EP1052093B2 - Electric drive for positioning one or more adjustable elements in a machine; driving device with an angle indicator and printing machine - Google Patents

Abstract

The system contains an electric motor (F,G) whose rotor (F) is designed for stiff direct connection to the functional part (D,D1-D4). One or more angular position transducers (44,46) detect the angular motion of the rotor and/or functional parts. A signal processing module (51) receives the transducer signals as actual angular position values and compares them with de values. The signal processor drives the electric motor via a power amplifier (47,48) . The rotor can be integrated with the functio part and/or made in one piece with it.

Description

The invention relates to an electric drive system for adjusting one or more rotatable and / or pivotable functional parts of devices and machines, in particular printing presses, according to the preamble of claim 1.

Einsbhägige drive systems, drive arrangements and methods and printing presses are from the DE-A-41 38 479 and EP-A-0 621 133 known.

According to the other prior art, the individual functional units of printing machines, such as unwinding / reel splicer, printing units, printing cylinders, dryers with chill rolls, folders, sheeters, trays, etc. coupled by mechanical shafts and / or gears with each other to bring about their mutual angular position orientation. If you want to isolate these functional parts or components and dispense with the mechanical coupling, so the individual functional parts are equipped with their own drive systems, after the above DE-A-41 38 479 are designed as direct drives. To achieve the necessary angular position orientation of the individual printing machine components with each other, a corresponding synchronization of the drive systems is required.

To solve the problems identified in the alleged in April 1993 published company publication "Electronic wave with digital intelligent drives for printing machines" (HMI / 04.93) by Mannesmann Rexroth Indramat an electric drive system of the type mentioned initially described. It is proposed as a replacement for mechanical coupling elements an electronic shaft or an electronic transmission with individual drives, wherein printing units and rollers can be flexibly assigned to any printing processes (for example, two-tooth operation). Furthermore, individual printing units or rollers can be flexibly connected or shut down. For guidance control, a real or a virtual master axis can be used. Thanks to a modular design, any number of drives for individual impression cylinders can be interconnected. Via an optical field bus (so-called SERCOS interface) and an IBM-compatible PC, central parameterization, operation and display can be carried out, whereby individual drive controllers with drive-internal position control for each pressure cylinder are coupled to the optical fieldbus. In particular, a so-called control card CLC is described in the company publication, which is to serve the data exchange between drive controllers, I / O modules, control computer, programmable logic controller and remote control units. This control card is optionally described as an option card for drive amplifiers, as a plug-in card for PCs and as a plug-in card for VME bus systems. To connect a programmable logic controller (PLC), a parallel I / O RS232 / 422/485 bus, a PC bus or a VME bus is specified.

It is off US-A-5,329,216 a fluid rotary device with multi-shaft drive known in which the synchronization of the individual waves with each other centrally by a pulse generator with downstream pulse filter for each wave, wherein the pulse generator and the pulse filter are each controlled by a central processor with dedicated control line. From the respective pulse filters, a first and a second phase-locked loop as well as an angle control loop (each per shaft to be driven) receive their control signals in parallel. The output signals of the first and second phase locked loops and of the respective angle control loop are fed to a downstream drive amplifier selectively via respective through-connection devices which are controlled or controlled by the central processor.

The invention has for its object to ensure a fast, highly dynamic signal processing for the angular position control with a maximum number of functional part axes in an electric drive system with a variety to be adjusted functional parts and their respective associated drive controllers and angle encoders. In addition, each assigned to a part of the controller or rows of control elements to be coupled together.

To solve the specified in claim 1, electric drive system for adjusting a plurality of rotatable and / or pivotable functional parts of equipment and machines proposed. Because of advantageous embodiments of this inventive solution, reference is made to the dependent claims.

In this case, the signal processing module forms a configurable and parameterizable drive controller with which even complex control algorithms and / or multiple control loops can be realized. With the invention, a concept for multiple control of a plurality of axes of rotation is created, with the associated control system can be configured modular. In particular application in printing, in particular offset machines, the drive system according to the invention is particularly suitable, because thus a high quality or accuracy of the angular position orientation, such. B. between the printing units where the halftone dots of different colors must be printed within a narrow tolerance range, can be achieved.

After a constructional specification of the drive system according to the invention, the rotor of the electric motor with the functional part, for. B. pressure cylinder, structurally integrated and / or executed in one piece. On the one hand this can be done by attaching the rotor to a stub shaft of the rotatable functional part. On the other hand, it may be advantageous in the Drive system according to the invention used electric motor with a roller or cylindrical outer rotor or rotor train. This ensures that the shape of the rotor corresponds approximately to the appropriate rotationally symmetrical shape of the functional part, and in particular it can be structurally incorporated.

Analogous to the said direct drive of the functional part is within the scope of the invention, a direct measurement of its angular position, speed, acceleration, etc. Thus, according to an advantageous embodiment of the invention, the angular position encoder directly attached to the functional part for direct measurement of its angular or rotary / pivotal movements , Especially in connection with high-resolution, fast angle encoders, as known per se, so an immediate and therefore extremely realistic observation of the controlled system, namely the rotating or pivoting functional part, can be performed.

According to an alternative embodiment, the electric motor is associated with a single angular position sensor, which receives the angular movements of the rotor of the electric motor; At the same time, an observer module, known per se in control engineering, for state variables of the functional part is set up, which is preferably coupled to the angular position sensor and / or the signal processing module in differential signal connection (known per se in control engineering). The Differenzsignalaufschaltung can be used on the basis of the invention also in connection with at least two Winkelellagegebem, which are each attached to the rotor of the electric motor and the functional part for immediate recording of their angular movements.

For the purposes of the invention are high-resolution, fast angular position encoder, for example in the design as a sine / cosine absolute encoder, as incremental encoder with square wave signals and zero pulse signal and as an incremental encoder with sine / cosine signal together with zero pulse signal in question. In order to permit axial adjustments of the functional part in operation, for printing machines, for example, the so-called side register adjustment, are suitable as angular position encoder in the context of the invention, especially hollow shaft encoder with a (tooth) graduation exhibiting encoder wheel and a donor head. These are radially spaced from each other via an air gap, and axial displacements against each other within a certain frame do not affect the scanning function of the encoder head relative to the encoder wheel. The advantage achieved with the use of the hollow shaft encoder consists in the fact that the sender wheel with the (functional part to be scanned) structurally integrated and / or can be made in one piece, so that an immediate observation or detection of its angular movements is ensured due to this direct connection.

Reaction-fast power amplifiers with digital phase-current regulators are advantageously used in the drive system according to the invention. The inverter can be designed with voltage intermediate claw or with direct supply and thus high DC link voltage (as known per se). With the latter, a large temporal change of current is possible. The digital phase current control is expediently carried out for the drive system according to the invention with pulse width modulation of high clock frequency, fast transistor switches and voltage precontrol, the phase current setpoints and / or the precontrol values being predetermined via fail-safe optical waveguide connections. Furthermore, a feedback of the phase current actual values and / or voltages for motor control as well as a specification of values for configuration and parameterization in addition to feedback of status information for diagnosis is advantageous.

Thus, a high dynamic is ensured for the control of the pivoting or rotational movements of the functional part, it is recommended for the drive system according to the invention, the use of faster signal processing. This is expediently structured into a digital signal processor and a separately connected Achsperipheriemodul. The signal processor is a configurable and parameterisable drive controller with realizable sampling times of 100μsec. (also for complex control algorithms and several control loops) as well as for calculation times in the range of 50μsec. available. The functions of the signal processor may include encoder evaluation, motor control, speed control, angular position control, fine interpolation of the default values and others. The Achsperipheriemodul is useful with an ongoing over fiber optic interface to the digital phase current regulators and also with an interface to the angular encoders preferably in the design as a sine / cosine absolute encoder, as incremental encoder with square wave signals and zero pulse signal and as an incremental encoder with sine / cosine signal with zero pulse signals Mistake.

By means of this structure for the signal processing module used according to the invention, simultaneous setting of the setpoint values in accordance with the principle of position control enables angular position-oriented operation for the relevant rotary masses or individual functional parts of a device or a machine, in particular a printing press. In this case, the setpoint values can be generated in the signal processing module, taking into account the limitations in the jerk, in the acceleration, in the speed. In particular, an activation or precontrol of the angular position speed, acceleration and pressure can be brought about.

If several functional parts rub against one another during their rotation, they represent rotating masses coupled via friction slippage. In the case of printing press cylinders, clean, shiny shell sections, which lie on one another due to pressure, are referred to as Schmitz rings. The problem of over Frictional slip coupled rotating masses is counteracted by a special embodiment of the invention, according to which the several, each associated with a functional part controller or rows with multiple control elements of the signal processing module are coupled to each other via additional, weighted feedbacks. Appropriately, a cross coupling is realized.

In the application "printing presses" occurs in the rotating printing cylinders as a disturbance known per se "channel impact", which is based on a longitudinal groove in the cylinder for mounting a blanket or a printing plate. The groove which emerges on the mantle surface leads to a changing normal force and thus to a changing torque. In the context of the drive system according to the invention, this phenomenon of "channel impact" can be expediently counteracted by evaluating the actual values with characteristic elements and feedforward control.

In view of the problem mentioned above is desirable in printing machines, watch their rotating or swivel functional parts reliable and be able to perform appropriate state variables a regulated drive system. In this case, distortions of the Meßergebnisaes are excluded as possible or possible lossless coupling with maximum force fit in force or torque transmission direction between the cylinders to be driven and the transmitter allows. For this purpose, it is expedient that the cylinders are directly connected for direct measurement of their angular sizes, each with an angular position sensor, which is connected to the output side of the drive system. The angular position encoder thus forms a direct observer for the functional part in the context of a drive control chain or a drive control circuit, which in particular brings about the circumferential register adjustment. With this direct observation, a play-free, low-inertia and mechanically stiff measuring strand or measuring chain can be constructed for each functional part, namely cylinder or printing-unit roller. This results in a high control accuracy and dynamics, so that it is possible to achieve exact web guidance, constant web tension and consistent coloring via the thus made possible, highly precise register control and pressure adjustment. The relevant rotational masses (for example, plate and blanket cylinders in a printing unit) according to the invention directly, without intermediate arranged spring, damping, friction members, etc., detected so that the absence of elasticities, resiliencies and games, the movement behavior of the press to be observed functional parts can be passed on faithfully in the control system. It is expedient to fix the sensing element of the angular position sensor on a stationary wall, for example, the printing machine wall, elasticity and play.

Fig. 1

das Schema eines erfindungsgemäßen Direkt-Antriebsystems teilweise in Längsansicht,

Fig. 2

im teilweisen Längsschnitt, einen mit einem zu drehenden Zylinder gekoppelten Direktantrieb,

Fig. 3

ein Blockschaltbild eines Signalverarbeitungsmoduls des erfindungsgemäßen Antriebssystems,

Fig. 4

ein Blockschaltbild des erfindungsgemäßen, modularen Antriebssystems zur Steuerung und Regelung einer Mehrzahl von Funktionsteile-Achsen, und

Fig. 5

das dynamische Verhalten eines Ausführungsbeispiels der Erfindung anhand eines Strukturblockschemas.

Further features, details and advantages based on the invention will become apparent from the following description of preferred Ansführungsbeispiele of the invention and the drawings. These show in:

Fig. 1

the scheme of a direct drive system according to the invention partially in longitudinal view,

Fig. 2

in partial longitudinal section, one with a cylinder to be rotated direct drive,

Fig. 3

a block diagram of a signal processing module of the drive system according to the invention,

Fig. 4

a block diagram of the modular drive system according to the invention for controlling and regulating a plurality of functional parts axes, and

Fig. 5

the dynamic behavior of an embodiment of the invention based on a structural block diagram.

According to FIG. 1 consists of the printing unit of a web offset machine from the four plate or blanket cylinders D1, D2, D3 and D4 (shown schematically), via bearings 40 on the stationary wall H (see Figure 6). the machine are rotatable. For their rotation, they each have an electric motor with a rotor stack F and a stator pair G assigned. The stub axle 41 of the rotor F is directly connected to the stub axle 42 of the cylinder D; in other words, both are integrated with each other so structurally that they merge into one another and thereby form a drive connection, which is about as torsionally stiff as a one-piece steel shaft. The projecting at the free end faces of the electric motors F, G stub axle 43 are provided with sine / cosine absolute angular position sensors 44. At the opposite end are stub axle 45 of the cylinders D1 - D4 before, which are also each provided with a similar absolute angular position sensor 46. The electric motors F, G are structurally designed as built-in motors. They can be designed with three-phase servomotors in synchronous design with permanent magnets. These are controlled by a power block 47 each with digital current controller 48. The power block 47 is powered by a DC link supply 49 from electrical energy. The digital current controllers 48 each communicate via interference-proof optical waveguides 50 with an axis peripheral module AP. The axle peripheral modules further have respective interfaces 44a, 46a on the one hand for each one of the angular position sensors 44 attached to the electric motors F, G and for one each on the opposite shaft ends or

Achsstummeln 45 at the free ends of the Cylinder D1 - D4 angular position sensor 46 on. The axis peripheral modules AP are controlled by a common digital signal processor 51. This can be configured as a drive controller for a maximum number of axes with position controller, speed controller, motor control and encoder evaluation.

In FIG. 3 is the respective internal structure of the signal processor 51 and the axis peripheral modules AP shown enlarged and referred to the skilled worker abbreviations, so that further explanations are basically unnecessary. SCC is a so-called serial communication control module.

In FIG. 4 is the integration of the drive system according to the invention Figure 1-3 into a global concept for a multiple control with configurable, modular control and regulation units. In addition to an IPC-486 host computer, CPU-68-3 blocks are also provided for programmable logic controller and setpoint generation. At this the signal processors 51 are coupled via a system bus.

The block scheme according to FIG. 5 represents an exemplary, inventive drive system for two coupled via friction slip (Schmitz rings), position-controlled axes I, II. From a setpoint generation (for example, according to FIG. 4 ) are each axis I, II to their position control angle setpoints φ _{soll I} , φ _{soll II} specified. After comparison with the actual values φ obtained via the angular position sensors 46 _{, I} , φ _II , the respective control difference is fed to a position controller K _VI , K _VII . Its respective output value is a difference formation 52I, 52II with the differentiated angular position actual value, ie the respective actual angular velocity Ω _IstI , Ω _IstII the axes I, II subjected. The resulting difference _{value in} each _{case is} fed to a speed controller K _pI , K _pII whose respective output _{strikes a} summer 53I, 53II. Each of these summers 53I, 53II the output of a characteristic element f (φ _I), f (φ _II) is supplied as a function of the angular position .phi..sub.i, φII for forming a disturbance variable. Accordingly, each characteristic link is connected on the input side to the output of the corresponding angular contactor 46I, 46II. The summing members 53I, 53II, the respective outputs of proportional feedback elements K _{I, II} ,, K _{II, I are also} supplied, which crosswise tap into the actual angular velocity Ω _{Ist II} or Ω _{Ist I} at the respective differentiating element 54II, 54I. The inputs of the differentiators 54I, 54II are respectively connected to the output of the respective angular position sensors 46I and 46II. This cross coupling by means of the proportional links K _{I, II} or K _{II, I} acts on the coupled for example via the Schmitz rings controlled systems / axes I and II decoupling.

The respective outputs of the summing members 53I and 53II lead directly into respective proportional members K ^-1 _SI , K ^-1 _SII , which, inter alia, represent factors related to the rotational masses of the functional parts comprising the axes I, II. Then follow. Current control circuits 55I, 55II, which convert the input current setpoints I _sollI , I _sollII into actual current _values I _istI , I _istII . The current control circuits 55I, 55II behave outwardly approximately as in control engineering known per se PT ₂ members. The respective actual current _values I _istI , I _istII are supplied to proportional _terms K _TI , K _TII , which represent the electric motor constant for converting current into an engine torque M _MotI , M _MotII . After linking with the respective proportional element I ^-1 _I , I ^-1 _II corresponding to the respective rotational mass of the axis I, II and immediately subsequent integration of the angular acceleration β _I , β _II by means of the integration member 56I, 56II results in the angular velocity ΩI, ΩII with which the rotating masses / functional parts rotate about their respective axes of rotation I, II. After integration with a further integrating member 57I, 57II, the angular position actual value φ _istI , φ _istII can be determined in conjunction with the respective angular position sensors 46I, 46II and the respective comparisons 58I, 58II at the input of the block diagram according to FIG FIG. 5 feed to the setpoint-actual value comparison.

It should also be considered that in the case of application in plate / blanket cylinders of a printing unit of a web offset press (see. FIG. 1 ) the respective cylinders D1, D2 and D3, D4 rub against one another with slip, resulting in a disturbing torque. This is in FIG. 5 in the output region of the block diagram or the drive structure by the pairs matching and parallel proportional elements R _I (corresponding to the half-diameter or radius of the axis I comprehensive rotating mass) on the one hand and R _II (corresponding to the radius or radius, the axis II comprehensive rotating mass ) on the other hand expressed. The respective web speeds v _I , v _{II of} the two rotational masses I, II are calculated according to a respective first or outer of the two proportional element pairs R _I and R _II , which have the respective angular velocities ΩI, ΩII of the two rotary masses as an input variable. The web speeds V _I , V _II are subtracted from each other within the scope of a difference formation 70. The slip s results from the quotient of this difference and one of the two circumferential path velocities V _I , V _{II of} the two rotational masses, as illustrated by the divider 59. The following characteristic curve element 60 represents the specific friction characteristic when rolling up cylinder jacket surfaces and, as a function value, yields the coefficient of friction μ _R. If this is multiplied by the normal force F _N according to the contact pressure of the cylinders, the disturbing frictional force results in the cylinder tangential or circumferential direction. This multiplied by the respective second or inner radius proportional element R _I or R _{II of} each parallel proportional element pair results in the influence of torque, which corresponds to each torque M _MotI generated by the associated drive _motor or M _MotII due to the slip friction opposite as illustrated by the each member I or II associated comparison member 61I and 61II.

Claims (15)

1. Electric driving system for adjusting a plurality of rotatable and/or pivotable functional parts (D1-D4) of appliances and machines, in particular of printing machines, in their angular position (ΦistI, ΦistII), with a plurality of electric motors (F,G), the respective rotor (F) of which is formed for rigid and direct connection to the functional part (D1-D4), with a plurality of angular position encoders (44,46) which register angular movements of the respective electric motor rotor and/or functional part (D1-D4), with a plurality of signal processing modules (51, AP) which are connected on the input side to the angular position encoders (44,46) to register the angular position signals (ΦistI, ΦistII) as actual values and comprise a plurality of regulators or rows with a plurality of regulating elements, which are associated with a respective functional part (D1-D4; I,II) and are formed to simultaneously register desired values (Φsoll) associated with a respective functional part (D1-D4; I, II) and to compare them with the actual values, and with a plurality of power amplifiers (47,48) which are controlled by the signal processing modules (51, AP) and are connected on the output side to the respective electric motor (F,G) to activate the latter, wherein the driving system also comprises a bidirectional system bus, via which a plurality of signal processing modules (51, AP), which each contain the regulators or rows of regulating elements, are connected to a processor (CPU-68-3) for desired value generation, wherein the regulators or regulating elements are formed to simultaneously register desired values associated with a respective functional part (D1-D4),
   characterised by a local bus via which the regulators or rows with a plurality of regulating elements of the signal processing module (51, AP) are connected to axial peripheral modules (AP) as interfaces (44a,46a,50) with the power blocks (47) of the electric motors (F,G) and with the angular position encoders (44, 46).
2. Driving system according to Claim 1, characterised in that the rotor (F) is structurally integrated and/or integral with the functional part (D1-D4).
3. Driving system according to Claim 1 or 2, characterised in that the electric motor (F,G) is formed for attachment to a shaft stub of a rotatable functional part (D1-D4).
4. Driving system according to Claim 1, 2 or 3, characterised in that the electric motor is formed with a roll-shaped or cylindrical external rotor, the shape of which corresponds to that of the functional part, being in particular constructed to be held therein.
5. Driving system according to any one of the preceding Claims, characterised in that a single angular position encoder (44) is associated with the electric motor, which angular position encoder is fastened to the rotor (F) of the electric motor (F,G) to directly register the angular movements (ΦistI, ΦistII) thereof, wherein the signal processing module (51, AP) and/or the angular position encoder (44) is/are coupled to an observer module for state variables of the functional part, preferably with differential signal feedforward.
6. Driving system according to any one of Claims 1 to 4, characterised in that at least two angular position encoders (44,46) are associated with the electric motor (F,G), which angular position encoders are each fastened to the rotor (F) of the electric motor (F, G) and to the functional part (D1-D4) to directly register the angular movements (ΦistI, ΦistII) thereof, wherein the signal outputs (44a,46a) of these two encoders are coupled to the signal processing module (51, AP), preferably with differential signal feedforward.
7. Driving system according to any one of the preceding claims, characterised in that the angular position encoder is constructed as a sine/cosine absolute encoder, incremental encoder with square-wave signals and zero pulse signal, as an incremental encoder with sine/cosine signal together with zero pulse signal or as a hollow shaft encoder with encoder head (66) and encoder wheel (63) having angular division.
8. Driving system according to Claim 7, characterised in that the encoder wheel (63) is structurally integrated and/or integral with the functional part (D1-D4).
9. Driving system according to Claim 8, characterised in that the encoder head (66) and the encoder wheel (63) can be axially displaced with respect to one another according to the rotational or pivot axis of the functional part (D1-D4).
10. Driving system according to Claim 8 or 9, characterised in that the encoder head (66) is fixed or supported to or with respect to the stationary part of the electric motor (F,G), in particular the stator (G) or the frame thereof.
11. Driving system according to any one of the preceding Claims, characterised in that the power amplifier (47) is constructed with a converter with intermediate voltage circuit (49) and/or with direct feed.
12. Driving system according to any one of the preceding Claims, characterised in that the power amplifier (47) is implemented with digital phase current regulation (48) on the basis of pulse-width modulation with high clock frequency, high-speed transistor switches, voltage precontrol and/or predetermination of the phase current desired values and/or the precontrol values via optical-fibre links (50).
13. Driving system according to any one of the preceding Claims, characterised in that a digital signal processor (51) is disposed in the signal processing module (51, AP) for implementing functions relating to encoder evaluation, motor control, rotational speed regulation, angular position regulation and/or fine interpolation of the desired or predetermined values.
14. Driving system according to any one of the preceding Claims, characterised in that the regulators or rows with a plurality of regulating elements are coupled together via additional, weighted feedback elements (KI, II, KII, I), preferably crosswise.
15. Driving system according to any one of the preceding claims, characterised in that the regulators and/or rows of regulating elements are linked to a characteristic element, which registers actual values (ΦistI, ΦistII) on the input side, for feedforward control (53I, 53II).

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