Search Results

This paper describes new concepts to detect side impact collisions. Based on the specific system requirements for side impact detection, two physically different concepts will be described and compared to each other. Acceleration sensing principles, applied in today's single point sensing systems, were adapted to cope with the unique requirements for side collision detection. A more advanced and completely new concept is based on the sensing of the pressure change within the cavity of the impacted door. Based on these sensing principles, different system configurations will be illustrated. The performance of both sensing principles will be compared on the basis of available crash and misuse test conditions. In conclusion, it can be stated that the aforementioned sensing principles support the rigid firing requirements of a timely airbag deployment.

The influence of vehicle and driving situation parameters in a rollover event are evaluated by numerical simulation. Sensors and an algorithm for the deployment decision are necessary for occupant protection with restraint systems. The algorithm must decide in a timely manner to deploy the restraint systems for various rollover scenarios. Given the great variety in rollover situations a numerical vehicle simulation is needed and is the suitable tool to cover all cases. All the different cases were divided into 6 test configurations for this simulation investigation. The computer programs ADAMS and MADYMO were used for the rollover simulation. The results from the vehicle dynamic simulation are the sensor input signals for the algorithm (angular rate and acceleration signal) and these signals are also the values for the MADYMO occupant simulation. In addition, the requirements for the restraint system activation in the different rollover scenarios are also obtained from MADYMO.

This paper describes the application and the algorithm concepts of a high volume product for a very fast side impact detection system. To activate a side airbag the inner-door air pressure is measured by the sensing system. Specific characteristics of this pressure signal reflect different crash modes and, in conjunction with intelligent algorithms, very short activation times for side impact restraint systems are reached. These deployment times are typically faster than those of acceleration based sensing systems æ usually less than 5ms in all legal test modes. In addition to this the system is very robust during real world driving conditions such as crossing railroad tracks and potholes or more generally in events which do not compress the air of the inner-door cavity. Result tables of firing times to compare the acceleration- and the pressure-based system are included for several platforms.

One important topic in future automotive safety systems will be a better protection of the occupants in rollover situations. Convenient systems are belt pretensioner and head airbags and, for convertibles, rollover bars. For an in-time detection of an imminent rollover and an activation of these safety systems by an electronic control unit there can be used different sensors, for example angular rate sensors, accelerometers, tilt switches. All kinds of these sensors were used in a vehicle test program in order to find out the best sensor architecture for this purpose. By use of a rotation table which is controlled according to the signals of the angular velocity sampled in these tests the rotation of the vehicle about the longitudinal axis can be simulated. This test equipment is used for the validation of trigger algorithms for the safety systems.

This paper describes the physical behavior of rollover situations from a sensor and an algorithm point of view. Algorithm solutions will be described with an emphasis on the rollover / no-rollover discrimination as well as the misuse scenarios. Integration of the Siemens advanced rollover sensing functionality as part of future airbag electronics will be discussed. The Siemens rollover algorithm technology and the performance will be demonstrated on some examples.