JPH02160955A - Method for optimum control of rotational speed of loom - Google Patents

Abstract

PURPOSE:To set the rotational speed of a loom to maximize the productivity by determining the productivity after changing the rotational speed of a loom and varying the rotational speed in the direction to maximize the productivity judged from the increasing or decreasing tendency of the productivity. CONSTITUTION:The optimum control of the rotational speed of a loom is performed by each loom-controlling part 5 or a specific loom-controlling part 5 designated by an optimum controller 1. The rotational speed of a driving motor 7 of the loom is successively changed at prescribed intervals in decreasing or increasing direction to increase the productivity under the restriction of the relationship between the stop frame level and the upper limit of the stop- frame level.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for automatically controlling the rotation speed of a loom to an optimum value in order to maximize the production of woven fabric.

The prior art patent applicant has already proposed an optimal control method for the rotational speed of a loom in order to maximize the production of woven fabric. These control methods take into consideration factors such as the operating rate of the loom and the leeway of the weavers, and change the rotation speed within a theoretical range to increase production. For example, JP-A-61-23905 '7
The invention of No. 1 attempts to increase production by increasing the rotational speed when the operating rate is above a certain level with the operating rate as a constraint condition. However, these methods assume that production will theoretically naturally increase, and it is difficult to demonstrate whether production actually increases after changing the rotation speed compared to before changing the rotation speed. No specific checks have been carried out. Therefore, in reality, contrary to the theoretical prediction, it is predicted that the production volume will decrease due to other factors.

Purpose of the Invention Therefore, the purpose of the present invention is to change the rotation speed so that the production volume tends to increase in accordance with the actual operating state of the loom, based on this theory, without relying solely on theoretical predictions, The final goal is to set the rotation speed to the maximum production amount.

SUMMARY OF THE INVENTION Therefore, the present invention aims to increase the production volume of woven fabric by making it possible to pattern the operating state into a typical state from the viewpoint of increasing or decreasing the production volume when controlling the rotation speed of the loom. Focusing on this, in the process of controlling the rotation speed, first try changing the current rotation speed and identify the increase or decrease trend in production volume (V1).
The direction in which the rotational speed is changed is determined based on the tendency of increase or decrease.

During this control, if the rotational speed increases or decreases more than necessary, it is predicted that the quality of the woven fabric will deteriorate. Therefore, in this optimal control process, the quality of the woven fabric can be a constraint on changing the rotation speed. In this embodiment, the quality is determined by the stopping level of the loom. Further, such control may be performed for each individual loom at predetermined intervals, or may be performed for a group of looms with the same textile specifications within a group of looms owned by the same weaver. This may be done every time the shift of the person in charge of the work changes.

When such control is performed, the optimum rotation speed can be automatically set based on the actual increase/decrease trend in production so that the actual production is maximized.

Structure of the Invention The optimal control method for the rotational speed of a loom according to the present invention is based on the following theoretical calculation formula.

Suppose that the following data is given while a certain loom is in operation.

Shift time T Rotation speed N Stopping level S Stop time/stop Operating time r Number of stops within shift n In addition, the above (cmpx) is It is the rank.

here, T=r The following equation can be derived from the above data.

+nt (min) Crpm) [Number of stops/cmpχ] (min) (min) [times] When a unit represents 100,000 picks, the production amount P and the operating rate E are determined by the following equations.

A+ t NS NT T A + t NS In general, when the rotation speed N is increased, the stoppage level S becomes a function of the rotation speed N because it increases as a result of various conditions. Therefore, if we set 5=f(N), An=NST and A+ tNS tNS from r=T-nt. In other words, the production amount P and the operating rate E are the rotational speed N
is expressed as a fractional function. Therefore, the optimal rotation speed N can be found by analytically finding the rotation speed N that maximizes the production amount P, but the above function f (N) is an unknown function, and in reality, A+tNS A+tNS Difficult to determine due to the complexity of the fluctuation situation.

By the way, if k is the rate of change in the stoppage level when the rotational speed N is changed by an increment ΔN, then the rotational speed N'', the stoppage level s', the production amount P', and the operating rate E゛
can be rewritten as follows.

N' = N+ΔN S = S+k ΔN A+t (N+ΔN) (ΔN to s+) A+t(N+
ΔN) (ΔN to S+) Here, the increases and decreases P, ΔE, and ΔS before and after the change are given below, respectively.

ΔP=P'-P ΔE=E'-E Δs=s'-s Therefore, the inventor performed a computer simulation by inserting various values into the above equation. As a result, it was found that there are three types of changes in the production amount P, and these can be classified into three patterns.

FIG. 1 shows these patterns I, ■, and ■, respectively.

In the graphs of these patterns I, ■, and ■, the horizontal axis represents the increase/decrease ΔN in the rotation speed, and the vertical axis represents the increase/decrease ΔP, ΔE, and ΔS in the production volume, operating rate, and stoppage level, respectively. The solid line represents the production amount ΔP. This production amount ΔP can always be expressed as an upwardly convex curve. The dotted line indicates the operation rate E, and the dashed-dotted line indicates the stoppage level ΔS. These straight lines simply show increasing or decreasing trends, and each pattern is shown with the same slope, but the slope itself has no special meaning.

First, pattern ■ is the current rotational speed N, that is, the increase/decrease ΔN
=O indicates that the maximum production amount P is given. Therefore, the rotation speed N at this time becomes the optimum rotation speed to obtain the maximum production amount.

In this pattern, when the rotational speed N is increased, the production amount P and the operating rate E decrease, but the stoppage level S increases. Further, when the rotational speed N is lowered, the production amount P and the stoppage level S decrease, but on the contrary, the operating rate E increases.

Next, in pattern (2), when the current rotational speed N is increased, the production amount P and the stop level S increase, and the operating rate E decreases. Further, when the current rotational speed N is lowered, the production amount P and the stoppage level S decrease, but the operating rate E increases.

Furthermore, in pattern ■, when the rotation speed N is increased, the production amount P
Although the operating rate E decreases, the stoppage level S increases. Further, when the rotational speed N is lowered, the production amount P and the operating rate E increase, but the stoppage level S decreases.

As is clear from these patterns I, ■, and ■, the graphs of the production amount P are all expressed as upwardly convex curves. The graphs of the production amount ΔP for patterns ① and ② are obtained by moving the graph of pattern E in the direction of the horizontal axis, that is, the rotation speed N.

In addition, according to the conventional control method in which the operating rate is kept constant and kept above Hell and the rotation speed is changed, if the current state is in pattern I, the operating rate at this time exceeds a certain level. If this were the case, the rotation speed would be controlled to increase, exceeding the rotation speed (optimal rotation speed) N that gives the maximum production volume P, and would instead be operated in the state of pattern ■, resulting in a decrease in production volume. It can be seen that there is a possibility that P may be decreased. Conversely, the conventional control method
This method can be said to be effective only when the current situation is in pattern ■.

From these graphs, the following conclusions can be drawn.

(1) In the case of pattern I, whether the rotational speed N is increased or decreased, the production amount P decreases. That is, pattern r provides the optimum rotation speed N from the viewpoint of maximizing production amount P.

(2) In the case of pattern H, by increasing the rotation speed N, the operation rate E decreases and the stoppage level S increases, but the production amount P increases further.

(3) In the case of pattern (2), by lowering the rotational speed N, the operating rate E increases, the stoppage level S decreases, and the production amount P increases.

(4) In the case of patterns ■ and ■, the production amount P can be maximized by changing the rotation speed N and shifting to the state of pattern ■.

Therefore, in the present invention, in order to shift from the current state to the state of pattern I that maximizes the production amount, the current rotation speed is first changed, and as a result, whether the production amount tends to increase or not. Check to see if it is around the corner of the decline,
Based on this tendency, it is determined whether to increase or decrease the rotation speed.

In general, in jet looms, the number of stops acts as a stop and has a great effect on the quality of the fabric, so when changing the rotation speed, it is necessary to By taking into account the constraint condition ``the quality decreases,'' it is possible to maintain a predetermined quality of 1 level.In addition, if the rotation speed N is increased too much during the control process, the flying condition of the weft thread during weft insertion will deteriorate, causing the weft thread to become loose. However, when such a loose condition occurs, the invention disclosed in Japanese Patent Application Laid-Open No. 63-92758 detects the loose condition and stops the loom. This can be reflected in Level S. Further, the rotational speed N must be changed within a range of rate of change that can be sufficiently followed not only by the rotational speed control system but also by other control systems such as the weft insertion control device of a loom. In addition, when such control is performed for each individual loom, the production iP data at a certain set rotation speed N is obtained by collecting data several times for one rotation speed N, taking into account the data dispersion. If these data are averaged and used, these variations can be absorbed. Furthermore, when performing this on a group of looms with the same fabric specifications within the same weaver group, data on the production amount P of each V& machine at a certain set rotation speed N may be averaged.

In addition, in actual control, as in Example 2 described below,
Operate the loom at the rotation speed N at the point (2 + 1) from ΔN at N- to ΔN at N+, perform regression analysis using a curve from the value of production volume P at each rotation speed, and find the optimal rotation speed N. You may also do so.

Control System Configuration FIG. 2 shows a group control system for carrying out the method of the invention. An optimal controller l such as a host computer is connected to each vIi machine control section 5 via a communication control section 2, a communication line 3, and a communication control section 4 of each loom control section 5.

Each loom control section 5 is connected to a drive motor 7 of the loom through a rotation speed changing section 6 such as a variable inverter. In this system, the optimal controller 1
specifies a specific loom control unit 5 for each predetermined period, for example, for each loom, for all looms in a factory, or for a group of looms with the same textile specifications belonging to the same weaver group. , collect data of the loom, and execute the optimal control of the present invention.

However, the optimum control method of the present invention can also be executed individually in each loom control section 5, without using the group control method using the host computer as described above.

Embodiment 1 FIG. 3 shows an example in which the method for optimally controlling the number of loom rotations of the present invention is executed for each number of looms having the same fabric specifications and belonging to the same weaver group.

The optimum controller 1 executes the control shown in FIG. 3 for a predetermined period of time, such as changing the weaver's shift or at regular time intervals. First, the V& machine is operated at a certain rotation speed N, and after a predetermined time T0 has passed, the average production volume P and stoppage level S for the number of looms are obtained, and then the predetermined quality level is satisfied. In order to determine whether
Expressing the equation S≧S between the platform stop level S and the upper limit platform stop level S0
.

Compare by. When this inequality does not hold, it is determined that the predetermined quality level is still satisfied, and the number of revolutions N of the loom is changed to increase to the number of revolutions (N + ΔN), and the number of revolutions after the change (N + ΔN) is Predetermined time T again
. After the elapse of , the production amount P and the stoppage level S' are determined, and here too, the changed stoppage level S′ and the upper limit stoppage level S are determined.

are compared using the inequality S" ≧So. If this inequality does not hold, there is still some margin in the quality level, so it is determined whether the production iP at this time is increasing, and if it is increasing, the corresponding It can be determined that the current operating state of the loom is in pattern (3).

In the case of this pattern H, the current rotation speed N is changed again to a new rotation speed (N + ΔN) in the increasing direction, the production amount P and the stoppage level S are newly calculated, and the stoppage level is determined by the inequality S≧So. S and the upper limit stop level S. If it holds, the series of control is completed by returning to the rotation speed (NΔN) before the change that satisfied the quality level, but if it does not hold, it is determined whether the production amount P has increased or not. A judgment is made, and if it is increasing, the process returns to the previous step again to set the direction of increase in the rotation speed, and if it is decreasing, the rotation speed before the change (which indicates the maximum value of the production amount P) is returned. N-ΔN) to complete the series of controls.

On the other hand, when the above-mentioned inequality S゛≧S is established, it is determined that the predetermined quality level is no longer satisfied due to the increase in the rotation speed, and in order to reduce the stoppage level S,
The current rotation speed N is returned to the rotation speed (N-ΔN) before the change. Furthermore, even if the inequality S゛≧S does not hold and it is determined that the quality level is still satisfied, if the production amount P has not increased, pattern r or pattern ■ may be true. Therefore, the rotation speed is similarly returned to the rotation speed (N-ΔN) before the change, when the production amount was larger than the current one.

In the next step, the rotation speed N is set in the decreasing direction, the production amount P is determined again, and it is determined whether it is increasing. If it is increasing, the process returns to the previous step and the rotation speed is determined. If N is set in the decreasing direction but not increasing, the rotation speed (N
+ΔN) and complete the series of controls.

In addition, when the inequality S≧So of the first step is established, it is determined that the predetermined quality level is not satisfied, and in order to reduce the stop level S, the current rotation speed N is set as the rotation speed in the decreasing direction. (N - ΔN), then obtain the production amount P and the stoppage level S, and again judge the inequality S≧30. As long as this inequality holds, the rotation speed N is repeatedly changed in the decreasing direction. Ru. When this inequality no longer holds true, the process moves to the step for setting the rotation speed decreasing direction, and the series of controls is completed by obtaining the rotation speed that maximizes the production amount.

In this way, the optimal control method of the present invention uses the comparison of the magnitude relationship between the stoppage level S and the upper limit stoppage level S0, that is, the comparison of the quality levels, as a constraint, and while determining the increase in production amount P, By setting the rotational speed N in a decreasing direction or in an increasing direction, the optimum rotational speed N, that is, the state of pattern I, is set in accordance with patterns I, (2), and (2).

Example 2 Next, Fig. 4 shows the production volume at each rotation speed by sequentially operating the rotation speed at (2 + 1) points, such as from the rotation speed (ΔN to N-) to the rotation speed (ΔN to N+). This is an example of calculating the optimum rotation speed N by performing a regression analysis on a function of the production amount P using the rotation speed N as a variable from the value of P.

First, the upper limit stop level S. , rotation speed N1 rotation speed increment ΔN and coefficient k that determines the number of changes are read, i=
− is set. After that, the new rotation speed NH=N+
The loom is operated at iΔN, and after the predetermined time T0 has elapsed,
The stoppage level S3 and the production amount P at that time are calculated and stored, and in the next step, a magnitude comparison is made using the inequality S, ≧80 to judge the quality level, and if this does not hold, the inequality i A magnitude comparison is made based on ≧k, and when it is not satisfied, after setting i=i+l, the process returns to the previous step and operates the loom at a new rotation speed (N,=N+iΔN). Thereafter, similar control is repeated until the inequality i≧k is satisfied.

During this repetitive control, when the inequality S, ≧30 is established, the upper limit rotation speed for satisfying a predetermined quality level is changed to the previous rotation speed (N+(i-1)Δ
N). Based on the data of the production amount P for each rotation speed obtained in this way, in the next step, P=f
A regression curve of (N) is found, and the number of revolutions N that maximizes the production amount P within the range of allowable number of revolutions is found. Thereafter, the optimum controller I operates the loom at the rotation speed N. In this way, the control program obtains a regression curve in the process of optimum control, and from there sets the optimum rotation speed N.

In each of the above embodiments, the stop level S and the upper limit stop level S are set in the control process. Although the constraint condition was a comparison of the size relationship with the material, that is, a comparison of the quality level, this constraint condition can be omitted in cases where quality is not an issue, such as in the case of industrial materials, for example.

Effects of the Invention In the present invention, in the process of setting the optimum rotation speed of the loom, the rotation speed is practically changed several times, and as a result of the changes, the optimum rotation speed is set based on the actual increase/decrease trend in production volume. Therefore, even though the stoppage level is an unknown function, the rotation speed that actually maximizes production is set accurately (.

Therefore, as in the past, the theoretical optimum rotation speed is
In reality, erroneous control such as the rotation speed not being set at the maximum production amount is eliminated. For this reason, an increase in production at a new rotation speed is actually demonstrated, and the theoretical results do not deviate from reality.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the pattern of the relationship between production volume, operating rate and stoppage level, Fig. 2 is a block diagram of the control system, and Figs. 3 and 4 are flowcharts of the optimal control method of the present invention. be. 1. Optimal controller, 2. Communication control section, 3. Communication line, 4. Communication control section, 5. Loom control section, 6..
Rotation speed changing section, 7...Driving motor. Patent applicant Tsudakoma Kogyo Co., Ltd. Agent
Person Patent Attorney Kuni Nakagawa5TART Get S≧S. Figure P: Production amount S: Stopping level flat button dark blue: Return r″′”″ ΔN: Turning Φ clothing soil dispute

Claims (5)

[Claims] (1) Sequentially change the rotation speed of the loom at predetermined intervals, calculate the production volume after the change, and change the rotation speed in the direction that maximizes the production volume based on the determined increase/decrease trend in the production volume. Features: Optimal control method for loom rotation speed. (2) Optimal control of the rotational speed of a loom according to claim 1, characterized in that a quality limit is set in the process of increasing and decreasing the rotational speed, and the rotational speed is changed within a range that does not exceed this limit value. Method. (3) Sequentially change the rotation speed of the loom every predetermined period, calculate the production volume each time, perform a regression analysis of the relationship between the production volume and the rotation speed using a curve from these values, and calculate the production volume from this approximate curve. An optimal control method for the rotational speed of a loom, characterized by finding the maximum rotational speed. (4) The quality information at each rotation speed is obtained each time, and the rotation speed at which the production volume is maximized without exceeding a preset quality limit is determined from the approximate curve obtained by regression analysis. A method for optimally controlling the rotational speed of a loom according to claim 3. (5) The optimum control method according to claim 1 or 3, characterized in that the rotation speed is changed in units of a group of looms with the same textile specifications within the same weaver group.