Introduction to Advanced Body Electronics: byteflight: Design

The Intelligent Safety Integration System (ISIS) consists, depending on equipment level, of up to 11 satellites (control units), the Safety Information Module (SIM) and the Central Gateway module (ZGM). Seven of the eleven satellites contain crash detection sensors.

In the event of an accident, the necessary restraint systems have to be activated within a fraction of a second in order to provide the maximum amount of protection for the vehicle's occupants.

The system also has to ensure that the restraint systems are not deployed accidentally. In order to ensure that the ISIS meets the requirements placed upon it, large volumes of data have to be exchanged between the control units. This is achieved by means of an extremely high data transmission rate.

The data is exchanged via a bus system. In order to protect the signals traveling along the bus system from interference caused by electrical or magnetic fields, the ISIS system does not use copper bus wires but optical fibers.

The layout of the ISIS takes the form of a star pattern. The Safety Information Module (SIM) is at the center of the system. Arranged radially around it are the satellite modules.

Each of the eleven satellites is connected to the SIM by a fibre-optic cable. Each of the satellites contains a transmitter/receiver module.

The SIM contains twelve transmitter and receiver modules. All information from each of the satellites is made available to every other satellite by the SIM. Each individual fibreoptic cable in the byteflight bus system is used for bi-directional data transmission.