新型開環(huán)自調(diào)勻整裝置的分析與設計.pdf

1、Drawframe is a very critical machine in the spinning process. Its influence on quality,especially on evenness is very big. If drawframe is not set properly, it will also resultin drop in yarn strength and yarn elongation

2、 at break. So the quality of yarn dependson the draw frame capability. To improve its performances, an autoleveller has oftenbeen used on the advanced drawframe.
　　The basic method is to keep the output sliver densit

3、y stability by adjusting the draftingratio continually according to the thickness of sliver fed into the drafting zone.
　　 In mechanical part, output part of drive system of the draw frame include front Roller,compre

4、ss Roller, coiler head and cans remain the same equipment withoutautoleveller. Draft part, checking Roller and gantry creel drive part was re-designedIn the design, speed of front Roller kept the same, speed of middle an

5、d back Rollerwas changed at the same time, thus realized autolevel. The method was convenient fordesigning, guaranteed stability of output sliver and overcame the disadvantage thathard to satisfy requirements of system i

6、nertia when changed the speed of front Roller.In the control system part, an ideal and more applicable control strategy is put forward.Because the modeling drafting process is hard to be obtained and the high speed isdem

7、and in practice, the linear drafting equation in the idea condition, in which onlythe delivery sliver deviation is calculated, has been adopted widely in present.However, the experts' experiences concluding the deviation

8、, the deviation change andthe stability demand of drafting may seem to reflect the process of the autolevellermore truly which establish the base of fuzzy controller's application in this field. Atthe same time, for the

9、difficulty of obtaining the full and precise control rules, byoptimizing the structure and the parameters of a basic fuzzy controller in severalaspects via neural network and gene algorithm, a new controller with quicker

10、response and better performance is obtained. Finally, a set of autoleveller digitalcontrol scheme is designed and realized on the base of the serial communicationamong PLC, IPC and servo controller. Through the analysis

11、and the compare of 4controllers, the optimized controller is approved to be an effective method in theprocess of autoleveller, and thus provides a new way in this field.
　　 Chaos non-linear time series method was use

12、d to discuss chaos phenomenon in sliverirregular data.As an important branch of non-linear science, chaos had showed anexciting prospect in scientific research and engineering technology. Chaos non-lineartime series unif

13、ied certainty and random of the system and was more accurate todescribe irregularity of sliver compared to traditional method.Fractional dimension,biggest Lyapunov index, time delay and inserted dimension number were fir

14、st calculated;
　　 Evaluation of fractional dimension was obtained by GP saturated correlationdimension number method and biggest Lyapunov index was calculated by Rosensteinalgorithm. Lap-correlation and inter informa

15、tion contend method were used tocalculate delay time of phase space, inserted dimension number was calculated bysaturation correlation dimension number method. The results showed that there wasplus Lyapunov index and fra

16、ctional dimension in the series, which meant the series,had the feature of chaos.
　　 The optimization of drafting system is another important aspect to improve sliverevenness. The motion of floating fibers during dra

17、fting has been considerably studiedwith the aim to control the floating fibers effectively, and to improve the sliverregularity. But for the speed change point distribution, it has been explained onlyqualitatively, espec

18、ially for the pressure bar drafting system, This paper tries for thefirst time to establish a mathematical model of floating fiber motion throughanalyzing the forces acting on it, and simulate the fiber movement under va

19、riousconditions by computer simulating calculation.
　　 The results can show the speed change point distribution with different statisticalcharacteristic under various processing conditions, which had been obtained be

20、foreonly through experiments. In addition, the effects of frictional force distribution, fiberlength, roller distance and drafting ratio on the speed change point distribution areanalyzed respectively from the simulation

21、 results.
　　 It provides a new way for studying the movement of floating fibers in the draftingzone and for designing newly drafting system and optimizing the press bar system.
　　 This thesis focused on the theme