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.

Safety-critical electronic control units within automotive applications, such as four-wheel-drive, anti-lock braking systems, and airbag systems, are all characterized by sophisticated internal and external monitoring circuitry. This paper is focused on the specific needs of monitoring circuitry in electronic control units (ECU) for airbag systems. After a short introduction, the main electrical components of an airbag system and their interconnections are described. In the following sections, the monitoring of components external to the ECU is discussed, such as the monitoring of the battery supply voltage, the warning lamp, the selection inputs, the firing loops, and external crash sensors. For each case, requirements are stated and practical solutions for the realization of the monitoring functions are provided. Furthermore, the pros and cons of simple and sophisticated solutions are compared.

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.

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.