Solutions for estimating the drying shrinkage of plywood

Abstract

The system for generating an estimate of drying shrinkage of a veneer sheet (135) comprises: a density measuring device (160) for generating data representative of the density of the veneer sheet (135), at least one other entity suitable for generating data representative of at least one property of the veneer sheet (135), and an apparatus (150) for receiving data from the density measuring device (160) and from the at least one other entity, the apparatus (150) configured to generate an estimate of drying shrinkage of the veneer sheet (135) based on the received data. The invention also relates to the apparatus (150), a method and a computer program product.

Description

[Technical Field]

[0001] This invention generally relates to the technical field of wood product production. More specifically, this invention relates to veneer production. [Background technology]

[0002] The manufacture of wood products is a process in which multiple production-related parameters are considered in order to achieve an efficient manufacturing process. In the production of plywood and veneer, the material is manipulated in different ways during the manufacturing process in order to optimize the final product, i.e., plywood. The manipulation techniques depend on the stage of the process, and the effect of the manipulation at a particular stage must be considered at one or more later stages. For example, the raw material in the production of plywood and veneer is typically logs that are prepared in the later stages of production. Preparation refers to heating and moistening the logs so that the wood material is optimized for peeling devices configured to produce thin, continuous sheets of veneer, i.e., veneer ribbons. In other words, the raw material is moistened to optimize the yield and quality of the peeling. However, in the later stages of plywood and veneer production, the veneer ribbons need to be cut into individual sheets of veneer and dried at least to some extent in preparation for bonding them together, for example, to produce plywood panels of the desired dimensions.

[0003] In materials science, it is generally known that, at least in most cases, materials shrink as they dry. This is true at least for wood products and influences the production of plywood and veneer, in the sense that shrinkage is favorably considered during cutting to minimize production waste. Accumulated experience and research have shown that the higher the density of the wood, the greater the observed volume shrinkage, so the conventional method for considering shrinkage is to monitor the density of the wood. Furthermore, it is known that defects in the wood, such as knots or decay, also affect the shrinkage of the wood, i.e., the shrinkage of veneer sheets during drying.

[0004] Drying shrinkage, particularly in the production of plywood and veneer from softwood, is addressed using models that represent the shrinkage of veneer sheets (e.g., tangentially) in response to moisture content. However, these models have been shown to be unreliable and unsuitable for plywood and veneer production. Therefore, there is a need to develop solutions to improve this situation. [Overview of the Initiative] [Means for solving the problem]

[0005] To provide a basic understanding of some aspects of the various embodiments of the present invention, a simplified outline is presented below. This outline is not a comprehensive overview of the invention. It is not intended to identify any major or important elements of the invention, nor is it intended to define the scope of the invention. The following outline merely presents some concepts of the invention in a simplified form as an introduction to a more detailed description illustrating embodiments of the invention.

[0006] The object of the present invention is to provide a system, apparatus, method, and computer program product for generating an estimate of the drying shrinkage of a plywood sheet.

[0007] The object of the present invention is achieved by the systems, apparatus, methods and computer program products defined by each independent claim.

[0008] According to a first aspect, a system is provided for generating an estimate of the drying shrinkage of a veneer sheet, the system comprising: a density measuring device for generating data representing the density of the veneer sheet; at least one other entity suitable for generating data representing at least one property of the veneer sheet; and an apparatus for receiving data from the density measuring device and data from at least one other entity, configured to generate an estimate of the drying shrinkage of the veneer sheet based on the received data.

[0009] Other entities may be at least one of the following: a peeling device, an image capture device, a moisture measurement device, data storage for storing data representing the properties of the raw material, and data storage for storing data representing the properties expected after a given stage of the manufacturing process.

[0010] For example, the system's apparatus may be configured to apply a classification function to data representing at least one property of a veneer sheet in order to classify the veneer sheet into one of several classes according to data representing at least one property of the veneer sheet. The system's apparatus may also be configured to access one or more internal parameters, each defined individually for each class, and these one or more internal parameters are combined with data received from a density measuring device to generate an estimate of the drying shrinkage of the veneer sheet. Furthermore, the system's apparatus may be configured to combine one or more internal parameters with data received from a density measuring device by using the internal parameters of the classes as constants in the equations and using the respective values ​​representing the density properties of the veneer sheet as parameters in the respective equations.

[0011] Furthermore, measurements using one of the density measuring device, image capture device, and moisture measuring device may be configured to be performed on the veneer ribbon before cutting the veneer sheet from the veneer ribbon. The system's apparatus is configured to define at least one veneer sheet that can be produced from the veneer ribbon, and to perform measurements on the veneer ribbon by generating multiple measurements for at least one veneer sheet using at least one of the density measuring device, image capture device, and moisture measuring device.

[0012] The system's device may be configured to select one of several estimation models to estimate drying shrinkage according to a value representing the moisture content of the plywood sheet.

[0013] The system's device may be configured to generate an estimate of the drying shrinkage of a plywood sheet by scaling a value representing pre-drying shrinkage using a value that can be derived from at least one measurement representing moisture content.

[0014] The system's apparatus may be configured to generate a control signal to a cutting device according to an estimated drying shrinkage of the veneer sheet, thereby causing the veneer sheet to be cut from the veneer ribbon.

[0015] According to a second embodiment, an apparatus is provided for generating an estimate of the drying shrinkage of a veneer sheet, the apparatus comprising at least one processor and at least one memory containing computer program code, the at least one memory and computer program code together with the at least one processor, which are configured to cause the apparatus to receive data from a density measuring device, the data received from the density measuring device representing the density of the veneer sheet, receive data from at least one other entity, the data received from at least one other entity representing at least one property of the veneer sheet, and generate an estimate of the drying shrinkage of the veneer sheet based on the received data.

[0016] The device may apply a classification function to data representing at least one property of a veneer sheet to classify the veneer sheet into one of several classes according to data representing at least one property of the veneer sheet. The device may have access to one or more internal parameters, each defined individually for each class, which are combined with data received from a density measurement device to generate an estimate of the drying shrinkage of the veneer sheet. The device may combine one or more internal parameters with data received from a density measurement device by using the internal parameters of the classes as constants in the equations and using the respective values ​​representing the density properties of the veneer sheet as parameters in each equation.

[0017] The device can select one estimation model from a plurality of estimation models to estimate dry shrinkage according to a value representing the moisture content of the veneer sheet.

[0018] Furthermore, the device can execute the generation of an estimated value of the dry shrinkage of the veneer sheet by scaling a value representing pre-drying shrinkage using a value derivable from at least one measured value representing moisture content.

[0019] Still further, the device can further generate a control signal for the cutting device according to the estimated value of the dry shrinkage of the veneer sheet to cause the cutting of the veneer sheet from the veneer ribbon.

[0020] According to a third aspect, a method for generating an estimated value of the dry shrinkage of a veneer sheet is provided, the method being executed by a device and including the steps of receiving data from a density measurement device, the data received from the density measurement device representing the density of the veneer sheet, and receiving data from at least one other entity, the data received from the at least one other entity representing at least one characteristic of the veneer sheet, and generating an estimated value of the dry shrinkage of the veneer sheet based on the received data.

[0021] Furthermore, the method can include applying a classification function to data representing at least one characteristic of the veneer sheet to classify the veneer sheet into one of a plurality of classes according to the data representing at least one characteristic of the veneer sheet.

[0022] In this method, one or more internal parameters defined individually for each class can also be accessed, and the one or more internal parameters are combined with the data received from the density measurement device to generate an estimated value of the dry shrinkage of the veneer sheet. For example, the one or more internal parameters and the data received from the density measurement device can be combined in this method by using the internal parameters of the class as constants in the formula and using the respective values representing the density characteristics of the veneer sheet as parameters of each formula.

[0023] Also, for estimating the dry shrinkage, the estimation model can be selected from a plurality of estimation models according to a value representing the moisture content of the veneer sheet.

[0024] Alternatively or additionally, the generation of the estimated value of the dry shrinkage of the veneer sheet can be performed by scaling a value representing the pre-dry shrinkage using a value derivable from at least one measured value representing the moisture content.

[0025] The method may further include the step of generating a control signal for the cutting device according to the estimated value of the dry shrinkage of the veneer sheet to cause the cutting of the veneer sheet from the veneer ribbon.

[0026] According to a fourth aspect, there is provided a computer program product for generating an estimated value of the dry shrinkage of a veneer sheet, which, when executed by at least one processor, causes the device to execute the method according to the third aspect defined in the foregoing description.

[0027] As used herein, the expression "some" refers to any positive integer starting from 1, for example, 1, 2, or 3.

[0028] As used herein, the expression "a plurality of" refers to any positive integer starting from 2, for example, 2, 3, or 4.

[0029] Various exemplary and non-limiting embodiments of the present invention relating to both structure and method of operation, along with their additional objectives and advantages, will be best understood from the following description of specific exemplary and non-limiting embodiments, when read in conjunction with the accompanying drawings.

[0030] In this document, the verbs “comprise” and “include” are used as open restrictions, neither excluding nor requiring the existence of features not listed. Features listed in dependent claims can be freely combined with each other unless otherwise specified. Furthermore, it should be understood that the use of “a” or “an,” i.e., the singular form, throughout this document does not exclude the plural form.

[0031] Embodiments of the present invention are shown in the accompanying drawings as examples, not as limitations. [Brief explanation of the drawing]

[0032] [Figure 1] A schematic diagram of a veneer production line according to an exemplary embodiment is shown. [Figure 2] An example of implementation using an exemplary embodiment is schematically shown. [Figure 3] Another example of implementation by a different exemplary embodiment is schematically shown. [Figure 4] Further examples of implementations by more exemplary embodiments are schematically shown below. [Figure 5] A schematic diagram of an apparatus according to an exemplary embodiment is shown. [Figure 6] A schematic representation of the method according to an exemplary embodiment is shown below. [Modes for carrying out the invention]

[0033] The specific examples provided in the following description should not be construed as limiting the scope and / or applicability of the attached claims.

[0034] The list and group of examples provided in the following explanation are not exhaustive unless otherwise specified.

[0035] Figure 1 schematically shows a veneer production line that can implement, at least in part, the solution according to an exemplary embodiment. Selected portions of the veneer production line may include several conveyor devices 110, such as conveyor belts, which can transport products along the veneer production line. The number of conveyor devices 110 can be varied and selected, for example, depending on the length of the production line and the need to separate different production stages with conveyor devices 110. The conveyor devices 110 may be configured to transport logs 115 to the peeling device 120, i.e., the lathe, so as to enable the peeling of logs by applying the blades 125 of the peeling device to the logs to be peeled, thereby producing continuous veneer sheets 130, i.e., veneer ribbons, as the output of the peeling device 120. Furthermore, the veneer production line may include a cutting machine 140, also called a clipper, which can cut the veneer ribbons 130 into individual veneer sheets 135 of predetermined dimensions.

[0036] As discussed in the previous explanation, the logs are prepared to be optimal for veneer production. One characteristic is that the logs are optimally moistened, depending on the type of wood used for veneer production. As a result, the veneer ribbon 130 and individual veneer sheets 135 are moist, and it can be assumed that the dimensions of the individual veneer sheets 135 will change due to shrinkage as they dry. Therefore, before cutting the veneer ribbon 130 into veneer sheets 135, it is beneficial to generate information such as an estimate of the expected shrinkage to take into account cutting and sorting the individual veneer sheets 135, thereby enabling the production of high-quality individual veneer sheets 135. In the described form, the cutting of the veneer sheets 135 can be optimized, resulting in a higher yield of raw materials.

[0037] According to an exemplary embodiment, the generation of an estimate of the shrinkage of a veneer sheet can be performed using an apparatus 150 configured to receive data from multiple devices or entities and to perform an analysis of the received data to enable the generation of an estimate of the shrinkage of a veneer sheet. The data received by the apparatus 150 includes at least several data values ​​representing the density of the veneer sheet obtained by measuring a veneer ribbon 130, and at least several other data representing at least one characteristic of the veneer sheet or production line, or the entity as described below. The data representing the density of the veneer sheet can be obtained using a density measuring device 160, which can refer to an apparatus equipped with appropriate sensors for acquiring data from the veneer ribbon 130 according to the sampling rate of the density measuring device 160. For example, density measurement can be based on the use of X-ray equipment, i.e., an X-ray tube and its respective sensors, in acquiring data to determine the density. However, other types of devices, such as microwave applications, can also be used to acquire measurement data to determine the density value. According to an exemplary embodiment, the density measuring device 160 can be placed in a production line after the peeling device 120, for example, on the veneer ribbon 130, at a measurement position. As the veneer ribbon 130 passes the measurement position of the density measuring device 160, several measurements can be collected, from which the density of the veneer ribbon 130 at different positions can be determined.

[0038] As described above, according to at least some exemplary embodiments, the apparatus 150 can receive data representing at least one characteristic of a veneer sheet or a production line, or the entity thereof, in addition to data representing the density of the veneer ribbon, in order to estimate the drying shrinkage of the veneer sheet. This information can be used, for example, to control the cutting of the veneer ribbon 130 into individual veneer sheets 135. The data representing at least one characteristic of the veneer sheet can be received from at least one of the following entities: peeling device 120; image capture device 170; moisture measuring device 180; data storage 190 that stores data representing the characteristics of the raw material; and data storage 190 that stores data representing the characteristics expected after a predetermined stage of the manufacturing process. The data storage can refer to a single entity that stores all the necessary data, or to multiple data storages, each storing a predetermined one piece of data.

[0039] For clarity, it is important to mention that at least some of the properties of the veneer sheet can be obtained by measuring the veneer ribbon 130 on the production line before cutting the veneer ribbon 130 into individual veneer sheets 135. Furthermore, some properties, such as those related to the raw materials, may be the same for all veneer sheets 135, i.e., they may not be specific to each veneer sheet 135.

[0040] The following describes in more detail, in an illustrative manner, the embodiments or characteristics that can be received from the density measuring device 160 and the other entities described above. Some embodiments may require calculations by processing the data received from each sensor. The calculations may be performed by each entity or device 150, or the calculations may be shared among the aforementioned entities.

[0041] The modes received from the density measuring device 160, or modes that can be derived from the data received from the density measuring device 160, may be, for example, the following: • For example, the average density of a veneer sheet determined from several measurements taken from a veneer ribbon. • Maximum and / or minimum density, • Density distribution along the width of the plywood sheet and / or along the length of the plywood sheet. • Surface density of the plywood sheet material, • Surface density of the plywood material and water absorbed by the plywood.

[0042] Other values ​​can also be derived from the measurement data obtained using the density measuring device 160. For example, a characteristic applicable to represent density may be a value representing the total mass of an object measured using the density measuring device 160.

[0043] The object can refer to the plywood ribbon 130 or a part thereof. In this context, the total density should be understood as the mass including both the material of the plywood ribbon 130 and the water absorbed by the plywood ribbon 130. However, the mass of water can be subtracted from the total mass by estimating the amount of water in the object based on information obtainable, for example, from a moisture measuring device 180.

[0044] Another data source to be considered in estimating drying shrinkage may be the peeling device 120. The data obtainable from the peeling device 120 depends on the function of the peeling device 120, but at least the following aspects can be derived from the data obtainable from the peeling device 120. • Measurements related to the raw material, i.e., the log, such as diameter, weight, shape (e.g., taper angle), and roundness. • Target parameters of the veneer sheet to be peeled off, such as length and thickness. • Setting of the peeling device, including technical parameters.

[0045] Again, the list given above provides some examples of embodiments, and other embodiments may be established based on data obtainable from the peeling device 120.

[0046] The image capture device 170 can refer to a so-called machine vision device configured to generate data representing a visual aspect of the veneer sheet 135 obtainable from the veneer ribbon 130 from several images captured by the image capture device 170. In other words, the image capture device 170 can be configured to analyze the captured image data and, based on that analysis, generate data representing one or more aspects of the veneer sheet obtainable from the veneer ribbon 130. These aspects may, for example, be as follows: • Defects such as knots, cracks, holes, amount of decay, amount of peel, and defects that occurred during the manufacturing process. These defects can be described as follows: 〇 Quantity, Size, ○ Position on the sheet (e.g., coordinates). • A combination of defects, such as knot lines, which are expressed as quantity, size, or location on a sheet.

[0047] Naturally, any other aspects can be derived from the data acquired by the image capture device 170, if possible.

[0048] A further device applicable for generating data in embodiments representing the plywood sheet may be a moisture measuring device 180, whose operation may be based, for example, on the application of microwaves in the measurement (such as measuring changes in phase or attenuation when microwaves come into contact with the plywood). The moisture measuring device 180 can acquire measurement data and, based on that data, can generate information in at least some of the following embodiments. For example, the average moisture content of a plywood sheet determined from several measurements taken from a plywood ribbon, • Maximum and / or minimum moisture content, • Dispersion of moisture along the width of the plywood sheet and / or along the length of the plywood sheet. • Number of moisture pockets, • Size of the moisture pocket, • The location of the moisture pocket on the sheet (e.g., coordinates).

[0049] It is also possible to derive other values ​​from the measurement data obtained using the moisture measurement device 160.

[0050] Furthermore, a further embodiment of the plywood sheet may be obtained from one or more data storages configured to store data obtainable from other sources. Such data may relate to products such as the final or intermediate products produced on the production line by defining, for example, the raw materials brought into the manufacturing process and / or the expected characteristics of the product at a given stage of the manufacturing process. This type of embodiment may, for example, be: • Parameters related to raw materials, for example, Identifying logs, 〇 Cutting area of ​​wood, 〇 Cutting time. • Parameters related to short logs, for example, 〇 Density, ○ Quantity of heartwood / sapwood, 〇 Parameters used for adjustment, 〇 The position of a short log in a complete log. • The target moisture content of the product at a predetermined stage of production, such as after drying, which allows individual plywood sheets to still contain X% moisture.

[0051] Because the veneer ribbon 130 is inherently long, data acquired using at least one measuring device, such as the image capture device 170, the moisture content measuring device 180, and the density measuring device 160, are advantageously configured to represent the characteristics of the same portion of the veneer ribbon 130. In other words, because the veneer ribbon 130 is long, there can be significant variations between different parameters over the length of the veneer ribbon 130, and consequently, there can be variations in the drying shrinkage of the veneer sheet 135 cut from the veneer ribbon 130. This means that the sampling rate of the measuring device can be adjusted according to the desired accuracy of the drying shrinkage estimate. If the required accuracy is at the level of a single veneer sheet 135, the measurement may be performed only once over the length of the veneer sheet 135 using each measuring device. On the other hand, if improved accuracy is required, multiple measurements must be performed over the length of the veneer sheet 135. An example of a measurement configuration can be illustrated by referring to Figure 2, which illustrates an implementation in which two measuring devices, such as a density measuring device 160 (measurement indicated by X) and a moisture measuring device 170 or an image capture device 180 (measurement indicated by O), are configured to acquire measurement data three times along the length of the veneer ribbon 130. Depending on the measurement configuration, i.e., if the measuring devices are positioned to acquire the same position on the veneer sheet simultaneously, or if they are configured to perform measurements successively with respect to each other, it may be necessary to coordinate their movements with respect to the movement of the veneer ribbon 130 across the measuring devices in order to control each measuring device to acquire measurement data from the same position on the veneer sheet 130 with an acceptable margin. This can be achieved by detecting the leading edge of the veneer sheet and acquiring information on the speed at which the veneer sheet is transported to each measuring device in the production line. This information makes it possible to determine the instantaneous time to perform the measurement in order to receive measurement data that is comparable to each other.Returning to Figure 2, each device can be configured to acquire a first measurement at position p1 on the veneer ribbon 130, a second measurement at position p2, and a third measurement at position p3, where these positions refer to locations on the veneer ribbon 130 or veneer sheet 135. In this type of measurement, the veneer ribbon 130 can be advantageously configured to be divided into sections corresponding to individual veneer sheets 135 (shown as S1, S2, and S3 in Figure 2), and measurements can be acquired at each section as shown. Thus, the accuracy of the data representing the characteristics of the veneer sheet 135 can be improved. Naturally, it is still possible to improve accuracy by increasing the sampling rate of the measuring device for each section, i.e., by acquiring multiple measurements, such as tens or hundreds, for each veneer sheet 135 represented as a section in Figure 2. The size of the sections, i.e., individual veneer sheets 135, can be specified for the production line as an input parameter.

[0052] The following description relates to the generation of an estimate of the drying shrinkage of the veneer sheet 135 according to an exemplary embodiment. Hereinafter, we refer to Figure 3, which schematically shows a simplified implementation according to the exemplary embodiment. As described above, the density measurement 310 can generate one or more measurement results D1, D2, D3, ... representing various properties of the veneer sheet 135, such as the average density (e.g., D1), maximum density (e.g., D2), and surface density of the wood material (e.g., D3) at one or more locations on the veneer sheet 135. The properties described can be determined based on one or more measurements. Accordingly, the data representing the properties of the veneer sheet 135 may be generated by another entity as described (320), and such data may represent the properties of the veneer sheet 135 at one or more locations on the veneer sheet 135, for example, corresponding to the locations where the density values ​​are derived. According to an exemplary embodiment, the apparatus 150 can be configured to classify veneer sheets into one of a plurality of predetermined classes (see Class I and Class II) 330 based on data values ​​(320) generated by at least one other entity. Furthermore, for each class 330, internal parameters (indicated in Figure 3 by X1a, Y1a, Z1a, ... for Class I, and X2a, Y2a, Z2a, ... for Class II) are determined to be assigned to the veneer sheets 135 classified into the class in question. The internal parameters may be defined for each class based on information related to shrinkage characteristics, either directly or indirectly. For example, the parameters may be defined according to the type of wood used to produce the veneer sheets, for example, by performing a preliminary analysis using a set of samples to understand the behavior of the veneer sheets during shrinkage. In other words, the definition of parameters may be performed by tracking multiple veneer sheets throughout the process and determining the shrinkage of each veneer sheet 135 by finding the parameters of the veneer sheets 135 that affect the shrinkage. Such parameters may be, for example, node size and moisture content, which are then combined with data values ​​representing density.In other words, it is possible to generate an estimated value of dry shrinkage (340) by combining a data value representing the density of the veneer sheet 135 and internal parameters of the class into which each veneer sheet 135 is classified based on data received from at least one other entity according to the classification. The generation of the estimated value of dry shrinkage 340 can be executed using a predetermined mechanism such as a predetermined mathematical formula, and the mathematical formula includes values D1, D2, D3,... representing characteristics related to density, and internal parameters of each class (in the case of the first class: X1a, Y1a, Z1a, X1b, Y1b, Z1b, X1c, Y1c, Z1c... and / or in the case of the second class: X2a, Y2a, Z2a, X2b, Y2b, Z2b, X2c, Y2c, Z2c... see), and at least some of them can be input. For example, in some embodiments, the estimated model of dry shrinkage can be determined by the following quadratic polynomial formula:. Dry shrinkage = (X1c * D1 2 + X1b * D1 + X1a) + (Y1c * D2 2 + Y1b * D2 + Y1a) + (Z1c * D3 2 + Z1b * D3 + Z1a)…… In the formula, D1, D2, D3,... correspond to values derived from some density values received from the density measurement device, and X nn , Y nn , Z nn ,... correspond to the internal parameters of the class into which the veneer sheet is classified. In another embodiment, the estimated model of dry shrinkage can be determined by the following exponential function formula: Dry shrinkage = (X1b * e X1a*D1 ) + (Y1b * e Y1a*D2 ) + (Z1b * e Z1a*D3 ) +...

[0053] In some embodiments, different types of formulas can be combined; for example, D1 can be used for a polynomial and D2 for an exponential function. The parameters of both formulas can be derived from the class to which the veneer sheet is classified. The formula can, for example, generate a value expressing drying shrinkage as a percentage (%). Thus, an estimate of drying shrinkage can be output from step 340 (350). In general, the formulas given above are non-restrictive examples, and other methods in which density values ​​are combined with class parameters can similarly be applied to determine a value representing drying shrinkage. For clarity, it is important to emphasize that the estimation models, i.e., formulas, provided above are non-restrictive examples and may be modified as needed. For example, the estimation model applied to the calculation of drying shrinkage may depend on various parameters, such as a value representing the moisture content of the veneer sheet in question. For example, if the moisture content is below the saturation point of the wood fibers, it can be assumed that the shrinkage of the wood depends linearly on the type of wood and the change in the moisture content of the wood. Typically, during plywood delamination, the wood moisture content is above the saturation point, but in response to detection, the formula can be adjusted to receive a more accurate estimate of drying shrinkage based on several measurements received from the moisture measuring device 180, for example, that the moisture content of the plywood sheet falls below the saturation point of the plywood sheet. In other words, the estimate of drying shrinkage can be calculated, for example, by selecting an estimation model defined by a formula among several estimation models according to a value representing the moisture content of the plywood sheet. Alternatively or additionally, the results of the estimation models may be scaled by a scaling factor calculated based on a value obtainable from the moisture measuring device 180, such as a value that can be derived from at least one measurement representing moisture content. In some advanced solutions, a target drying moisture content may be set to apply a particular model representing shrinkage, i.e., a particular model is applied when the moisture content of the plywood sheet is detected to be between the target moisture content and the saturation moisture content. For example, in one embodiment, the result of the drying shrinkage estimation model, called pre-drying shrinkage, can be corrected by the following formula: Drying shrinkage (correction) = ((M1-2) / 32) *Drying shrinkage (preliminary) In the formula, M1 represents the average moisture content of the plywood, 2 is the target dry moisture content of the model, and 32 is the saturation point for the tree species in question. In some embodiments, the constants 2 and 32, or one of them, can be replaced with parameters from data storage or from each class of plywood. For completeness, it is important to note that moisture values ​​may be derived from a single measurement, or they may represent values ​​calculated, for example, by using statistical analysis from multiple measurements.

[0054] Figure 4 schematically illustrates a further embodiment for generating an estimate of the drying shrinkage of a veneer sheet 135 in an exemplary embodiment, where other data representing the properties of the veneer sheet 135 are obtained from multiple sources. In a non-limiting example, sources include a moisture measuring device 180 that generates measured values ​​M1, M2, M3, ..., an image capture device 170 that generates measured values ​​V1, V2, V3, ..., a peeling device 120 that generates and provides measured and / or constituent values ​​L1, L2, L3, ..., and a data storage 190 that generates and provides values ​​DS1, DS2, DS3, ... representing the properties of the raw materials of the veneer sheet 135, for example. Inputs from multiple sources 320 are fed into a classification function 410 configured to apply a predetermined plan (i.e., a classification model) defined by one or more predetermined rules on the inputs, thereby allowing the veneer sheet 135 in question to be classified into one of the classes (classes shown in 330 in Figure 4) according to the input values. As already described in the explanation of Figure 3, the internal parameters (X1a, Y1a, Z1a, ...; X2a, Y2a, Z2a, ...; X3a, Y3a, Z3a, ...) may be defined for class 330 and may be applied in step 340 along with one or more properties representing density 310 when generating an estimate or multiple estimates of drying shrinkage that are finally output from process 350.

[0055] For completeness, the classification function 410 may be configured to operate by monitoring one or more predetermined rules that may correspond to one or more parameters representing the plywood sheet 135, and based on those parameters, the plywood sheet 135 can be classified into a specific class. For example, in some embodiments, the classification function 410 may compare data from multiple sources 320 one by one with predetermined limits for each class, reducing the number of classes until only one class remains. The parameters for that class can then be used in step 340.

[0056] In some exemplary embodiments, at least one piece of information regarding moisture content may also be taken into account in generating the drying estimate in step 340. For example, average moisture content, shown as M1, may be input into the formula for generating the drying shrinkage estimate, as shown in the preceding description, in order to improve the accuracy of the estimate. Such an input is shown in Figure 4 by reference no. 420. For clarity, it is important to mention that the input is optional and may only be valid in some exemplary embodiments of the invention, such as situations where the preliminary estimate of drying shrinkage is corrected by a coefficient that depends on the moisture content of the veneer sheet, as proposed in the formula in the preceding description.

[0057] According to one embodiment, the classification function 410 may be manually defined by an operator, such as a system commissioning engineer, based on a large amount of data collected from the system or a similar system. In some examples, defining or tuning the classification function 410 may be configured as a computer implementation task, for example, by utilizing artificial intelligence for the task. For example, a neural network may be trained to perform the tuning task by providing several parameters used for classification, namely input data defining the properties of the plywood sheet 135, and data defining the actual shrinkage of the plywood sheet after drying.

[0058] Furthermore, according to one embodiment, the parameters of class 330 may be manually defined by an operator, such as a commissioning engineer, based on a large amount of data collected from the system or a similar system. In some examples, tuning the class 330 parameters is configured as a computer implementation task, for example, by utilizing artificial intelligence for the task. In other words, for example, a neural network may be trained to perform the tuning task by providing several parameters used for classification, namely input data defining the properties of the veneer sheet 135 and data defining the actual shrinkage of the veneer sheet after drying.

[0059] In general, tuning, or adjusting, the model, including the parameters of the classification function 410 and the shrinkage calculation parameters of class 330, can be favorably achieved so that it works in a way that allows it to find such properties from the data, thereby resulting in a better correlation between the classification and the properties representing actual drying shrinkage and density than the entire dataset.

[0060] For completeness, as a non-restrictive example, it is important to note that the mathematical method of the classification function 410 may be a multidimensional array into which measured values ​​and possibly other values ​​can be input, which can produce the best class among several classes as output.

[0061] As described above, the apparatus 150 can be configured to determine one or more estimates of the drying shrinkage of the veneer sheet. According to an exemplary embodiment, one or more estimates may be used as parameters to control the cutting of the veneer ribbon 130 into individual veneer sheets 135. For example, the apparatus 150 may be configured to generate a control signal to the cutting device 140 to perform a cut such that the individual veneer sheet 135 is cut longer than the planned size of the final product, taking into account the shrinkage of the veneer sheet 135 during drying. In some exemplary embodiments, where multiple estimates are generated and a more advanced understanding of the behavior of the veneer sheet 135 is derived, such as when it can be assumed that the shrinkage is not uniform over the length of the veneer sheet 135, the cutting device 140 may be controlled to perform a cut according to a predetermined shape. For example, the cut may be performed diagonally to the length of the veneer sheet 135 to account for or to offset uneven shrinkage in the same direction.

[0062] According to an exemplary embodiment, the solution for generating estimates and ultimately generating a control signal to the cutting device 140 can be performed individually and favorably for each veneer sheet 135, i.e., the width of the veneer sheet 135 is determined before cutting the veneer sheet 135 from the veneer ribbon, such that the characteristics of the portion to be cut are taken into consideration, as described in order to estimate the drying shrinkage of each portion of the veneer ribbon in order to cut a veneer sheet 135 having the optimal width. In other words, data is obtained from all measuring devices before cutting so that estimates are generated and thereby taken into consideration the determination of the cutting position. Thus, the portion of the veneer ribbon on which the analysis is performed changes continuously, resulting in various cutting widths of the veneer sheet 135 according to the drying shrinkage estimates for each portion.

[0063] For example, apparatus 150 may refer to a computing device schematically shown in Figure 5. Figure 5 schematically shows a non-limiting example of apparatus 150 applicable to performing the method as a block diagram. The block diagram of Figure 5 shows some components of a device that may be used to implement the operation of apparatus 150. This apparatus comprises a processor 510 and memory 520. Memory 520 can store data and computer program code 525. This apparatus may further comprise communication means 530 for wired and / or wireless communication with other entities such as other systems and / or devices forming the above entities and analogous. Furthermore, I / O (input / output) components 540 may be configured together with parts of the processor 510 and computer program code 525 to provide a user interface for receiving input from a user of the system and / or providing output to the user, as needed. In particular, user I / O components may include user input means such as one or more keys or buttons, a keyboard, a touchscreen or touchpad. User I / O components may include output means such as a display or touchscreen. The components of the device can be coupled together in a way that allows them to communicate with each other via a bus 550 that enables the transfer of data and control information between the components.

[0064] Memory 520 and a portion of the computer program code 525 stored therein may be further configured with a processor 510 to cause a device to perform the methods described below. The processor 510 may be configured to read from and write to memory 520. Although each processor 510 is shown as a single component, each may be implemented as one or more separate processing components. Similarly, although each memory 520 is shown as a single component, each may be implemented as one or more separate components, some or all of which may be integrated / removable, and / or may provide permanent / semi-permanent / dynamic / cached storage.

[0065] The computer program code 525 may include computer executable instructions that, when loaded into the processor 510, implement functions corresponding to the steps of the method. For example, the computer program code 525 may include a computer program consisting of one or more sequences of one or more instructions. The processor 510 can load and execute the computer program by reading one or more sequences of one or more instructions contained therein from the memory 520. One or more sequences of one or more instructions may, when executed by the processor 510, cause the apparatus to execute the described method. Thus, the apparatus may comprise at least one processor 510 and at least one memory 520 containing computer program code 525 for one or more programs, and the at least one memory 520 and the computer program code 525, together with the at least one processor 510, are configured to cause the apparatus to execute a method for generating an estimate of the drying shrinkage of a veneer sheet.

[0066] The computer program code 525 may be provided as a computer program product including, for example, at least one computer-readable non-temporary medium having the stored computer program code 525, which, when executed by the processor 510, causes the device to execute a method. The computer-readable non-temporary medium may include a memory device or recording medium, for example, a CD-ROM, DVD, Blu-ray disc, or another product that explicitly embodies the computer program. In another example, the computer program may be provided as a signal configured to reliably transfer the computer program.

[0067] Furthermore, the computer program code 525 may include its own applications, such as computer program code for generating an estimate of the drying shrinkage of the veneer sheet, as described herein.

[0068] Any of the programmed functions mentioned can also be performed by firmware or hardware adapted or programmed to perform the required task.

[0069] Furthermore, as described above, the functionality of the device can be shared among multiple devices as a distributed computing environment. For example, a distributed computing environment can comprise multiple devices configured to cooperate with each other in a predetermined manner to implement a method, as schematically shown in Figure 5. For example, each device can be configured to perform one or more method steps and, in response to the completion of its dedicated step, can hand over the continuation of the process to the next device.

[0070] Some aspects of the present invention may relate to a method for generating an estimate of the drying shrinkage of a veneer sheet 135. An example of such a method according to an exemplary embodiment, in which the method may be performed by apparatus 150, is schematically shown in Figure 6. The method may include a step 610 of receiving data from a density measuring device 160, the data received from the density measuring device 160 representing the density of the veneer sheet 135. Furthermore, the method may include a step 620 of receiving data from at least one other entity, the data received from at least one other entity representing at least one property of the veneer sheet 135. The steps of receiving the data pieces mentioned may be performed at least partially simultaneously or sequentially with respect to each other. Receiving the data may include retrieving the data from the respective measuring device or data storage that stores the data. In response to receiving the data, the method may include a step of generating an estimate of the drying shrinkage of the veneer sheet 135 based on the received data. For example, the generation of a drying shrinkage estimate may include a substep of applying a classification function to data representing at least one characteristic of the veneer sheet 135 in order to classify the veneer sheet 135 into one of several classes according to data representing at least one characteristic of the veneer sheet 135. Furthermore, in this method, the apparatus may have access to one or more internal parameters defined individually for each class, and one or more internal parameters may be combined with data received from the density measuring device 160 to generate a drying shrinkage estimate of the veneer sheet 135. Moreover, this method may include combining one or more internal parameters and the data received from the density measuring device 160 by using the internal parameters of the class as constants in the equations and using the data from the density measuring device as parameters in each equation. Furthermore, this method may include combining results from two or more equations by summing them up in order to achieve a more accurate estimate of the drying shrinkage of the veneer sheet 135.According to an exemplary embodiment, the method may further include the step of generating a control signal for a cutting device 140 according to an estimate of the drying shrinkage of the veneer sheet 135 to cause the veneer sheet 135 to be cut from the veneer ribbon 130. Further embodiments of the method may be described in the preceding description.

[0071] The solution described above and defined in the attached claims offers several advantages compared to prior art solutions. Specifically, applying the described solution reduces the variation in the width of dried veneer sheets, thereby enabling the cutting of narrower veneer sheets than conventional methods. Furthermore, the width of dried veneer sheets can be estimated in an improved manner, resulting in a lower production of wider veneer sheets and thus improving the yield of raw materials. Moreover, the classification of veneer sheets in the described procedure improves the quality of the raw composite sheets and reduces sheet breakage during drying, because the sheets are classified according to their properties to achieve common behavior during shrinkage. The drying process can also be adjusted and adapted according to the raw materials, as properties that improve the process outcome are known and / or valued. Overall, for example, with respect to product strength, product quality is at least partially achieved as a result of a more accurate drying process.

[0072] The specific examples provided in the above description should not be construed as limiting the applicability and / or interpretation of the attached claims. The list and group of examples provided in the above description is not exhaustive unless otherwise specified.

Claims

1. A system for generating an estimated value of the drying shrinkage of a plywood sheet (135), A density measuring device (160) for generating data representing the density of the plywood sheet (135), Suitable for generating data representing at least one property of the veneer sheet (135), and comprising at least one other entity which is at least one of a peeling device (120), an image capture device (170), a moisture measuring device (180), a data storage (190) for storing data representing the properties of the raw material, and a data storage (190) for storing data representing the properties predicted after a predetermined stage of the manufacturing process, An apparatus (150) for receiving data from the density measuring device (160) and for receiving data from the at least one other entity, configured to generate an estimate of the drying shrinkage of the veneer sheet (135) based on the received data, and configured to apply a classification function to the data representing at least one characteristic of the veneer sheet (135) in order to classify the veneer sheet (135) into one of a plurality of classes according to data representing at least one characteristic of the veneer sheet (135), and A system equipped with these features.

2. The system according to claim 1, wherein the apparatus (150) of the system is configured to access one or more internal parameters defined individually for each of the classes, the one or more internal parameters being combined with data received from the density measuring device (160) to generate the estimated drying shrinkage of the veneer sheet (135).

3. The system according to claim 2, wherein the apparatus (150) of the system is configured to combine one or more internal parameters with data received from the density measuring device (160) by using the internal parameters of the class as constants of the formulas and using the respective values ​​representing the density characteristics of the plywood sheet (135) as parameters of the respective formulas.

4. The system according to any one of claims 1 to 3, wherein the measurement by one of the density measuring device (160), the image capture device (170), and the moisture measuring device (180) is performed on the veneer ribbon (130) before the veneer sheet (135) is cut from the veneer ribbon (130).

5. The system according to claim 4, wherein the apparatus (150) of the system defines at least one veneer sheet (135) that can be produced from the veneer ribbon (130), and the measurement is performed on the veneer ribbon (130) by generating a plurality of measurements for the at least one veneer sheet (135) using at least one of the density measuring device (160), the image capture device (170), and the moisture measuring device (180).

6. The system according to any one of claims 1 to 5, wherein the apparatus (150) of the system is configured to select one estimation model from a plurality of estimation models in order to estimate the drying shrinkage according to a value representing the moisture content of the plywood sheet (135).

7. The system according to any one of claims 1 to 6, wherein the apparatus (150) of the system is configured to generate an estimate of the drying shrinkage of the plywood sheet (135) by scaling a value representing pre-drying shrinkage using a value that can be derived from at least one measured value representing moisture.

8. The system according to any one of claims 1 to 7, wherein the apparatus (150) of the system is configured to generate a control signal to a cutting device (140) according to the estimated value of the drying shrinkage of the veneer sheet (135) to cause the veneer ribbon (130) to cut the veneer sheet (135).

9. An apparatus (150) for generating an estimated value of the drying shrinkage of a plywood sheet (135), wherein the apparatus (150) At least one processor (510), A memory (520) containing computer program code (525) and Equipped with, The at least one memory (520) and the computer program code (525), together with the at least one processor (510), are in the device (150). Data is received from a density measuring device (160), the data received from the density measuring device (160) represents the density of the veneer sheet (135), data is received from at least one other entity, the data received from at least one other entity represents at least one property of the veneer sheet (135), the at least one other entity being at least one of a peeling device (120), an image capture device (170), a moisture measuring device (180), a data storage (190) that stores data representing the properties of the raw material, and a data storage (190) that stores data representing the properties predicted after a predetermined stage of the manufacturing process. The system is configured to generate an estimate of the drying shrinkage of the plywood sheet (135) based on the received data, and to apply a classification function to the data representing at least one characteristic of the plywood sheet (135) in order to classify the plywood sheet (135) into one of a plurality of classes according to the data representing at least one characteristic of the plywood sheet (135). Apparatus (150).

10. The apparatus (150) according to claim 9, wherein the apparatus (150) accesses one or more internal parameters defined individually for each of the classes, and the one or more internal parameters are combined with data received from the density measuring device (160) to generate the estimated value of the drying shrinkage of the veneer sheet (135).

11. The apparatus (150) according to claim 10, wherein the apparatus (150) combines one or more internal parameters with data received from the density measuring device (160) by using an internal parameter of a class as a constant of the formula and using a value representing the density characteristics of the plywood sheet (135) as a parameter of the respective formula.

12. The apparatus (150) according to any one of claims 9 to 11, wherein the apparatus (150) selects one estimation model from a plurality of estimation models to estimate the drying shrinkage according to a value representing the moisture content of the plywood sheet (135).

13. The apparatus (150) according to any one of claims 9 to 12, wherein the apparatus (150) generates an estimate of the drying shrinkage of the plywood sheet (135) by scaling a value representing pre-drying shrinkage using a value that can be derived from at least one measured value representing moisture.

14. The apparatus (150) according to any one of claims 9 to 13, wherein the apparatus (150) further generates a control signal to the cutting device (140) according to the estimated value of the drying shrinkage of the veneer sheet (135) to cause the veneer ribbon (130) to cut the veneer sheet (135).

15. A method for generating an estimated value of the drying shrinkage of a plywood sheet (135), wherein the method is performed by an apparatus (150), A step of receiving data from a density measuring device (160), wherein the data received from the density measuring device (160) represents the density of the veneer sheet (135); and a step of receiving data from at least one other entity, wherein the data received from the at least one other entity represents at least one characteristic of the veneer sheet (135), wherein the at least one other entity is at least one of a peeling device (120), an image capture device (170), a moisture measuring device (180), a data storage (190) that stores data representing the characteristics of the raw material, and a data storage (190) that stores data representing the characteristics predicted after a predetermined stage of the manufacturing process; The steps include generating an estimated value of the drying shrinkage of the plywood sheet (135) based on the received data, The steps of applying a classification function to data representing at least one characteristic of the plywood sheet (135) in order to classify the plywood sheet (135) into one of a plurality of classes according to data representing at least one characteristic of the plywood sheet (135), and Methods that include...

16. The method according to claim 15, wherein one or more internal parameters defined individually for each of the classes are accessed, and the one or more internal parameters are combined with data received from the density measuring device (160) to generate the estimated value of the drying shrinkage of the veneer sheet (135).

17. The method according to claim 16, wherein one or more internal parameters are combined with data received from the density measuring device (160) by using the internal parameters of the class as constants in the formulas and using the respective values ​​representing the density characteristics of the plywood sheet (135) as parameters in the formulas.

18. The method according to any one of claims 15 to 17, wherein an estimation model is selected from a plurality of estimation models to estimate the drying shrinkage according to a value representing the moisture content of the plywood sheet (135).

19. The method according to any one of claims 15 to 18, wherein the generation of the estimated drying shrinkage of the plywood sheet (135) is performed by scaling a value representing pre-drying shrinkage using a value that can be derived from at least one measured value representing moisture content.

20. The method according to any one of claims 15 to 19, further comprising the step of generating a control signal for a cutting device (140) according to the estimated value of the drying shrinkage of the veneer sheet (135) to cause the veneer ribbon (130) to cut the veneer sheet (135).

21. A computer program product for generating an estimate of the drying shrinkage of a plywood sheet (135), wherein when the computer program product is executed by at least one processor, the apparatus (150) A computer program product that causes a computer to perform the method described in any one of claims 15 to 20.

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