Adaptive Nip Pressure Control for Winding Roll Stability
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Solution Overview
Problem
Conventional winding machines struggle to maintain optimal nip pressure control during the winding process, leading to issues such as poor tightness profiles, roll instability, and safety hazards due to uncontrolled friction, especially when facing varying roll diameters and increased speeds.
Innovation Solution
A winding machine with a control unit that adaptively adjusts the second nip pressure based on the ascent rate of the rider roll, calculated using geometric properties and material velocity, to maintain a constant or slightly decreasing first nip pressure, thereby stabilizing the winding process across different situations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional nip pressure control is used, then the winding machine operates at limited speeds, but the tightness profile deteriorates and roll instability occurs at higher speeds
Solution Approach 1:
The nip pressure control system transitions from static to dynamic operation by continuously adjusting the rider roll pressure based on real-time ascent rate measurements. The control unit modifies the nip pressure dynamically throughout the winding process to maintain optimal values despite changing roll diameter and speed conditions, thereby achieving both high-speed operation and consistent tightness profile.
Solution Approach 2:
The system implements feedback control by measuring the actual ascent rate of the rider roll and using this information to adjust the nip pressure. The control unit receives ascent rate data and automatically modifies the rider roll pressure to compensate for deviations, ensuring stable operation and consistent tightness profile even at elevated speeds.
2Manufacturing precision
If aggressive nip pressure control is applied, then tightness profile improves, but vibrations and roll instability increase
Solution Approach 1:
The control system changes the nip pressure parameter dynamically based on the measured ascent rate rather than applying constant aggressive pressure. By adjusting the pressure magnitude according to actual process conditions, the system achieves the necessary tightness profile while avoiding excessive pressure that would cause vibrations and instability.
3Manufacturing precision
If PI controller values are optimized for certain web thickness, then control performance improves for that specific case, but performance deteriorates for other web thickness and diameter increase rates
Solution Approach 1:
The control system replaces fixed PI parameters with dynamic adjustment based on real-time ascent rate measurement. Instead of optimizing for specific web thickness conditions, the system continuously adapts the nip pressure according to the actual ascent rate, providing consistent performance across varying web thickness and diameter increase rates.
Solution Approach 2:
The system changes the control approach from fixed parameter optimization to dynamic parameter adjustment. The nip pressure is modified in real-time based on measured ascent rate, enabling the controller to adapt to different web thickness and winding conditions without requiring re-optimization of PI values.
4Object-affected harmful factors
If rider roll pressure is not controlled, then the finishing roll may be thrown out causing safety hazards, but excessive pressure control causes vibrations and instability
Solution Approach 1:
The system uses feedback from ascent rate measurement to automatically adjust rider roll pressure, preventing both insufficient pressure (which could cause roll throw-out) and excessive pressure (which causes vibrations). The control unit continuously monitors and adjusts pressure to maintain optimal values for safety and stability.
Solution Approach 2:
The nip pressure parameter is dynamically adjusted based on measured ascent rate to achieve the minimum necessary pressure for preventing roll throw-out without exceeding levels that would cause vibrations and instability.
Data Source
Figure 1
Figure 2
AI summary
A winding machine (100) for winding a finishing roll (110) having a radius R of a sheet material (M) on a core (115) having a radius rc is provided. The winding machine (100) includes: a support drum assembly (120) arranged on a first side of the finishing roll (110) and configured to support the finishing roll (110) from the first side; a rider roll (130) arranged on a second side of the finishing roll (110) opposite to the first side and configured to apply a first nip pressure onto the finishing roll (110) from the second side the finishing roll (110) being supported by the support drum assembly (120); and a control unit (140) configured to adaptively control the second nip pressure applied by the rider roll (130) onto the finishing roll (110) depending on an ascent rate (AR) of the rider roll ( 130).