Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

A new method is described that can be used to decompose human controlled agricultural operations into an autonomous tractor. Four main levels of subsumption have been identified: Operation, Task, Optimisation and Primitive Actions where each level is subsumed by the level above. Tasks were classified into two distinctive roles, deterministic tasks that can be planned and optimised before the operation begins and reactive tasks and their associated behaviours that deal with unknown conditions whilst in the field. The tasks and optimisations can be further decomposed into primitive actions, which in turn are converted into the tractor directrix. Examples of this method are given for exploring an unknown area and ploughing a field.