This Push AFC UC describes the process of pushing the AFC towards the coal face depending on the Shearer’s position.

The Roof Support System cyclically reads the position and the running direction of the Shearer. By taking the Shearer’s position and dimensions and the actual position of the AFC sections into account, the Roof Support System calculates which sections shall be pushed. The Roof Support System advances the corresponding sections, if necessary. This state is reflected by setting the AFCPushStatus to ONGOING. If the AFC has successfully advanced all sections (i.e. all sections are in the desired position), the AFCPushStatus is set to FINISHED. The Shearer can use the AFC’s AFCPushStatus in its automation states if necessary. Figure 4 illustrates the sequence diagram of this UC.


Figure 4 – Sequence diagram of the Push AFC Use Case