Method and device for controlling production plant for plate-shaped or linear objects

Abstract

The invention relates to a method for controlling a production plant for plate-shaped or linear objects, wherein the objects are conveyed in a conveying direction through a measuring region; irradiating the object in the measurement region by means of measurement radiation in the frequency range of kilomegahertz or terahertz; measuring radiation reflected by the object is detected and a refractive index of the object and an absorptivity of the measuring radiation by the object are determined from the detected measuring radiation, at least one production parameter of the production plant is controlled on the basis of the refractive index determination and the absorptivity determination, the refractive index and the absorptivity are determined at a plurality of times during the transport of the object through the measurement region and the at least one production parameter is controlled on the basis of a change in the refractive index and the absorptivity over time, and the measurement radiation is emitted at different positions of the object, the refractive index and the absorptivity are determined at different locations of the object and the at least one production parameter is controlled based on spatial variations in the refractive index and the absorptivity. The invention also relates to a corresponding device.

Description

[0001] This application is a divisional application of the invention patent application with international application number PCT / EP2019 / 076396, national application number 201980064642.9, application date September 30, 2019, and name “Method and device for controlling production equipment for plate-shaped or linear objects”. Technical Field

[0002] The invention relates to a method for controlling a production device for plate-shaped or linear objects, in which method: the object is transported along a transport direction through a measuring area; in the measuring area, the object is irradiated with the aid of measuring radiation in the gigahertz or terahertz frequency range, the measuring radiation at least partially penetrating into the object; and the measuring radiation reflected by the object is detected and the refractive index of the object and / or the absorption rate of the measuring radiation by the object is determined based on the detected measuring radiation.

[0003] The present invention also relates to a device for controlling a production device for plate-shaped or linear objects, the device comprising: a conveying device for conveying the object along a conveying direction through a measuring area of ​​the device; a transmitting device for irradiating the object with measuring radiation in the gigahertz or terahertz frequency range in the measuring area, the measuring radiation at least partially entering the object; a detection device for detecting the measuring radiation reflected by the object; and an evaluation device, the evaluation device being configured to determine the refractive index of the object and / or the absorption rate of the measuring radiation by the object based on the measuring radiation detected by the detection device. Background Art

[0004] For example, DE 10 2016 103 298 A1 discloses a terahertz measuring device and a terahertz measuring method for determining at least one layer thickness of a test object by propagation time measurement. In addition, WO 2016 / 139155 A1 discloses a device and a method for measuring the diameter and / or wall thickness of a linear element even when the refractive index is unknown. This makes it possible to accurately determine the diameter and wall thickness of, for example, a tube even when the refractive index is unknown or not reliably known.

[0005] DE 20 2018 006 144 U1 discloses a device for measuring a tubular wire element emerging from an extrusion device, wherein the diameter and / or the wall thickness and / or the shape deviation of the tubular wire can be determined using, in particular, terahertz radiation. Based on the values ​​of the determined diameter and / or wall thickness and / or shape deviation, the extrusion device can be controlled and / or regulated. In order to determine the diameter or wall thickness or shape deviation, the refractive index of the material of the wire element can also be determined.

[0006] Furthermore, DE 10 2015 110 600 B3 discloses a method and a device for determining the layer properties of an extruded product produced in an extrusion process by irradiating a feed material supplied to an extruder with terahertz radiation and measuring at least one feed rate or feed amount of the feed material. DE 10 2015 110 600 B3 deals with the problem that for a foamed layer of the extruded product, the refractive index, which is related to the material density, is unknown. In contrast, for the unfoamed layer, it is assumed according to DE 10 2015 110 600 B3 that the refractive index is known. In order to obtain the refractive index of the foamed layer, DE 10 2015 110 600 B3 proposes, in addition to measuring the extruded product with terahertz radiation, to use data or measurement signals about the amount of material supplied to the extrusion process. According to DE 10 2015 110 600 B3, the amount of material is obtained gravimetrically or volumetrically. The refractive index of the foamed layer thus determined should give a conclusion about the degree of foaming of the foamed layer. Based on the determined refractive index, the extruder feed rate can be adjusted to achieve the desired degree of foaming. According to DE 10 2015 110 600 B3, the weight of the material supplied to the extruder as particles is measured by means of a weighing device. But at this time, the volume can only be determined when the specific gravity of the particles is known and constant. In practice, these two conditions usually do not exist. In addition, according to DE 102015 110 600 B3, the amount of extruder material input is measured and on this basis, the refractive index of the section of the extruded product irradiated by terahertz radiation is predicted. However, the prerequisite for obtaining a conclusion about the refractive index of a determined section of the extruded product manufactured by the extruder from the input of the extruder is that, during extrusion, the rotation speed and extraction speed of the extruder are constant, and the shrinkage caused by temperature changes is also constant. These prerequisites cannot be reliably present in practice, so this known method has corresponding inaccuracy.

[0007] According to DE 10 2015 110 600 B3, the refractive index of the foam layer can be determined and used to control the feed rate to obtain the desired degree of foaming, while for the unfoamed layer, DE 10 2015 110 600 B3 assumes a known refractive index. However, in practice, the refractive index of the unfoamed layer also varies for different reasons. According to DE 10 2015 110 600 B3, this variation is not recognized. In addition, since according to DE 10 2015 110 600 B3 the refractive index is indirectly determined by volumetric or gravimetric measurement from the material supplied to the extruder for extrusion, as explained, it is difficult to obtain a correspondence with a certain section of the object extruded from the material. Accordingly, the control or regulation of the extrusion device set according to DE 10 2015 110 600 B3 is also imprecise.

[0008] In addition, there is a need to obtain more information about the production process in order to achieve more targeted and more accurate control of the production equipment. Summary of the invention

[0009] Starting from the described prior art, the object of the invention is to improve the control of a production system for plate-shaped or linear objects.

[0010] The invention achieves this object by the features of the independent claims 1 and 12. Advantageous embodiments are given in the dependent claims, the description and the drawings.

[0011] For a method of the type described above, the objects of the present invention are achieved in that at least one production parameter of the production device is controlled based on a refractive index determination and / or an absorbance determination, in which case the refractive index and / or the absorbance are determined at multiple times during the transport of the object through a measurement area and the at least one production parameter is controlled based on the change in the refractive index and / or the absorbance over time, and / or the measurement radiation is emitted to different positions of the object, in which case the refractive index and / or the absorbance are determined at the different positions of the object and the at least one production parameter is controlled based on the change in the refractive index and / or the absorbance over space.

[0012] For devices of the type described above, the present invention achieves the object in that a control device is provided, which is configured to control at least one production parameter of the generation system based on a refractive index determination and / or an absorbance determination, wherein: the evaluation device is configured to determine the refractive index and / or the absorbance at multiple times during the transport of the object through the measurement area, and the control device is configured to control the at least one production parameter based on the change of the refractive index and / or the absorbance over time; and / or the transmitting device is configured to transmit measurement radiation to different positions of the object, at which time the evaluation device is configured to determine the refractive index and / or the absorbance at the different positions of the object, and the control device is configured to control the at least one production parameter based on the change of the refractive index and / or the absorbance over space.

[0013] The linear or plate-shaped objects produced in the production device can be, for example, objects made of plastic or glass. The objects can be non-foamed objects in particular, that is, such objects do not have foamed parts, such as foaming layers. Linear objects can be, for example, tubular objects, such as plastic or glass tubes. Plate-shaped objects can be, for example, plastic or glass plates. The objects produced in the production device can already (essentially) completely have their final shaping at the time of measurement according to the invention. But it is also possible that the shaping is not yet completed at the time of measurement. The object can also have a very high temperature of, for example, more than 2000° C. at the time of measurement, especially when the object is a glass body. In particular, the object is conveyed through the measurement area in the longitudinal direction and irradiated with gigahertz or terahertz radiation here. In particular, difficult measurement conditions exist in production devices of the type involved here. This situation also exists during the final shaping of the object or just when the shaping of the object is completed, especially for early measurements. In order to be able to react to possible impermissible deviations of the production device at an early stage and to avoid unnecessary defective products, this is in principle desirable. However, there is a high risk of contamination from the production process in the measuring area. In addition, in order to cool the object or the components of the production system, a cooling liquid, such as cooling water, is usually applied to the object or the components of the production system. This can lead to splashing water and the generation of steam. Optical measurement methods, for example using lasers, are basically problematic in such measurement environments. These problems can be avoided by using gigahertz or terahertz radiation according to the invention, because such measurement radiation is basically insensitive to harsh measurement environments of the type described.

[0014] The measuring radiation is emitted by a transmitting device and directed onto the object to be measured. Here, the measuring radiation enters the object at least partially, preferably completely. In particular, the measuring radiation can completely penetrate the object. The measuring radiation is reflected at the boundary surface of the object, and the reflected measuring radiation is received by a receiving device. The transmitting device and the receiving device can be combined into a transceiver in a particularly practical manner. Of course, a plurality of transmitting devices and a plurality of receiving devices can also be provided, which, for example, illuminate the object from different directions and receive the reflected measuring radiation. If a plurality of transmitting devices and receiving devices are provided, these transmitting devices and receiving devices can be combined into transceivers in pairs in a particularly practical manner.

[0015] Based on the detection of the reflected measurement radiation, the refractive index of the material of the object and the absorption of the measurement radiation by the object can be determined. DE 10 2015 110 600 B3 assumes that the refractive index is known for the non-foamed layer, while the present invention takes into account that the refractive index of the non-foamed material, in particular, can also change in practice for different reasons. Thus, additives are added to extrusion materials for extruded products, such as plastic pipes, for example in order to reduce the conductivity of the material as a sunscreen or the like. For this purpose, users of extrusion equipment sometimes use premixed material mixtures, to which additives have already been added by the manufacturer. However, users sometimes also produce material mixtures themselves, in that they add additives to the base material themselves. In the latter case in particular, the amount of additives added can change undesirably. If the proportion of the additives added to the extruded material changes, this can be quickly and reliably detected according to the present invention based on the determination of the refractive index and eliminated by corresponding control interventions in the production equipment.

[0016] According to the invention, the determination of the refractive index or the determination of the absorption index is carried out here, in particular directly on the basis of the measurement radiation reflected by the object. According to the invention, in particular, it is not necessary, for example, to carry out a gravimetric or volumetric measurement of the material extruded in the extrusion device in order to determine the refractive index or the absorption index, as is also provided in DE 10 2015 110 600 B3. According to the invention, therefore, an assignment of the determined refractive index to a specific section of the object can be reliably established, and control can thus be carried out more accurately.

[0017] According to the present invention, at least one production parameter of a production device is controlled based on the determination of the refractive index and / or the absorption rate. The present invention is based on the unexpected recognition that the refractive index and / or the absorption rate of the measured object, especially the change of these values ​​over time or over space, provides information about the production process, based on which the production process can be controlled. In practice, irradiation with gigahertz or terahertz radiation is often used to determine the geometric parameters of the object, such as, for example, the surface profile, diameter, thickness or wall thickness. Accordingly, according to the present invention (by means of an evaluation device), at least one geometric parameter of the object can also be determined, such as its surface profile, its diameter, its thickness or its wall thickness. As mentioned above, the refractive index can also be determined here in order to accurately determine the geometric parameters. According to the present invention, gigahertz or terahertz radiation and, if necessary, the refractive index and / or the absorption rate are now continued to be determined in order to draw conclusions about the production process and control the production process accordingly, and this control can be carried out automatically in particular. In this way, according to the present invention, the production process can be improved in a simple and reliable manner.

[0018] The invention is based in particular on the recognition that the temporal or spatial variation of the refractive index and / or the absorptivity is an important parameter for controlling or regulating the production plant. To this end, according to the invention, the refractive index and / or the absorptivity is determined for a plurality of positions of the object at a plurality of times and / or distributed in particular over the periphery of the object. According to the invention, the change of the temporally or spatially distributed data of the determined refractive index and / or absorptivity is inferred from the occurrence of an undesirable change in the production process. The production plant is controlled on this basis.

[0019] During the transport of the object through the measuring region, the refractive index or the absorption index can be determined, for example, at regular time intervals. In this way, trends in the data can be identified. Necessary control interventions in the production plant can be derived from this. For example, a decreasing or increasing value of the refractive index or the absorption index over time indicates an undesirable change in the production process.

[0020] For linear objects, in particular, the measuring radiation can be emitted to the object at different positions distributed on the periphery of the object. In the above-described embodiment, a plurality of emitting devices and receiving devices, such as a plurality of transceivers, can be provided, which are arranged so that the emitting devices and receiving devices guide the measuring radiation to different positions of the object and receive the respectively reflected measuring radiation. For example, a plurality of emitting devices and receiving devices, such as a plurality of transceivers, can be arranged distributed on the periphery of the linear object. However, it is also conceivable that at least one emitting device and at least one receiving device, such as at least one transceiver, are arranged variably in space, for example, can be rotated around the linear object. The spatial distribution of the refractive index or the absorption rate can be identified by the above-described embodiment. From this, the necessary control intervention for the production equipment can be derived. For example, a systematic change of the value of the refractive index or the absorption rate with position indicates that there is a fault in the production process. For example, when the extruded plastic material undergoes an undesirable flow, the refractive index or absorption rate of the lower side of the linear object may be different from that on its upper side. This situation can be identified and taken into account when controlling the production process.

[0021] For example, the absorption rate can be determined by comparing the intensity of the measurement radiation emitted by the transmitting device with the intensity of the measurement radiation received after reflection on the boundary surface of the back side of the object facing away from the transmitting and receiving device. The refractive index determination can be performed, for example, as explained in WO 2016 / 139155 A1. Here, for example, the propagation time of the measurement radiation emitted by the transmitting device through the measurement area when the object is arranged in the measurement area can be compared with the propagation time of the measurement radiation through the measurement area when no object is arranged in the measurement area. The refractive index of the material can then be determined mathematically from the propagation time change, as will be described in detail below. For this purpose, the transmitting device and the receiving device can be arranged, for example, on opposite sides of the measurement area. However, it is also possible to arrange a transmitting device and a receiving device on one side of the measurement area, and a reflector on the opposite side of the measurement area.

[0022] As described above, the determination of the refractive index can be achieved by comparing the propagation time of the measuring radiation emitted by the emitting device through the measuring region when the object is arranged in the measuring region with the propagation time of the measuring radiation through the measuring region when no object is arranged in the measuring region. In particular, when the object is a tubular object, the propagation time of the measuring radiation emitted by the emitting device through a first wall section facing the emitting device and through a second wall section facing away from the emitting device can also be taken into account for the determination of the refractive index.

[0023] As explained in WO 2016 / 139155 A1, for example, for a tubular object, the wall thickness W of the wall section of the object facing the at least one transmitting device can be determined according to the following formula: d1 or the wall thickness W of the wall section of the object facing away from the at least one transmitting device d2 :

[0024]

[0025]

[0026] in:

[0027] : a propagation time difference between the measurement radiation reflected on an outer boundary surface of a wall section of the object facing the at least one transmitting device and on an inner boundary surface facing away from the at least one transmitting device,

[0028] : a propagation time difference between the measurement radiation reflected on an inner boundary surface of a wall section of the object facing away from the at least one transmitting device and on an outer boundary surface facing away from the at least one transmitting device,

[0029] : a propagation time change of the measuring radiation emitted by the at least one transmitting device and received by the at least one receiving device after having passed through the object, caused by the material of the object guided through the devices,

[0030] : Measures the speed of radiation propagation in air

[0031] For example, for W d1 , the above equation can be transformed into:

[0032]

[0033] In addition:

[0034]

[0035] in:

[0036] c K : Measures the speed at which radiation travels through an object

[0037] Further from this:

[0038]

[0039] Therefore, the refractive index n of the tubular object is:

[0040]

[0041] The refractive index of the object can thus be determined computationally by taking into account the propagation time change caused by the object and the propagation time of the measuring radiation through the first and second wall sections. No volumetric or gravimetric measurement is required for this.

[0042] According to another embodiment, a data trend can be established from the values ​​of the refractive index and / or the absorbance determined at multiple times during the transport of the object through the measurement area. The production device can then be controlled based on the identified changes in the data trend over time, for example a decrease or increase in the data trend over a certain time period. For this purpose, for example, the data trend can be derived over time. If the value calculated by the derivation exceeds or falls below a predetermined expected value, a control intervention can be carried out on the production device.

[0043] According to another embodiment, a spatial value distribution can be established based on the values ​​of the refractive index and / or absorptivity determined at different positions of the object. The production equipment can then be controlled based on the changes in the space identified by the value distribution. As already explained, the refractive index and / or absorptivity can be determined distributedly at multiple positions, for example, on the periphery of a tubular object. In this way, the spatial distribution of the obtained values ​​of the refractive index and / or absorptivity on the periphery of the tubular object can be determined. If a particularly systematic change occurs at this time, for example, the value of the refractive index and / or absorptivity on the lower side of the object is significantly higher than that on the upper side, it can be concluded that there is an undesirable downward flow of the material, that is, there is so-called sagging. At this time, this situation can be eliminated by corresponding control intervention of the production process. On the other hand, for example, the value distribution can be spatially derived. If the value calculated by the derivation exceeds or is lower than the predetermined expected value, the production equipment can be controlled and intervened.

[0044] According to another embodiment, the object can be made of plastic material, and the production equipment includes an extrusion device for extruding the plastic material, and at least one production parameter of the extrusion device is controlled based on the refractive index and / or the absorption rate. According to another embodiment related to this, the output capacity of the extrusion device can be controlled as a production parameter. Alternatively or additionally, the mixing ratio of at least two materials to be extruded supplied to the extrusion device can also be controlled as a production parameter. In the extrusion device, two materials can be mixed into a mixture to be extruded. This usually refers to an admixture added to the main plastic material. For example, graphite or glass fiber can be mixed into a carrier plastic, such as polypropylene (PP) or polyethylene (PE). Such admixtures are usually only present in a small proportion of, for example, less than 1% by weight. It is difficult to adjust the mixing ratio, and it is usually impossible to reliably find an incorrect mixing ratio. For example, finished mixtures purchased from different manufacturers may also have significant changes in the mixing ratio. Depending on the specific material, such admixtures have a significant effect on the refractive index, for example. This is especially applicable to materials whose refractive index is significantly different from the refractive index of the carrier material. For example, this is the case when graphite or glass fiber admixtures are added to carrier plastics, such as PP or PE. The above-described embodiment makes use of this. Thus, it has surprisingly been found that, based on the determination of the refractive index or the absorption index according to the invention, even with small admixture proportions, it is possible to reliably detect that the mixing ratio has inadmissible deviations from a predetermined mixing ratio and to intervene in the mixing process in the extrusion device accordingly.

[0045] As already explained, additives added to the base material, especially in extrusion equipment, sometimes have a significant influence on the refractive index or absorptivity of the material. According to another embodiment, the proportion of additives added to the material for producing the object can be determined accordingly based on the determined values ​​of the refractive index and / or absorptivity, and the production equipment can be controlled based on the determined proportion of additives. In this way, it can be ensured that the desired mixing ratio between base material and additive is always maintained.

[0046] According to another embodiment, at least one production parameter of the production device can be adjusted in a closed control loop based on the refractive index determination and / or the absorbance determination. This is so-called closed-loop control. That is, the control device forms a regulating device. In particular, fully automatic regulation can be performed, in which no manual intervention is required. The regulating device can, for example, obtain the determined value of the refractive index and / or absorbance as a control variable. The control variable is compared with the expected value of the refractive index and / or absorbance as a reference variable. If the comparison shows that there is a regulation deviation, the regulating device can manipulate the production parameters, such as the mixing ratio of the extruder, until the regulation deviation is again within the permissible range. All the embodiments mentioned in this case for controlling the production device can also be used to regulate the production device accordingly.

[0047] The method according to the invention can be implemented using the device according to the invention. Accordingly, the device according to the invention can be configured to implement the method according to the invention.

[0048] The invention also relates to a production plant for plate-shaped or linear objects, the production plant comprising a device according to the invention for controlling the production plant and comprising a conveying device for conveying the objects in a conveying direction through the measuring region of the device according to the invention. Here, the device according to the invention or the production plant according to the invention can also comprise plate-shaped or linear objects. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0050] Schematically:

[0051] Figure 1 shows a diagram in which the refractive index of a tubular object determined using the device according to the invention or the method according to the invention is plotted over time,

[0052] Figure 2 shows a diagram in which the refractive index determined using the device according to the invention or the method according to the invention is plotted over the rotation angle about the tubular object,

[0053] Figure 3 A device according to the invention is shown with a tubular object shown in a transverse section. DETAILED DESCRIPTION

[0054] Unless otherwise indicated, the same reference numerals in the drawings denote the same objects.

[0055] exist Figure 1The graph of FIG. 1 shows the time curve of the refractive index determined according to the invention for an object, for example a tubular object, measured in a production plant with the device according to the invention or the method according to the invention. In this graph, the refractive index n is plotted over the time t. In the example shown, the refractive index n decreases over time.

[0056] exist Figure 2 The determined spatial curve of the refractive index is again shown for an especially tubular object measured with the device according to the invention or the method according to the invention in a production plant. Figure 2 In the case of a graph, the refractive index at different positions has been determined distributedly around the circumference of a tubular object. For this purpose, a transmitting and receiving device, for example, combined as a transceiver, is rotated around the circumference of the tubular object, wherein measurement radiation is respectively emitted toward the tubular object and the measurement radiation reflected by the object is measured by the receiving device. Figure 2 In the diagram of , the refractive index n is shown over the rotation angle ω of the transmitting and receiving device. It can be seen here that the refractive index first passes through a minimum in the angle range between 0° and 180° and then approaches its original value again.

[0057] exist Figure 3 The apparatus according to the invention is shown by way of example, with which it is possible to determine Figure 1 and 2 In the example shown, the device comprises a transceiver 10, which comprises a transmitting device and a receiving device for gigahertz or terahertz radiation. The transceiver 10 transmits measurement radiation in the gigahertz or terahertz frequency range to a tubular object 12 which is conveyed through the measurement region of the device in its longitudinal direction, e.g. Figure 3 The measuring radiation penetrates the tubular object 12 and is reflected at various boundary surfaces of the tubular object 12, as indicated by arrows 14, 16, 18 and 20. Figure 3 As shown by the arrow 22 in FIG. 1 , a certain radiation component is emitted again from the tubular object 12. In the example shown, this radiation component is reflected by the reflector 34 so that it returns to the transceiver 10. The measurement radiation reflected at the boundary surfaces is also received again by the transceiver 10. The measurement data of the transceiver 10 are transmitted to the evaluation device 24, as in Figure 3 As indicated by the dashed arrow 26 in FIG. 2 . The evaluation device 24 can determine the refractive index of the material of the tubular object 12, for example, in the manner described above. This refractive index determination can be repeated at regular intervals, for example over a predetermined time period, while the tubular object 12 is being transported through the measuring region of the device, thereby obtaining the following: Figure 1It is also conceivable, for example, to rotate the transceiver 10 (and the reflector 34) around the tubular object 12, during which the measuring radiation is emitted in a distributed manner at different positions on the circumference of the tubular object 12 and the reflected measuring radiation is received in each case, and thereby to obtain a spatial distribution of the refractive index, as in Figure 2 Here, in particular when the determination of the refractive index is carried out in the manner described above, the measured values ​​are repeated with an angular period of 180°.

[0058] In the example shown, the value of the refractive index obtained by the evaluation device 24 can be transmitted to the adjustment device 28, such as in Figure 3 As shown by the dashed arrow 30 in FIG. 2 . The adjusting device 28 can be adjusted in Figure 3 At least one production parameter of a production plant shown very schematically at 32 is indicated, for example, Figure 3 As shown in FIG. 1 by the dashed arrow 34. The at least one production parameter may be, for example, the mixing ratio of two materials supplied to an extruder of the production plant.

[0059] Reference numerals list

[0060] Refractive index

[0061] t time

[0062] ω Rotation angle

[0063] 10 Transceiver

[0064] 12 Tubular objects

[0065] 14 Arrow

[0066] 16 Arrow

[0067] 18 Arrow

[0068] 20 Arrow

[0069] 22 Arrow

[0070] 24 Evaluation Device

[0071] 26 dotted arrow

[0072] 28 Adjustment device

[0073] 30 dotted arrow

[0074] 32 Production Equipment

[0075] 34 dotted arrow

[0076] 36 reflectors

Claims

1. A method for controlling a production plant (32) for plate-shaped or linear objects (12), in which: the object (12) is transported in a transport direction through a measuring region; in the measuring region the object (12) is irradiated with measuring radiation in the gigahertz or terahertz frequency range, the measuring radiation at least partially penetrating into the object (12); and the measuring radiation reflected by the object (12) is detected and the refractive index (n) of the object (12) and the absorption of the measuring radiation by the object (12) are determined based on the detected measuring radiation, characterized in that At least one production parameter of the production device (32) is controlled based on the refractive index determination and the absorption index determination, the refractive index (n) and the absorption index are determined at multiple times during the transport of the object (12) through a measurement region and the at least one production parameter is controlled based on the temporal variation of the refractive index (n) and the absorption index; and measuring radiation is emitted to different locations of the object (12), the refractive index (n) and the absorption index are determined at the different locations of the object (12) and the at least one production parameter is controlled based on the spatial variation of the refractive index (n) and the absorption index, wherein the object (12) consists of a plastic material, the production device (32) comprises an extrusion device for extruding the plastic material, and at least one production parameter of the extrusion device is controlled based on the refractive index determination and the absorption index determination, wherein the output capacity of the extrusion device and / or the mixing ratio of at least two materials to be extruded supplied to the extrusion device are controlled as production parameters, and the refractive index is determined by comparing the propagation time of the measuring radiation emitted by the emitting device through the measurement region when the object is arranged in the measurement region with the propagation time of the measuring radiation through the measurement region when no object is arranged in the measurement region, A data trend is established based on the values ​​of the refractive index and the absorbance determined at multiple times during the transportation of the object (12) through the measurement area, and a spatial value distribution is established based on the values ​​of the refractive index and the absorbance determined at different positions of the object (12), and the production equipment is controlled based on the identified changes in the data trend over time and the identified changes in the value distribution over space, wherein the data trend is derived over time and the value distribution is derived over space, and control intervention is performed on the production equipment based on the values ​​calculated by the derivatives.

2. The method according to claim 1, characterized in that The object (12) is a tubular object (12) and, for determining the refractive index, the propagation time of the measuring radiation emitted by the transmitting device through a first wall section facing the transmitting device and through a second wall section facing away from the transmitting device is also taken into account.

3. The method according to claim 1 or 2, characterized in that: The proportion of an additive added to a material for producing the object (12) is determined according to the determined value of the refractive index and / or the absorptivity, and the production device is controlled based on the determined additive proportion.

4. The method according to claim 1 or 2, characterized in that: Based on the refractive index determination and / or the absorbance determination, the at least one production parameter of the production device (32) is adjusted in a closed control loop.

5. The method according to claim 1 or 2, characterized in that: The method is implemented by means of a device according to any one of claims 6 to 9.

6. A device for controlling a production device (32) for plate-shaped or linear objects (12), the device comprising: a conveying device for conveying the object (12) in a conveying direction through a measuring region of the device; a transmitting device for irradiating an object (12) in a measuring region with measuring radiation in the gigahertz or terahertz frequency range, the measuring radiation at least partially penetrating into the object (12); a detection device for detecting measuring radiation reflected by the object (12); an evaluation device (24), the evaluation device being configured to determine a refractive index (n) of the object (12) and an absorptivity of the measuring radiation by the object (12) based on the measuring radiation detected by the detection device, characterized in that a control device is provided, the control device being configured to control at least one production parameter of the production device (32) based on the refractive index determination and the absorptivity determination, the evaluation device (24) being configured to determine the refractive index (n) and the absorptivity at multiple times during transport of the object (12) through a measuring area, the control device being configured to control the at least one production parameter based on a change in the refractive index (n) and the absorptivity over time; and the emission device being configured to emit measuring radiation to different positions of the object (12), the evaluation device (24) being configured to determine the refractive index (n) and the absorptivity of the object (12) The invention relates to a method for determining a refractive index (n) and an absorptivity at different locations of a body (12), and a control device is configured to control the at least one production parameter based on the spatial variation of the refractive index (n) and the absorptivity, wherein the object (12) is made of a plastic material, the production device (32) comprises an extrusion device for extruding the plastic material, and the control device is configured to control at least one production parameter of the extrusion device based on the refractive index determination and the absorptivity determination, wherein at least one production parameter is the output capacity of the extrusion device and / or at least one production parameter is the mixing ratio of at least two materials to be extruded supplied to the extrusion device, and the evaluation device (24) is configured to determine the refractive index by comparing a propagation time of a measurement radiation emitted by a transmitting device through the measurement region when the object is arranged in the measurement region with a propagation time of the measurement radiation through the measurement region when no object is arranged in the measurement region, The evaluation device (24) is configured to establish a data trend based on the values ​​of the refractive index and the absorption rate determined at multiple times during the transportation of the object (12) through a measuring area and to establish a spatial value distribution based on the values ​​of the refractive index and the absorption rate determined at different positions of the object (12), and the control device is configured to control the production equipment based on the identified changes in the data trend over time and the identified changes in the value distribution over space, wherein the evaluation device is configured to differentiate the data trend over time and the value distribution over space, and to perform control intervention on the production equipment based on the values ​​calculated by the differentiation.

7. The device according to claim 6, characterized in that The object (12) is a tubular object (12), and the evaluation device (24) is designed to determine the refractive index by also taking into account the propagation time of the measuring radiation emitted by the transmitting device through a first wall section facing the transmitting device and through a second wall section facing away from the transmitting device.

8. The device according to claim 6 or 7, characterized in that The control device forms a regulating device (28) which is designed to regulate the at least one production parameter of the production facility (32) in a closed control loop based on the refractive index determination and / or the absorbance determination.

9. The device according to claim 6 or 7, characterized in that The device is designed to carry out the method according to any one of claims 1 to 5 .

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