JPS58224946A - Electric tension control apparatus - Google Patents

Abstract

PURPOSE:To set tension with high accuracy in an apparatus for electrically controlling tension of a thread at the time of winding and drawing out the thread by providing a tension control portion with a mechanical loss compensating portion and an acceleration and deceleration compensating portion so as to compensate a mechanical loss and fluctuation in a turning energy. CONSTITUTION:A tension control portion 15 of a feedback control system is provided with a mechanical loss compensating portion 19 of a feed forward control system and an acceleration and deceleration compensating portion 20. By these control operations, a mechanical loss of a take-up beam 10 as a rotor and fluctuation in turning energy at the time of acceleration and deceleration are always compensated so as to set tension with high accuracy. As a result, at the time of winding and feeding out a thread, paper, a film sheet or the like as a control object, the winding and feeding operations can be accomplished with low tension.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for electrically controlling the tension of a controlled object such as a belt-shaped object, such as a thread, when the object is wound or fed out at high speed.

For example, a warp sizing machine is equipped with a winding device.

This winding device winds the yarn at high speed under constant tension using the rotational force of the motor.

If the thread tension increases, thread breakage may occur, so the tension must be controlled with high precision.

The patent applicant has already developed a control system effective for this type of tension control. Under feedback control, the tension control system controls the rotational speed of the variable speed DC motor for winding υ using the supplied current, and at the same time controls the tension of the yarn to be controlled and the outer diameter of the winding beam. is electrically detected, and this detection signal is input to the supply current feedback system.

The above tension control technology enables highly accurate and stable high-speed winding control compared to conventional friction winding systems or variable speed motor winding systems. However, today there is a need for tension control technology that can handle even higher speeds and lower tensions.

In order to realize the above requirements, two items must be met. One of these is to reduce the time constant of the motor and mechanical system as much as possible to achieve high response. The other problem is the control system. Under fast-response current control, a current command corresponding to the tension as the target value is issued, and the proportional gain of the feedback tension control system is set low. The aim is to construct a control system that is resistant to external disturbances, and to stabilize the control by responding to instantaneous tension fluctuations through differential operation and to responding to long-term tension fluctuations through integral operation. .

On the other hand, as already mentioned, this type of control system is based on feedback control. For this reason, there is a time delay in the control system, and disturbances are likely to occur. If the proportional gain of the tension control system is set low, disturbances are less likely to occur, but they are not completely suppressed. This random loss is caused by fluctuations in rotational energy during acceleration and deceleration and transient changes in the thread during startup.

These mechanical losses and fluctuations in rotational energy are unique to the mechanical system and electrical control system, and are determined in advance by calculation. The inventor focused on this point and attempted to develop an ideal control that can be applied to high speed and low tension.

Therefore, an object of the present invention is to provide a tension control device that is effective in compensating for mechanical loss and fluctuations in rotational energy during acceleration and deceleration. Based on the above object, the present invention adds a mechanical loss compensating section and an acceleration/deceleration compensating section of a feedforward control system to a tension control section of a feedback control system, and by these control operations, the machine By sequentially calculating the loss and the amount of compensation during acceleration and deceleration and applying these to the tension control section, more complete compensation is achieved.

Hereinafter, the present invention will be specifically explained based on an embodiment shown in the drawings.

FIG. 1 shows an example in which the electric tension control device 1 of the present invention is applied to a winding device 2 of a warp sizing machine. The thread 3 whose tension is to be controlled is passed through a roll 4° and a delivery roll 15. Roll 6 Lamichi roll 7, tension detection roll 8. roll 9
The winding beam IOl/c is wound up from the winding beam IOl/c. The delivery roll 5 is driven by a direct current variable speed line motor 11, and this motor 11 is controlled by a delivery speed control device 12. Feed speed setting signal V from the feed speed control device 12d1 feed speed setting device 13
v is input, the line motor 11 is given rotation at a predetermined speed based on it, and the rotation of the delivery roll 5, that is, the rotation of the line motor 11, is detected by the tacho generator 14, and the line motor is output as the output of the tacho generator 14. The speed signal vL is used as a feedback amount, and the rotation of the line motor 11 is controlled under feedback control while comparing it. The characteristics of this feed speed control device 12 are fast response speed and stability.

The winding beam 10 is a rotating body that rotates together with the yarn 3 to be controlled, and is controlled by the electric tension control device 1 of the present invention. i.e. electric tension control device l
The tension control unit 15 is a control system in which current feedback is used as an auxiliary feedback loop and tension feedback is used as the main feedback loop.
The tension setting signal VT given by is input, and the current and current of the DC variable speed motor 17 is controlled based on this. This motor 17 rotates the winding beam 10 and winds up the thread 3 under a predetermined tension.

Here, the tension of the yarn 3 appears on the tension detection roll 8, and the tension value is electrically detected by the tension detector 18 and fed back to the tension control section 15 as a tension detection signal Vs.

A mechanical loss compensator 19 of a digital feedforward control system is connected to the tension controller 15. Acceleration/deceleration compensator 20
．． A startup compensation section 21 and a correction section 22 for these components are provided. The mechanical loss compensation section 19 sequentially inputs the tension setting signal VT and the rotational speed signal VR from the rotational speed detector 23, calculates a mechanical loss M, and sends a compensation signal VM corresponding to this loss value to the tension control section. Output to 15. Further, the acceleration/deceleration compensator 20 inputs the line motor speed signal v'L and the rotational speed signal VR, and detects the differential value dVvdt by detecting the outer diameter of the rotating body, that is, the winding beam 10, and differentiating the line motor speed signal VL. Then, during acceleration and deceleration, a compensation signal V is generated corresponding to the fluctuation of the rotational energy of the winding and coil 10 for a short period of time, and the compensation signal VA is transmitted through the mechanical loss compensation section 19 to the tension control section 15.
In addition to outputting to the field controller 24 of the motor 17,
A rotational torque corresponding to the winding diameter of the winding beam 10 is generated. Further, the starting compensation section 21 corresponds to the operation of the starting switch 25, and includes an acceleration/deceleration compensation section 20 and a mechanical loss compensation section 19.
A transient compensation signal VD is applied to the tension control section 15 through the tension control section 15. Further, the correction unit 22 uses the PjD output of the main feedback loop CP peak control of the tension control unit 15 to perform correction calculations for fine adjustment, and calculates the correction values α, α2, . Send α to each part.

Now, FIG. 2 shows a specific configuration of the electric tension control device 1. As shown in FIG. The tension setting signal VT of the tension setting device 16 enters the P peak actuator 27 from the summing point 26, where it becomes the PiD output V, passes through the summing point 28, 29 and the current controller 30, and is sent to the motor 17 as a target value. A current corresponding to the tension is applied. The output of the current controller 30, that is, the current value, is sent to the summing point 2 via the current detector 31.
Negative feedback is given to 9. Current controller 30 and current detector 31 thus form an auxiliary feedback loop to control speed by current 31 of motor 17. On the other hand, the tension detection signal v8 of the tension detector 18 is negatively fed back to the addition point 26. This tension detector 1B also constitutes a main feedback loop with the PiD operation element 27. Here, the PiD operation element 27 performs proportional, differential, and integral operations, compares the tension setting signal VT and the tension detection signal 1st, and controls the current controller 30 based on the deviation. This current controller aO is composed of a bidirectional builister or the like. Incidentally, in a steady state, the tension setting signal VT and the tension detection signal v8 are canceled out at the addition point, so the output of the PiD operation element 27iD is close to (b). Therefore, the actual target value is given inside the mechanical loss compensator 19, as will be described later.

The tension setting signal VT is also input to the mechanical loss compensator 19, converted into a digital quantity by the A/D converter 33, and similarly converted by the A/D converter 34 into a rotational speed signal "/". Together with R, it is input to the function unit 35&C.

This function unit 35 stores in advance a mechanical loss function fz (VR* VT) for each number of rotations (rotational speed) of the rotating body for each tension from low tension to high tension. Determine mechanical losses based on content. The mechanical loss function fs (Vx e VT ) is determined by the broken-line Konpi curve in FIG. Mechanical loss M increases in proportion to tension setting signal VT and rotational speed vRVc.

The output of the function unit 35 is then input to the coefficient unit 36.

Here, the coefficient unit 36 applies the output signal of the function unit 35 to the setting unit 3.
The gain setting coefficient given in 7 is multiplied by 3, and this and the correction value α8 are added at an addition point 38, and the result is applied to an addition point 39 as a compensation signal VM for the mechanical loss M. Here, the compensation signal VM(t) as a function of time t can be expressed by the following equation.

VM(t) ”” Km ” f2(VR, VT')
+ αa (VR, VT) On the other hand, the tension setting signal VT is multiplied by 4 by the coefficient given by the setting device 40 in the coefficient multiplier 41, passed through the addition point 42.39, and converted into an analog signal by the A/D converter 43. ii After K conversion, the addition point 28 of the tension control unit 15
added to. The coefficient unit 41 always gives a current command corresponding to the target tension to the current controller 30.

Therefore, the PiD operation element 27jD output vi is close to zero in the steady state, as described above. Therefore, the tension control section 15 operates stably against disturbances. Note that this coefficient multiplier 41 is connected to the tension control section 15 due to its nature.
It may be inside the .

Next, the output of the tacho generator 14, that is, the line motor speed signal VL, is converted into a digital quantity by the A/D converter 44, and is input to the divider 45 together with the rotational speed signal VR. This divider 45 calculates the take-up diameter of the take-up beam lO with respect to the delivery roll 5 from these signal ratios. The output of the divider 45 is multiplied by the coefficient H of the setter 46 in the coefficient unit 47 to become the winding diameter signal VK, which is then passed through the D/A converter 48 and amplifier 49 of the field control section 24 to the motor 17. is applied to the field winding 50. As a result, the field control section 24 changes the field current of the winder 17 in accordance with the change in the winding diameter of the winding beam 10.

In this way, even if the outer diameter of the winding beam 10 changes due to winding of the yarn 3, the necessary winding torque is applied.

The winding diameter signal Vx is also input to a deceleration compensator 51 and an acceleration compensator 52. Deceleration compensator 51 and acceleration compensator 5
2 outputs the fluctuation of the rotational energy A of the rotating mechanical system during deceleration or acceleration, respectively, in accordance with the outer diameter of the winding beam 10, and outputs it as a signal that is the basis of the compensation signal Vh. The rotational energy during acceleration changes in a quadratic curve shape as the outer diameter R of the take-up beam 10 changes, as shown in FIG. This relationship also holds true during deceleration.

Therefore, the deceleration compensator 51 and the acceleration compensator 52 store values corresponding to the rotational energy function fl(VK) and selectively output them. The line motor speed signal VIJ is also input to the differentiator 53 after being A/D converted by the A/D converter 44 .

This differentiator 53 performs a differentiating operation on the line motor speed signal VL, calculates a differential value dVL/ctt, and outputs it to a coefficient unit 54 and an acceleration/deceleration discriminator 55 over the transient time during acceleration/deceleration. There is. The acceleration/deceleration discriminator 55 identifies the positive or negative sign of the differential value dVL/(it, generates an identification signal Sα2 based on it, and operates the changeover switch 56. This changeover switch 56 determines the function during acceleration or deceleration. In order to selectively output the output to the coefficient unit 54, the coefficient unit 54 generates an output of rotational energy fluctuation corresponding to acceleration or deceleration.

The output of the coefficient unit 54 is multiplied by 2 by the coefficient unit 58 for the gain setting given by the setter 57, and then added to the correction value α2 at the addition point 59 to become the quasi-compensation signal V'h. It passes through the delay circuit 60 and is added to the addition A61 as a compensation signal 'VA.

Here, the compensation signal VA (1) and the quasi-compensation signal V'h(t) as a function of time t can be expressed by the following equations, respectively.

VA(t) = V'hCt-Ta)VA(t)-
2” f t(Vx) ・dVL/dt + αz(
VK) In this way, the acceleration/deceleration compensator 20 calculates the fluctuation of the rotational energy A in relation to the rotation ratio and acceleration and deceleration of the delivery roll 5 and the take-up beam IO, and calculates the fluctuation of the rotational energy A,
2, it is applied to the tension control section 15 as a compensation amount.

On the other hand, at the time of startup, transient tension fluctuations appear, but the tension compensation at the time of startup is performed by the startup compensator 21. That is, when the start switch 25 is closed, the start signal Sαl is input to the nox generator 62. The pulse generator 62 receives a starting signal Sα as shown in FIG.
1, the switch 65 is turned on for a period of time given by the rising timing T1 of the timing setter 63 and the falling timing T2 of the timing setting device 64.

Therefore, the gain setting value of the setter 66 corresponding to the startup compensation at startup, and the correction value αl are added from the addition point 67 to the switch 6
5, is applied to the addition point 61, and is finally applied to the tension control section 1.
Sent to 5. Here, the compensation signal Vd as a function of time t
(t) is determined by the following formula, when the unit step function of the activation signal Sαl is defined as .

In this way, the mechanical loss compensator 19. Acceleration/deceleration compensator 20
The starting compensation section 21 calculates in advance mechanical loss, rotational energy during acceleration/deceleration, and compensation amount during starting, and applies them to the addition point 28 of the tension control section 15. Therefore, highly accurate tension control is possible.

On the other hand, the correction unit 22 inputs the PiD output Vi and uses the correction value α1. α3. Calculate α3, add 3 points
Output on 8,59.67. That is, the PiD output Vi is converted into a digital quantity by the A/D converter 68 and sent to the calculator 69. Here, the calculator 69 checks the above-mentioned compensation result by the change in the P1D output Vi, and calculates the correction value α1. α! , α3 are calculated and added to the above compensation equation as a correction amount. Note that calculation of the startup correction and acceleration/deceleration correction is performed using the startup signal Sα1. This is performed by the command of the identification signal SαS. For this reason, the mechanical loss compensation section 19. Acceleration/deceleration compensation section 2
0 and the activation compensation unit 21 have a kind of learning function and correct their respective compensation amounts.

Correction value α1 at startup. The correction value α during acceleration/deceleration and the correction value α3 for mechanical loss are each calculated using the following formulas.

First, the correction value α1 at startup is −/l, Vict
The value of the correction value α1 is determined as =o N so that t =o s'A Vj(')=o. That is, the next correction value α1. n+1 is the following formula %
Formula % () FIG. 6 shows a change curve (solid line) when starting compensation is performed and a curve (broken line) when starting compensation is not performed regarding the PiD output Vi. During compensation, the amount of variation is suppressed, but when no compensation is performed, there is a large overhang.Next, the correction value α2 (VK) during acceleration/deceleration is obtained by the following formula in the same way as above.

6g(VK)n+1=α2(Vx)n+1fTVi
cttO In addition, the mechanical loss correction value αs (vRI VT ) is
Find it as follows. Mechanical loss function fs(VR+
VT ) is approximated by one straight line in the interval CVRla vT l), and VR(tl)=VR1, VR(tll
) = VRII, the settling time, that is, the next correction amount α
a (VR#'/T)n+1 is obtained from the following formula.

"5(VRsVT)n+1 = ('a(VR,VT)
n + 〒ft d”Vidt=as(vR,VT), low'avi(-!”-)Nk=ON Note that in the above embodiment, the electric tension control device 1 of the present invention is applied to the take-up beam 10. However, this device can also be applied to overexposed beams. Moreover, the control target is not limited to the processing of threads and woven fabrics, but can also be used for winding up nine windings of thin strips such as paper and film sheets, or of filamentous materials.

In the present invention, a mechanical loss compensation section and an acceleration/deceleration compensation section are attached to the tension control section of the feedback control system. Since the tension is compensated, it is possible to set the tension with high accuracy. Therefore, the present invention
When winding or feeding out yarn, paper, film sheets, etc. as objects to be controlled, winding or feeding is possible under a low set tension. −

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment in which the electric tension control device of the present invention is incorporated into a winding device, Fig. 2 is a block diagram of the electric tension control device of the present invention, and Fig. 3 is a mechanical loss 4 is a graph of rotational energy fluctuations, FIG. 5 is a timing chart at startup, and FIG. 6 is a graph of transient phenomena at startup. 1... Electric tension control device, 2... Winding device, 3
... Thread as a controlled object, 10... Winding beam as a rotating body, 15... Tension control unit, 16...
- Tension setting device, 17... Motor, 18... Tension detector, 19... Mechanical loss compensation section, 20... Acceleration/deceleration compensation section. 21... Startup compensation section, 22... Correction section, 23.
...Rotation speed detector.

Claims (1)

[Claims] A variable speed motor that drives a rotating body that rotates with the controlled object, a rotation speed detector that detects the rotational speed of this motor and generates a rotational speed signal, and a rotational speed detector that detects the tension of the controlled object and generates a tension detection signal. a tension detector that generates a tension setting signal, a tension setting device that generates a tension setting signal, a tension control section of a feedback control system that inputs the tension setting signal and tension detection signal to control the rotation of the motor, and a tension control section that controls the rotation of the motor; and a mechanical loss compensation section of the feedforward control system that calculates the mechanical loss of the electromechanical system by inputting the rotational speed signal and outputs a compensation signal corresponding to the mechanical loss to the addition point of the tension control section; an acceleration/deceleration compensator of a feedforward control system that detects the outer diameter of the rotating body and outputs a compensation signal corresponding to fluctuations in rotational energy of the rotating body for a short period of time during acceleration/deceleration to an addition point of the tension control unit; An electric tension control device comprising: