International Commission of Agricultural and Biosystems Engineering
Abstract
"Mapping systems" (“mapping approach”), real-time sensor-actuator systems ("sensor
approach") or the combination of both (“Real-time approach with map overlay”) determine the
process control in mobile application systems for spatially variable fertilization. Within the
integrated research project “Information Systems Precision Farming Duernast” (IKB Duernast)
the implementation of the “Real-time approach with map overlay” was done for intensive
nitrogen fertilization. The bottom line of this sophisticated approach is a comprehensive situation
assessment, a typical multisensor data fusion task. Based on a functional and procedural
modelling of the multisensor data fusion and decision making process, it could be pointed out
that an expert system is an adequate fusion paradigm and algorithm. Therefore, a software
simulation with an expert system as core element was implemented to fuse on-line sensor
technology measurements (REIP), maps (yield, EM38, environmental constraints, draft force)
and user inputs in order to derive an application set point in real-time. The development of an
expert system can be viewed as a structured transformation in five levels from the “specification
level”, the “task level”, the “problem solving level” and the “knowledge base level” to the “tool
level”. In the “tool level” the hybrid expert system shell JESS (Java Expert System Shell) was
selected for implementation due to the results of preceding levels. Knowledge acquisition was
done within another IKB-subproject by the means of data mining. Typical and maximal times of
10 ms and 60 ms for one fusion cycle were measured running this application on a 32-bit
processor hardware (Intel Pentium III Mobile, 1 GHz)