JPS6188776A - Roll drive monitor - Google Patents

Abstract

PURPOSE:To obtain a roll monitor which does not need mounting of a speed detector by providing calculators for calculating a disorder load torque applied to a roll drive system, a roll speed, a motor speed and an intermediate twisting angle. CONSTITUTION:An observer circuit for calculating a shaft twisting angle theta, a drive motor speed omega1, a roll speed omega2 and a disorder load torque TL from a drive motor terminal voltage Va, an armature current Ia is composed as shown. When the roll drive is monitored by calculating the theta, omega1, omega2, TL by the observer circuit, the mounting of a speed detector is not necessary. Accordingly, the existing roll drive system can be applied.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a monitoring device for a roll drive system used in a rolling mill or the like.

(Prior Art) In recent years, the steel industry has implemented various measures in order to satisfy the increasingly strict quality requirements of users.

In particular, strip thickness is closely related to yield and production efficiency, but since strip thickness accuracy is mostly determined by the rolling mill, rolling mill control devices are becoming more sophisticated and responsive. . On the other hand, the roll drive system of a rolling mill consists of a drive motor, an intermediate shaft, and a rolling roll, but there is a shaft torsional resonance point on the intermediate shaft determined by the rigidity coefficient of the intermediate shaft and the moments of inertia of the drive motor and rolls. , Wear of the intermediate shaft due to excessive shaft torsion torque generated when the strip is bitten,
The strip shape is defective due to resonance phenomenon. Conventionally, these phenomena have been dealt with by monitoring the drive motor armature current and sacrificing the performance of the roll speed control device, but these methods are not sufficient.

To address the above-mentioned problems, the inventors have recently proposed a roll drive monitoring device that estimates the roll speed and shaft torsion angle using arithmetic formulas from the drive motor speed and armature current (Japanese Patent Application No. 1986- No. 34037), in order to adopt this estimation method, it is necessary to install a speed detector on the drive motor, which is a constraint when adopting the above-mentioned monitoring device.

(Object of the Invention) The present invention was made to solve the above-mentioned drawbacks, and an object of the present invention is to provide a roll monitoring device that does not require the installation of a speed detector and can be easily applied to an existing roll drive system. .

(Summary of the Invention) The feature of the device of the present invention for achieving the above object is to measure the terminal voltage and armature current of the drive motor in a roll drive system consisting of a drive motor, a roll, and an intermediate shaft connecting these. From the signal, the disturbance load torque applied to the roll drive system, the roll speed, the drive motor speed, and the intermediate shaft speed are calculated using an arithmetic formula in which coefficients are determined so that at least one of impact drop, shaft torsion angle, and speed followability becomes a desired value. The reason is that a calculation device for calculating the helical angle is provided.

(Structure of the invention) The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a control block diagram of the roll drive system.

In FIG. 1, block 1 shows the transfer function of the drive motor armature circuit, 2 shows the drive motor inertia moment block, 3 shows the shaft torsional rigidity coefficient block, and 4 shows the roll inertia moment block. From Fig. 1, equations for armature current 1a, drive motor speed ω10 - wheel speed ω2, and shaft torsion angle θ are found as follows (1)2 to (5).
The formula becomes

y=cx...
(2) X=(θ ω2 (Ill Ia),
u=Va −−−−−・(3)・・・・・・(4) ・・・・・・(5) Here, θ is the shaft torsion angle, ω2 is the roll speed, ω1 is the drive motor speed, Ia is armature current, Ks is shaft torsional rigidity coefficient, KT is torque coefficient, Ke is electromotive force coefficient, La is armature reactance, Ra is armature resistance, Jl is motor inertia moment, J2 is roll inertia moment, Va is The terminal voltage, TL, is the disturbance load torque.

Assuming Equation 6) for the disturbance load torque TL
'-TL=O (6) t Substituting the equation (6) into the above equations (1) 2 to (5) gives the following equations (7) 2 to (11).

-X'= A X' + B u -(
71t y=c'x'...
...(8)X"-(TL, θ, ω, , ω,
Ia)", u=Va-f9)...αO) C'-(00001)... (11
)(7)2~In order to obtain θ, ω2, and TL from equation (11), it is necessary to satisfy the condition of equation (12), but this actually means that equation (12) is combined with equation (10) and ( 11) It can be confirmed by substituting the formula.

Formulas for calculating the shaft torsion angle θ, drive motor speed ω1, roll speed ω2, and disturbance load torque TL from the drive motor terminal voltage Va and armature current Ia are obtained by the Gopinath method known in control engineering, and the observer − design is possible. The results are shown in equations (13)2 to (17).

(16) (15) In equations 2 to (16), α, β, T, and δ are parameters that determine the estimated speed. Above (13) 2～(
FIG. 2 shows equation 17) in the form of a block diagram of the observer. Further, the circuit shown in FIG. 2 can be easily realized using a digital circuit.

(Effects) Conventional roll drive monitoring methods require the installation of a speed detector, which limits the scope of application, but the device of the present invention has no such limitations and can be widely applied. Also, compared to conventional devices, the calculation formula is a little more complicated,
In the form of programs thanks to recent advances in digital technology,
It's not that big of a problem because it can be done.

[Brief explanation of the drawing]

FIG. 1 is a control block diagram of the roll drive system, and FIG. 2 is a block diagram of the observer. In the drawings, Va is the terminal voltage, la is the armature current, TL is the disturbance load torque, ω2 is the call speed, ω1 is the drive motor speed, and θ is the shaft torsion angle.

Claims (1)

[Claims] In a roll drive system composed of a drive motor, a roll, and an intermediate shaft connecting these, at least one of impact drop, shaft torsion angle, and speed followability is determined to a desired value from measurement signals of the drive motor's terminal voltage and armature current. A roll drive monitoring device comprising a calculation device that calculates a disturbance load torque applied to a roll drive system, a roll speed, a drive motor speed, and an intermediate shaft torsion angle using a calculation formula with coefficients determined such that