Method of controlling the welding of a three-dimensional structure

A method of forming a welded structure composed of a three-dimensional support base and a plurality of pieces employing welding equipment that is operable in a three-dimensional X-Y-Z coordinate system, said method comprising:

• arranging the pieces on the support base to provide an assembly in accordance with the structure to be welded,
• photographing the assembly and making a picture map of the assembly,
• identifying weld points and determining welding parameters from the picture map,
• supplying control data specifying said weld points and welding parameters to the welding equipment,
• moving the welding equipment in the X-Y plane on the basis of the picture map and said control data,
• repeatedly measuring the Z-axis position of the support base by laser pointing and supplying Z-axis position data to the welding equipment, and
• moving the welding equipment along the Z-axis on the basis of the Z-axis position data so as to maintain the welding equipment at a constant Z-axis distance from the support base.