Development of ISIS into ACSM: Notes
The number of interfaces to the control units have multiplied as a result of the rapid and continuous development of new passive safety components in the 1990s. At that time, the increase in the number of sensors and actuators in the control units were limited by the computing performance of the microcontrollers.
The sensors and actuators were spread out over various control units in order to make available to the customer the maximum possible levels of passive safety.
This resulted in the development of the Intelligent Safety Integration System (ISIS) in the E65. The control units were interconnected via an ultra fast optical bus system, the byteflight .
With the launch of the E60, Advanced Safety Electronics (ASE) was used as the passive safety system. ASE is based on the technology of Intelligent Safety Integration System (ISIS) with the byteflight .
Due to the rapid further development of microcontrollers with ever greater computing performance and speed, it is now possible to process and calculate all the functions in one or two microcontroller in one control unit. Because of this, Advanced Crash and Safety Management (ACSM) will be introduced from 09/2005 in all 5 Series and 6 Series models and from 01/2006 in the E85 MU.
ACSM is characterized by the fact that it fulfills the same range of functions as the ASE system. The ASE system consists of seven individual ECUs. ACSM consists of only one ECU, the Crash Safety Module. The use of a single ECU delivers the following benefits:
- Reduced number of ECUs
- Reduced weight
- Easier diagnosis
- Easier programming/updates.