This thesis describes the operation principle of the linear displacement inductosyn measuring system working on amplitude discrimination in the scale-excited manner,and one method based on D/A chip is proposed for function transformer which is the key component of digital-an.

The magnetic rulers detecting the magnetic markers are consisted of 8 magnetoresistive sensors which are fastened straightly on a plexiglas plate.

Based on the process control and requirement of the continuous casting machine(CCM),with the PLC control system,full automatic cntrol of cut-to-length was realized by combining cutting technology of the flames cutter machine with manipulating the imagines to length of steel billet by untouched-mode.

The technology of using image analysis and pattern recognition to implement the non-touching automatic billet cut-to-length is mainly introduced.

5 continuous caster at the Steelworks by heavier interference of flame cutting to infrared non-contact cut-to-length system and not high enough cutting precision,the PLC cut-to-length system was developed,satisfactorily solving the cut-to-length problem.