JPS6341696B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a traveling shearing control device that cuts a plate-like object such as a steel plate while the vehicle is traveling.

For convenience of explanation, cutting of a steel plate will be described below, but a plate-shaped body such as paper may also be used.

In this type of device, the position of the cutting blade at the time of cutting is required to be well controlled to accurately obtain the cutting position of the steel plate. Another important function is to control the position of the cutting edge while maintaining an appropriate speed so as not to impede the movement of the steel plate during and after cutting.

However, with conventional equipment, after knowing the set cutting position and steel plate speed, the timing to start the shear blade is determined assuming that the steel plate traveling condition is constant from then on, and a fixed acceleration pattern is commanded. This realized control of the cutting position and cutting speed during cutting. Therefore, there is no control over changes in the speed of the steel plate after the start of the shear, delays in the response of the shear drive motor, and any other unforeseen disturbance components.

As another conventional example that was made to improve this,
There is a system in which the deviation between the shear blade position and the steel plate traveling position is always fed back to the shear motor speed control system even after the shear is started, as shown in FIG. 1.

FIG. 1 is a block diagram showing a conventional traveling shear control device, in which 1 is a steel plate to be cut, 2 is a shear having a shear blade 21 for cutting the steel plate 1, and 3 is a shear having a shear blade 21 for cutting the steel plate 1.
A length measuring roller 4 rotates as the length measuring roller 3 moves, and is a length measuring device, which measures the moving length of the cutting position of the steel plate 1 based on the number of rotations of the length measuring roller 3. 5 is a driving motor for the shear 2, 6 is a reduction gear for the motor 5, and 7 is a drive motor for the shear 2;
is the speed detector of the motor 5, that is, the shear 2, and 8 is the shear rotation position detector, which is a straight line that converts the distance traveled by the shear blade 21 of the shear 2 toward the cutting position on the circumference into the movement of the steel plate. is detected as the distance L _s . 9 is a command speed calculator, which inputs the outputs L _B and L _s of the length measuring device 4 and the shear rotation position detector 8;
The commanded speed V _s ^* of the shear 2 is calculated using these, the preset gain K, and the speed V _B of the steel plate 1.
The length measuring device 4 generates pulses corresponding to the rotation of the length measuring roller 3, and the command speed calculator 9 calculates L _B by counting the pulses.
, and V _B is obtained by counting the pulses for a unit time. Reference numeral 10 denotes a speed control device which feeds back an actual value V _s from the speed generator 7 in order to control the speed of the motor 5 according to the command speed V _s ^* of the command speed calculator 9 . In addition, L is the distance between the length measuring roller 3 and the shear 2, and L _B is the distance between the length measuring roller 3 and the shear 2.
indicates the distance to the cutting target position of the tip of the steel plate.

That is, the command speed calculator 9 obtains L _B , V _B and L _s from the outputs of the length measuring device 4 and the shear rotation position detector, and performs the calculation process of the following equation.

V _s ^* = K(L _B −L _s ) +V _B …(1) However, K is a gain constant.

Command speed calculated by command speed calculator 9
V _s ^* is input to a speed control device, and this speed control device 10 controls the command speed V _s ^* and the speed detector 7.
Actual speed of shear 2 fed back from V _s
The speed of the motor 5 is controlled to eliminate the deviation.

Here, the gain constant K in equation (1) calculated by the command speed calculator 9 has an upper limit depending on the responsiveness of the speed control system of the drive motor, and the higher it is, the higher the accuracy of position control (cutting length) will be. However, it is widely known in automatic control theory that if the value is increased too much, the cutting edge speed becomes oscillatory with respect to the steel plate running speed. Therefore, there is a limit to conveniently controlling both the position deviation and the shear blade speed deviation, and this type of motor control usually sets K to about 3.0. This will be explained in detail with reference to FIG.

FIG. 2 shows the experimental results of the apparatus shown in FIG. 1 when K=3.0.

In Fig. 2a, the horizontal axis shows the time since the planned cutting point of the tip of the steel plate 1 passed the length measuring roller 3, and the vertical axis shows the time since the planned cutting point passed with respect to the position of the length measuring roller 3. The distance L _B and the distance L _s converted to a straight line of the shear blade 21 are shown. Also, in FIG. 2b, the horizontal axis shows time, as in FIG. 2a, and the vertical axis shows the speed of the shear blade 21.

As can be seen from this figure, the position of the shear blade 21 and the position of the planned cutting point appear to match one second after the planned cutting point passes the length measuring roller 3 (during cutting), but (in reality) ), the speed of the shear blade 21 has not reached V _s ^* = 1.00 m/sec. On the other hand, if the gain constant K is set larger than K=3, the speed _Vs of the shear blade 21 can be made to reach the command speed before cutting. However, in this case, due to the poor responsiveness of the speed control system, a phenomenon occurs in which ^the shear blade 21 speed V _s becomes vibratory with respect to the command speed V _s ^* , and the speed V _s is around 1.00 m/sec. It vibrates at the value of , and in the end, it is not possible to control the command speed at a constant level.
Furthermore, since V _s becomes oscillatory, L _s also follows L _B while vibrating.

That is, in equation (1), the first term on the right side is a term that performs control to match the steel plate cutting position and the shear blade position, but in order to realize position control, it is necessary to change the speed. Therefore, in order to increase the gain of position control and improve accuracy, it is necessary to increase the responsiveness of the speed control system. However, conventional control devices are not designed to provide sufficient response, and therefore, by setting a large gain K, the shear blade speed V _s becomes vibrational with respect to the command speed. Become. Furthermore, since a change in velocity is eventually expressed as a moving length, when V _s becomes oscillatory, L _s also becomes oscillatory with respect to L _B.

Here, according to FIGS. 2a and 2b, the shear 2 starts to start about 0.20 seconds after the start of the control, but this is because L _s is larger than L _B at the start of the control.
This is because V _s ^* in equation (1) takes a negative value. In other words, the shear normally rotates in the reverse direction once and then shifts to the normal rotation, but this is useless in actual control, and a limiter or the like is used to prevent the motor 5 from issuing a reverse rotation command.

As described above, the apparatus shown in FIG. 1 focuses only on the deviation between the advancing position of the steel plate 1 and the tracking position of the shear blade 21, and the speed control response of the shear blade 21 is poor. Therefore, the gain K cannot be made large, and the accuracy of the cutting device and the speed of the shear blade during cutting are poor.

As mentioned above, the speed accuracy of the shear blade plays an important role in traveling cutting, as it affects the traveling stability and cutting quality of the steel plate. Furthermore, it is necessary to fulfill the original function of cutting control, which is to achieve cutting accuracy at a set position.

This invention was made in order to meet the above-mentioned demands for traveling cutting, and it is a traveling shearing system that can improve both the accuracy of the cutting device and the accuracy of the shear blade speed during cutting by improving the responsiveness of the speed control system. The purpose of this invention is to provide a control device.

FIG. 3 is a block diagram showing one embodiment of the present invention, and numerals 1 to 10 are the same as those in FIG. 1, and their explanation will be omitted. Reference numeral 11 is a speed detector that detects the speed of the steel plate 1, and 12 is a time calculator that measures the moving distance L _B after the scheduled cutting point of the tip of the steel plate 1 passes the length measuring roller 3 and the moving speed of the steel plate 1. V _B is introduced from the length measuring device 4 and the speed detector 11, and the time from when the scheduled cutting point of the steel plate 1 passes the length measuring roller 3 and the time until cutting is calculated. 14 is a gain setting device which derives gains K _L (t) and K V (t) according to the time signal from the time calculator 12, and outputs the gains K L (t) and K _V (t) according to the time signal from the time calculator 12;
Output to 3. Reference numeral 13 denotes a command speed calculator, which receives gains K _L (t) and K _V (t) from the gain setter 14, shear blade speed V _s and steel plate speed V _B from the speed detectors 7 and 11, length measuring device 4 and Steel plate movement distance L _B and shear blade movement distance from shear rotation position detector 8
The command speed V _s ^* of the shear 2 is derived by introducing each L _s and performing calculations to be described later. The command speed V _s ^* derived by the command speed calculator 13 is input to the speed control device 10 and compared with the shear speed V _s detected by the speed detector 7, and the speed control device 10 is operated so as to eliminate these deviations. to control the speed of the motor 5, thereby controlling the shear speed.

Next, the contents of the calculation by the command speed calculator 13 will be described.

The command speed calculator 13 receives the gains K _L (t) and K _V (t) from the gain setter 14, the shear blade speed V _s and the steel plate speed V B from the speed detectors 7 and 11, and the length measuring device 4 and the steel plate speed V _B. L _B and L _s are introduced from the shear rotational position detector 8, and the following calculation is performed.

V _s ^* = K _L (t) (L _B - _{L s} ) + K _V (t) (V _B - V _s ) + V _B ... (2) However, L _B is the measured length of the planned cutting point of the tip of steel plate 1 _Ls is the moving distance of the shear blade 21 converted into a straight line distance, _VB is the speed of the steel plate 1, and _Vs is the speed of the shear blade 21.

Here, the gains K _L (t) and K _V (t) output from the gain setter 14 to the command speed calculator 13 are shown, for example, as shown in FIG. FIG. 4 shows an example of gains K _L (t) and K _V (t) when good cutting control is simulated based on equation (2). The characteristic is that immediately after the planned cutting point passes the length measuring roller 3, both K _L and K _V are small, and when the planned cutting point approaches the shear, K _L suddenly increases, and then becomes small again at the time of cutting. , it is not necessarily necessary to make it smaller when cutting. K _V gradually increases towards the time of cutting.

In other words, when the shear is first started, both the distance deviation (L _B −L _s ) and the speed deviation (V _B −V _s ) are large, and if the gain is large from the beginning, the command speed calculator 13 calculates the current capacity of the motor. The above excessive speed command V _s ^* will be calculated and output. On the other hand, a motor usually has an attached limiter circuit, and even if an excessive speed command V _s ^* is given, the motor will only respond within the allowable limit of the motor. As time progresses and the deviation decreases, even if a large gain is applied, the motor can be operated effectively within its allowable limits. Therefore, the gain setter 14 uses the time signal from the time calculator 12 to reduce the gain at the beginning of the control, and gradually increases the gain as it progresses to the latter half, so that good control can be achieved. There is.

Figures 5a and 5b show experimental results using the apparatus shown in Figure 3. In this case, it can be seen that at the time of cutting one second after the scheduled cutting point passes the length measuring roller 3, L _s and L _B match, and the speed V _s also becomes the command speed 1.00/sec. .

In other words, in the past, the shear speed was controlled by the deviation signal between the advancing position of the steel plate and the position of the shear blade 21, but in the present invention, as seen in the second term on the right side of equation (2), Second, the shear speed is controlled even if there is a deviation between the steel plate speed and the shear blade speed. Therefore, the responsiveness of the speed control system can be improved, and the deviation between the steel plate speed and the shear blade speed can be reduced at an early point. This will be explained with reference to FIG. 3. In FIG. 3, a speed control loop consisting of a speed detector 7, a command speed calculator 13, and a speed control device 7 is added compared to the conventional system. Then,
The response speed of the speed control loop is 1+ compared to the conventional one.
K _V (t) due to being twice as fast.

On the other hand, when the deviation between the steel plate speed and shear blade speed becomes smaller, the gain K _L (t) for position control can be increased, and needless to say, the gain K _V (t) for speed deviation can also be increased. can. Therefore, the accuracy of position control and speed control becomes good.

According to FIGS. 5a and 5b, the shear 2 starts immediately after the control starts, but when controlling using equation (2), even if (L _B −L _s ) becomes negative, (V This is because V s ^* becomes a positive value immediately after the start of control because _B − V _{s )} is positive and takes a reasonable value. However, if the distance between the cutting position and the length measuring roller 3 is increased, V _s ^* becomes negative at the start of control, so it is necessary to provide a limiter or the like.

As described above, according to the present invention, in addition to position control regarding the scheduled cutting point of the steel plate and the shear blade position, speed control regarding the steel plate speed and shear blade speed is performed, so that the speed control system Since the responsiveness can be improved and the gains of position control and speed control can be increased, there is an effect that both cutting length accuracy and shear blade speed accuracy during cutting can be improved.

Further, if each control gain is gradually increased with respect to the time from the start of the shear to the time of cutting, it is effective to perform control favorably.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional traveling shear control device, FIG. 2 is a diagram showing experimental results using the device shown in FIG. 1, and FIG. 3 is a block diagram showing an embodiment of the traveling shear control device of the present invention. , FIG. 4 is a gain characteristic diagram used in the device of FIG. 3, and FIG. 5 is a diagram showing experimental results using the device of FIG. 3. In the figure, 1 is a steel plate, 2 is a shear, 21 is a shear blade, 3 is a length measuring roller, 4 is a length measuring device, 5 is a drive motor, 6 is a speed reducer, 7 and 11 are speed detectors,
8 is a shear position detector, 9 and 13 are command speed calculators, 10 is a speed controller, 12 is a time calculator, 1
4 is a gain setter. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. In a traveling shearing control device that cuts a moving plate-shaped body with a shear blade driven by a motor in a running state, the shear blade is fixed at a position that is constant from the position of the shear blade when cutting the plate-shaped body. Distance L _B that the above-mentioned plate-shaped body has moved from a reference point that is a distance away toward the cutting position
A length measuring device that detects the traveling speed of the plate-shaped body V _B
a traveling speed detector that detects the movement of the shear blade; a shear position detector that detects the circumferential distance that the shear blade has moved toward the cutting position as a straight-line distance _Ls converted to the moving direction of the plate; Shear blade speed detector to detect shear blade speed, predetermined gain K _L
(t), K _V (t), a gain setting device that sets the gains K _L (t), K _V (t) set in this setting device, and the distance detected by the above-mentioned length measuring device and traveling speed detector.
By inputting L _B and traveling speed V _B , the distance L _s detected by the shear position detector and shear blade speed detector, and the shear blade speed V _s , the command speed V _s ^* of the motor that drives the shear blade is input. The command speed calculator calculates V _s ^* = K _L (t) (L _B - _{L s} ) + K _V (t) (V _B - V _S ) + V _B , and the command calculated by the above command speed calculator. Traveling characterized by comprising a speed control device that compares the speed V _s ^* with the shear blade speed V _s detected by the shear blade speed detector and controls the speed of the motor so as to eliminate these deviations. Shear control device. 2. Traveling shear according to claim 1, characterized in that the gains K _L (t) and K _V (t) are gains that increase as time elapses until the plate-shaped body is cut. Control device.