JPH0211504B2 - - Google Patents

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-like object, such as a thread, when the object is wound up 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. The tension control system controls the rotational speed of the variable speed DC motor for winding using the supplied current under feedback control.
At the same time, the tension of the yarn to be controlled, the outer diameter of the winding beam, etc. are electrically detected, and the detection signals are input to the feedback system for the supply current.

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 matters must be fulfilled. 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 one is
Due to a control system problem, under fast response current control,
A current command corresponding to the tension as a target value is issued, and the proportional gain of the feedback tension control system is set low to configure a control system that is strong against disturbances, and differential operation is used to handle instantaneous tension fluctuations. In addition, the tension fluctuations over a long period of time can be dealt with by integral operation to stabilize the control.

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. The causes of this disturbance are mechanical loss in the motor and other rotating mechanical parts, 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 mechanical systems and electrical control systems, and are calculated in advance. 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 compensation section and an acceleration/deceleration compensation section of a feedback control system to a tension control section of a feedback control system, and uses these control operations to control the machine according to the operating conditions. 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 an electric tension control device 1 of the present invention is applied to a winding device 2 of a warp sizing machine. The yarn 3 whose tension is to be controlled is a roll 4,
It is wound up onto a winding beam 10 via a delivery roll 5, a roll 6, a roll 7, a tension detection roll 8, and a roll 9. The delivery roll 5 is driven by a DC variable speed line motor 11, and this motor 11 is connected to the feed speed control device 1.
2. Feed speed control device 1
2 inputs the feed speed setting signal V _F from the feed speed setting device 13 and gives the line motor 11 rotation at a predetermined speed based on it, and also controls the rotation of the feed roll 5, that is, the rotation of the line motor 11, to the tachometer generator 14. The line motor speed signal V _L as the output of the tachometer generator 14 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 rate 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. That is, the tension control section 15 of the electric tension control device 1 is a control system in which the current feedback is used as an auxiliary feedback loop and the tension feedback is used as the main feedback loop. The tension setting signal V _T thus obtained is input, and the 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 thread 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 unit 15 as a tension detection signal V _S. .

A mechanical loss compensation section 19, an acceleration/deceleration compensation section 20, a starting compensation section 21, and a correction section 22 for these components are attached to the tension control section 15, which are digital feedforward control systems. Mechanical loss compensation section 1
9 is a tension setting signal V _T and a rotation speed detector 2
The rotational speed signal V _R from 3 is inputted sequentially, the mechanical loss M is calculated, and the compensation signal corresponding to this loss value is calculated.
V _M is output to the tension control section 15. Further, the acceleration/deceleration compensator 20 inputs the line motor speed signal V _L and the rotational speed signal V _R , detects the outer diameter of the rotating body, that is, the winding beam 10, and differentiates the line motor speed signal V _L to obtain a differential value dV _L / dt is detected, and a compensation signal V _A corresponding to the variation in the rotational energy A of the winding beam 10 is generated for a short period of time during acceleration/deceleration, and the compensation signal V _A is applied to the tension through the mechanical loss compensator 19. In addition to being output to the control section 15, the field control section 24 of the motor 17 is controlled to generate rotational torque corresponding to the winding diameter of the winding beam 10. In addition, the startup compensation section 21 controls the startup switch 2
5, a transient compensation signal V _D is applied to the tension control section 15 through the acceleration/deceleration compensation section 20 and the mechanical loss compensation section 19. Further, the correction unit 22
The main feedback loop (PiD control) of the tension control section 15
Input the PiD output Vi, perform correction calculations for fine adjustment, and send the correction values α ₁ , α ₂ , α ₃ 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 V _T from the tension setting device 16 enters the PiD actuator 27 from the summing point 26, where it becomes the PiD output Vi and is sent to the summing points 28, 2.
9 and a current controller 30, a current corresponding to the tension as a target value is applied to the motor 17.
The output of the current controller 30, that is, the current value, is negatively fed back to the summing point 29 via the current detector 31. In this way, the current controller 30 and the current detector 31
forms an auxiliary feedback loop, and controls the speed by the amount of current of the motor 17. On the other hand, the tension detector 18
The tension detection signal V _S is negatively fed back to the addition point 26 . This tension detector 18 and the PiD actuator 27 constitute a main feedback loop. Here PiD
The actuator 27 performs proportional, differential, and integral operations, compares the tension setting signal V _T and the tension detection signal V _S , and controls the current controller 30 based on the deviation. This current controller 30 is composed of a bidirectional thyristor or the like. In addition, during steady state, the tension setting signal
Since V _T and the tension detection signal V _S are canceled out at the addition point, the PiD output Vi of the PiD actuator 27 is close to zero.
Therefore, the actual target value is given inside the mechanical loss compensator 19, as will be described later.

The tension setting signal V _T is the mechanical loss compensator 19
It is also inputted to the function unit 35, converted into a digital quantity by the A/D converter 33, and inputted to the function unit 35 together with the rotational speed signal V _R similarly converted by the A/D converter 34. This function unit 35 stores in advance a mechanical loss function f ₂ (V _R , V _T ) for each number of rotations (rotational speed) of the rotating body for each tension from low tension to high tension. Mechanical loss is calculated based on the memory contents. Mechanical loss function f ₂ (V _R ,
V _T ) is determined by the approximate curve of the broken line in FIG.
Mechanical loss M is determined by tension setting signal V _T and rotation speed
It increases in proportion to _VR . and function unit 35
The output of is input to the coefficient unit 36. Here, the coefficient unit 36 multiplies the output signal of the function unit 35 by the gain setting coefficient K ₃ given by the setting unit 37, adds this and the correction value α ₃ at the addition point 38, and compensates for the mechanical loss M. It is applied to the addition point 39 as the signal V _M. Here, the compensation signal V _M (t) as a function of time t can be expressed by the following equation.

V _M (t) = K ₃ · f ₂ (V _R , V _T ) + α ₃ (V _R , V _{T )} On the other hand, the tension setting signal _V is multiplied by the addition points 42 and 39, converted into an analog quantity by the A/D converter 43, and then added to the addition point 2 of the tension control section 15.
Added to 8. The coefficient unit 41 always gives a current command corresponding to the target tension to the current controller 30. Therefore, the PiD output Vi of the PiD operating unit 27
As already mentioned, is close to zero in steady state. Therefore, the tension control section 15 operates stably against disturbances. Note that this coefficient multiplier 41 may be located inside the tension control section 15 due to its nature.

Next, the output of the tachogenerator 14, ie, the line motor speed signal V _L , 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 V _R. This divider 45 is
From these signal ratios, the winding diameter of the winding beam 10 with respect to the delivery roll 5 is calculated. This divider 4
The output of No. 5 is multiplied by the coefficient H of the setting device 46 by the coefficient unit 47 to become the winding diameter signal V _K , which is sent to the field control unit 2.
4 D/A converter 48 and amplifier 49,
It is applied to the field winding 50 of the motor 17. Thereby, the field control unit 24 changes the field current of the motor 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 the winding of the yarn 3, the necessary winding torque is applied.

The winding diameter signal V _K is also input to a deceleration compensator 51 and an acceleration compensator 52 . The deceleration compensator 51 and the acceleration compensator 52 each output a variation in the rotational energy A of the rotating mechanical system during deceleration or acceleration according to the outer diameter of the winding beam 10, and use this as the basis of the compensation signal V _A. output as a signal.
The rotational energy A 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 f ₁ (V _K ) and selectively output them. Line motor speed signal V _L is A/D converter 4
After being A/D converted in step 4, it is also input to the differentiator 53. This differentiator 53 performs a differential operation on the line motor speed signal V _L to calculate a differential value dV _L /dt, which is applied to a coefficient unit 54 and an acceleration/deceleration discriminator 55 over the transient time during acceleration/deceleration. It is output to. The acceleration/deceleration discriminator 55 discriminates the sign of the differential value dV _L /dt, generates the discrimination signal Sα ₂ based on it, and operates the changeover switch 56. Since the changeover switch 56 selectively outputs the acceleration or deceleration function to the coefficient multiplier 54, the coefficient multiplier 54
Generates an output of rotational energy fluctuations corresponding to acceleration or deceleration. The output of the coefficient unit 54 is multiplied by the coefficient K ₂ for gain setting given by the setting unit 57 by the coefficient unit 58, and then added to the correction value α ₂ at the addition point 59 to become the quasi-compensated signal V′ _A. Addition point 61 as compensation signal V _A via delay circuit 60
added to.

where the compensation signal V _A (t) as a function of time t
and the quasi-compensation signal V' _A (t) can be expressed by the following equations, respectively, where _T3 is the dead time caused by the dead time setting device 62.

V _A (t) = V' _A (t - T ₃ ) V' _A (t) = K ₂ · f ₁ (V _K ) · dV _L /dt + α ₂ (V _K ) In this way, the acceleration/deceleration compensator 20 calculates the variation in rotational energy A in relation to the rotation ratio and acceleration and deceleration of the delivery roll 5 and take-up beam 10, and applies it to the tension control unit 15 through the addition point 42 as a compensation amount.

On the other hand, at the time of startup, transient tension fluctuations occur, 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 Sα ₁ is input to the pulse generator 62. As shown in FIG. 5, the pulse generator 62 switches over a period of time given by the rising timing T ₁ of the timing setter ₆₃ and the falling timing T ₂ of the timing setting device 64 based on the activation signal Sα 1. Turn on 65. Therefore, the gain setting value K ₁ of the setting device 66 corresponding to startup compensation at startup and the correction value α ₁ are added at the addition point 6
7, is applied to the addition point 61 via the switch 65, and finally sent to the tension control section 15. Here, the compensation signal Vd(t) as a function of time t is given by the unit step function of the starting signal _Sα1 as u(t).
It is calculated using the formula below.

Vd(t)=( _K1 + _α1 ) {u(t- _T1 )-u(t- _T1 - _T2 )} In this way, the mechanical loss compensator 19, the acceleration/deceleration compensator 20, and the start-up compensator 21 calculates in advance the mechanical loss, the rotational energy during acceleration/deceleration, and the compensation amount at the time of startup, and calculates them in advance at the addition point 28 of the tension control unit 15.
to be applied. Therefore, highly accurate tension control is possible.

On the other hand, the correction unit 22 inputs the PiD output Vi,
From this, the aforementioned correction values α ₁ , α ₂ , α ₃ are calculated and output to addition points 38 , 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 based on the change in the PiD output Vi, calculates the correction values α ₁ , α ₂ , α ₃ , and
Added to the above compensation formula as a correction amount. Note that the calculation of the startup correction and the acceleration/deceleration correction is performed according to the commands of the startup signal Sα ₁ and the identification signal Sα ₂ . Therefore, the mechanical loss compensator 19, the acceleration/deceleration compensator 20, and the start compensator 21 have a kind of learning function and correct their respective compensation amounts.

The correction value α ₁ at the time of startup, the correction value α ₂ at the time of acceleration/deceleration, and the correction value α ₃ for mechanical loss are each calculated by the following formulas.

First, the correction value α ₁ at startup is calculated as ∫ ^T ₀ Vidt= time T≧t until PiD output Vi settles to zero
0,
Determine the value of the correction value α ₁ so that _N 〓 ^k=0 Vi (kT/N)=0. That is, the next correction value α ₁ , n+1 can be expressed by the following formula.

α ₁ , n+1=α ₁ , n+1/T∫ ^T ₀ Vidt = α ₁ , n+1/N _N 〓 ^k=0 Vi (kT/N) Figure 6 shows the change curve when starting compensation is applied to PiD output Vi. (solid line) and a curve (broken line) when starting compensation is not provided. When compensated, the amount of variation is suppressed, but when no compensation is used, a large overshoot appears.

Next, the correction value α ₂ (V _K ) at the time of acceleration/deceleration is determined by the following formula in the same manner as above.

α ₂ (V _K ) _o+1 = α ₂ (V _K ) _o +1/T∫ ^T ₀ Vidt = α ₂ (V _K ) _o +1/N _N 〓 ^k=0 Vi (kT/N) Also, mechanical loss The correction value α ₃ (V _R , V _T ) is obtained as follows. Mechanical loss function f ₂ (V _R , V _T )
is approximated by one straight line in the interval [V _R1 , V _T1 ], and if V _R (t ₁ )=V _R1 and V _R (t ₂ )=V _R2 , then settling time T=t ₂ −t ₁ , ∫ ^t2 _t1 = 0,
The correction value α ₃ (V _R , V _T ) is determined so that _N 〓 ^k=0 Vi (kT/N)=0. In other words, the next correction amount α ₃
(V _R , V _T ) _o+1 is obtained from the following formula.

α ₃ (V _R , V _T ) _o+1 = α ₃ (V _R , V _T ) _o +1/T∫ ^t2 _t1 Vidt = α ₃ (V _R , V _T ) _o +1/N _N 〓 ^k=0 Vi (kT/N) In the above embodiment, the electric tension control device 1 of the present invention is applied to the take-up beam 10, but this device can also be applied to the delivery beam. Furthermore, the objects to be controlled are not limited to the processing of threads and woven fabrics, but also thin strips such as paper and film sheets, etc.
It can also be used for winding and feeding 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, and compensation corresponding to the mechanical loss of the rotating section and fluctuations in rotational energy during acceleration/deceleration are constantly compensated. Therefore, the tension can be set with high precision. Therefore, the present invention makes it possible to wind up or send out paper, film sheets, etc., in addition to yarn as a control object, under a low set tension.

[Brief explanation of drawings]

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.
4 is a graph of mechanical loss, FIG. 4 is a graph of rotational energy fluctuation, 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...
Yarn 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... Starting compensation section, 22... Correction section, 23... Rotation speed detector.

Claims (1)

[Claims] 1. A variable speed motor that drives a rotating body that rotates together with the controlled object, a rotation speed detector that detects the rotation speed of this motor and generates a rotation speed signal,
A tension detector that detects the tension of the controlled object and generates a tension detection signal, a tension setting device that generates a tension setting signal, and a feedback device that inputs the tension setting signal and tension detection signal to control the rotation of the motor. A tension control section of the control system, and a filter that inputs the above-mentioned tension setting signal and rotational speed signal, calculates the mechanical loss of the electromechanical system, and outputs a compensation signal corresponding to this mechanical loss to the addition point of the above-mentioned tension control section. The mechanical loss compensation section of the yield forward control system detects the outer diameter of the rotating body and adds a compensation signal corresponding to the fluctuation of the rotational energy of the rotating body for a short period of time during acceleration/deceleration to the tension control section. 1. An electric tension control device comprising: an acceleration/deceleration compensator of a feedforward control system that outputs an output to a point.