JPH0447310A - Deceleration control method - Google Patents

Abstract

PURPOSE:To prevent the sudden change of a speed command from being caused, and to improve control performance by predicting a speed limit value, operating a machine for a definite period of time as limiting its speed at this speed after the completion of acceleration, and after that, decelerating and stopping the machine. CONSTITUTION:An upper limiter 1 outputs the smaller one of either a speed set value V0 or an automatic deceleration signal VL, and the upper limiter 1A outputs the smaller one of either the output of the upper limiter 1 or the output of a automatic deceleration interference suppression signal generator 3, and outputs it as a speed command value V** through a shockless signal generator 4. Namely, on the supposition of a winding machine, it is acceleratively operated at some acceleration rate alpha from a stopped state by an acceleration command, and after reaching the speed limit value VTOPHL, it is operated at this speed for a definite period of time, and afterwards, it is decelerated automatically at deceleration rate beta, and is stopped. Thus, at the time of transition from the acceleration to the deceleration, by decelerating the machine after passing through the definite speed, the sudden change of the speed command is prevented from being caused, and the control performance can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a deceleration control method suitable for use in controlling the winding of long objects including steel plates.

[Conventional technology]

FIG. 4 shows a conventional control device for a winding machine. In the same figure, 1. IA is an upper limiter, 2 is an automatic deceleration signal generator, and 4 is a shockless signal generator. 0 In normal operation, acceleration is performed from a stopped state at an acceleration rate α according to an acceleration command, and the set speed ■. When reaching , the speed is constant ■. drive with

Incidentally, a deceleration command may be input during acceleration operation at the acceleration rate α as described above, but in such a case, conventionally, for example, the set speed ■. When it reaches, the upper limiter 1 sets the remaining length Lo (tc take-up length setting value - actual take-up length value)
From and deceleration rate β, VL= (2βL0)I/! Generally, the upper limit value is changed to the automatic deceleration signal (2) from the automatic deceleration signal generator 2 determined as follows, and automatic deceleration and stop is performed.

Figure 5 shows the speed command signal V'' in such a case, and Figure 6 shows the speed command signal V0 in such a case.
(a) in FIG. 5 shows the speed command signal v'' (b) shows the acceleration/deceleration rate (acceleration rate α) in the case of no Shirakkuresu control.

Deceleration rates β) and (c) respectively indicate the acceleration/deceleration rates (acceleration rate i, deceleration rate -b) in the case of shirakuless control.

[Problem to be solved by the invention]

However, in the above method, when switching from acceleration to deceleration, a sudden change in the speed command signal v2 occurs when transitioning from acceleration to deceleration, as shown in Fig. 4, and as a result, the long object may break. There are problems such as slipping, product defects, and incorrect stopping positions.

Therefore, an object of the present invention is to prevent sudden changes in speed command from occurring and to improve control performance.

[Means to solve the problem]

When accelerating from a stop or constant speed operating state while performing position control, and decelerating during acceleration, this is indicated by the amount moved so far during acceleration and the deviation between the travel amount set value and the travel amount set value. A speed limit value is calculated from the sum of the remaining length, the acceleration rate, and the deceleration rate, and when this limit value is reached during acceleration, the speed is limited to this value, and after driving for a certain period of time, the speed is decelerated.

[Effect]

When the speed limit value is reached during acceleration, the speed is limited to this speed and the speed is decelerated after driving for a certain period of time, thereby preventing a sudden change in speed command.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention.

In the figure, 1. IA is an upper limit device, 2 is an automatic deceleration signal generator consisting of a computing unit, etc., 3 is an automatic deceleration interference suppression signal generator also consisting of a computing unit, etc., 4 is a shockless signal generator consisting of a frequency generator, etc. The upper limiter I outputs the smaller of the speed setting value V0 and the automatic deceleration signal V, and the upper limiter IA outputs the smaller of the output of the upper limiter 1 and the output of the automatic deceleration interference suppression signal generator 3. Then, it is outputted as a speed command value V'''* via the shockless signal generator 4.

In other words, assuming a winding machine here as well, an acceleration command from a stopped state causes the machine to accelerate at an acceleration rate α,
Speed limit value ■7゜pHL (When Z is reached, the motor will operate at that speed for a certain period of time, and then automatically decelerate at the deceleration rate β and stop. In other words, when transitioning from acceleration to deceleration, as shown in Figure 5) , as shown in Figure 2, by decelerating after reaching a constant speed, a sudden change in speed command is prevented.The relationship between the speed command and acceleration/deceleration rate at that time is shown in Figure 3. The figure is the same as Figure 5.
(b) shows the acceleration/deceleration rate in the case of shockless control heat (acceleration rate α, $i speed rate β), and (c) shows the acceleration/deceleration rate in the case of shockless control (acceleration rate i, deceleration rate - b), respectively. ing.

The speed limit value VtO□ is the automatic deceleration interference suppression signal generator 3
The method for finding it will be explained below.

Is the current speed during acceleration VI3? . Then, the distance traveled at this speed is given by the following equation, where α is the acceleration.

On the other hand, the remaining length from the previous stop position to the next stop position is L”
Then, from the relationship shown in Figure 2, L' = L, +L, ... (2)
becomes. Further, assuming that the maximum attainable speed that can be predicted from a stopped state is VrorhL, the acceleration rate is α, and the deceleration rate is β, the following relationship holds between these and the remaining length L'.

Transforming equation (3), Vtop=(2αβL'/(α+β)) ””...
(4) Therefore, the speed limit value ■7°PHL is expressed as follows by multiplying (4) 2 by the limiting constant K.

7th floor 0F) IL -K・ (2αβL゛ / (α+β) ) ””...
(5) In this way, shockless control is performed by the shockless signal generator 4 with each rate of change of acceleration rate α and deceleration rate β set as b. It is desirable to make the dead time 1e as close to O as possible, and this adjustment is performed using the limiting constant K.

Although the above description has mainly focused on winding control, the present invention can be generally applied to anything that performs position control similar to this. Furthermore, although an example in which acceleration is started from a stop position has been described here, the same method as described above can also be applied to a case where acceleration is started from a constant speed.

Furthermore, although the speed limit value is determined using the automatic deceleration interference suppression signal generator in the above example, it can also be determined using software.

〔Effect of the invention〕

According to this invention, when starting acceleration from a stopped state or a constant speed state, an arithmetic circuit for calculating a speed limit value is added to predict this speed limit value, and after acceleration is completed, the speed is limited to this speed and kept constant. After operating for a period of time, the motor decelerates to a stop, which eliminates sudden changes in speed command.
As a result, there is an advantage that breakage, slippage, product defects, and stopping position defects can be improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram for explaining an example of the speed command in Fig. 1, and Fig. 3 is the relationship between the speed command and acceleration/deceleration rate in Fig. 1. 4 is a block diagram showing a conventional control device for a winding machine. FIG. 5 is an explanatory diagram illustrating an example of a conventional speed command. FIG. 6 is a conventional speed command. FIG. 3 is an explanatory diagram for explaining the relationship between commands and acceleration/deceleration rates. 1, IA... Upper limit device, 2... Automatic deceleration signal generator,
3... Automatic deceleration interference suppression signal generator, 4... Shockless signal generator.

Claims (1)

[Claims] 1) When accelerating from a stopped or constant-speed operating state while performing position control, and decelerating during acceleration, it is expressed as the amount moved so far during acceleration and the deviation between the set value of the travel amount and the actual value of the travel amount. A deceleration control method characterized in that a speed limit value is calculated from the sum acceleration rate and deceleration rate with the remaining length, and when this limit value is reached during acceleration, the speed is limited to this speed and the operation is continued for a certain period of time, and then decelerated. .