Fuzzy-PI double-layer stability control of an online vision-based tracking system

In many manufacturing processes (e.g., welding, spraying, coating adhesive), the control for the velocity in the main direction heavily affects operation quality. In addition to traditional manual operations, the industrial robot with a tracking system is capable of accurate and stable velocity control. In this paper, an intelligent robot tracking system is designed for implementing an appropriate velocity control and improving the performance of an autonomous system with online structured light vision tracking. For this aim, an effective tracking algorithm is proposed based on position-based visual servoing (PBVS), and motion compensation is implemented according to both detected path and taught path. To improve the adaptability of the system, a Fuzzy-PI double-layer controller is developed, which adjusts the movement of the end effector in both cases of large and small deviation. Welding experiments demonstrate the effectiveness of the proposed vision tracking system.