TWI

With regard to the need to control process temperature in friction stir welding to enhance process stability and weldment mechanical properties, a feedforward feedback control system was designed based on two nonlinear single input single output (SISO) control strategies, temperature measurement with a pyrometer and tool rotational speed as the manipulated variable. In order to accomplish offline design of different controllers, a process model was developed via experimentation using the step response method and employed to tune PID and PI regulators with saturation and anti-windup to address actuator limits. A gain scheduling method was employed to account for nonlinear process behaviour. Welding experiments were conducted on AW 6082-T651 aluminium alloys using specially designed workpieces to cause heat accumulation and a tool with an integrated temperature measurement system to demonstrate the validity of the control and measurement methodology.

11th International Symposium, 17-19 May 2016, Session 3B: Process Control and Techniques, Paper 02