the immunity tests. The analysis methodology described herein can be used in design evaluations before the prototype hardware is developed.