Development of seam tracking system with ultrasonic sensor using self-tuning fuzzy control

One kind of the SAW seam tracking system with contactless ultrasonic sensor is presented in this paper. The new contactless ultrasonic sensor for seam tracking and the working principle of the seam tracking with the sensor are introduced. Based on the experiments, the optimal values of the fuzzy control parameters α and k3 are defined by means of the off-line adjusting method. Because the self-tuning fuzzy control is adopted in the seam tracking system, the overshoot of the system is restrained, the steady-state error is reduced, and the system’s response speed is improved effectively. The results of the SAW seam tracking experiments show that this system’s tracking accuracy is up to ±0.5mm and the system can satisfy the requirements of the engineering application.