Tow tension controller for robotic automated fiber placement based on fuzzy parameter self-adjusting PID

Robotic automated fiber placement (Robotic AFP) was a cost-effective and highly innovative approach to produce large and complex composite structures. In order to achieve desired qualities, the tow tension of the process required to be controlled accurately. Due to the high nonlinearity of the system, such as the large elastic modulus, flexibility and viscosity of the tow, traditional methods failed to work effectively. Afuzzy parameter self-adjusting PID combining fuzzy logic and PID together was proposed in this work. Fuzzy logic was able to respond quickly to disturbances without the need for an accurate model and PID control could eliminate the steady-state error. With this method, the tow tension could be precisely regulated thus improved the quality of the composite structures.