In this research, the dynamics and control of web handling in roll-to-roll (R2R) systems using a driven roller are presented. The viscoelasticity effect for systems with and without the driven roller is analyzed to study web dynamics. To achieve high precision control performance, the driven roller is responsible for regulating web speed, while the winders regulate tension control. A tension feedback control is used as a cascade control to achieve a fast system response, and feedforward compensators are provided to account for changes in the winders’ radius. Control performances are verified under several scenarios using an experimental setup. The web tension is validated with errors of ±0.625%, ±1%, and ±1.25%, while the web speed is validated with errors of ±0.0007 m/s, ±0.002 m/s, and ±0.0008 m/s at speed levels of 0.01 m/s, 0.05 m/s, and 0.1 m/s, respectively. Furthermore, it is verified that the tension error in the desired linear tension profile change is around ±0.25 N at 0.01 m/s.

In this paper, experimental validation of high precision web handling for a two-actuator-based roll-to-roll (R2R) system is presented. To achieve this, the tension control loop is utilized to regulate the tension in the unwinder module, and the velocity loop is utilized to regulate the web speed in the rewinder module owing to the limitation of the number of actuators. Moreover, the radius estimation algorithm is applied to achieve an accurate web speed and the control sequence of the web handling in the longitudinal axis is developed to manipulate the web handling for convenience. Having these, the tension control performances are validated within ±0.79, ±1.32 and ±1.58 percent tension tracking error and 1.6, 1.53 and 1.33 percent web speed error at the speeds of 0.1 m/s, 0.2 m/s, and 0.3 m/s, respectively. The tension control performance is verified within ±0.3 N tracking error in the changes of the reference tension profile at 0.1 m/s web speed. Lastly, the air floating roller is used to minimize the friction terms and the inertia of the idle roller in the tension zone so that tension control performance can be better achieved during web transportation.

In this paper, the development of an ultra-precision XY nanopositioning stage is presented.For system structure, the actuator decoupled parallel compliant mechanism is designed to have the samedynamics in both x- and y-direction so that the coupling crosstalk between two axes can be minimized.Throughout the simulation validation of the deformed XY stage, the motion in the x-axis is not transferredto the motion in the y-axis. For the control structure, the simplified feedforward compensator provides the piezoelectric actuator to reduce the control effort of the system. A proportional double integral (PII) feedback controller is used to minimize the ramp-like disturbances so that the compensation of hysteretic nonlinearityand other disturbances can be effectively reduced. Moreover, the jerk-based optimal reference trajectory isdesigned so that 10μm displacement at the constant speed with the smooth accel/deceleration period canbe achieved. Having an experimental setup with several scenarios such as the constant speed of 10μm/s,20μm/s, and 40μm/s, the tracking error can minimize with in ±2.5 nanometers,±3 nanometers, and ±5 nanometers in the x-axis for each case. Moreover, the hysteresis variable is well compensated that the relationship between the reference trajectory and output displacement is almost linear. The proposed control strategies and implementation methods can operate the piezoelectric actuated XY stage system with the nanoscale precision motion for convenience.

This article investigates the effects of idle rollers, web span, and sensor location on web tension control performance in roll-to-roll (R2R) continuous manufacturing systems. The web dynamics are modeled as a mass-spring-damper system using a Kelvin–Voigt viscoelastic formulation and are validated through frequency response comparison with experimental data. The analysis shows that increasing the number of idle rollers lowers the first minimum resonance frequency, thereby reducing the achievable control bandwidth; specifically, the addition of a single idle roller shifts the first resonance from 11.5 to 10.6 Hz. Sensor placement is also found to significantly affect system dynamics, including both resonance and antiresonance behavior. A cascade control strategy with a notch filter is implemented to attenuate the dominant resonance and improve tension control performance. Experimental results reveal that when the loadcell is placed to cover all idle rollers in the tension zone, the system achieves a steady-state tension error within ±0.35 N and a settling time of 1.00 s at 40 mm/s web speed. In contrast, when the loadcell is located near the actuator, the step response is faster (e.g., 0.78 s) but tension regulation is limited to a partial zone, resulting in larger steady-state errors (up to ±2.0 N). These findings provide practical insights for optimizing sensor placement and mechanical configuration to enhance dynamic stability and tension regulation in high-speed R2R systems.