Laser processing control for automated composite placement

A method of making a composite part by automated fiber placement with a compaction roller, comprising the steps of:

• pre-heating a composite tape to be adhered to a substrate surface by beaming with a pre-heating laser source a pre-heating laser beam at least 5 mm before the composite tape reaches a compaction point with the compaction roller, the pre-heating producing a pre-heat beam temperature distribution line across the pre-heated composite tape;
• registering with an infrared detector an image of the pre-heat beam temperature distribution line pre-heated by the preheating laser beam to generate a control signal controlling a laser array, the control signal recording deviations from a target temperature in a pre-heated thermal image curve derived from the pre-heat beam temperature distribution line by the infrared detector, the control signal compensating for the deviations from the target temperature by signaling increases or decreases in power in individually controlled laser elements in a laser array;
• heating the composite tape close before the compaction point with laser array beams from the laser array, the laser array being controlled by the control signal, the laser array beams on the composite tape close before the compaction point generating a laser array beam temperature distribution line, the laser array beam distribution line being achieved on the composite tape immediately before the tape and the substrate reach the compaction point;
• and
• bringing the laser array beam temperature distribution line of the heated composite tape to the compaction point and compressing the heated composite tape at the laser array beam temperature distribution line to adhere onto the substrate surface as the compaction roller is applied.