The safety-relevant hardware interacts with a fail-safe control system which transmits control data of the mission software to the hardware abstraction. Safety implementation is provided in a reactive minimalistic way.
The blind spots are covered by four safety laser sensors which creates safety zones around the vehicle. The virtual bumpers are created and react on an unintended object which is entering into working zones that are critical.
The detection of an unsafe system is possible and the system reacts accordingly. Let us explain it with an example if a pedestrian is entering into a blind spot of the vehicle, a full stop is created.
So, let us see how the functionality works? As per the safety considerations, it is unsafe for the default system state. The safety behavior network which is reactive is included with a virtual bumper for the different mounted laser scanners, combined with a maximum fusion.
The highest bumper activity is determined by the fusion which is notified by the violation of the threshold in a successive order which can disable the state of the safety system. In addition, the safety checks are included with a control value which is a result of a comparison between desired and actual control values.
- A small and robust perception is contained in the fail-safe component where the control system is verified formally.
- Sensors that are limited and have access to control can make the system insusceptible to errors.
- The higher levels are monitored by the fail-safe system.
- The mission control software by heartbeat signals and failures reacting to the system.
Source:- Commercial Vehicle Technology 2018 by Karsten Berns, Klaus Dressler.