MXPA99007447A - Method and apparatus for controlling the tissue tension by actively controlling the speed and acceleration of a dancing roller - Google Patents

Abstract

This invention relates to processing continuous fabrics such as paper, film, composites and the like, in continuous and dynamic processing operations. More particularly, it relates to controlling the tension in such continuous fabrics during the processing operation. The tension is controlled in a dancer control system by connecting a dancer roller corresponding to an actuating device or the like, perceiving the variables such as position, tension, speed and acceleration parameters in relation to the fabric and the roller dancer, and provide active force commands in response to the perceived variables, to cause the translation movement generally including an acceleration of the target, in the dancer roller to control the tension disturbances in the fabric. In some applications of the invention, the dancer control system is used to attenuate voltage disturbances. In other applications of the invention, the dancer control system is used to create voltage disturbances.

Description

METHOD AND APPARATUS FOR CONTROLLING THE TISSUE TENSION BY ACTIVELY CONTROLLING THE SPEED AND THE ACCELERATION OF A ROLLER DANCER Field of the Invention This invention relates to the processing of continuous fabrics such as paper, film, composites or the like in continuous and dynamic processing operations. More particularly, the invention relates to controlling the tension in such continuous fabrics during the processing operation Background of the Invention In the plastic film and paper industries, a dancer roller is widely used as a buffer between the first and second sets of the driving rolls or between the first and second pressing points which drive a continuous web. The dancer roll, which is placed between the two sets of driving rolls, is also used to detect the difference in speed between the first and second sets of the driving rolls.

Typically, the basic purpose of the dancer roller is to keep the tension constant on a continuous web which traverses the space between the first and second sets of the drive rollers, including traversing the dancer roller.

By traversing the fabric the extension, passing over the dancer roller, the dancer roller moves upwards down a track, serving two related functions to stabilize the tension in the fabric. First, the dancer rodill provides a tensioning force to the tissue. And secondly the dancer roller temporarily absorbs the difference in the drive speeds between the first and second sets of the driving rollers, until the moment when the driving speeds can be properly coordinated.

A fabric that extends between two drive rollers constitutes a tissue space. The first drive roller moves the tissue mass into the space and the second drive roller moves the mass of tissue outside of said space. The amount of tissue mass entering a space, per unit time, is equal to the cross-sectional area of the fabric before it enters the space, times its velocity of the first drive roller. The amount of tissue mass leaving a space, per unit of time, is equal to the cross-sectional area of the tissue in space, times its velocity in the second drive roller. The conservation of mass requires that over time, the mass of tissue that comes out of space must be equal to the mass that enters space. The tension of the fabric, which is proportional to the tension, alter a cross-sectional area of the fabric or fabric. Typically, the dancer roller is suspended on a support system in which a generally static force supplied by the support system holds the dancer roller against an opposing force applied by the tension in the fabric and the weight of the dancer roller. The tissue tensioning force created by the dancer system causes a particular level of tension which produces a particular cross-sectional area in the tissue. Therefore, the mass of tissue that flows out of space is established by the second speed of the impeller and the tensioning force of tissue because the tensioning force of the tissue establishes the tightness of the tissue which in turn establishes the cross-sectional area of the tissue. If the mass of the tissue that comes out of space e different from the mass of the tissue that enters the space, the dancer roller moves to compensate for the mass of unbalance of flow.

A dancer roller generally operates in the center of its displacement range. A position detector connected to the dancer roller recognizes any changes in the position of the dancer roller, which signals a control system at any speed to either accelerate or decelerate the first drive roller to bring the dancer back to the center of its range. displacement and establish the mass flow balance.

When the dancer roller is stationary, the strength of the dancer support system, the weight of the dancer rod and the tissue tension forces are in static equilum, and the tissue tension forces are at their steady state values. When the dancer moves, the tissue tension forces change from their steady state values. This change in the tension force of the fabric provides the force that overcomes the friction, the viscous drag, and the inertia, causes the movement of the dancer. When the dancer moves very slowly, the forces of inertia and viscous drag are low and therefore the change in the tension of the fabric is slight However, during abrupt changes in the flow of mass as during a rise or fall of the ramp machine speed, viscous drag, and inertial forces can be several times the steady state voltage values of the fabric The advantages of the dancer roller are that it provides a tissue storage cushion which allows time to coordinate the speed of the machine impulses, and the dancer provides a relatively constant tissue tension force during the operation of steady state, or periods of gradual change. A limitation of the dance rolls, as conventionally used, is that under more dynamic circumstances, the ability of the dancer to maintain the constant fabric tension depends on the mass, drag and friction of the dancer system.

It is known to provide an active impeller for the dancer roller in order to improve the operation on that of a static system, where the fabric is kept under tension, but is not moving along the length of the fabric, so that the dynamic disturbances, and the natural resonance frequencies of the dancer roller and the fabric are not taken into consideration and therefore the resulting oscillations of the dancer roller can become unstable. Kuribayashi et al., "An Active Dancer Roller System for Sheet and Wire Tension Control", University of Osaka Prefecture, Osaka Japan, 1984.

More information about voltage disturbances and response times is set forth in U.S. Patent No. 5,659,229 issued August 19, 1997, which is hereby incorporated by reference in its entirety. U.S. Patent No. 5,659,229, however, controls the speed of the dancer roller and does not directly control the acceleration of the dancer roller.

Therefore, it is not known to provide an active dancer roller in a dynamic system wherein the dynamic variations in the operating parameters are used to calculate the variable active response force components to apply an active and variable acceleration to the dancer roller, where the appropriate gain constants are used to affect the response time without allowing the system to become unstable.

Synthesis of the Description This invention describes an apparatus and methods for controlling voltage and voltage disturbances in a continuous fabric during tissue processing. In a first aspect, the invention can be used to attenuate the desired stress disturbances in the tissue. In a second aspect, the invention can be used to create desired stress disturbances in the tissue.

In a typical conversion process, a parent roll of paper, composite, or similar fabric of material if processed is unwound at one end of the processing line, and processed through the process line to thereby convert the material unprocessed, such as narrower or shorter product rolls, or to shape raw material products into separate products of unprocessed material, and / or to combine raw material with other input elements to thereby create a product or product precursor. Such processing operations are generally considered "continuous processes" because the roll of raw material generally runs "continuously" for an extended period of time, supplying the raw material to the processing system.

A first family of embodiments of the invention is illustrated in a processing apparatus for advancing a continuous web of material through a processing pass wherein the web or fabric undergoes an average dynamic tension along a given section of a web. woven, the processing apparatus comprises a dancer roller which is operable to control the tension of the respective section of the fabric; and an optional apparatus (i) for applying a first static force component to the dancer roller, having a first value and direction, and balancing the dancer roller against the static forces and the average dynamic tension in the respective section of the fabric , and its controller connected to the actuator, the controlled by removing a second variable force component through the actuator apparatus, effective to control the network actuation force imparted to the dancer roller by the actuator apparatus, and to periodically adjust the value and direction of the second variable force component, each such value and direction of the second variable force component replaces the previous value and the direction of the second variable force component, and acts in combination with the first component d static force to impart a translational acceleration d network from target to dancer roller, the second component d variable force has a second value and direction, modifying the first static force component, so that the net translation acceleration of the dancer roller is controlled by the net driving force allowing the dancer rod to control the fabric tension.

In some embodiments of the invention, the processor apparatus includes a sensor for sensing the tension of the tissue after the dancer roller, the controller being adapted to use the perceived voltage in computing the value and direction of the second variable force component, and to impart the computed value and the direction through the actuator to the dancer roller. The sensor can effectively perceive the voltage in at least one time per second, and is effective to recompute the value and direction of the second variable force component, thus to adjust the value the direction of the second variable force component computed by less once per second.

In other embodiments, the sensor can be effective to sense the voltage at least 500 times per second, the controller being effective to recalculate the value and the direction of the second variable force component therefore to adjust the value and direction of the variable force component segund computed at least 500 times per second, the actuator apparatus being effective to apply the second component of variable force recomputed to the dancer rod at least 500 times per second according to the values and addresses computed by the actuator , by tant to control the net translation acceleration.

In some embodiments, the sensor may be effective to sense the voltage at least 1000 times per second, the controller comprises an effective computer controller to recalculate the value and direction of the second variable force component and therefore to adjust the value and direction of the second variable force component computed at least 1000 times per second, the actuator being effective to apply the second component d variable force recomputed to the dancer roller at least 100 times per second according to the values and direction computed by the computer controller, therefore to control the translation acceleration.

In some embodiments, the controller regulates the actuation force imparted to the dancer roller and therefore the acceleration of the dancer roller, including compensating for an inertial imbalance of the dancer roller not compensated for by the first static force component.

In some embodiments, the processing apparatus includes an apparatus for computing the translation acceleration p) of the dancer roller, the controller providing the control commands to the actuator apparatus based on the computed acceleration of the dancer roller. The apparatus may comprise an observer.

In some embodiments, the observer comprises a subroutine in a computer program that computes an estimated translational acceleration and an estimated translation speed for the dancer roller. In other embodiments, the observer comprises an electrical circuit.

In another embodiment of the invention, the processor apparatus includes the first apparatus for measuring a first speed of the fabric after the dancer roller; the second apparatus for measuring a second speed of the fabric in the dancer roller; and a third apparatus for measuring the translation speed of the dancer roller; and a fourth device to perceive the position of the dancer roller.

In another embodiment of the invention, the processor apparatus further includes: a fifth apparatus for measuring tissue tension before the dancer roller; and a sixth apparatus for measuring the tension of the fabric after the dancer roller. In such additions the computer controller can compute a force command using the equation: - Fc) + Ma (A * p - p) where the fixed point of dancer translation speed V * reflects the equation: V = [EA0-FC)] [V2 (l- Fb / EA ") - V3 (l - Fc / EA] to control the driven apparatus based on the calculated force, where: F * d estate = component of static force on the dancer roller equals Mg + 2F * C, Fc = tension in the fabric after the dancer roller, F * c = tension in the tissue, fixed point objective, by process design parameters, Fb = tension in the fabric in front of the dancer roller, F * friction = friction in any direction of the resistance movement of the dancer roller, F * servo = force to be applied by the actuator, ba = constant of control gain in relation to the translation speed of the dancer in Newtons seconds / meter, k ^ = control gain constant in relation to the tension d tej gone, Mg = mass of the dancer roller sometimes gravity, Mg = active mass, Mj = active mass and physical mass, Vp = instantaneous translation speed of the dancer roller immediately before the application of the second variable force component, Sign (Vp) = positive or negative value depending on the direction of movement of the dancer roller, V2 = speed of the fabric in the dancer roller, V3 = speed of the fabric after the dancer roller, V * = reference translation speed of the dancer roller. fixed point, r = radius of the respective pulley on the actuator, E = modulus of elasticity of the tissue, A ,, = area in cross section of unrestricted tissue, A * p = target translation acceleration of the fixed point dancer roller, and Ap = the translational acceleration of the dancer roller.

In some embodiments, the acceleration A * p d objective can be computed using the equation: = [V * VpJ /? where? T = scan time for the computer driver.

In some embodiments, the computer controller provides control commands to the powered apparatus based on the perceived position of the dancer roller, and the measured fabric tensions, acceleration and speeds, thereby controlling the actuation force imparted to the dancer rod by the actuator apparatus and therefore to maintain the web tension essentially constant.

In some embodiments, the computer controller provides control commands to the powered apparatus based on the perceived position of the dancer roller, and the measured fabric tensions, acceleration and speeds, thereby controlling the actuation force imparted to the dancer rod by the actuator apparatus to provide a predetermined pattern of variations in tissue tension.

In another embodiment of the invention, the processing apparatus includes: a first apparatus for measuring the translation speed of the dancer roller; a second apparatus for measuring the tensile force of the cloth after the dancer rodill and the third apparatus for perceiving the actuality of the apparatus actuators.

In some embodiments, the controller computes a derivative of a weaving tension force from the tissue tension force over the past perception intervals includes, an observer computing the translatory speed of the dancer roller, and the controller computing a derivative. d the tension force of cloth.

In some embodiments, the processing apparatus includes an observer to compute a derivative d of the fabric tension force from the tension force of tel and the translation speed of the dancer roller.

In some embodiments, the controller comprises a restless logic subroutine stored in the computer controller, the disturbing logic subroutine inputs the tissue tension force error, the derivative of the tissue tension force error, and the acceleration error, Uneasy logical subroutine proceeds through the step d restless interference of the above-mentioned errors by then applying rules to the restless games and disinquietand the rules to generate a command output signal, the uneasy logic subroutine are being executed during the scanning of the sensing device.

In another embodiment of the invention, the processing apparatus includes: the first apparatus for measuring the translation speed of a dancer roller; and a second apparatus for sensing the current of the actuator apparatus. In such incorporation, the computer controller can compute the estimated translation acceleration of the dancer roller of the equation: A ^ = [^ Vp - Vj + k, eI - F * d static - F * frictíónSign (Vp)] / M ^ where: Ape = estimated translation acceleration of the dancer roller, Static F * d = component of static force on the dancer roller and which is equal to Mg + 2F * C, F * fpction = friction in any direction resisting movement of the dancer roller, Sign (Vp) = positive or negative value qrue depends on the direction of movement of the dancer roller, a = observer gain, = instantaneous translation speed of the dancer roller Vpe = estimated translation speed, kte = servo motor (actuator) estimated constant d torsional force, I = drive device current, and I2 ?? e = estimated physical mass of the dancer roller.

In some embodiments, holding a zero-order can be used to store the force values for the application to the dancer roller.

In some embodiments, the processing apparatus actively compensates for the viscous friction coulomb and acceleration, to actively cancel the mass effects.

In another embodiment of the invention, the processing apparatus includes: the first apparatus for measuring the translation position of the dancer roller; the second apparatus for measuring the tensile strength of the tissue after the dancer rodill; and a third apparatus for sensing the motor current of the actuator apparatus.

In some embodiments, the controller computes a derivative of the fabric tension from the measured measured fabric tension and the measured fabric tension in the previous perception interval.

In some embodiments, the processing apparatus includes an observer to compute the estimated translation speed and the estimated translation acceleration of the dancer roller from the change in position of the dancer rod.

In another embodiment of the invention, the processing apparatus includes: the first apparatus for measuring the translation position of the dancer roller; and the second apparatus for sensing the current movement of the actuator apparatus.

In some embodiments, the controller computes a dancer translation speed estimated by subtracting the decent value by the translation position of the previous value for the translation position and then dividing the time interval between the perception of the values.

In some embodiments, the processing apparatus includes an observer to compute the translation acceleration of the dancer roller.

In some embodiments, the processing apparatus computes a new force command for the actuator in response to the values computed above.

In another embodiment of the invention, the processing apparatus includes: the first apparatus for measuring web tension Fc after the dancer roller; and the second apparatus for sensing the motor current of the actuator apparatus.

In some embodiments, the processing apparatus includes an observer using the motor current and force on the tissue in combination with an estimate of the mass of system M, to compute an estimated translational velocity and a derivative of the tissue tension.

In some embodiments, the processing apparatus includes an observer that uses the current motor force of the tissue in combination with an estimate of the mass of the system M ^, to compute an estimate of the translation acceleration A ^.

In some embodiments, an observer integrates the translation acceleration to compute an estimate of the translation velocity V ^ e and integrates the estimated translation speed to compute a cloth tension force F ^.

In operation, an observer generally changes the values until the estimated web tension force is equal to the actual web tension force.

In another embodiment, the processing apparatus for advancing a continuous web of material through a processing step comprises: a dancer roller operative to control the tension on the respective section of the fabric; an actuator apparatus connected to the dancer roller and therefore to provide a driving force for the dancer roller; the first apparatus for measuring a first speed of the fabric after the dancer roller; a second device to measure a second speed of the dancer's rodill fabric; a third apparatus for measuring the motor current of the actuator apparatus; a third apparatus for measuring fabric tension before the dancer roller; a fifth apparatus for measuring the fabric tension after the dancer roller; and a controlled to provide the force control commands for the actuator apparatus based on the above measured values, at least on the computed acceleration A * p of the dancer rod, the controller therefore regulates the actuating force imparted to the dancer roller by the actuator apparatus to control the tension of the fabric.

In such an embodiment, the processing apparatus may include: the sixth apparatus for measuring the translation speed of the dancer roller; the seventh apparatus to perceive the position of the dancer roller; and the eighth apparatus for measuring the acceleration of the dancer roller; In some embodiments, the controller can effectively provide control commands to the actuator at a frequency of at least once per second.

In some embodiments, the controller may effectively provide control commands to the actuator at a frequency of at least 500 times per second, In some embodiments, the controller may comprise an effective computer controller for providing control commands to the drive apparatus at a frequency of at least 1000 times per second.

In some embodiments, the controller provides the control commands to the driven apparatus thereby controlling the driving force imparted to the dancer roller by the actuator apparatus, and thereby controlling the acceleration of the dancer roller, so that the actuator maintains the inertial compensation. for the dancer system.

In some embodiments, the processing apparatus includes an uncoiling roll upwardly from the dancer roll, the controller sending control signals to the unwind roll and the drive rolls. In some embodiments, the eighth apparatus comprises an accelerometer secured to the driving element by driving the dancer roller, so that it movers translationally with the dancer roller to measure the acceleration thereof.

In some embodiments, the computer controller intentionally periodically varies the force component to unbalance the system, and therefore tensioned it on the fabric by periodically placing a force command from the actuator causing a sudden upward movement of the dancer roller. , followed by a corresponding downward movement so that the dancer roller intermittently imposes alternating upper and lower tension levels on the fabric. The periodic entry of force can cause the upward movement of the dancer roller to be repeated more than 200 times per minute.

In another family of embodiments, the invention is illustrated in a method for controlling the tension in the respective section of the fabric, comprising, providing an operating dancer roller on the respective section of the fabric; applying a first generally static force component to the dancer roller, through the first generally static force component, having a first value and direction; applying a second variable force component to the dancer roller, the second variable force component has a second value and direction, modifying the first generally static force component, and thus modifying (i) the effect of the first generally static force component on the dancer roller and (ii) the corresponding translation acceleration of the dancer roller; and adjusting the value and direction of the second variable force component repeatedly, each of such value and adjusted direction of the second variable force component (i) replaces the previous value and direction of the second variable force component (ii) acts in combination with the first static force component to provide a net translation acceleration of the target to the dancer roller.

In some embodiments, the method includes adjusting the value and direction of the second variable force component at least 500 times per second.

In some embodiments, the method includes sensing the tension in the tissue after the dancer roll, and using a perceived tension to compute the value and direction of the second variable force component. In some embodiments, the method includes sensing the tension in the respective section of the fabric at least once per second, recomputation of the value and direction of the second component of variable force and therefore adjusting the value and direction of the second component of variable force computed at least once per second, and apply the recomputed value and direction to the dancer roller at least once per second.

In many embodiments, the first and second force components are applied simultaneously to the dancer roller as a single force, by means of an actuator.

In some embodiments, the force and acceleration components of net translation of co-adjusted targets so that the tension in the tissue maintains an average dynamic tension through the processing operation while the translation acceleration is controlled so that the The effective mass of the system is equal to the polar inertia of the dancer roller divided by the outer radius of the square roller.

In some embodiments, the force and acceleration components of net translation of targets are adjusted periodically to intentionally unbalance the dancer roller so that the tension in the dancer roller moves through a sudden, temporary upward movement, followed by the corresponding downward movement, to intermittently impose alternating levels higher than lower tension on the fabric. In such an embodiment, the periodic force input can cause the upward movement of the dancer roller to be repeated more than 200 times per minute.

In some embodiments, the method, wherein the first and second force components are applied simultaneously to the dancer roll as a single force by an actuator, includes: measuring a first speed of the cloth after the dancer roll; measure a second speed d the fabric on the dancer roller; measure the transfer speed of the dancer roller; and perceive the position of the dancer rodill.

In some embodiments, the method also includes measuring the fabric tension before the dancer roller measuring the fabric tension before and after the dancer roller.

In some embodiments, the method includes and measures the translation speed of the dancer roller, measuring the web tension force after the dancer roller sensing the current of the actuator apparatus, the perception measurement occurring during the periodic perception intervals.

In some embodiments, the method includes computing a derivative of the web tensile force from the web tension force of past perception intervals present, computing the translation speed of the dancer rodill and computing a derivative of the tensile force of cloth.

In some embodiments, the method includes executing a restless logical sub-ru by inserting the fabric tension force error, the derivative of the cloth tension force error and the acceleration error, the restless logic sub routine proceeds through the restless interference step of the aforementioned errors, by applying the rules to the restless games and removing the concern of the results of rules to generate a command output signal, the logical sub-routine is still executed during each one of the measurement and perception intervals.

In some embodiments, the method includes: measuring the translation speed of the dancer roller; and I sensed the current of an actuator.

In some embodiments, the method includes the steps of: measuring the translation position of the dancer roller; measure the tensile strength of cloth after the dancer roll; and perceiving the motor current of an actuator apparatus applying force to the dancer roller, the measurement and perception mentioned above occur at each sensor interval.

In some embodiments, the method includes computing a derivative of fabric tension from the measured fabric tension present and the fabric tension measured in the previous perception range.

In some embodiments, the method includes computing the estimated translation speed of the dancer roller from the position change of the dancer roller.

In some embodiments, the method includes measuring the translation position of the dancer roller and can perceive the current motor of an actuator apparatus by applying force to the dancer roller.

In some embodiments, the method includes computing an estimated translation speed of the dancer by subtracting the previous perceived value for the translation position for the present perceived value of the translation position and then dividing by the time interval between the perception of the values .

In some embodiments, the method includes measuring the web tension Fc after the dancer roller sensing the motor current of an actuating device.

In some embodiments, the method includes using the current and motor force of the tissue, and combining it with an estimate of the system mass M ^ pair to compute a translation speed and a derivative of the fabric tension.

In some embodiments, the method includes using current and motor force on the cloth, in combination with an estimate of the mass of system M ^, to compute an estimate of the translation acceleration A ^.

In some embodiments, the method includes integrating the translation acceleration to compute a translation velocity V ^ and integrate the estimated translation velocity to compute an estimated force force force F ^.

In another family of embodiments, the invention is illustrated in a processing operation in which a continuous web of material is advanced through the processing step, a method of controlling the tension in the respective section of the fabric, comprising: providing a dancer rodill operative to control the tension on the respective section of the fabric; providing an actuating apparatus for applying a driving force of the dancer roller; measure a first speed of the fabric after the dancer roller; measured a second speed of the fabric on the dancer roller; measure the motor current of the actuator apparatus; measure the fabric tension before the dancer roller; measure the fabric tension after the dancer roller; and providing force control command to the actuator apparatus based on the values measured above and at least on the computed acceleration A * p of the dancer rod, to tby control the driving force.

In some embodiments, the method includes measuring the translation speed of the dancer roller by perceiving the position of the dancer roller and measuring the acceleration of the dancer roller.

In some embodiments, the method includes the steps of sending control signals to the winding roll down from the dancer roll and driving the rolls upwardly from the dancer roll.

In some embodiments, the method includes computing a target speed command V * p using the first and second perceived velocities and the tel voltage after the dancer roll.

Brief Description of the Drawings The present invention will be more fully understood and the additional advantages will become more apparent when reference is made to the following detailed description of the invention and the drawings in which: Figure 1 is a pictorial view of part of a conventional processing operation showing a dancer roller on one side of the unwinding station.

Figure 2 is a pictorial view of an embodiment of the invention, again showing a dancer rodill on one side of the unwinding station.

Figure 3 is a free body force diagram showing the forces acting on the dancer roller.

Figure 4 is a control block diagram for an observer computing a fixed point for the translation acceleration of the dancer roller.

Figure 5 is a control block diagram for an observer computing the dancer roller translation acceleration from the dancer's translation speed command.

Figure 6 is a flow chart of program control representing a control system for a first embodiment of the invention.

Figure 7 is a control block diagram for the control flow diagram of Figure 6.

Figure 8 is a flow chart of the control program for a second embodiment of the invention.

Figure 9 is a block diagram of the control system for the control flow diagram of Figure 8.

Figure 10 is a control block diagram for an observer computing the derivative of the tel voltage for the incorporation of Figures 8-9.

Figure 11 is a flowchart of control program for a third embodiment of the present invention.

Figure 12 is a block diagram of the control system for controlling the flow chart of Figure 11.

Figure 13 is a logical and restless sub-routine to be used in the control program flow diagram of Figure 11.

Figure 14 is a flow chart of control program for a fourth embodiment of the invention.

Figure 15 is a control block diagram for the control flow diagram of Figure 14.

Figure 16 is a control flow diagram for a fifth embodiment of the invention.

Figure 17 is a control block diagram for an observer computing the speed and acceleration d translation from a position perceived for incorporation of Figure 16.

Figure 18 is a control block diagram for the control program flow diagram of Figure 16 Figure 19 is a flowchart of control program for a sixth embodiment of the invention.

Figure 20 is a control block diagram for the control program flow diagram of Figure 19.

Figure 21 is a flow chart of control program for a seventh embodiment of the invention.

Figure 22 is a control block diagram for an observer computing the fabric tension derivative, the translation speed and the translation acceleration of the embodiment of Figure 1.

Figure 23 is a control block diagram for the control program flow diagram of Figure 21.

Figure 24 is a flowchart of control program for an eighth embodiment of the invention.

Figure 25 is a control block diagram for an observer that computes the dancer translation speed and the acceleration from the web tension.

Figure 26 is a control block diagram for the control program flow diagram of Figure 24 Figure 27 is a flow chart of control program for a ninth embodiment of the invention.

Figure 28 is a control block diagram for the control program flow diagram of Figure 27.

Detailed Description of Preferred Additions The following detailed description was made in the context of the conversion process. The invention can be applied appropriately to other flexible fabric processes.

Figure 1 illustrates a conventional and typical dancer roller control system. The speed of advance of the cloth material is controlled by an unwinding motor 14 in combination with the speed of the downward pressure point of the dancer roller. The dancer system employs the lowest turning rollers before and after the dancer roller itself. The dancer roller moves vertically upwards downwards within the operating window defined by the lower overturning rollers and the upper rotating rollers in the endless cable system. The position of the dancer roller in an operation window, in relation to (i) the upper part of the window adjacent to the upper turning pulleys and (ii) the bottom of the adjacent window of the turning rollers is perceived by the transducer of position 2. A generally static force having a vertical component is provided in the support system of the dancer roller by means of an air cylinder 3.

In general, to the extent that the speed of taking the process exceeds the speed at which the raw material web is supplied to the dancer roller, the static forces on the dancer roller will cause said dancer roller to move downward within its operation window. As the dancer roller moves downward, the change in position is sensed by the position transducer 2, which sends a correct signal to the unwinding motor 14 to increase the speed of unwinding. The unwinding speed increases enough to return the dancer roller to the midpoint in its operation window.

By color, if the picking speed loosens the speed at which the woven material is supplied to the dancer roller, the static forces on the dancer roller will cause said dancer roller to move upwardly within its operating window. As the dancer roller moves upwards, the change in position is perceived by the change in position being perceived by the position transducer 2. When the dancer is raised above the midpoint of the operation window, the position transducer sends a corrective signal corresponding to the unwinding motor 14 to decrease the speed of unwinding 14 to decrease the speed of unwinding, thus returning the dancer roller to the midpoint in the operation window.

The aforementioned conventional dancer roller system is limited in the sense that its response time is controlled by the gravitational contribution to the vertical acceleration of the dancer roller, and by means of the mass of equipment in for example the unwinding apparatus which must change the speed in order to effect a change in the unwinding speed.

Referring to Figure 2, the process system 10 of the invention incorporates unwinding 12 including an unwinding motor 14 and a roll of raw material. When the fabric of the raw material is supplied from the roll 16 through a dancer system 20 to further process the elements of the downward conversion process of the dancer roller 20.

In the dancer system 20, the material fabric 1 passes under the turning roller 22 before passing over the dancer roller 24, and passes under the roller 26 after passing over the dancer roller 24. As shown here, the dancer roller 24 is carried by a first endless drive cable 28.

Starting with a first turning pulley up to 30, the first endless drive cable 28 passes downstream as the segment 28A to a first end 32 of the dancer rod 24 and is securely attached to the dancer roller at a first end 32. From the first end 32 of dancer rod 24, drive cable 28 continues downward with segment 28C to a second lower tumbler pulley. From the second lower tumbler pulley 36, the drive cable passes upwardly as the segment 28D to a second upper tumbler pulley 38. From the second upper tumbler pulley 38, the drive cable extends downwardly as a segment 28E to secure one end 40 of the dancer roller 24 and securely attached to the dancer roller at the second end 40. From the second end 40 the dancer roller 24, the drive cable continues downward as the segment 285 to a third turn pulley 42 , therefore back under the fabric 18 as segment 28G for the fourth lower turning force pulley 44. From the fourth lower pulley 44, the drive cable extends upwards as does the segment 28H and is securely fixed to the connection block 46. From the connection block 46, the drive cable continues upwards as segment 28 to a first turning pulley 30, thereby completing the endless circuit of the driving cable 28.

The connection block 46 connects the first endless drive shaft 28 to a second non-drive drive chain 48 from the connection block 46, the second endless drive chain 48 extends upwardly as the segment 48A to a third pulley 50. From the upper flip pulley 50, the endless drive chain extends down as the segment 48B to the fifth lower flip pulley 52. From the fifth lower flip pulley 52, the drive chain is it extends back up as the segment 48C to the connection block 46 completing by the endless circuit of the drive chain 48.

The shaft 54 connects the fifth lower tumbler pulley 52 to a first end of the actuating apparatus 56. The position sensor of the dancer roller 58 and the translation speed sensor of the dancer roller 60 extend from a second end of the actuator apparatus 56 onto the 61 axis.

The load sensors 62 and 64 are placed on the ends of the turning rollers 22 and 26 respectively to perceive the tension load on the turning rollers transverse to their axes, the tension load on the respective turning rollers have been interpreted tension on the fabric 18.

The speed sensor 66 is positioned at one end of the roller tip 26 to sense the speed of the tumbling roller 26. The speed sensor 68 is placed on one side of the second end 40 of the dancer roller 2 to sense the The turning speed of the dancer roller, the turning speeds of the respective rollers are interpreted as corresponding to the web speeds of the respective rollers.

The acceleration sensor 69 is placed on the connection block 46 and therefore moves in tandem with the dancer roller 24. The acceleration sensor 69 perceives the acceleration on the dancer roller in response to the acceleration of the connection block 46. Since then, the acceleration direction for the connection block is directly opposite to the dancer roller acceleration direction 24. Thus, the perceived acceleration direction is given a value opposite to the actual value of the acceleration of the connection block 46.

The acceleration sensor 69 may also be mounted in a suitable orientation on the selected segments such as 28A of the drive cable 28 moving in the same direction as the dancer roller 24, or directly on the dancer roller. The dancer roller acceleration 2 was measured and sent to the computer controller 70.

The dancer system 20 is controlled by the computer controller 70. The computer controller 7 is a conventional digital computer, which can be programmed in conventional languages such as basic language, pascal language, C language or the like. Such computers are generically known as "personal computers" and are available from such manufacturers as "compact and IBM" The position sensor 58, the speed sensors 60, 66, 68, the load sensors 62, 64 and the acceleration sensor 69 all feed their inputs to the computer controller 70. The computer controller 70 processes the var inputs, computing a fixed point of target velocity velocity using the equation: V * = [E (EA ^ c) 1 [V2 (l- Fb / EA0) - V3 (l - Fc / EA] • where V, = speed of the fabric 18 on the roller 24 V3 = speed of the fabric after the dancer's rodill.

V * p = target translation speed d dancer roller 24 to be reached and the fixed point V * p not subsequently adjusted or changed otherwise.

E = current modulus of elasticity of the fabric.

A ,, = current cross-sectional area of the unstressed tel.

Fh = tension in the fabric forward of the dancer and Fc = tension in the fabric after the dancer roller.

In one embodiment, the fixed point of acceleration or acceleration of target translation was calculated using the equation: = [V * p - Vp]? T where? T = the scan time for the control time and A: = dancer roller target acceleration command 24 to be achieved if the fixed point A * p is not subsequently adjusted or otherwise changed.

Using the calculated target acceleration A'p a target actuator force is generated using the equation: F * d static + ^ friction Sign (Vp) + ba (V * p - V) + ka (F * - Fc) M, (A * p - A,) + A pMe] where: F * d static = M2g + 2F * C, in combination with F friction comprises a first force component having a static force in the equation. The above equation used the following constants and variables: Static F * d = Static vertical force component on the dancer roller, friction Friction, in any direction, resisting the movement of the dancer roller.

F * c = Target voltage in the fabric 18 after the dancer roller 24 comprising a fixed target point, by process design parameters.

F * servo = Force generated by the driven device 56, preferably a servo motor. ba = Gain constant of dancer translation force speed control, in seconds Newton / meter predetermined by the user as a constant. k, = Gain of force control circuit (P times K, -) / (Ee times A ^.) kf = Active spring constant M2g = Real physical mass of the dancer rodill system times gravity.

M -i, 2"e = Estimated physical mass of the dancer roller. j = Active mass of the dancer roller.

} - Effective mass defined as active mass, physical mass of the dancer roller (M2 +.

Vp = Instantaneous vertical velocity of the dancer rod immediately before the application of the variable vertical force component, the vertical velocity equaling the translation speed of the dancer roller 24 within its operating window.

Sign (Vp) = Positive or negative value depending on the direction of movement of the dancer roller.

Ap = Acceleration of the current translation of the dancer roller immediately before the application of the second variable vertical force component.

? P = Change in the dancer position in the direction of translation.

P = Dancer position in the direction of translation, inside the operation window.

Ee = Estimated modulus of elasticity of the fabric.

Aoe = Estimated cross-sectional area of unrestricted fabric, and ZOH = Latch or Stop Zero Order (retains the last force command value).

The overall torsional force applied by the actuator 56 can be described by the equation: dancer = using the following variables t * ba? iarin = force or torsional force command d actuator device, and r = Pulley radius on the actuator.

The response time is affected by the value selected for the gain constant "ba". The constant d gain "ba" is selected to impose a damped effect on especially the variable force component of the response, so that the active variable component of the response does not make the dancer roll 24 so active as to become unstable such as wherein the frequency of application of the responses approaches a natural resonant frequency of the tissue and the dancer roller. Therefore, the gain constant "ba" acts somewhat like a viscous drag on the system. For example, in a system that is being sampled and controlled at 1000 times per second, where the mass of the dancer roll 24 is 1 kilogram a suitable control gain constant "ba" is 2.

Similarly, the gain constant "k," generally compensates for fabric tension errors in the system. A suitable gain constant "k," for the processing system described above is 20. The constants d gain "ba" and "l," vary depending on the system sampling rate.

It is contemplated that the operation and functions of the invention have become completely apparent from the previous description of the elements and their relationships with one another, but to complete the description, the use of the invention will be briefly described hereafter.

In order for the dancer roller 24 to operate as a "dancer" roller, the various forces acting on the dancer rod must in general be balanced as shown in FIG. 3. FIG. 3 illustrates the forces being applied by the actuator 56 balanced against the tension forces in the fabric 18, the weight of the dancer roll 24, any existing viscous drag effects times the existing translation speed Vp of the dancer roller, any existing spring effect Kf times the change in placement of? P of the dancer roller, and the dancer mass times its vertical acceleration at any given moment.

Through the request the phrases "actuator device" as well as servo motor, and F * serv0 are used. All phases refer to an apparatus that applies force to the dancer roller 24. Such actuators may be conventional motors, rotating electric motors, linear electric motors, pneumatically driven motors or the like. The phrase "F ^ ,," does not infer or imply a specific type of engine in this application.

The actuator force Fserv0 generally includes a first generally static force component F * d is a8 having a relatively fixed value, which responds to the relatively fixed static components of the load on the dancer roller. The generally static force component F * d watertight provides the general support that keeps the dancer roller 24 balanced (vertically) in its operation window, between the tumbling rollers 22, 26 and the upper tumbling pulleys 30 and 38, responding with base on static force plus gravity. To the extent that the dancer roller 24 spends significant time outside of a central area of the operation window, the computer controller 70 sends conventional commands to line shaft drives or the like to adjust the relative speeds between, for example, the unwinding 12 and the pressure point 72 in the conventional manner so as to bring the dancer roller generally back to the center of its operation window.

The force actuating device Fservo can optionally include the force component F ^, ^, which refers to the friction force exceeded to start the movement of the dancer roller 24 in a direction of translation, or to continue the movement of the dancer roller. A value for the force component F * friction may comprise a second value d static force selected according to the particular dancer system 20. The force component F * fpction is then added or subtracted from the overall force applied by the actuator device. 46 depending on the direction of movement of the dancer roller 24.

In other embodiments, the force component F * friction can be varied by the computer controller 7 depending on the speed of the dancer roller 24. For example, when the dancer roller 24 is stationary (n moving in either direction) the force component F * Africa requires greater force to initiate movement in a given direction. Similarly, after the dancer rod 24 begins to move in a given direction, the amount of friction resisting the continued movement of the dancer roller is less than the movement of the dancer roller that resists friction at rest. Therefore, the value of the force component F * fiicc¡ÓII decreases during the movement in a given direction. The computer controller 70, in response to the perceived velocity Vp, can appropriately change the value of the force component F * ^^, ^, as necessary, to be used in the equations described above by controlling the dancer roller 24 In other embodiments, the force component F * friction does not need to be taken into account depending on the accuracy required for the overall system. However, the computer controller 70 can generally be used to at least store a constant value that can be added to or subtracted from the force applied by the servo motor. Taking into account the force component F * friction generally improves the operation of the dancer system 20.

In addition to the static force component F * of the force component F * friction, the actuator 56 exercises a dynamically active variable force component which responds to stress disturbances in the cloth 18. The variable force component, when added to the static force component, the net vertical force command is issued by the computer controller 70, to the actuator apparatus 56. The actuator apparatus 56 expresses the net vertical force command as a torsion T * dancer delivered through the chain of drive 48, of the drive cable 28 and of the connection block 46 to the dancer roller 24.

Therefore, in addition to the normal passive response of the dancer roller 24, based on the static forces such as mass, gravity and fabric tension, the dancer system 20 of the invention adds a dynamic control component, removed in the actuator 46. The result is a typical normal dancer system response score with vertical short-term force being applied to the dancer roller 2 by the actuator 46 with the result that the dancer rodill is much more proactive, making compensating changes in speed of translation and in the acceleration of translation much more frequently and more accurately than a conventional dancer system that responds alone or passively. Then, the net translation acceleration or the net translation speed at any given time point can be either a positive upward movement, a negative downward movement or a non-movement of the whole, corresponding to a net translation speed of zero and / or a net translation acceleration of zero, depending on the force command d output from the computer control 70. The computer controller 70, of course, computes both the value and the direction of the variable force as well as the net force F * " Another system for indirectly determining a fixed point for the translatory acceleration A * p or target translation acceleration is established in the observer of the block diagram of Figure 4.

The observer of Figure 4, and the observers shown in other Figures that follow, all model relationships between the physical properties of the elements of the dancer system 20. In some embodiments, the observer merely comprises a computer program or a subroutine stored in the computer. computer controller 70. In other embodiments, the respective observers may comprise a discrete electronic circuit separate from the computer controller 70. The various observers described herein all model various physical properties of the various elements of the various dancer systems.

In the observer of Figure 4, an equation for a fixed target point for the estimated acceleration A * ^ (Applied force divided by mass) is defined as follows: A * pe = [k? (* p - V'j + kfcl - F * d esIáüco - F * fpcaón Sign íVpH / M ^ where : k! = Observer gain.

I = Current actuator device, ^ = Estimated torsional force constant of actuator device.

M ^ = Estimated physical mass of the dancer roller 24.

A * pe = Estimated net acceleration acceleration command value (not a measured value).

V * ^ = Target or estimated speed d translation for the dancer roller.

Therefore, the estimated target acceleration A * can be calculated from the known parameters of the system using the aforementioned block diagram showing the observed of Figure 4.

Similarly, a similar block diagram for the observer shown in Figure 5 can use the following equation for the estimated current acceleration A ^ com follows: = t ^ Vp - Vj + kfcl - F * d static - F * friction Sign (Vp)] / M ^ where Apg = Estimation of current translation acceleration of the dancer roller (not a measured value) and Vpg = Estimated current translation speed of the dancer roller.

Therefore, an estimated current acceleration can quickly be computed from known parameters of the system using the observer of Figure 5.

Of course, another way of determining the current translation acceleration of the dancer roller e using the following equation: = [Vp (present) - Vp (previous)]? T where? T = the scan time for the process system 10.

In this way, the average current translation acceleration A ^ can also be determined without directly accelerating.

The calculations established in Figures 4 and 5, when incorporated into the system established in the flow chart of the control program and the control block diagram of Figures 6 and 7, allow the dancer system 20 to function effectively without a Direct measurement of the acceleration Ap (optional). Therefore, in the embodiment shown, the accelerometer 69 may be an optional element depending on the process system, and the computer program being used.

The general flow of information and the commands in a command sequence used in the control of the dancer system 20 is shown in the flow chart of the control program of Figure 6. In step 1, in the command sequence, the parameters variables Ap (some additions), Vp, P, Fb, Fc V2, V3 and I (some additions) are measured. The acceleration Ap can also be indirectly estimated V instead of being measured as described in the equations described above.

In step 2, the variables are combined with the constants known in the computer controller 70, and the controller computes V * p a fixed point for the desired translation speed or target of the dancer roller 24.

In step 3, V * p can be combined with Vp divided by the scan time? T to compute a value for A * ^. In another embodiment, as shown in Figure 4, the observer can use the motor current I, the fixed point V * p and the other variables or constants shown to estimate the target translation acceleration as described above.

In step 4, a new F * savo command is computed using the computed variables and the constants F * destáüca, F ^^^, Fc, F * c, ba, k ,, Vp / Sign (Vp), Ap, A * p, V * p and Ma.

In step 5, the new force command F * servo e combined with a servo constant "r" (radius) to reach proportional torsional force command Tbai] arin output from the actuator 56 to the dancer roller 24 through the chain d drive 48 and drive cable 28.

In step 6, the sequence is repeated frequently as necessary, preferably at the predetermined desired sample intervals (scan time? T or computation frequency) for the system to obtain a response that controls stress perturbations in the fabric 18 under the dynamic conditions to which the fabric is exposed.

In a first embodiment of a method for using the invention, a primary objective of a dancer system 20 is to attenuate the voltage disturbances in the fabric 18. Such voltage disturbances may come, for example, if intension, but nevertheless of Normal vibrations emanating from the down dancer roller equipment 24. Support vibration, motor vibration and other similar occurrences are examples of vibration sources that can affect the system. In the alternative, such stress perturbations can also be intensionally imposed on the fabric 18 when the fabric is processed. An example of such intentional stress disturbances is shown in U.S. Patent No. 4,227,952 issued to Sabee, incorporated herein by reference to show a stress perturbation which is being created with the formation of each fold in the fabric of the fabric. material that is being processed.

Whether the stress perturbations are intensionally or non-intensionally imposed, the effect on the tissue 18 is generally the same. Upon passing through the fabric 18 of the processing system 10, the fabric is exposed to an average dynamic tension, representing a normal range of stresses as measured on an extension of the fabric, for example, between the roll 16 of the raw material and the next pressure point 72 down to the dancer system 20.

The voltage and other conditions should be perceived in a time scanner at least once per second, preferably at least 5 times per second, more preferably at least 500 times per second, and more preferably at least 500 times per second. at least 1000 times per second. Similarly, the computer controller 70 preferably recomputes the net Fserv force applied to the dancer roll 24 at least once per second, preferably at least 5 times per second, more preferably at least 500 times per second, and more preferably at least 1000 times per second. The faster scan times and computation rates improve the web tension control of the dancer system 20 and the overall operating characteristics of the process system 10.

Since, as discussed above, the first step in the control cycle is the perception / measurement of the variables used in the computation of the variable force component of the response, it is critical that the sensors measure the variables frequently to detect any disturbance of tension that must be controlled early enough, to respond and suppress the disturbance of tension.

Thus having a short scan time (large frequency) is important for the overall operation of process system 10.

In order to have an adequate control of the dancer system 20 it is important that the responses be applied to the dancer roller 24 sufficiently frequently to control the dancer system. Therefore, at least responses during the period of any disturbance d tensions are preferred. In order to provide a sufficient frequency in the response application, especially where there is a variation in the frequency of occurrence of voltage disturbances, it is preferred to measure the variables to apply a response to a multiple of the anticipated disturbance frequency.

In general, the most critical frequency is the frequency at which steps 1 through 6 are executed in the flow diagram of Figure 6.

The dancer system 20 of this invention can be advantageously used with any dancer roller and any place in the processing line. If there is no abrupt disturbance in the fabric 18, the dancer roller 2 will operate like a conventional dancer roller. Then, when abrupt disturbances occur, control system 2 will respond automatically to attenuate any voltage disturbances.

Referring to Figure 7 showing the control block diagram of the first incorporation, the dotted delineació, represents the calculations that occur inside the interior computer controller 70, with the resultant force output F * ^, the output applied to the driven apparatus 56 through the zero order maintainer (ZOH). Figure 7 illustrates the relationship between the dancer roller acceleration p, the dancer roller speed Vp, the change in the position? P and the fabric tension Fc downwardly of the dancer roller 24. The symbols of integration in the boxes merely illustrate the relationship between the various elements perceived.

In some embodiments, the integration symbols, contained in a block, such as in the Figure, illustrate a physical integration. The integration block in Figure 7 as well as in other Figures, may comprise an operational amplifier or other separate physical circuit, as well as a computer software routine in the computer controller 70 that integrates the value input. The control block diagram operation of Figure 7 generally corresponds to the relationship described above in the flow diagram of the control program of Figure 6 and of the observers of Figures 4 and 5.

The zero order stop (ZOH), found in all the incorporations, includes a latch that stores and then removes as appropriate the value computed for F * servo. Other elements having an equivalent function can be substituted for the zero-order retention element.

RELATION OF ACTIVE MASS GAIN AND CURRENT SYSTEM MASS The relationship between the active mass gain and the current mass gain helps the system to provide inertial compensation for the process system 10.

Using the algebra of the block diagram and n taking into account the zero-order retention dynamics, the closed circuit system equation for the acceleration circuit is: From the aforementioned equation, the mass d system effective for the dancer system 20 is: Me = M2 + Ma The inertial compensation for the dancer system 20 can be obtained by adjusting ^ so that: where : J2 = polar inertia of the dancer roller R2 = outer radius of the dancer roller Mj = mass of the system.

Solving the aforementioned equation for inertial compensation allows the dancer system 20 to operate as an effective inertia compensating system. In the assigned United States Patent No. 3,659,767 Martin, incorporated herein by reference in its entirety, describe a voltage regulation apparatus using a flywheel to physically produce an apparatus having an inertial compensation.

Using the computer controller 70 the invention allows the control of the computer and the adjustment of M. so that the dancer system 20 is inertially balanced without using physical weights. Thus, the system described here allows the computer controller, using the aforementioned equations to adjust for changes in polar inertia, in the mass of the system or in other conditions, while maintaining the dancer system 20 in a compensated state. inertially By measuring all the values set in box 1 of the control program, the flow diagram in Figure 6 can be used to obtain extremely accurate results. However, in the modalities that follow, few conditions need to be perceived, and reasonably similar results are obtained. Therefore, other embodiments have the advantage of fewer sensors that can fail to be trained or bias the output results of the computer controller 70. Therefore, all the incorporations have unique advantages depending on the required conditions that are to be perceived.

Through the description, the subscription annotation "e" is used to indicate when a value is estimated, or computed in such a way that an accurate precise value is generally not received. For example, the acceleration values "A ^" and "Ap" can be considered interchangeable in use. In some embodiments, the value can be measured directly such as by the accelerometer sensor 69, and in other embodiments, the value can be estimated. For purposes of explanation, each occurrence of "V ^" in the claims can be considered to include "Vp", vice versa, where no statement to the contrary is established therein. The current and estimated exchange of values is not limited to the example of the translation speed listed above.

SECOND INCORPORATION Figure 8 shows the flowchart of the control program for a second embodiment of the invention. In this embodiment, in step 1, the perceived variables are the dancer translation speed Vp, the fabric tension Fc after the dancer roller 24, and the actuator apart or the servo motor current I are measured.

In step 2, the fabric tension derivative dFre / dt is computed. In a method, the average force derivative is estimated using the equation: dFcedt = [Fc (present) - Fc (previous) 3 /? T where : ? T = scan time, Fc = measured fabric tensions (most recent and previous explorations), and dFce / dt = derivative of fabric tension. * Therefore, the cloth tension derivative is simply calculated from changes in fabric tension with and time interval or time of system exploration.

In step 3, the estimated acceleration of dancer Apg can be computed using the translation speed as described above. Similarly, motor current I can be used, in combination with the other perceived values of step 1, to compute the acceleration of a dancer.

In step 4, a new force command of actuator F * servo is computed using the computed variable values and the stored constants F * d static 'friction Fc / dt dF * c / dt, Fe, F * c, ,, Vp, Sign (Vp), Ap, A * p, ba, and Ma, respectively In step 5, the new force command F * serv0 e combined with the servo constant "r" (radius) to arrive at the proportional torsional force order T * dancer removed from the actuator 56 to the dancer roller 24 through the chain d drive 48 and drive cable 28.

In step 6, the sequence is repeated ta frequently as necessary, generally in periodic form, as desired by the sample intervals (scan time? T or computation frequency) which allows the dancer system 20 to obtain a response that it controls the extension of tension disturbances in the fabric 18 under the dynamic conditions to which the fabric is exposed.

The second embodiment allows the computer controller 70 to operate the dancer system 20 in an active mode with better results than the passive systems or dance systems not accounting for the acceleration properties. For ease of understanding, Figure 9 shows a control block diagram illustrating the control program flow diagram of Figure 8.

Figure 10 illustrates an observer for estimating e derived from web tension. Such an observer may comprise a separate electronic circuit that performs calculations, or a subroutine in the computer controller 70. The observer of Figure 10 comprises a control block diagram showing physical results of the observer. The integration block in Figure 10 may comprise an operational amplifier or a computer program routine that integrates the force estimate derivative and outputs an estimated fabric tension value. Thus the observer illustrated in Figure 10 can be used to compute the derivative of the knitting tension established in step 2.

In the observer of Figure 10, the derivative of the tissue tension is computed using the closed-circuit equation: dF ^ / dt = k2 (Fc - Fre) + Vp íE ^ e / Pe) where : K = gain of observer, F, = fabric tension force, = estimated fabric tension force, Vp = translation speed of the dancer rodill, E = estimated elastic modulus of the fabric, ^, = estimated cross-sectional area of tissue, and Pe = estimated roll position.

The observer of Figure 10 moderates the physical properties of the dancer system 20 and assists in the exact control of the cloth 18.

THIRD INCORPORATION Figure 11 shows a flow chart of the control program for a third embodiment of the invention. In this embodiment, in step 1, the variables d of translational velocity of the dancer Vp, fabric tension after the dancer roller 24 and of the servo motor current driving apparatus I are measured.

In step 2, the voltage derivative of tel dF8 / dt is computed. In a method the average force derivative is estimated the equation established above in the second incorporation. Of course, the tel voltage derivative can also be estimated using the observer set forth above in Figure 10 of the second embodiment.

In step 3, the acceleration of the dancer estimated Apg can be computed using the translation speed as described above. In another method for step 3, the current of actuator apparatus I can be used, in combination with the other perceived values of step 1, to compute the translation acceleration of the dancer A ^. Then, in some embodiments, accelerometer 69 can be used to measure translational acceleration directly. Even though the additional element 74, shown in Figure 1 computes the force derivative, such additional element may be equivalent to the observer described above. In like manner the additional element 76 shown in Figure 12, for the computation acceleration, may comprise the observed previously described or other means for calculating or estimating the acceleration.

In step 4, the tissue tension force error, derived from the fabric tension force error, and the dancer acceleration error, as shown in the control block diagram of Figure 12, enters the control Restless logic 78. Restless logic control 78 operates the restless logic subroutine shown in Figure 13.

The restless logic subroutine preferably comprises a computer software program stored in computer controller 70 and executed at the appropriate time with the appropriate error values in step 4 of Figure 11 as shown in step 1 of Figure 13 , the three variables are put into the restless logical subroutine. Disturbing interference occurs in the step of subroutine 2. In step d subroutine 3, the output is disengaged and an output command is computed in response to the three input signals. In the country of subroutine 4, the output command of the disturbing logic subroutine is sent to the main control program. In the country of subroutine 5, the subroutine returns to the main program.

Suitable subroutines are generally known in the art of signal processing. Uneasy logical subroutines are available from Inform Software Corporation of Oa Brook, Illinois and other companies. Restless logic control circuits are generally known in the electrical arts and are explained in detail in the text "Rational Logic Applications Neurolnquietas Explained" by Constantin vo Altrock, published by Prentice Hall. However, to the knowledge of the applicants, this application contains the only known description of the restless logic in a dancer system.

In step 5 of the main control program flow diagram of Figure 11, the output of the restless logic subroutine was used to compute a target force command F * servo for the drive apparatus 56.

In step 6, a force command torque proportional to F * servo was sent to the actuating apparatus 56 to activate the dancer roller 24. In step 7, the flow diagram of the control program of FIG. 11 is repeated and d again executes the restless logic subroutine to generate an output command.

The novel use of the restless logic in a dancer system 20 provides superior results and performance when comparing other dance systems perceiving the same variables. Therefore, the restless logical subroutine provides previously unknown advantages and n recognized in the art of dancer rodill control systems.

FOURTH INCORPORATION Figure 14 shows a control flow program for a fourth embodiment of the invention. In this embodiment, in step 1, the only variables measured or perceived are the translation speed of the dancer Vp and the actuator device or the current of the servo motor I.

In step 2, the acceleration of the dancer A ^ can be computed or estimated by an observer using the equation described above: Ape = [kl (Vp - Vpe) kteI - static d - friction Sign (Vp)] / M2e Therefore the dancer acceleration estimated and computed by an observer, as described above, using only the translation speed of the dancer Vp and l servo motor current I as measured inputs. All other elements are constants or computed values of the translation speed Vp.

In step 3, a new force command F * servo is estimated using the equation shown there. In step 4 a new output force command proportional to F * is output to the drive apparatus 56 through zero order hold (ZOH). The actuator 56, in most embodiments, comprises a servo motor for receiving the servo motor control signal and controlling the force applied to the dancer roller 24.

Using the above-mentioned values and A * ^, V * ^ computed from Ape, Vp, and other constants or values shown in the control block diagram of Figure 15, the embodiment of Figures 14 and 15 operate the dancer system. Such a system actively compensates for a coulomb and viscous friction also the acceleration to actively cancel the mass effects. The result is virtually a pure fabric tension force free of dynamic mass and drag effects. The dancer roller 20 still has polar inertia that is not compensated but the polar inertia can be minimized. For example, polar inertia can be minimized by decreasing the mass and / or radius of the dancer roller 24.

FIFTH INCORPORATION The fifth embodiment of the invention comprises an embodiment that uses the translation position of the dancer to help generate force commands for the actuator 56. As shown in step 1 of the control program flow diagram of FIG. 16, the position d translation of the dancer P, the fabric tensions Fc after the dancer roller 24 and the actuator apparatus or the servo motor current I, are measured or periodically explored. The measured values are entered into the computer controller 70.

In step 2 of the diagram of Figure 16, the measured values are then used to compute a derivative of the fabric tension dfc / dt. The derivative of the tension of the dFc / dt fabric can be computed or estimated using the present and previous tel sections established above in the second embodiment.

In step 3, the speed of the Vp dancer is computed. Such computation can use the change in position P during the period of time between sensor position scans. The speed of the dancer Vp ,, may also be computed using the observer shown in Figure 17. The observer of Figure 17 may be a separate physical circuit or may be a model of a computer program established in the computer control 70. The observer functions in a manner similar to previous observers described here, except that the positional error is multiplied by the observer gain k3. The other terms of the equation and the relationships of the same are known from previous descriptions indicated here. The integration of the estimated translational acceleration A ^., In step 4, computes an estimated translational velocity V ^. Similarly, integrating the estimated translation speed Vpg generates an estimated translational position P.

In step 5, a force command for the actuator 56 is computed using the equation listed therein described above.

In step 6, a torque command e removed to the drive apparatus 56 proportional to F * setvo.

In step 7, the aforementioned routine of l steps is repeated again at a predetermined scan time frequency.

To be used in the force command equation, box 5 of Figure 16, the value for A * p may be zero or value may be computed using an observer as described herein.

Figure 18 shows a control block diagram corresponding to the control program flow diagram of Figure 16. The control block diagram shows the operations of the control system and sensors This fifth embodiment allows the computer controller 70 to operate the dancer system 20 in an active mode with better results than passive dancer systems or active dancer systems not taking into account the acceleration properties.

SIXTH INCORPORATION Figure 19 shows the flow control program for a sixth embodiment of the invention. In this embodiment, in step 1, the measured or perceived variables are the translation position of the dancer P and the actuator or servo motor of current I.

In step e, the dancer translation speed V ^ is computed or estimated using the equation described above or the equation: 'pe [P (last) - (previous)] /? T Similarly, a fixed target point for the translational velocity of the dancer V * pe can also be computed using an observer as stated earlier in Figure 17, in response to the actuator apparatus or to the servo motor current I and to the P position.

In step 3, the translation acceleration of the dancer Ap can be computed using the previously computed values of V * ^ and Vp. or other methods including one observed using the actuator or servo motor of current I.

In step 4, a new target force command F * serv0 was estimated using the equation shown there. In step 5, a new force command proportional to F * serv0 was drawn to the drive apparatus 56 through zero order hold (ZOH). The actuator 56 receives the signal force and controls the force applied to the dancer roller 24. In step 6, the previous steps are repeated in the next sampling interval.

To be used in the force command equation of step 4, the values for A * p and V * p can be computed for an observer as described here.

This incorporation has the advantage of requiring only the current drive apparatus I and the position d translation of the dancer P. Therefore this mode is simpler to operate and maintain than other incorporations that have more sensors. However this incorporation uses l speed and acceleration to provide improved results over other active dancer systems 20.

SEVENTH INCORPORATION The seventh embodiment is illustrated in the flow diagram of the control program of Figure 21. In this embodiment, the web tension Fc and the driven device or the current servo motor I are the only measured variables. This approach is attractive because the measured tel voltage is the variable that needs to be controlled and therefore should preferably be perceived.

The observer of Figure 22 comes from the recognition that cloth strength is related to cloth deflection which is currently a change in the position? P. The observer, as in all the cases described here, can be thought of as a model of the physical system. The derivative of the cloth force therefore refers to the velocity Vp and the second derivative of the force refers to the acceleration p.

The observer output F ^ corresponds to the physically measured stat, in this case the fabric tension force Fc, which is the input to the observer's closed-loop controller. The value of the physically measured state is compared to the estimated value and the error is multiplied by a gain d controller k, The controller gain has no direct physical meaning. However, the controller gain has units of force per unit of error. The complete force, both components of static and variable force (as in the previous incorporations) is divided by an estimate of the mass M ^ system. The result is an estimate of the acceleration A * ^. The estimated acceleration is integrated to give an estimate of speed. The speed estimate is integrated to give an estimate of fabric deflection. The estimated fabric deflection is multiplied by the cloth property estimates to give the estimated fabric tension force Ftt.

This process continues until the closed loop control forces the estimated fabric tension F8 to converge with the current measured fabric tension Fc. The front part of the observer's command supply improves the observer's accuracy during a steady-state operation. This is so, because the current actuator I is directly related to the motor effort, which is directly proportional to the acceleration. In this observer, the measured value of the current drive I is multiplied by u estimated of the motor force constant K ^ that d a value proportional to force. This value is added directly to the force computed in the error section of the observer. Therefore the dynamic accuracy is improved because the changes in the effort immediately change the fabric tension estimate, as opposed to waiting for the error to accumulate.

In step 1, the fabric tension Fc and the servo motor current I were measured as described above.

In step 2, a derivative of the fabric tension dF ^ / dt can be computed as described above in the second embodiment. Otherwise, the derivative of the web tension can be computed using the observer used in Figure 22. The observer can be implemented in the program in the computer 70 or by using the operational amplifiers. As shown in Figure 22, the output force is divided by the estimated physical mass M ^ of the system to compute the acceleration of the dancer as required in step 4. Similarly, the acceleration value and integrated by the program or an operational amplifier designated by the symbol "|" in Figure 22 to obtain an estimated speed as established in step 3. Finally the equation is: dFtt / dt = Vp ÍE? / Pe.

In this way the observer can compute all the required values, including F ^ as illustrated in Figure 22.

In step 5, the equation is solved for F * ¡¡e ^ and in step 6 the force value is applied by the actuator apparatus 56 to drive the dancer roller 24. Additional variables, as required, are computed by the methods recited above. Figure 23 illustrates a control block diagram for the control program flow diagram. Figure 23 illustrates a control block diagram for the control program flow diagram of Figure 21 and better illustrates many of the computed values, such as ^ and F ».

For use in the force command equation of step 5, the values for A * p and V * p can be computed by an observer as previously described here or pre-set to zero, if desired.

In step 6, a new torsion force command proportional to F * ^ o is drawn to the drive apparatus 56 through zero order hold (ZOH).

In step 7, the flow chart of Figure 2 is repeated, and the sampling of the tissue tension Fc and the current motor servodrice I reoccurs. Again, the powered device 56 readjusts the force F * serv0 applied to the dancer roller 24 to maintain the tension of the weave Fc at a constant value.

In conclusion, the seventh embodiment describes a dancer system 20 that accounts for speed and acceleration changes and maintains an improved fabric tension while only the fabric tension and the servo current is perceived. Only perceiving two variables requires a much simpler wiring and other arrangements than for example in the first incorporation.

EIGHTH INCORPORATION In the eighth embodiment, as in the seventh embodiment, the only values that need to be measured are the web tension Fc after the dancer roller 24 and the servo motor I. However, unlike the seventh embodiment, a derivative of the command of force F * c does not need to be computed. The control program flow diagram of FIGURE 24 illustrates the operation of the dancer system 20 in the eighth embodiment.

In a first step, the values for the fabric tension Fc after the dancer roller 24 and the current servo motor I are measured.

In a second step, an observer, shown in Figure 25, computes the translation speed Vpe.

In a third step, the observer computes the translational acceleration Ape of the dancer roller 24. Then, the third and second steps can be computed in reverse order. The observer of Figure 25 operates in a manner similar to the observers described above.

In a fourth step, a new force command F * ^ is computed using the above computed values as well as the previous applied force by the drive apparatus 56 derived from the running motor I. The equation to compute the force is shown in the block of the fourth step. In addition, the control block diagram of Figure 26 also shows all the forces applied to the dancer system 20.

To be used in the force command equation of step 4, the values for A * p, F * c and V * p can be computed by or observer as previously described here or pre-set to zero or another pre-selected value as required.

In a fifth step, a new torsional command e is drawn to the actuator 56. In a sixth step, the process is repeated in the next scan time or interval.

The eighth embodiment recognizes that the cloth force is related to the deflection of cloth which is currently a change in position? P. Said? P represents e change in the position of the dancer due to the lengthening of tissue. The derivative of force is therefore related to the speed of elongation of the fabric.

The observer operates as a model of the dancer system 20 connected to a closed circuit controller. Assuming the position of operation point P of the dancer rod 24 is essentially constant and that the tissue never loosens, one can assume that Vp =? Vp (life speed at elongation of the fabric) and that p =? Ap (rate of change of the elongation speed of the fabric). The output of the model F ,, corresponds to the actual physically measured state, for the fabric tension force, which puts the closed circuit controller into the observer as shown in Figure 25. The value of the physically measured state Fc is compared to the value estimated and the error is multiplied by the gain of controller k3. The gain d controller k3 does not have a direct physical meaning, per units of force per unit of error. As shown in the observer of Figure 25, the estimated velocity Vpe is integrated to give an estimate of the deflection of tel? P. Said? P is then multiplied by the cloth properties shown in Figure 25 to compute an estimated tel voltage F, ^. The steps mentioned above continue until the closed-loop control forces the estimated fabric tension to converge to the measured fabric tension. The front portion of the observer's command supply improves the observer's accuracy during a nonstable state operation.

The actuator apparatus or the current motor I is directly related to the motor force or the force applied to the dancer roller 24. In the embodiment of Figures 24-26, the measured value of the current motor is multiplied by an estimate of the constant force motor power K ^ that d a value proportional to the force. This value is added directly to the force computed in the impulse section of the observer error. The forward supply order improves the dynamic accuracy due to changes in stress or forces an immediate change of the tissue tension estimate Faf as opposed to waiting for an accumulated error to change the estimate. Therefore, the forward supply order can be defined as a detected variable immediately supplied to the control variable of interest (Fre) to allow rapid convergence of the observing system.

NINTH INCORPORATION The ninth modality measures more variables than the eighth modality. However, this modality has all the advantages of the first modality with three less variable measures. The addition of the specialized state observer of FIG. 25 used in the eighth embodiment and used here in the nodal modality allows an accurate estimate of? P, Vpg and Ape. Therefore, the accuracy of the first incorporation can essentially be maintained with a system having fewer sensor and equipment requirements.

In a first step shown in the flow diagram of the control program of figure 27, the values for the fabric tension Fb before the dancer roll 24, the fabric tension Fc after the dancer roller 24, the speed of the fabric V2, the tissue speed V3, and the current servo motor or actuator 1 were measured.

In a second step, the observer, shown in figure 1, computes the translation acceleration Ape.

In a third step, the observer computes the translation speed Vpe by integrating the previously computed value for the translation acceleration.

In a fourth step, a fixed point for a desired target translation velocity V * ^ was computed using the equation shown in Figure 27 including variables V2, v3, and FC.

In a fifth step, the observer computes a desired target translation acceleration A * pe that acts as a fixed point.

In a sixth step, a new force command F * servo is computed using the above computed values as well as the force applied by the drive apparatus 56 and derived from the current motor I. The equation to compute the force is shown in the block of the sixth step. Fig. 28 illustrates a control block diagram essentially depicting the equation in block 6 of Fig. 27.

In the seventh step, a new torque command is output to the actuator 46. In an eighth step, the process is repeated in the next scan interval or time.

INCORPORATION OF VARIABLE VOLTAGE The incorporations described above discuss the use of a dancer system 20 with respect to the attenuation of voltage disturbances in the fabric. In coronary use, the dancer system 20 can also be used to temporarily intentionally create controlled stress disturbances. For example, the process of incorporating the threads or strands of LYCRA® (from DuPont Corporation of Delaware) into a garment, eg, At a pressure point between the underlying tissue and the tissue that lies above, it may be advantageous to increase the decrease of the LYCRA tension in specific places as it is incorporated in each garment. The dancer system 20 of the invention can effect such short-term variations in tension in the LYCRA.

Referring to Figure 2, and assuming that LYCR (not shown) is being added at the pressure point 72, the tension on the fabric can be temporarily reduced or eliminated by inserting a force from the actuator 56 causing a downward movement. sudden temporary dancer roller 24, followed by a corresponding upward movement of the dancer roller. Similarly, the tension can be temporarily increased by inserting a force from the actuator apparatus 56 causing a temporary and sudden upward movement of the dancer roller 24, followed by the corresponding downward movement. The cycle of increase and decrease of tension can be repeated more than 200 times, for example, up to 300 times per minute or more using a dancer system 20 of the invention.

For example, to reduce the voltage rapidly and temporarily to zero, the computer controller 70 sends commands, and the actuator apparatus 56 acts to impose a temporary translation motion on the dancer roller 24 during the short period over which the voltage must be reduced. eliminated. The distance of the sudden translation movement corresponds to the amount of tension relaxation and the duration of relaxation. At the appropriate time, the dancer roller 24 is again raised positively by means of the actuator 56 to correspondingly increase the fabric tension. By such cyclic activity, the dancer roller 24 can routinely and intermittently impose alternating (for example, essentially zero) upper and lower levels of tension on the woven fabric 18.

All the previously discussed incorporations can be used to provide this effect. However, incorporations having a target fabric tension F * c or a fixed point must be more effective. The desired value for web tension F * c may be varied periodically, preferably as part of an established time pattern. to form folds as described previously in the United States of America patent granted to Sabee or to vary the tension of LYCRA in specific places on the tejid 18.

Those skilled in the art will now see what certain modifications to the invention discussed herein can be made with respect to the illustrated embodiments if depart from the spirit of the present invention. And even though the invention has been described above with respect to the preferred embodiments, it will be understood that the invention is adapted to numerous rearrangements, modifications and alterations, all of which arrangements, modifications and alterations are intended to be within the scope of the appended claims.

To the extent that the following claims use a media language plus function, this does not mean that nothing that is not structurally equivalent to what is shown in the embodiments described in the specification is included here or in the present description.

Claims (86)

R E I V I N D I C A C I O N S

1. A processing apparatus for advancing a web of continuous material through a step d processing along a given section of the fabric, and processing apparatus comprises: (a) an operating dancer roller for controlling the tension on the respective section of the fabric or fabric; (b) an actuating device (i) for applying the first static force component to the dancer roller having a first value and direction, and balancing said dancer rod against the static forces and the average dynamic tension in the respective section of the fabric, Y (c) a controller connected to said actuator, said controller drawing a second component d variable force, through said actuator apparatus, effective to control the net actuating force imparted to said dancer roller by said actuator apparatus, and to periodically adjust the value and the direction of the second variable force component d, each such value and direction of the second variable force component replaces the previous one of said direction value of the second variable force component, and acts in combination with the first static force component to impart an acceleration of net translation from objective to dich dancer roller, the second component of variable force has a second value and direction, modifying the first component d static force, so that the acceleration of translation net of said dancer roller is controlled by force d net performance allowing the dancer roller to control the tension e the cloth.

2. The processing apparatus as claimed in clause 1, characterized in that it includes a sensor for sensing the tension in the fabric after the dancer rod, said controller is adapted to use the perceived tension in computing the value and direction of the second component. of variable force, and to impart the computed value and the direction through said actuator apparatus to the dancer rodill.

3. The processing apparatus as claimed in clause 2, characterized in that said sensor is effective to sense the voltage at least 1 time per second, and is effective to re-compute the value and direction of the second variable force component. , therefore to adjust the value and direction of the second variable force component computed at least once per second.

. The processing apparatus as claimed in clause 2, characterized in that said sensor is effective for sensing the voltage at least 500 times per second, said controller being effective for recomputing the value and direction of the second force component. variable, therefore to adjust the value and direction of the second variable force component computed at least 50 times per second, said actuator being effective to apply the second variable force component that has been computed to said dancer roller by at least 500 times per second according to the values and addresses computed by said controller, therefore to control the acceleration net translation.

5. The processing apparatus as claimed in clause 2, characterized in that said sensor is effective to sense the voltage at least 1000 times per second, said controller comprises an effective computer controller to re-compute the value and direction of the second variable force component and therefore for adjusting the value and direction of the second variable force component computed at least 1000 times per second, said actuating apparatus being effective to apply the second component of variable force recomputed to said dancer roller so less 1000 times per second according to the values and addresses computed by said computer controller, therefore, to control the net translation acceleration.

6. The processing apparatus as claimed in clause 1, characterized in that said controller regulates the actuation force imparted to said dancer roller, and therefore the acceleration of said dancer rod, including compensating for any inertial imbalance of said roller. dancer not compensated by the first static force component.

7. The processing apparatus as claimed in clause 1, characterized in that it includes an accelerometer to measure the translation acceleration of said dancer roller.

8. The processing apparatus as claimed in clause 1, characterized in that it includes or apparatus for computing the translation acceleration (Ap) of said dancer roller, said controller comprises a computer controller that provides control commands to said actuator based on said actuator. on the computed acceleration of dich dancer roller.

9. The processing apparatus as claimed in clause 8, characterized in that said apparatus for computing the translation acceleration (Ap) of said dancer roller comprises an observer.

10. The processing apparatus as claimed in clause 9, characterized in that the observer comprises a subroutine in said computer program that computes an estimated translation acceleration, an estimated translation speed for said dancer roller.

11. The processing apparatus as claimed in clause 9, characterized in that the observer comprises an electrical circuit.

12. The processing apparatus as claimed in clause 8, further characterized by including (d) a first apparatus for measuring a first speed of the fabric after said dancer roller; (e) a second apparatus for measuring a second speed of the fabric in said dancer roller; (f) a third apparatus for measuring the translation speed of the dancer roller; Y (g) a fourth apparatus for perceiving the position of said dancer roller.

13. The processing apparatus as claimed in clause 12, further characterized by including: (h) a fifth apparatus for measuring the tension of the fabric before the dancer roller; Y (i) a sixth apparatus for measuring fabric tension after the dancer roller.

14. The processing apparatus as claimed in clause 13, characterized in that said controller comprises a computer controller that computes a force command using the equation: * «» O = F * d static + F * fpcciónSÍgn (Vp) + ba (V * p - Vp) + k, (F * c) + Ma (A * P - Ap) where the fixed point of translation speed of the dancer V * p reflects the equation: V * p = [EV IEA-Fc)] t V2 (l- Fb / EAo) - V3 (l - F ../ EA ,,)] to control said actuator apparatus based on the force thus calculated, wherein: static = static component on the dancer roller and is equal to Mg + 2F * C Fc = tension in the fabric after the dancer rodill. F * c = tension in the fabric, objective fixed point by process design parameters. Fb = tension in the fabric in front of the dancer rodill. F * friction = friction in any direction resisting the movement of the dancer roller. F * servo = force to be applied by said actuator. »Ba = constant control gain in relation to the dancer's translation speed in Newton seconds / meter. _, = constant control gain in relation to fabric tension. M "= gravity mass times dancer roller. MA = active mass. Me = active mass and physical mass. Vp = instantaneous translation speed of the dancer roller immediately before the application of the second variable force component. Sign (Vp) = positive or negative value depending on the direction of movement of the dancer roller. V2 = speed of the fabric in said dancer roller, V3 = speed of the fabric after the dancer roller, Vp = reference translation speed of said dancer roller, fixed point. r = radius of a respective pulley on said actuator apparatus, E = modulus of elasticity of the tissue. A ,, = area in cross section of unrestrained weave. A * = acceleration of translation of objective d said dancer roller, fixed point, and * P = acceleration of translation of said dancer rodill.

15. A processing apparatus as claimed in clause 14, characterized in that the acceleration of objective A * p is computed using the equation: A * D = [V * "- V /? T where? T = scan time for said computer controller.

16. A processing apparatus as claimed in clause 15, characterized in that said computer controller provides control commands for said actuator apparatus based on the perceived position of said dancer roller, and the measured fabric tensions, acceleration and speeds, and therefore, it controls the actuating force imparted to said dancer roller by said actuator apparatus to thereby maintain a substantially constant tel voltage.

17. A processing apparatus as claimed in clause 15, characterized in that said computer controller provides control commands for said actuator apparatus based on the perceived position of said dancer roller, and the measured fabric tensions, acceleration and speeds, and therefore, it controls the actuation force imparted to said dancer roller by said actuator to provide a determined pattern of variation in the fabric tension.

18. A processing apparatus as claimed in clause 1, further characterized because it includes: (d) a first apparatus for measuring the translation speed of said dancer roller; (e) a second apparatus for measuring the web tension force after said dancer roller; Y (f) a third apparatus for sensing the current of the actuator apparatus.

19. The processing apparatus as claimed in clause 18, characterized in that said controller comprises a computer controller that computes a derivative of the tensile force from the web tension force on the past perception intervals, and including an observer which computes said translation speed of said dancer roller, and said computer controller computed or derived from the fabric tension force.

20. The processing apparatus as claimed in clause 18, characterized in that it includes or observer to compute a derivative of the fabric tension force from the web tension force and the d translation speed of said dancer roller.

21. The processing apparatus as claimed in clause 20, characterized in that said controller comprises a computer controller, said observer comprises a disturbed logic subroutine stored in said computer controller, said logic subroutine inquiet mete fabric tension force error. , the derivative of the error d fabric tension force and the acceleration error, the restless logical subroutine proceeds through the restless interference step of the aforementioned errors, and removes the interference concerns to generate a command output signal d, said uneasy logic subroutine being executed during each scan of said sensor apparatus.

22. The processing apparatus as claimed in clause 1, further characterized in that it includes: (d) a first apparatus for measuring the translation speed of said dancer roller; Y (e) a second apparatus for sensing the current of said actuator apparatus.

23. A processing apparatus as claimed in clause 22, characterized in that the controller computes the estimated translation acceleration of said dancer roller of the equation: = [kl (Vp Vpe) d static F'tfaanSign íV l / je where V = estimated translation acceleration of dich dancer roller. static d = component of static force on dich dancer roller and is equal to Mg + 2F * F friction = friction in any direction resisting the movement of the dancer roller. Sign (Vp) = positive or negative value depending on the direction of movement of the dancer roller, kj = observer gain. Vp = instantaneous translation speed of dich dancer roller. Vp "e = estimated translation speed. k ^ I = servo motor (actuator device) constant estimate of torsional force. I = drive device current, and Mje = estimated physical mass of the dancer roller.

24. The processing apparatus as claimed in clause 23, characterized in that said processing apparatus includes a zero hold command for storing force values for application to said dancer roller.

25. The processing apparatus as claimed in clause 23, characterized in that said processing apparatus actively compensates for the viscous friction and coulomb and the acceleration to effectively cancel the mass effects.

26. The processing apparatus as claimed in clause 23, further characterized by which includes: (d) the first apparatus for measuring the translation position of said dancer roller. (e) the second apparatus for measuring the fabric tension force after the dancer roller; Y (f) third apparatus for sensing the motor current of said actuator apparatus.

27. The processing apparatus as claimed in clause 26, characterized in that said controller computes a derivative of the fabric tension from the measured fabric tension present and the fabric tension measured in the previous perception range.

28. The processing apparatus as claimed in clause 26, characterized in that it includes or observer to compute the estimated translation speed and the estimated translation acceleration of the dancer roller for the change in position of said dancer roller.

29. The processing apparatus as claimed in clause 1, further characterized in that it includes (d) first apparatus for measuring the translation position of said dancer roller; Y (e) second apparatus for sensing the motor current of said actuator apparatus.

30. The processing apparatus as claimed in clause 29, characterized in that said controller computes an estimated translational velocity by subtracting the present value by the translation position of the previous value for the translation position then dividing by the interval of time between perception of the values.

31. The processing apparatus as claimed in clause 29, characterized in that it includes or observer to compute the translation acceleration d dancer.

32. The processing apparatus as claimed in clause 1, further characterized by including: (d) the first apparatus for measuring the fabric tension Fc after the dancer roller; and (e) the second apparatus for measuring the motor current of said actuator apparatus.

33. The processing apparatus as claimed in clause 32, characterized in that it includes or observes that it uses the motor current and the force on the cloth, in combination with an estimate of the mass of system M ^, to compute a speed of translation estimated in derivative d fabric tension.

34. The processing apparatus as claimed in clause 32, characterized in that it includes or observer that uses the motor current and the force on the tissue, in combination with an estimate of the mass of the system K to compute an estimated acceleration of translation A ^.

35. The processing apparatus as claimed in clause 34, characterized in that said observer integrates the translation acceleration to compute an estimate of translation speed Vpe and integrates the estimated translation speed to compute an estimated fabric tension force F " .

36. The processing apparatus as claimed in clause 35, characterized in that said observer changes values until the estimated web tension is equal to the current web tension force.

37. A processing apparatus for advancing a web of continuous material through a processing step along a given section of the web, and processing apparatus comprises: (a) an operating dancer roller for controlling the tension on the respective section of the fabric; (b) an actuator device connected to a dancer roller and therefore providing a driving force to the dancer roller; (c) a first apparatus for measuring a first speed of the fabric after the dancer roller; (d) a second apparatus for measuring a second speed of the fabric on said dancer roller; (e) a third apparatus for measuring the motor current of said actuator apparatus; (f) a fourth apparatus for measuring fabric tension before the dancer roller; (g) a fifth apparatus for measuring the web tension after the dancer roller; Y (h) a controller for providing force control commands to said actuator apparatus based on the above measured values, and at least on the computed acceleration A * p of the dancer roller, said controller by tant controls the actuation force imparted to said actuator. dancer rodill by said actuator apparatus to control the cloth tension.

38. The processing apparatus as claimed in clause 37, characterized in that it includes: (i) a sixth apparatus for measuring the translation speed of said dancer roller; (j) a seventh apparatus for perceiving the dancer roll position; Y (k) an eighth apparatus for measuring the acceleration of the dancer roller.

39. The processing apparatus as claimed in clause 38, characterized by said controller comprising a computer controller that is effective to compute a control force command using the equation: F * servo = F * d est nco + F * fpca nS Ígn (Vp) + ba (V * p-Vp) + ka (F * c- Fc) + Ma (A * p - Ap where the fixed point of translational velocity of dancer V * p reflects the equation: V * p = [EA0 / EA0 -Fc) j [V2 (l- Fb / EA0) - V3 (l - Fe / EV]. and to control said actuator apparatus based on the force thus computed in which: Static F * d = component of static force on the dancer roller and is equal to Mg + 2F * C, friction Friction in any direction resisting in movement of the dancer roller, F * servo = target force that will be applied by the actuator, Fc = tension in the fabric after the dancer's rodill, F * c = target tension in the fabric, fixed point, Fb = tension in the fabric in front of said dancer rodill. ba = gain of constant speed control d translation in Newton seconds / meter, k ^ = control gain constant re tensioned cloth, Mg = dancer roll mass times gravity, MA = active mass. Me = active mass and physical mass, Vp = instantaneous translation speed of said dancer roller immediately before the application of the second variable force component, Sign (Vp) = positive or negative value depending on the direction of movement of the dancer roller, V2 = speed of the fabric on the dancer roller. V3 = web speed after the dancer roller, V * p = reference translation speed d said dancer roller, fixed point, r = respective pulley radius on said actuator apparatus. E = modulus of elasticity of the fabric, cross-sectional area of the restricted fabric, Ap = reference translation acceleration d said dancer roller, fixed point and p = translation acceleration of said dancer rodill.

40. The processing apparatus as claimed in clause 39, characterized in that the target acceleration Ap that is being computed uses the equation. A * p = [V * p - Vp] /? T where? T = scan time or interval to said computer controller.

41. The processing apparatus as claimed in clause 40, characterized in that said controller is effective to provide control commands to said actuator apparatus at a frequency of at least one ve per second.

42. The processing apparatus as claimed in clause 40, characterized in that said controller is effective to provide control commands to said driving apparatus at a frequency of at least 50 times per second.

43. The processing apparatus as claimed in clause 40, characterized in that said controller comprises an effective computer controller for providing control commands to said actuator apparatus at a frequency of at least 1000 times per second.

44. The processing apparatus as claimed in clause 37, characterized in that said controller provides control commands to said actuator apparatus thereby controlling the actuation force imparted to said dancer roller by said actuator apparatus, and therefore controlling the acceleration of the roller dancer, so that the actuator apparatus maintains an inertial compensation for said dancer system.

45. The processing apparatus as claimed in clause 37, characterized in that said processing apparatus includes a roll down roll dancer roller and drive rolls that form a pressure point up from the dancer roller, dich controller sends control signals to said winding roller and said drive rolls.

46. The processing apparatus as claimed in clause 38, characterized in that said octav apparatus comprises an accelerometer secured to said drive element that drives said dancer roller to thereby move translationally with said dancer roller to measure the acceleration thereof.

47. The processing apparatus as claimed in clause 37, characterized in that it includes an observer that computes the translation acceleration Ape and integrates the translation acceleration to compute the translation speed Vpe of the dancer roller.

48. The processing apparatus as claimed in clause 47, characterized in that said controller comprises a computer controller that computes a speed command V * p using the first and second perceived velocities and the web tension before and after the dancer roller .

49. The processing apparatus as claimed in clause 37, characterized in that said controller comprises a computer controller periodically and intentionally varying the force component to unbalance the system, and therefore the voltage on the tel by periodically inserting a force of said actuator apparatus causing a sudden and temporary upward movement of the dancer roller, followed by a corresponding downward movement so that the dancer roller intermittently imposes alternating lower upper levels of tension on the fabric.

50. The processing apparatus as claimed in clause 49, characterized in that the periodic entry of force causes the upward movement of the dancer roller being repeated more than 200 times per minute.

51. The one processing operation in which a continuous web is advanced through a step d processing, a method to control the tension in the respective fabric section,. comprising: (a) providing an operating dancer roller on the respective fabric section; (b) applying a first generally static force component to the dancer roller, through the first generally static force component having a prime value and an address; (c) applying a second variable force component to the dancer roller, the second variable force component having a second value and direction, modifying the first generally static force component, and therefore modifying (i) the effect of the first force component. generally static on the dancer roller and (ii) the corresponding translation acceleration of the dancer roller; Y (d) adjusting the value and direction of the second component and variable force repeatedly, each adjusted value and direction of the second variable force component (i) replacing the previous value and direction of the second variable force component and (ii) acting in combination with the first static force component to provide a net translation acceleration of target to the dancer roller.

52. A method as claimed in clause 51, characterized in that it includes adjusting the value and direction of the second variable force component at least 500 times per second.

53. A method as claimed in clause 51, characterized in that it includes perceiving the fabric attention after the dancer roller, and using the perceived tension to compute the value and direction of the second component of variable force.

54. A method as claimed in clause 51, characterized in that it includes perceiving the tension in the respective section of the fabric at least once per second, re-computing the value and direction of the second component of variable force and by both adjust the value and direction of the second component of variable force computed at least once per second, and apply the recomputed value and direction to the dancer roller at least once per second.

55. A method as claimed in clause 51, characterized in that the first and second force components are applied simultaneously to the dancer roller, as a single force by an actuator.

56. A method as claimed in clause 51, characterized in that the force components and the net translational acceleration of the target are adjusted so that the tension in the fabric maintains an average dynamic tension through the processing operation while the translation acceleration is controlled so that the effective mass of the system equals the inertia by that of the dance rollers divided by the outer radius of the square rollers.

57. A method as claimed in clause 51, characterized in that the components of force and the acceleration of net translation of objective are adjusted periodically to intentionally unbalance the dancer roller so that the tension in the dancer roller moves through the movement upward temporary and sudden, followed by a corresponding downward movement to intermittently impose alternating upper and lower levels of tension on the fabric.

58. A method as claimed in clause 57, characterized in that the periodic entry of force causes the upward movement of the dancer roller to be repeated more than 200 times per minute.

59. A method as claimed in clause 51, characterized in that said first and second force components are applied simultaneously to the dancer roller, as a single force, by an actuator, and wherein the step of applying a force to the dancer roller It includes: (a) measuring a first speed of the fabric after the dancer roller; (b) measuring a second speed of the fabric on the dancer roller; (c) measuring the translation speed of the dancer rodill; and (d) perceive the position of the dancer roller.

60. A method as claimed in clause 59, characterized in that the step of applying a force to the dancer roller also includes: (e) measuring the fabric tension before the dancer's rodill; Y (f) Measure the fabric tension after the dancer rodill.

61. A method as claimed in clause 60, characterized in that the step of applying a force to the dancer roller was computed using the equation: F * servo = F * d (Vp) + ba (V * p -Vp) + k, (F * c- Fc) +, (A * p - Ap) where : Static F * d = component of static force on the dancer roller and is equal to Mg + 2F * C, F * friction = Friction in any direction resisting in movement of the dancer roller, Fc = tension in the fabric, set point d objective, for process design parameters, F * c = tension in the fabric, set point for process design parameters, servo = force generated by the actuator, ba = constant of gain of control in relation to the speed of translation of the dancer, in seconds Newton / meter, kj = control gain constant in relation to web tension, Mg = gravity mass dancer roll times, MA = active mass. Me = active mass and physical mass, Vp = instantaneous translation speed of the dancer roller immediately before the application of the second component of variable force, Sign (Vp) = positive or negative value depending on the direction of movement of the dancer roller, A * p = reference translation acceleration d said dancer roller, fixed point, Ap = translation acceleration of said dancer rodill; Y where the fixed point of translational velocity of dancer V * p reflects the equation: V * p = [E EAc. ~ FC) J [V2 (l- F ../ E - V3 (l - FC / E 1 to control the actuator apparatus based on the force thus computed, where: Fb = tension in the fabric in front of said dancer rodill. V2 = speed of the fabric on the dancer roller. V3 = speed of the fabric after the dancer's rodill, Vp = reference translation speed d said dancer roller, fixed point, r = radius of the respective pulley on the actuator device, E = modulus of elasticity of the fabric, and Ag = area in cross section of the fabric n restricted.

62. A method as claimed in clause 61, characterized in that the acceleration of target A * is computed using the equation: A * p = [V * p - Vp]? T where? T = scan time, the computations being repeated and the force adjusted to at least once per second.

63. A method as claimed in clause 51, characterized in that the first and second force components are applied simultaneously to the dancer rod as a single force, and wherein applying a force to the dancer roller includes: (a) measure the translation speed of the dancer rodill; (b) measuring the fabric tension force after the dancer roller; Y (c) perceiving the current of the actuator apparatus, measuring and perceiving occur during the periodic perception intervals.

64. A method as claimed in clause 63, characterized in that applying a force to the dancer roller includes: (a) computing a derivative of the cloth tension force of the cloth tension force from the present and past perception intervals; (b) compute the translation speed of the dancer roller; Y (c) compute a derivative of the fabric tension force.

65. A method as claimed in clause 63, characterized in that it applies a force to the dancer rod and includes executing a logical subroutine inquiet by inserting the fabric tension force error, e derived from the fabric tension force error, and the acceleration error, the restless logical subroutine proceeds through the restless interference step of the aforementioned errors and disinquisites the inferences to generate a command output signal, the restless logic subroutine is executed during each of the measurement and perception intervals.

66. A method as claimed in clause 51, characterized in that the first and second force components are applied simultaneously to the dancer rod as a single force, and wherein applying a force to the dancer roller includes: (a) measure the translation speed of the dancer rodill; Y (b) perceive the current of an actuator.

67. A method as claimed in clause 66, characterized in that it includes computing the estimated translation acceleration of the dancer roller of the equation: pe = F * d watertight + * fnctionS Ígn (Vp) + k, (Vp - Vj + ^ I] / M2e where A ^ = estimated translation acceleration of the dancer roller. d static = component of static force on the dancer roller and is equal to Mg + 2F * C. friction friction in any direction resisting the movement of the dancer roller, Sign (Vp) = positive or negative value depending on the dancer roller movement direction, kj = observer gain. Vp = instantaneous translation speed of said dancer roller. V "= estimated translation speed. kjg = Servo motor (drive device) constant estimate of torsional force. I = actuator drive current; Y M2e = estimated physical mass of the dancer roller.

68. A method as claimed in clause 51, characterized in that the first and second force components are applied simultaneously to the dancer rod as a single force, and wherein applying a force to the dancer roller includes: (a) measure the translation position of the dancer rodill; (b) measuring the web tension force after the dancer roller; Y (c) sensing the motor current of an actuator apparatus by applying force to the dancer roller, Measurement and perception occur in each perception interval.

69. A method as claimed in clause 68, characterized in that it includes computing a fabric tension derivative of the measured fabric tension present and the fabric tension measured in the pre-perception range.

70. A method as claimed in clause 68, characterized in that it includes computing the estimated translation speed and the estimated translation acceleration of the dancer roller from the change in position of the dancer roller.

71. A method as claimed in clause 51, characterized in that the first and second force components are applied simultaneously to the dancer roller as a single force, and wherein applying a force to the dancer roller includes: (a) measuring the translation position of the dancer roller; Y (b) sensing the motor current of an actuator apparatus by applying force to the dancer roller.

72. A method as claimed in clause 71, characterized in that it includes computing an estimated dancer translation speed by subtracting the previous perceived value for the present perceived value translation position from the translation position and then dividing by the time interval between the perception of values.

73. A method as claimed in clause 72, characterized in that it includes computing a new force order to apply to the actuator apparatus in response to the values computed above.

74. A method as claimed in clause 51, characterized in that the first and second force components are applied simultaneously to the dancer rodill as a single force, wherein applying a force to a dancer roller includes: (a) measuring web tension Fc after dancer roller; Y (b) perceive the motor current of an actuator device.

75. A method as claimed in clause 74, characterized in that it includes the use of motor current and force on the web, in combination, with an estimated system mass M ^ to compute an estimated translation speed and a derivative of fabric tension.

76. A method as claimed in clause 74, characterized in that it includes the use of motor current and force on the web, in combination, with an estimate of system mass to compute an estimate of the translation acceleration Ape.

77. A method as claimed in clause 76, characterized in that it includes integrating the translation acceleration to compute an estimate of the translation speed Vpe and integrate the estimated translation speed to compute an estimated fabric tension force F ^.

78. In a processing operation wherein a continuous web of material is advanced through a processing step, a method for controlling the tension in the respective section of the fabric comprising: (a) providing an operating dancer roller for controlling the tension on the respective fabric section; (b) providing an actuating apparatus for applying a driving force to the dancer roller; (c) measuring a first speed of the fabric after the dancer roller; (d) measuring a second speed of the fabric in the dancer roller; (e) measuring a motor current of the actuator; (f) measuring the fabric tension before the dancer's knee; (g) measuring the web tension after the dancer rodill; Y (h) providing force control commands to actuator apparatus based on the above measured values, at least on the computed acceleration A * p of the dancer rod to therefore control the actuation force imparted to the dancer roller by the actuator apparatus to control Fabric tension.

79. A method as claimed in clause 78, characterized in that it includes: (i) measure the translation speed of the dancer rodill; (j) perceive the position of the dancer roller; (k) measure the acceleration of the dancer roller.

80. A method as claimed in clause 79, characterized in that the force control commands the actuator apparatus being on the equation: * servo = F * d static + * frictions Ígn (Vp) + ba (V * p - Vp) + ^ (F "- Fc) + Ma (A * p Ap). to control the drive apparatus based on the force as calculated where: F * d estiti8 = component of static force on the dancer roller and is equal to Mg + 2F * C. friction friction in any direction resisting the movement of the dancer roller; target force to be applied to the actuator. Fc = tension in the fabric after dancer rodill. F * c = target tension in the fabric, fixed point Fb = tension in the fabric in front of the dancer rodill. ba = constant control gain re d dancer translation speed in seconds Newton / meter. kj = control gain constant re tensioned fabric, Mg = dancer roller mass times gravity. MA = active mass, Me = active mass and physical mass. Vp = instantaneous translation speed of dancer roller. Sign (Vp) = positive or negative value depending on the direction of movement of the dancer roller. V, = speed of the fabric on the dancer roller. V3 = speed of the fabric after the dancer's rodill. V * = fixed point dancer roller target translation speed. r = respective pulley radius on the actuator. E = modulus of elasticity of the fabric. A "= area in cross section of the restricted fabric n. A * = dancer roller target translation acceleration, fixed point, and A ,, = translation acceleration of the dancer rodill.

81. A method as claimed in clause 80, characterized in that the acceleration of objective A * is computed using the equation: where? T = scan time or interval between the perception of the translation speed.

82. A method as claimed in clause 81, characterized in that the interval between the perception of the translation speed being at a frequency of at least 1 time per second.

83. A method as claimed in clause 78, characterized in that the force control commands the actuator apparatus to control the acceleration of the dancer roller so that the actuator apparatus maintains a compensation of inertia for said dancer system.

84. A method as claimed in clause 78, characterized in that it includes the steps of sending control signals to an up roll roller of a dancer roller.

85. A method as claimed in clause 78, characterized in that it includes: (i) compute the translation acceleration Ape, and (j) integrate the translation acceleration to compute the translation speed Vpe of the dancer roller.

86. A method as claimed in clause 78, characterized in that it includes the computation of a target velocity command V * p using the first and second perceived velocities and the web tension after the dancer rodill. SUMMARY This invention relates to continuous web processing such as paper, film, composites and the like, and continuous and dynamic processing operations. More particularly, it relates to controlling the tension in such continuous fabrics during the processing operation. The tension is controlled in a dancer control system by connecting a dancer roller corresponding to an actuating device or the like, perceiving the variables such as position, tension, speed and acceleration parameters in relation to the fabric and the roller. dancer, and provide active force commands in response to the perceived variables, to cause the translation movement generally including an acceleration of the target, in the dancer roller to control the tension disturbances in the fabric. In some applications of the invention, the dancer control system is used to attenuate voltage disturbances. In other applications of the invention, the dancer control system is used to create voltage disturbances.