Without traditional sensor, dynamic monitoring technology can obtain the importation of dynamic state system, input discharge value and mechanical impedance through direct importation of voltage and current in the measurement electrical engineering system. This technique applies the patent developed by professor Ling of NTU, Singapore to combine the electric resistance, friction stirs welding manufacturing process and monitoring technique in creating smart welding system and increasing the reliability of manufacturing process and welding quality.

　　The resistance variety is obtained through grabbing current and voltage in the welding process as welding quality is identified by resistance variety. In the sample of good welding quality, its resistance curve can be classified into five districts after a quick, abrupt descending. However non-welding sample has three districts of resistance curve only. There are more than 400,000 local-made automobiles in Taiwan market with annual production value amounting NT$400 billion. In 2005, production value of domestic sheet metal market estimates to be NT$57.6 billion. This industrial system includes steel makers, mold & die factory, cutting factory, electroplating factory, stamping/welding equipment factory. This technique is an efficient way to increase welding quality and inspection method and is estimated to create the production value of NT$0.3 billion per year.