Carding Machine Sliver Mass Control via Dynamic Time Delay
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for producing slivers during card production at high speeds result in quality deviations due to inconsistent time delays between the speed reduction of the feed roller and the doffer, leading to thin or thick spots, which are difficult to manage, especially during can changes.
Innovation Solution
A method that uses sensors to determine the mass of the sliver and calculates the optimal time delay between the speed changes of the feed roller and the doffer, allowing for automatic adjustment based on average values, regardless of fiber quality, to maintain uniform sliver quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the peripheral speed of the feed roller is reduced before can change, then the mass deviation during can change is reduced, but the time delay between feed roller speed change and take-up roller speed change must be precisely controlled
Solution Approach 1:
The control system uses sensor signals to continuously monitor the mass of the fiber ribbon and calculates the standard deviation and mean value. This feedback mechanism allows the system to automatically determine and optimize the time delay between feed roller and take-up roller speed changes, resolving the contradiction by using automated feedback control rather than complex manual adjustment mechanisms
Solution Approach 2:
The control system automatically determines the optimal time delay using sensor data without requiring external intervention or stored empirical values. The system serves itself by processing sensor signals to calculate statistical parameters and automatically adjust the time delay, eliminating the need for complex pre-programmed control mechanisms
2Reliability
If empirical values are stored in the control system for time delay, then the time delay can be maintained, but fiber-related data must be stored which increases system complexity
Solution Approach 1:
The control system calculates the optimal time delay in real-time using sensor signals from the fiber ribbon mass measurement. Instead of storing empirical values or fiber-related data, the system dynamically computes the time delay based on current operating conditions, maintaining reliability while eliminating the need for data storage
Solution Approach 2:
The system replaces the need for data storage and empirical value retrieval with real-time mathematical calculations based on sensor signals. By substituting the mechanical/data-based approach with computational processing of sensor feedback, the system achieves consistent time delay control without requiring storage infrastructure
3Manufacturing precision
If the time delay is optimized for each can change, then the sliver quality uniformity is improved, but the control calculations must be performed continuously
Solution Approach 1:
The control system continuously processes sensor signals to calculate the mass of the fiber ribbon, standard deviation, and mean value. This feedback loop enables real-time optimization of the time delay parameter, improving sliver quality uniformity through continuous adaptive control rather than periodic adjustments
Solution Approach 2:
The control system dynamically adjusts the time delay parameter based on real-time sensor data and calculated statistical parameters. By making the time delay dynamic rather than fixed, the system optimizes sliver quality uniformity while the computational load is distributed across continuous processing rather than intensive periodic calculations
Data Source
Figure 1~2
Figure 3~6
AI summary
The invention relates to a method for controlling a carding machine (100) and to a carding machine (100), comprising: at least one feed roller (1) and a doffer (5) which each have separate controllable drives, wherein the carding machine (100) is designed to produce a sliver, which can be deposited in cans (15), from fibre flocks or a cotton stock, wherein, to exchange cans, the circumferential speed of the feed roller (1) is changed and the circumferential speed of the doffer (5) is subsequently changed with a time delay (Δts; Δte); a sensor (S2) which is designed to measure the mass of the sliver produced or the change in mass of the sliver produced, wherein, during each can exchange, a controller (20) of the carding machine determines the standard deviation (Ss2) of the change in mass (Δm) of the sliver based on the signal from the sensor (S2) and assigns a mean value (Ms2) to this standard deviation, wherein the controller (20) is designed to optimise the time delay (Δts; Δte) by means of at least two mean values (Ms2).