Argument A1.2.2.3.3.4.4.3.2.1.2.2.1 Watch Dog Timers (WDT) have been employed to place the the robot in a safe state if the processing freezes

• Supports Argument: A1.2.2.3.3.4.4.3.2.1.2.2 Runtime Monitors and a WDT are implemented

Child nodes:

• Has evidence Evidence: E1.2.2.3.3.4.4.3.2.1.1.1.1.2.4.1 Design Justification Report (DJR)
• Has evidence Evidence: E1.2.2.3.3.4.4.3.2.1.1.6.1.2 SIF Functional and Non Functional Description
• Has evidence Evidence: E1.2.2.3.3.4.4.3.2.1.1.5.2 Non functional test reports

NB. A WDT cannot be based on timer interrupt patting the dog

Separate WDTs are provide for the:

• (Intelligent) Collision Sensor
• Decision making (symbolic AI)
• Conventional Controller (including hardware platform)
• Runtime monitors

The safe state is that of removing power to the motors using relays.