179 
Process: 
5. Recording the present situation 
Name 
Date 
Created: 
Mathes 
28.5.98 
Data flow: 
Sensor data 
Checked: 
1. Origin 
• The origin of sensor data must be known. 
2. Validity 
• The validity of sensor data must be checked by the particular sensor technology. The 
result must be made available. 
3. Quality 
• The accuracy of sensor data must be made available. 
• It must be ensured that sensor data are sufficiently up-to-date. This property must be verifiable. 
Appropriate criteria should be selected for topicality (e.g. consideration of link between speed and 
necessary topicality of position data). 
• Sensor data of the same type from differing sources must be reciprocally checked for 
plausibility. Sensor data must not be mutually contradictory. 
4. Harmonisation 
• The reference system of sensor data must be known. This refers in particular to the installation 
point of the particular sensor and to the geographical reference system in the 
case of position sensors. 
5. Criticality 
6. Limit values and alarm facilities 
• Alarm on loss of validity of sensor data. 
• Alarm on deterioration of the accuracy (e.g. loss of satellites In the case of GPS). 
• Alarm if the topicality of a sensor datum is inadequate. 
• Alarm in the event of contradictions between sensor data. 
7. Representation/display 
• There must be an overview of the connected sensors available in the system. The sensor sup 
plying the particular system datum of one type (i.e. a certain state variable) must be 
identified.