High-precision and high-speed flow rate control with nonlinear disturbance compensation using valve body position feedback
Koki Hattori, Wataru Ohnishi, Takafumi Koseki
Abstract
Pneumatic valves play a crucial role in controlling flow rates across various industrial applications. This study aims to achieve faster and more precise gas flow rate control to improve throughput and product quality. However, inherent nonlinearities such as solenoid hysteresis and compressible fluid dynamics degrade the control performance of pneumatic valves. To address these challenges, this study proposes a mass flow rate control system incorporating an inner feedback loop for valve body position control to compensate for nonlinear disturbances. Furthermore, a data-driven feedforward control approach based on iterative learning control (ILC) is implemented to mitigate repetitive disturbances and enhance flow rate response speed. Experimental validation demonstrates that the inner feedback loop effectively reduces steady-state error, while the proposed feedforward control achieves a 9 ms settling time, 98% faster than conventional industrial control using the same hardware. • Cascaded flow rate control design reduced a steady-state error owing to hysteresis. • Data-driven feedforward control reduced settling time under various conditions. • Developed control achieved a 9 ms settling time, 98% faster, using the same hardware.