This brief proposes a robust subspace-aided fault detection approach for rolling mill processes with roll eccentricity. The novelty of this brief relies on the closed-loop identification of the so-called data-driven realization of the stable kernel representation (SKR) of the rolling mill process. In order to ensure an accurate and robust closed-loop identification, the mappings among the ...
بیشترEccentricity is measured while the turbine is on slow roll (1 to 240 RPM below the speed at which the rotor becomes dynamic and rises in the bearing on the oil wedge) and requires special circuitry to detect the peak- to-peak motion of the shaft.
بیشترECCENTRICITY INSPECTION DEVICE FOR ROLLED PAPER: 2005115205: 2007102556: Attorney, Agent or Firm: Fleck, Hermann-Josef (Klingengasse 2, DE) Claims: 1. A method for detecting a shape of a sheet roll (40), comprising: positioning at least two cameras (11, 11') on a cylindrical side surface of the sheet roll …
بیشترRoll eccentricity is a periodic disturbance caused by a structure of back up rolls in rolling mills, and it affects product thickness accuracy. It cannot be measured directly by sensors, so it should be identified by measured thickness or measured roll force. When there is a large difference of diameters between top and bottom back up roll, the performance of roll eccentricity control using ...
بیشترA progressive roll edge misalignment that can be concave or convex. Observed only after the roll has started to be unwound. Non-uniform cross-deckle caliper: Reduce cross-deckle caliper variation. Winding too soft at same radius of the roll with respect to other radius: Control hardness of …
بیشترmonitoring and detecting eccentricity problems in the cross-roll piercing mill. The remainder of this paper is organized as follows. Section 2 describes the product quality information obtained from UT results and operation condition information extracted from the vibration signals at the hot piercing stage. Section 3 presents the
بیشترThis research focuses on the roll eccentricity signal detection from the rolling signal. Traditional roll eccentricity signal detection methods like Fourier Analyzer of Roll Eccentricity (FARE) method and Wavelet method are reviewed. Some traditional roll eccentricity compensation methods like the Dead Band method are also reviewed. A new signal identiftcation method based on the Lissajous ...
بیشترLaserLinc understands how critical your in-process and off-line measurements are, for outside diameter, ovality, wall thickness, concentricity, eccentricity, profile and more. We support a full range of in-process and off-line non-contact and sample measurement solutions for medical, wire & cable, automotive, industrial, monofilament, and other ...
بیشترBut, this method is known to worsen plate thickness accuracy by amplification of roll eccentricity effect which is an inner disturbance in hydraulic servo loop of screw down control. For this situation, at present, the method of fourier analysis of roll separating force to detect roll eccentricity vector is attempted.
بیشترEccentricity . Eccentricity is the change in the shape of the earth's orbit around the sun.Currently, our planet's orbit is almost a perfect circle. There is only about a 3% difference in distance between the time when we're closest to the sun (perihelion) and …
بیشترEccentricity is the measurement of Rotor Bow at rotor slow roll which may be caused by any or a combination of. In extreme cases of thermal/gravity bow, caused by a …
بیشترNeural networks to detect eccentricity of induction motors 153 to the stator or the rotor damage. It can also intensify the influence of other negative phenomena such as power asymmetry, damage of the rotor or stator circuits, overloading motor operation, etc. There are three types of eccentricity: static, dynamic and a mixed one.
بیشترRoll eccentricity is an important factor causing thickness variations during hot strip rolling and might define the limit of strip thickness control accuracy.
بیشترA common objective in the web transport industry is to increase the velocity as much as possible. Some disturbances drastically limit this velocity. Time-varying eccentricity of the rolling winder is one of the major disturbances which affect the quality of the rolling winder. This unsuitable factor can lead to a web break for a high-speed winding process.
بیشترValmet offers a front-running range of parent roll handling systems, winders, roll wrapping and handling systems for the paper and board manufacturers. Over the years Valmet has delivered more than 500 winders and 200 roll wrapping machines and 100 parent roll carts or transfer rail systems to satisfied customers around the world. Our wide experience and contribution to parent roll handling ...
بیشترthe first step change in eccentricity, another step change occurs, almost always increasing the eccentricity. 0 0.2 0.4 0.6 0.8 1 1.2 1.4 0 200 400 600 800 1000 Eccentricity caused by the queen roll only Eccentricity caused by the king & queen roll Eccentricity caused by king & queen roll & random variation Diameter [m] Eccentricity [um]
بیشترBecause of roll eccentricity in backup rolls, the exit thickness deviates periodically. In this paper, we design PI controller in outer loop for the strip exit thickness while PD controller is used in inner loop for the work roll actuator position. Also, in order to reduce the periodic thickness deviation, we propose roll eccentricity ...
بیشترA misaligned roll with one edge concave and another convex. Trash in Roll Any foreign material such as loose piece of paper, dust, dirt etc. caught up or blown in to a roll of paper during manufacturing or rewinding. Trim in Roll A paper roll defect caused by the rewinder slitter trim shaving inadvertently being wound up in the roll.
بیشترAbstract: Roll eccentricity in rolling mills has an important influence on the delivery gauge of rolled strips. An online back propagation algorithm with memory range was used to identify roll eccentricity and compared with the simple online back propagation algorithm on identification.
بیشترRoll eccentricity is widespread in the strip mill, has cyclical impact on strip thickness, so disturbance compensation is required to improve the product quality. The key step of disturbance compensation is to obtain reliable roll eccentricity signal. Existing direct measurements of roll eccentricity signal method requires special equipments with high precision but not practical enough.
بیشترE x is an eccentricity value of a point x at the circumference of the top backup roll in contact with the top work roll, E y is an eccentricity value of a point y at the circumference of the bottom backup roll in contact with the bottom work roll, M is the mill modulus, and . F is the variation in the rolling force caused by the eccentricity;
بیشترPaper Roll Eccentricity Inspection Automatic optical measurement of ovality, eccentricity, and other dimensional features helps to assess product quality and ensure worker safety. If the core center is off from the roll center by more than a few millimeters, the roll may cause damage or create a safety hazard when unwound at the customer site.
بیشترMar 03, 2011· But, this method is known to worsen plate thickness accuracy by amplification of roll eccentricity effect which is an inner disturbance in hydraulic servo loop of screw down control. For this situation, at present, the method of fourier analysis of roll separating force to detect roll eccentricity vector is attempted.
بیشترWall-thickness eccentricity is a major dimensional deviation problem in seamless steel tube production. Although eccentricity is mainly caused by abnormal process conditions in the cross-roll piercing mill, most seamless tube plants lack the monitoring at the hot piercing stage but only inspect the quality of finished tubes using ultrasonic testing (UT) at the end of all manufacturing processes.
بیشترEccentricity is measured while the turbine is on slow roll (1 to 240 RPM below the speed at which the rotor becomes dynamic and rises in the bearing on the oil wedge) and requires special circuitry to detect the peak- to-peak motion of the shaft. Assuming uniform stiffness and weight, the rotor mid- span eccentricity may be expressed as the ...
بیشترRoll eccentricity compensation systems [2013-01] B21B 37/68. Camber or steering control for strip, sheets or plates, e.g. preventing meandering [2013-01] ... Methods or devices for measuring, {detecting or monitoring} specially adapted for metal-rolling mills, e.g. position detection, inspection of the product ...
بیشترmonitoring and detecting eccentricity problems in the cross-roll piercing mill. The remainder of this paper is organized as follows. Section 2 describes the product quality information obtained from UT results and operation condition information extracted from the vibration signals at the hot piercing stage. Section 3 presents the
بیشترRoll eccentricity is of major significance because it may be ampI ified by the "gaugemeter" control system and result in more serious thickness errors along the entire product length than would have been present wi thout the "gaugemeter" control. That is. the potential benefits of installing fast response actuators are not attained and the ...
بیشترAn on-line monitoring system has been developed to detect roll anomaly in a hot strip mill. The system calculates the roll eccentricity value for each roll and alerts the operators of a risk of roll spall when the value is largely changed. The presentation will show the …
بیشترDiameter, Eccentricity, concentricity. The diameter of an object can be established in different ways. If the center of the object is known, a single sensor is sufficient for the measurement whose result is evaluated with the position of the center point or the axis.
بیشترThe term balance eccentricity, or permissible residual specific unbalance as detailed in ISO 1940 (see References), is defined by the amount of unbalance present divided by the mass of the rotor or component. When this term is used, it can be physically related to the runout of a previously balanced component as follows: = = 2
بیشتر21SPP 05 -020]jw2]j jöf Qûm gâgªvbl^ x¾gò k~ jÖ Xzb eÇuâ nÊWî Condition Diagnosis of Roll Eccentricity Disturbance . in Roll -to -roll Continuous Systems. *k*{®S(QzRsXz_RV), lzl*m" (QzRsXz_RV), a a×|r(QzRsXz_RV), #lzqCk¶ (QzRsXz_RV). *H. Oh, Y. Lee, B. Park, #C. Lee Key words : Diagnosis, Eccent ricity disturbance, Kullback -leibler divergence, Roll -to-roll continuous systems ...
بیشترLarge Stator/Rotor Eccentricity – A Unit Failure Case Study. A 120 MW Kaplan unit failed in December 2015. The reason for the failure was the detachement of the tangential keys from the rotor causing damage to the stator core (Fig. 1). To find the root cause a detailed analysis of the data from the database of the installed monitoring system ...
بیشترWe propose an off-line method for detecting a faulty backup roll that generates eccentricity components when the feeding velocity, equivalently the angular velocity of roll, is not constant. From a newly devised speed-angle conversion algorithm, we transform all process data into those of a virtual process under a constant feeding speed.
بیشترLong eccentricity was extracted using a Taner filter with half power points at 1/650 ka and 1/250 ka, and a roll-off rate of 10 4. Short eccentricity was extracted using a Taner filter with half power points at 1/140 ka to 1/80 ka and a roll-off rate of 10 4. (b) The observed precession envelope (black line) and the long-eccentricity band-pass ...
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