Open-End Spinning Yarn Piecing with Expert System Control
Solution Overview
Problem
Existing methods for piecing threads in open-end spinning devices often result in thick and thin areas, leading to quality issues during the piecing process and subsequent processing, despite previous attempts to mitigate these issues through speed adjustments and empirical parameter calculations.
Innovation Solution
An expert system calculates specific points in time for thin spots in the piecing process, allowing for precise control of the take-off device's speed to compensate for these areas by reducing and then accelerating the take-off speed, thereby adjusting the fiber mass and improving uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the feeding rate is gradually reduced after initial feeding to regulate fiber amount, then the amount of fibers in the feeder is controlled, but thick and thin spots still occur in the setter
Solution Approach 1:
The patent implements a control device that continuously monitors the combing state of the fiber beard and provides feedback to adjust the yarn take-off speed dynamically. This closed-loop feedback system detects variations in fiber distribution and compensates for them in real-time, preventing thick and thin spots from forming in the final yarn product.
Solution Approach 2:
The patent transitions from static feeding rate reduction to dynamic adjustment of both feeding rate and take-off speed. The control device modifies operational parameters in real-time based on the combing state, allowing the system to adapt to varying fiber distribution conditions and maintain yarn uniformity throughout the spinning process.
2Reliability
If the rotor speed is reduced from starting speed to lower speed and then increased back to production speed, then spinning reliability is increased, but the process time is extended
Solution Approach 1:
The patent applies preliminary action by adjusting the feeding rate and take-off speed during the critical initial phase of starter formation, before the rotor reaches full production speed. This preliminary control of fiber distribution prevents defects from forming in the first place, eliminating the need for subsequent speed reductions and extending the spinning process.
3Manufacturing precision
If the yarn take-off speed is adjusted to match fiber feed rate based on combing state, then thick and thin spots are mitigated, but complex control mechanisms are required
Solution Approach 1:
The control device performs multiple functions: it monitors the combing state of the fiber beard, calculates the appropriate yarn take-off speed, and executes the speed adjustment all in one integrated system. This multi-functional approach consolidates what would otherwise require separate monitoring and control mechanisms, reducing overall system complexity while maintaining yarn uniformity.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
In a method for spinning a thread (3) in an open-end spinning device (1), fiber material (5) is fed to the spinning element (2) by means of a feeding device (4) to form a starter, a thread end (3') is returned to the spinning element (2), and the newly spun thread (3) is drawn off by means of a take-up device (6). At least the feeding device (4) and the take-up device (6) are controlled by a control device (8) of the open-end spinning device (1), wherein settings (ES, EA) for controlling the feeding device (4) and the take-up device (6) are calculated by an expert system (9). A corresponding device for spinning a thread (3) has a control device (8) with an expert system (9).The expert system (9) predicts at least one time (t1, t2) of the occurrence of at least one thin spot, and the calculated time(s) (t1, t2) are used to determine the settings (EA) for controlling the extraction device (6). Using the determined settings (EA), the extraction rate (vA) of the extraction device (6) is controlled in such a way that the at least one thin spot is at least partially compensated.