Method for determining a peeling program and control system of a peeling system and computer program

Abstract

A method for determining a peeling program for a block (100, 200) to be peeled with a peeling system comprising at least two lathes (110, 210) is provided, wherein the block (100) is first peeled with a first lathe (110) and a remaining portion of the block (200) is peeled with the second lathe (210), the method comprises: determining (410) data descriptive of a size of the remaining portion of the block (200); and generating (420), in accordance with the data descriptive of a size of the remaining portion of the block (200), a peeling program for the block (100, 200) to peel the block (100, 200) with the first lathe (110) and the second lathe (210) Also, a control system (600), a computer program and a peeling system are provided to.

Description

[0001] CONTROL OF PEELING OF A BLOCK

[0002] TECHNICAL FIELD

[0003] The invention concerns in general the technical field of manufacturing wood products. More particularly, the invention concerns controlling of a peeling of logs.

[0004] BACKGROUND

[0005] Plywood production is a multi-stage process that shall operate seamlessly in order to generate high yield from the raw material. The plywood is manufactured by glueing together veneer sheets on top of each other and finalizing the structure in various manners. The manufacturing process of the veneer sheets, or veneers in short, starts from log handling continuing with veneer peeling to generate a veneer ribbon from blocks cut from the logs. The veneer ribbon is clipped to veneer sheets having desired size(s). In response to that the veneer sheets are dried and patched when necessary. The clipping phase also generates portions not matching the desired size(s) of the veneer sheets and those may be scarf-jointed and / or composed together to form further veneer sheets. As a result, only a minor portion of the veneer ribbon end up to a waste.

[0006] The peeling stage consists of various sub-operations, such as block centering for peeling, roundup and the peeling itself. The peeling itself may be conducted with one or more lathes. In peeling lines equipped with two or more lathes a typical approach is that a first lathe is a spindleless roundup lathe for rounding up the received blocks it prepares the block to a second spindleless veneer lathe that is configured to peel the veneer ribbon. In other words, the typical known solutions are operated so that the first lathe is arranged to perform the rounding up of the block whereas the second lathe is arranged to continue with the roundup block, or core, to generate the desired veneer ribbon. The second lathe is arranged to perform peeling until a predefined diameter of the block is reached. In view of the known arrangement the second lathe is typically more powerful than the first lathe due to that its operation is longer in duration and in order to achieve efficiency in the production line, the peeling shall be performed as fast as possible.

[0007] Further, various characteristics of the blocks need to be taken into account in order to avoid a breakage of the lathe(s). For example, traditionally dry duramen of the block is taken into account e.g. by reducing the peeling speed in order to prevent damaging of the knife of the main lathe. This reduces a capacity of the main lathe that is typically very expensive system. On the other hand, an engagement of the block by applying the small inner spindles of the lathe may also cause problems especially when peeling a soft inner portion of the block even having knots. This is because the inner spindles may loose the contact at the end of the block due to its softness and as a result the block starts to spin leading to a situation that the peeling of the block cannot be completed with the lathe having the spindles. Thus, the remaining block becomes waste and the yield is reduced. Hence, the use of the inner spindles in accordance with the known approaches is not always an optimal approach.

[0008] Hence, there is a possibility to improve an operation of a peeling stage comprising at least two lathes and, thus, to increase yield in the plywood production.

[0009] SUMMARY

[0010] The following presents a simplified summary in order to provide basic understanding of some aspects of various invention embodiments. The summary is not an extensive overview of the invention. It is neither intended to identify key or critical elements of the invention nor to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of exemplifying embodiments of the invention.

[0011] An object of the invention is to present a method, a control system, a computer program and a peeling system for determining a peeling program for a block. The objects of the invention are reached by a method, a control system, a computer program and a peeling system as defined by the respective independent claims.

[0012] According to a first aspect, a method for determining a peeling program for a block to be peeled with a peeling system comprising at least two lathes is provided, wherein the block is first peeled with a first lathe and a remaining portion of the block after peeled with the first lathe is peeled with the second lathe, the method, performed by a control system, comprises: determining data descriptive of a size of the remaining portion of the block, the data is determined by requiring that a number of veneer sheets having predefined sizes is obtainable from a veneer ribbon peelable from the remaining portion of the block, generating, in accordance with the data descriptive of a size of the remaining portion of the block, a peeling program for the block to peel the block with the first lathe and the second lathe.

[0013] The size of the remaining portion of the block may be defined at least by means of a diameter of the remaining portion of the block at which the peeling is initiated with the second lathe. For example, the size of the remaining portion of the block may further be defined by means of a diameter of a core to be left from the remaining portion of the block after peeling with the second lathe.

[0014] The method may also comprise, prior to determining the data descriptive of the size of the remaining portion of the block, a step of: receiving data at least descriptive of a number of physical characteristics of the block.

[0015] The data descriptive of the physical characteristics of the block may e.g. comprise data indicative of a moisture distribution of the block over a volume of the block. Moreover, the diameter of the remaining portion of the block may be defined to correspond to a diameter at which the moisture distribution over the volume of the block in the remaining portion of the log is below a moisture reference level. Generally speaking, the data descriptive of the physical characteristics of the block may comprise data indicative of a density distribution of the block over the volume of the block. Hence, the diameter of the remaining portion of the block may be defined to correspond to a diameter at which the density distribution over the volume of the block in the remaining portion of the block meets at least one density reference value.

[0016] The generation of the peeling program may at least comprise defining an operating speed of the first lathe and the second lathe.

[0017] For example, the determination of the size of the remaining portion of the block may comprise a definition of at least one waste portion in the veneer ribbon peelable from the remaining portion of the block.

[0018] The peeling system may further comprise a third lathe arranged to operate prior to the first lathe and the second lathe, the method further comprises: generating a peeling program to the third lathe for performing a rounding up operation to a raw block received in the peeling system to generate the block for the first lathe.

[0019] According to a second aspect, a control system of a peeling system for determining a peeling program for a block to be peeled with the peeling system comprising at least two lathes is provided, wherein the block is first peeled with a first lathe and a remaining portion of the block after peeled with the first lathe is peeled with the second lathe, the control system is configured to carry out the method according to the first aspect as defined above.

[0020] According to a third aspect, a computer program is provided, the computer program comprising instructions, when the program is executed by a control system according to the second aspect as defined above, cause the computer to carry out the method according to the first aspect as defined above. According to a fourth aspect, a peeling system is provided, the peeling system comprising: a first lathe, a second lathe, and the control system according to the second aspect as defined above.

[0021] Further, the peeling system may further comprise: a round-up lathe for pre-processing of a raw block for the first lathe.

[0022] The expression "a number of” refers herein to any positive integer starting from one, e.g. to one, two, or three.

[0023] The expression "a plurality of” refers herein to any positive integer starting from two, e.g. to two, three, or four.

[0024] Various exemplifying and non-limiting embodiments of the invention both as to constructions and to methods of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplifying and non-limiting embodiments when read in connection with the accompanying drawings.

[0025] The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of unrecited features. The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of “a” or “an”, i.e. a singular form, throughout this document does not exclude a plurality.

[0026] BRIEF DESCRIPTION OF FIGURES

[0027] The embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

[0028] Figure 1 illustrates schematically a peeling process according to an example. Figure 2 illustrates schematically a method according to an example.

[0029] Figure 3 illustrates schematically a veneer ribbon according to an example.

[0030] Figure 4 illustrates schematically a veneer ribbon according to another example.

[0031] Figure 5 illustrates schematically a peeling process according to another example.

[0032] Figure 6 illustrates schematically an apparatus according to an example.

[0033] DESCRIPTION OF THE EXEMPLIFYING EMBODIMENTS

[0034] The specific examples provided in the description given below should not be construed as limiting the scope and / or the applicability of the appended claims. Lists and groups of examples provided in the description given below are not exhaustive unless otherwise explicitly stated.

[0035] Figure 1 illustrates schematically various phases of peeling in accordance with an embodiment of the present invention. The embodiment depicted in Figure 1 consists of two lathes 110, 210. The operation of the peeling system is that first a block 100, also called as a first block 100, is brought to a first lathe 110. The block 100 originates from a log cut therefrom and the log and / or alternatively the block 100, may be pre-processed in some manner. Typically, the log is at least conditioned wherein the log material is softened with water or steam in order to make it more suitable for processing, such as for peeling. Additionally, the block 100 is rounded up so that the first lathe 110 may start generating veneer ribbon from the block 100 rounded up from the original raw block cut from the log in a manner as described in the forthcoming description. The round-up of the raw block may be performed with a specific roundup lathe prior to bringing the block 100 to the first lathe 110 or the round-up may be performed with the first lathe 110 with a specific round-up program to the block 100. Advantageously, the first lathe 110 is a spindle lathe, i.e. it comprises spindles (the spindle 115 in one side of the respective lathe 110 is illustrated in Figure 1 ) for handling and rotating the block 100 during the peeling. For avoidance of doubt, it is worthwhile to mention that the first lathe 110 may also be a spindleless lathe in at least some implementations of the invention. The peeling of the block 100 with the first lathe 110 generates a first veneer ribbon 120. For sake of completeness, the diameter of the first block 100 prepared for peeling with the first lathe 110 is denoted with di in Figure 1 .

[0036] As described, during the peeling process the first lathe 110 is configured to peel the block 100 to a stage defined in accordance with the present invention as is described in the forthcoming description. In response to that the original diameter di of the block 100 reaches a target diameter denoted with d2 the remaining portion of the block called as a second block denoted with 200 in Figure 1 is transported to the second lathe 210 for processing, i.e. for peeling. The transport of the second block 200 between the lathes 110, 210 may be performed by applying techniques according to prior art. For example, the transport of the second block 200, i.e. the remaining portion of the first block 100, may be performed by guiding the second block 200 to a conveyor device that is configured to transport the block to the second lathe 210. Another example of transporting the remaining block 200 from the first lathe 110 to the second lathe 210 may be by applying controllable arms to grip the remaining portion of the block in the first lathe 110 and transporting the second block 200 to the second lathe 210. In accordance with at least some embodiments of the invention, the second lathe 210 is a spindleless lathe. Again, the second lathe 210 is controlled to perform the peeling and to generate a second veneer ribbon 220. The second lathe 210 is controlled so that it performs the peeling until the block reaches a predefined diameter ds as shown in Figure 1 . Upon reaching the diameter ds the peeling is discontinued with the second lathe 210 and a core 300, also called as a waste core, is removed from the respective lathe 210. Generally speaking, the lathes 110, 210 are controllable from a control system wherein the control system shall be understood as a common control system for both the lathes 110, 210 or as dedicated control systems to each lathe 110, 210. In the latter case the dedicated control systems may receive control from a separate control system, such as a master control system. It may also be arranged that one of the dedicated control systems of the lathes may be assigned with the role of the master control system to the other dedicated control systems of the lathes.

[0037] In accordance with the present invention the control of the lathes 110, 210 shall be understood as an operation by means of which a peeling program at least for a first block 100 and for a second block 200 is determined. The determination of the peeling program may comprise a determination of a number of parameters by means of which the lathes 110, 210 are achieved to operate in a desired manner and their mutual involvement in the peeling is optimized. In other words, in accordance with at least some embodiments at least part of the peeling program may be provided to lathes 110, 210 e.g. by providing the number of determined parameters as an input to the lathe(s) 110, 210 to cause the respective lathe 110, 210 to operate in a desired manner. It may also be arranged that the determination of the peeling program is implemented so that a comprehensive peeling program, or lathe-specific peeling programs, defined by one or more computer programs having operational parameters applied in the peeling program is generated and the computer program(s) is delivered to the respective lathe(s) 110, 210. The peeling program, or at least part of it, may be provided to the lathes 110, 210 with one or more control signals, i.e. the peeling program, or at least part of it, may be transmitted to the lathes 110, 210 by using applied communication channels between the entities. This may e.g. refer to internal communication channel or external communication channel, or any combination of these. The peeling program may comprise, e.g. as the parameter(s) or as the comprehensive computer program(s), definitions with respect to one or more of the following: a peeling speed (cf. rotation speed), a duration of peeling, knife gap and pitch angle, and so on. The peeling program are advantageously such that lengths of the veneer ribbons generated by the lathes 110, 210 may be controlled in a manner as described herein.

[0038] Next, at least some aspects are described by referring to Figure 2 schematically illustrating a method according to at least one embodiment of the invention wherein the method is implemented by a control system. For example, the control system may be implemented in one of the manners as described in the foregoing description. The method illustrated in Figure 2 defines a way to determine a peeling program for the peeling system comprising a first lathe 110 and a second lathe 210 wherein the peeling program is executable in the peeling system by the first lathe 110 and the second lathe 210. In other words, the peeling program defines at least in part how the first lathe 110 and the second lathe 210 shall operate during the peeling. In the method according to the embodiment as schematically illustrated in Figure 2 it is assumed, as a starting point, that the raw block, i.e. the raw material, is pre-processed and, thus, prepared for peeling to generate at least veneer ribbon. The pre-processing may at least comprise that the block, or even the log, is rounded up, but also that it is conditioned so that it is optimal for peeling. The control system may be provided with data that is at least descriptive of a number of characteristics of the object to be peeled, i.e. the block obtained from the log through the pre-processing wherein the preprocessing comprises at least the rounding up the block to generate an object for peeling with the first and the second lathes 110, 210. In other words, in accordance with at least some embodiments of the invention the peeling program is generated for the peeling system wherein the block is transferred from a processing of the block with the first lathe 110 to a processing of the remaining block (i.e. the remaining portion of the block after the peeling the original block with the first lathe 110) with the second lathe 210. The processing herein comprises at least peeling of the block under processing to veneer ribbons, i.e. a first veneer ribbon 120 is generated with the first lathe 110 and a second veneer ribbon 220 is generated with the second lathe 210. It is also clear that the control system by means of which the peeling program is determined comprises data descriptive of capabilities of the lathes 110, 210 and operational settings of the lathes 110, 210 which may be adjustable e.g. in accordance with the peeling program.

[0039] Reverting back to the method as schematically shown in Figure 2, in the step 410 the control system is configured to determine, computationally, data descriptive of a size of a remaining portion of the block 200, i.e. the portion of the original block 100 that is to be peeled with the second lathe 210 in response to peeling of the original block 100 with the first lathe 100. In accordance with the invention the data descriptive of the size of the remaining portion of the block 200 is determined by requiring that a number of veneer sheets having predefined sizes is obtainable, i.e. is to be obtained, from a veneer ribbon 220 peelable from the remaining portion of the block 200 with the second lathe 210. In other words, the size of the remaining portion of the block 200 may be defined by using information on the number of veneer sheets to be obtained during the peeling from the remaining portion of the block 200 with predefined settings of the peeling, such as a thickness of the veneer ribbon to be peeled, or the veneer sheets eventually cut from the veneer ribbon. Hence, the length of the veneer ribbon 220, i.e. the second veneer ribbon 220, peelable from the remaining portion of the block 200 may be determined and defined. In accordance with at least some embodiments of the invention the size of the remaining portion of the block 200 may be defined by means of a number of diameters of the object in question. In other words, the size may be defined by determining a diameter of the remaining portion of the block 200, cf. the diameter denoted with ds in Figure 1 , into which the remaining portion of the block 200 may be peeled with the second lathe 210 wherein the diameter ds defines the size of the waste core 300. The final diameter ds may e.g. be dependent on a capability of the second lathe 210 to perform the peeling, but also characteristics of a duramen of the block 200 may be taken into account. Now, as the final diameter ds is known, the step 410 of the method may be performed by matching computationally the number of veneer sheets having predefined size(s), i.e. the widths, into an imaginary veneer ribbon and, thus, it is possible to reach the diameter d2 the defines a starting point from the remaining portion of the block for peeling with the second lathe 210. The matching of the veneer sheets in the computational manner may also be arranged to take into account one operational aspects of the second lathe 210. The operational aspects especially refer to a so-called wedge portions that result when the peeling is initiated and completed. In other words, when the knife enters the block under peeling a portion of the veneer ribbon has a shape of a wedge due to that the knife is controlled to reach the position generating the veneer ribbon having a predefined thickness. The wedge portion is also generated when the peeling is coming to an end and the knife is instructed to move away from the peeling position. For sake of completeness it is worthwhile to mention that the wedge portions are known by size, cf. by width, and be a result of the driving settings of the second lathe 210, and its capabilities. As a result, the imaginary second veneer ribbon 220 computationally determined by the control system may correspond to one shown in Figure 3. In other words, as the diameter ds is determined as described, the end wedge portion WP having a width wwis taken as granted and then a first number of veneer sheets (denoted with S in Figure 3) are matched in the second veneer ribbon. The veneer sheets S has a predefined width w. For sake of clarity it is worthwhile to mention that the veneer sheets matched into the second veneer ribbon 220 may have the same size or differing sizes with respect to at least some others matched in the second veneer ribbon 220. Further, the second veneer ribbon 220 is computationally provided with the wedge portion WP in the beginning of the second veneer ribbon 220, i.e. generated when starting peeling from the diameter of the block denoted with d2. The widths wwof the wedge portions WP in the leading edge and in the trailing edge of the second veneer ribbon 220 are indicated to be the same, but for sake of clarity it is worthwhile to mention that it is not necessarily the case and the widths wwmay vary from each other e.g. due to different operational settings of the second lathe 220 when starting and ending the peeling operation with the second lathe 110.

[0040] In accordance with at least some further embodiments of the invention the size of the remaining portion of block 200 may be determined 410 by taking into account further aspects in the determination 410. The determination of the size, and the determination of the diameter d2, may be performed based on one or more requirements, or limitations, wherein some requirement(s) may be dependent on one or more characteristics of the peeling system whereas some requirement(s) may origin from one or more characteristics of the block, cf. physical characteristics, to be peeled. As it comes to the characteristics of the peeling system the diameter d2 may at least in part be dependent on a capability of the first lathe 110, i.e. if the first lathe 110 is such a type, e.g. a spindle lathe, that it has limitation(s) to peel the block until a predefined diameter is reached. For example, the size of the spindles, i.e. the diameter of them, may limit the diameter into which the peeling is possible with the first lathe 110. Moreover, some requirements in the determination of the diameter d2 may be dependent on at least one physical characteristic of the block 100 to be peeled with the first lathe 110, and eventually with the second lathe 210. In other words, the control system may be configured to computationally evaluate at least one characteristic of the block 100, 200, 300 to be peeled with the first and the second lathes 110, 210 so as to determine the diameter d2. According to at least some embodiments of the invention, the at least one physical characteristic of the block 100, 200, 300 may be at least one that is indicative of a moisture of the block over a volume of the block under peeling. In other words, a moisture distribution over the volume of the block 100 is evaluated to determine the diameter d2 at which the remaining portion of the block 200 is to be assigned from the first lathe 110 to the second lathe 210 for peeling. The data representing at least one characteristic indicative of the moisture distribution may be received, by the control system, from an analyzer configured to perform at least an analysis of the moisture distribution of the block 100 to be peeled. The analysis may be performed in a known manner and may also take into account information on a conditioning of the log during the pre-processing. In accordance with an embodiment according to the invention the diameter d2 is, based on the moisture distribution, determined to reside in a position at which the moisture in the inner block meets a predefined moisture reference level, such as being above or below a value or within a predefined range. This corresponds to a situation wherein the duramen of the block is dryer than the outer portion of the block. The selection of the diameter d2 in the described manner has an advantage that the drying phase at the later stage in the manufacturing process may be optimized due to that the sheets obtainable from the various veneer ribbons 120, 220 are more uniform at least in terms of the moisture. As mentioned, the data descriptive of the moisture distribution may be received from an analyzer and a quantity descriptive of the moisture may be a moisture value itself, but any other quantity may be applied to especially if it is indicative of the moisture distribution at a required accuracy.

[0041] In addition to above, it is worthwhile to mention that according to at least some other embodiments of the invention another physical characteristic of the block 100, 200, 300 may be at least one that is indicative of a density distribution of the block 100, 200, 300. Thus, the block 100, 200, 300 under processing is analyzed through a density analysis and the diameter d2 is selected based on the density distribution. The different types of characteristics to determine the diameter d2 may be utilized alone or in combination.

[0042] Alternatively or in addition to the application of the moisture distribution in the determination of the size of the remaining portion of the block 200, and especially the diameter d2 a density, or a density distribution, of the block 100, 200, 300 may be applied in a similar manner. In other words, the control system may receive data at least descriptive of a number of physical characteristics of the block 100, 200, as already mentioned, from a predefined source, such as from an applicable analyzer or a data storage and perform operations to determine the size of the remaining portion of the block 200 by taking into account the physical characteristics in the determination of the peeling program. Hence, the application of the density distribution may be performed in the same manner as the application of the moisture distribution, i.e. requiring that the density shall meet at least one predefined density reference value in the remaining portion of the block 200, such as being above or below a value or within a predefined range. As a result, the size of the remaining portion of the block 200 is determined e.g. through determining the diameter d2 accordingly. In some embodiments, the determination 410 of the size of the remaining portion of the block 200 may take into account a plurality of physical characteristics of the block 100, 200 in question, such as the moisture distribution and the density distribution among others.

[0043] In view of the above the size of the remaining portion of the block 200, e.g. through the diameter d2, is determined computationally so that the number of veneer sheets is obtainable from the block 200 in question so that also the at least one characteristic, such as the moisture and / or density, of the veneer sheets S, and, thus, the second veneer ribbon 220 corresponds to at least one reference value as described. The control system may advantageously be configured to operate so that it defines at least the second diameter so that it matches the number of veneer sheets to the size of the remaining portion of the block 200, i.e. with respect to the veneer ribbon obtainable from the remaining portion of the block 200 wherein the at least one characteristic meets the at least one reference value. In case the matching leaves a width fulfilling the one or more requirements to the physical characteristics into which a further veneer sheet cannot be matched, i.e. it does not fit there anymore, that width may be provided to the portion that is to be peeled with the first lathe 110, especially if the quality meets the requirements.

[0044] In response to the determination of the size of the remaining portion of the block 200 in one of the manners as described in the foregoing description, the control system is configured to generate 420 a peeling program for the block 100, 200 to peel the block 100, 200 with the first lathe 110 and the second lathe 210. The generation 420 of the peeling program comprises a generation of data that at least defines a number of parameters to control the first lathe 110 and the second lathe 210 to operate in a desired manner. The data expressed at least with the number of parameters define, in a predefined manner, portions of the block 100, 200 that are to be peeled with the first lathe 110 and with the second lathe 210. For example, the parameters may e.g. define the size of the remaining portion of the block 200 with the diameter d2 until which the peeling is to be performed with the first lathe 110, but the parameters may also define the size of the core 300 with the diameter ds until which the peeling is to be performed with the second lathe 210. In case the mentioned sizes are expressed by means of the mentioned diameters d2, ds the first and the second lathe 110, 210 are provided with means to continuously determine the diameter during the peeling with the respective lathe 110, 210 so as to determine an instant of time the responsibility of the peeling is transferred from the first lathe 110 to the second lathe 210. The parameters may also be expressed in another way than by means of the diameters. Namely, in case the operational parameters of the lathes are known, such as the operational speeds of them as well as thicknesses of the veneer ribbons 120, 220 peeled with the lathes 110, 210, the peeling of each lathe 110, 210 may be determined with parameters defining durations of the peelings in time for the lathes 110, 210. As mentioned in the foregoing description the data at least defining the number of parameters may be formed as a computer program and the generation 420 step as discussed generates a complete computer program as the peeling program. Thus, in response to the generation of the peeling program the generated data is provided to at least one entity, such as a control system, configured to control the operations of the lathes 110, 210 so that when the block 100 is input to the first lathe 110, the peeling operation in accordance with the peeling program may be executed. Worthwhile to mention is that the determination of the peeling program as described may comprise a generation of a control program to one or more conveyor devices that control a transport of the block 100, 200, 300 to and from the respective lathes 110, 210 in accordance with the process synchronized with the operations of the lathes 110, 210.

[0045] For sake of completeness, it is worth mentioning that the generation of the peeling program shall be understood as a process that generates a necessary amount of data for enabling operating the first and the second lathes 110, 210 in the manner as described herein. This may refer to a generation of a number of parameters applied by a control system, or control systems, operating the respective lathes 110, 210, or a generation of the peeling programs for the mentioned control system(s) for execution. The generated peeling program is provided to the respective entities through applied communication mechanisms, such as transmitting the peeling data, i.e. the program and / or parameters as defined, to the respective entities over the communication channel(s) applied thereto.

[0046] In addition to the above-described aspects in relation to the data defining the peeling program, also further aspects in relation to the peeling may be defined. Such aspects may be data, such as parameters, that define thicknesses of the veneer ribbons 120, 220 as well as the widths ww of the wedge portions WP both in the leading edge and the trailing edge of the respective veneer ribbons 120, 220. Moreover, information on the widths of the veneer sheets S, the widths Ww of the wedge portions WP as well as random piece(s) RP, if any, to be cut from the respective veneer ribbons 120, 220 is delivered to cutting device(s) so as to control the overall operation of the veneer production. Thus, in response to the determination of the peeling program with respect to the first and the second lathes 110, 210 the block 100 may be taken into peeling in accordance with the determined peeling program.

[0047] In relation to the peeling of the block 100 and in response to that the control system has determined the size of the remaining portion of the block 200 e.g. as a length of the second veneer ribbon 220 in the predefined manner the control system may perform an operation by computationally determining aspects relating to the peeling with the first lathe 110. This is possible since the control system is aware of the dimension d2 determined in the described manner, but also of the diameter di since the block 100 to be peeled is known and information on the characteristics of it is provided to the control system e.g. from the analyzer and / or from the pre-processing stage, such as from the entity performed, or evaluated, the rounding up process. Additionally, the operational settings of the first lathe 110 are also known, by the control system, which also comprise data descriptive of the wedge portions, such as widths of them. Thus, in accordance with an embodiment the control system may be configured to match a second number of veneer sheets S having predefined sizes, such as the same sizes or differing sizes at least in part into the first veneer ribbon 120 peelable from the block 100 starting from the first diameter di and ending to the second diameter d2. Figure 4 illustrates schematically an imaginary first veneer ribbon 120 computationally determined by the control system. In addition to the wedge portions WP and the second number of veneer sheets S the computational matching may generate so-called random portion RP which has a width that is left out from the length of the first veneer ribbon when the second number of veneer sheets S and the wedge portions WP in the first veneer ribbon 120 are taken into account. In some situations, it may even occur that no random piece RP is generated. In case the random portion is generated it may be, depending on its characteristics, used in composing of further sheets S from a plurality of random portions. Again, even if the widths wwof the wedge portions WP in the leading edge and in the trailing edge of the first veneer ribbon 120 are indicated to be the same, it is worthwhile to mention that it is not necessarily the case and the widths wwmay vary from each other e.g. due to different operational settings of the second lathe 220 when starting and ending the peeling operation with the first lathe 110. As mentioned, the matching of the veneer sheets to the veneer ribbon 110 peelable with the first lathe 110 may be performed by the control system generating the peeling program and the information also on the veneer sheets may be carried to further entities, such as to a cutting stage from the control system in question. Alternatively, the control system configured to perform the determination of the peeling program may only be configured to provide, as a parameter, a thickness of the veneer ribbon to be peeled with the first lathe 110 so that a desired veneer ribbon 110 may be generated with the first lathe 110 and a matching of the veneer sheets thereto is performed by another entity in the production line.

[0048] For avoidance of doubt, the lengths of the first and the second veneer ribbons 120, 220 obtainable from the respective block 100, 200 are also dependent on the thicknesses of the respective veneer ribbons 120, 220 and the thicknesses may be dependent on a desired production plan. In any case, the thickness value(s) is taken into account by the control system in the generation of the peeling program and it may be included as a parameter in the peeling program so as to be applied by the respective lathes 110, 210 at least in adjusting the knifes of the lathes 110, 210 for peeling. The thickness value may be individually defined to each lathe 110, 210. In some embodiments of the invention, the lathes 110, 210 are configured to perform peeling with a fixed thickness and in such a case the peeling program does not necessarily comprise a parameter descriptive of the thickness of the peeling. Generally speaking, the control of peeling with respect to the thickness of the veneer ribbon is performed by controlling a position of a number of knives of the respective lathe 110, 210, 510. Even if the enclosed Figures illustrate that the lathes 110, 210, 510 are provided with only one knife, typically the lathes 110, 210, 510 are provided with two knives that operate at different sides with respect to the veneer ribbon generated by peeling. The positions of the knife and a nose bar (cf. a counter-knife) are mutually adjusted so that the desired peeling effect is achieved. Moreover, the control of the knives is performed in different ways if the same lathe may be applied for rounding up the raw block and for peeling veneer ribbon out of the block 100, 200. In the former situation the nose bar is not involved at all to the procedure. As such the control of the lathes 110, 210, 510 during the peeling may be performed in a manner as is known from prior art solutions.

[0049] In some further embodiments of the invention, the peeling system may comprise a further lathe, called as a roundup lathe, that is positioned prior to the first lathe 110 in the production line of the peeling system as schematically illustrated in Figure 5. The task of the roundup lathe denoted with the reference 510 in Figure 5 is to perform pre-processing of a raw block, for the first lathe 110, and eventually for the second lathe 210. The pre-processing with the roundup lathe 510 at least refers to an operation by means of which the raw block is rounded up for peeling with the first lathe 110 as described in the foregoing description. Advantageously, the roundup lathe 510 is selected and controlled so that it operates efficiently and wood chips generated by peeling for the rounding up is good in quality for further use. The advantage of introducing the roundup lathe 510 in the peeling system is that it enables a preparation of the blocks optimal for the latter lathes 110, 210 and having the rounded up blocks in place for the first lathe 110 improves a centering of the block in the first lathe 110, and even in the second lathe 210.

[0050] Figure 6 illustrates schematically an example of an apparatus suitable for implementing the control system 600 as described. For sake of clarity, it is worthwhile to mention that the block diagram of Figure 6 depicts some components of an entity that may be employed to implement a functionality of the control system 600. The apparatus of Figure 6 comprises a processor 610 and a memory 620. The memory 620 may store data, such as pieces of data as described, but also computer program code 625 consisting of one or more software portions enabling the operation in the described manner. The apparatus may further comprise a communication interface 30, such as a wireless communication interface or a communication interface for wired communication, or both to communicate with other entities as described. The communication interface 630 may thus comprise one or more modems, antennas, and any other hardware and software for enabling an execution of the communication e.g. under control of the processor 610. Furthermore, I / O (input / output) components may be arranged, together with the processor 610 and a portion of the computer program code 625, to provide a user interface for receiving input from a user, such as from a technician, and / or providing output to the user of the apparatus when necessary. In particular, the I / O components may include user input means, such as one or more keys or buttons, a keyboard, a touchscreen, or a touchpad, etc. The I / O components may include output means, such as a loudspeaker, a display, or a touchscreen. The components of the apparatus may be communicatively connected to each other via data bus that enables transfer of data and control information between the components.

[0051] The memory 620 and at least a portion of the computer program code 625 stored therein may further be arranged, with the processor 610, to cause the apparatus to perform at least a portion of a method as is described herein. The processor 610 may be configured to read from and write to the memory 620. Although the processor 610 is depicted as a respective single component, it may be implemented as respective one or more separate processing components. Similarly, although the memory 620 is depicted as a respective single component, it may be implemented as respective one or more separate components, some, or all of which may be integrated I removable and I or may provide permanent / semi-permanent / dynamic / cached storage. The computer program code 625 may comprise computer-executable instructions that implement functions that correspond to steps implemented in the method when loaded into the processor 610 of the respective control system. As an example, the computer program code 625 may include a computer program consisting of one or more sequences of one or more instructions. The processor 610 is able to load and execute the computer program by reading the one or more sequences of one or more instructions included therein from the memory 620. The one or more sequences of one or more instructions may be configured to, when executed by the processor 610, cause the apparatus, such as a computer as the control system, to perform a method as described. Hence, the apparatus may comprise at least one processor 610 and at least one memory 620 including the computer program code 625 for one or more programs, the at least one memory 620 and the computer program code 625 configured to, with the at least one processor 610, cause the apparatus to be involved in performing the method.

[0052] The computer program code 625, or at least some portion of It, may be provided e.g. a computer program product comprising at least one computer- readable non-transitory medium having the computer program code 625 stored thereon, which computer program code 625, when executed by the processor 610 causes the apparatus to perform the method. The computer- readable non-transitory medium may comprise a memory device or a record medium, such as a CD-ROM, a DVD, a Blu-ray disc, or another article of manufacture that tangibly embodies the computer program. As another example, the computer program may be provided as a signal configured to reliably transfer the computer program.

[0053] Still further, the computer program code 625 may comprise a proprietary application, such as computer program code for causing an execution of the method in the manner as described in the description herein.

[0054] Any of the programmed functions mentioned may also be performed in firmware or hardware adapted to or programmed to perform the necessary tasks. For sake of completeness, it is worthwhile to mention that the entity performing the method in the role of the control system 600 may also be implemented with a plurality of apparatuses, such as the one schematically illustrated in Figure 6, as a distributed computing environment. For example, one of the apparatuses may be communicatively connected with the other apparatuses, and e.g. share the data of the method, to cause another apparatus to perform at least one other portion of the method. As a result, the method performed in the distributed computing environment generates the control signal indicative of the assignment of the responsibility as described. The functionalities of the control system as described may also be integrated to an entity also configured to perform other operations. For example, the different stages of the peeling system as e.g. schematically illustrated in Figures 1 and 5 may comprise their own control systems, whereas one of them, or a separate entity, may be a master device to perform the operation as described, i.e. generate the peeling program as described and deliver at least part of it to the respective entities, i.e. control systems of the lathes 110, 210, 510, for example.

[0055] In accordance with an implementation of the peeling system wherein the peeling system consists of a first lathe 110 being a spindle lathe and a second lathe 210 being a spindleless lathe the approach may be such that the core 300 left out as a waste portion from the second lathe 210 is aimed to have a diameter of 40 mm. The second lathe 210 may e.g. driven so that the speed of generating veneer ribbon is of 90 - 120 m / min, even up to 150 m / min. The first lathe 110, in turn, may be driven at the speed of 350 - 500 m / min and the diameter of the remaining portion of the block 200 is greater than 110 mm. The roundup of the raw block may be performed so that the roundup lathe 510, or the first lathe 110 during the roundup operation, is driven so that a rounding thickness is 8 mm. By applying such driving parameters and settings the peeling stage may be performed efficiently and the yield is optimized.

[0056] Generally speaking, the present invention has various advantages wherein the overall result is an improved yield and utilization rate both the raw material, but also the devices being involved in the peeling. Especially, because of the determination of the size of the remaining portion of the block 200 according to the invention, the size, i.e. the diameter, is larger compared to prior art solutions and this allows the drive of the first lathe 110 with higher speeds and the improved efficiency may at least in part gained through that. The specific examples provided in the description given above should not be construed as limiting the applicability and / or the interpretation of the appended claims. Lists and groups of examples provided in the description given above are not exhaustive unless otherwise explicitly stated.

Claims

WHAT IS CLAIMED IS:1 . A method for determining a peeling program for a block (100, 200) to be peeled with a peeling system comprising at least two lathes (110, 210), wherein the block (100) is first peeled with a first lathe (110) and a remaining portion of the block (200) after peeled with the first lathe (110) is peeled with the second lathe (210), the method, performed by a control system (600), comprises: determining (410) data descriptive of a size of the remaining portion of the block (200), the data is determined by requiring that a number of veneer sheets having predefined sizes is obtainable from a veneer ribbon (220) peelable from the remaining portion of the block (200), generating (420), in accordance with the data descriptive of a size of the remaining portion of the block (200), a peeling program for the block (100, 200) to peel the block (100, 200) with the first lathe (110) and the second lathe (210).

2. The method according to claim 1 , wherein the size of the remaining portion of the block (200) is defined at least by means of a diameter of the remaining portion of the block (200) at which the peeling is initiated with the second lathe (210).

3. The method according to claim 2, wherein the size of the remaining portion of the block (200) is further defined by means of a diameter of a core to be left from the remaining portion of the block (200) after peeling with the second lathe (210).

4. The method according to any of the preceding claims, the method comprises, prior to determining the data descriptive of the size of the remaining portion of the block (200), a step of: receiving data at least descriptive of a number of physical characteristics of the block (100, 200).

5. The method according to claim 4, wherein the data descriptive of the physical characteristics of the block (100, 200) comprises data indicative of a moisture distribution of the block (100, 200) over a volume of the block (100, 200).

6. The method according to claim 5, wherein the diameter of the remaining portion of the block (200) is defined to correspond to a diameter at which the moisture distribution over the volume of the block in the remaining portion of the log (200) is below a moisture reference level.

7. The method according to any of claims 4 to 6, wherein the data descriptive of the physical characteristics of the block (100, 200) comprises data indicative of a density distribution of the block (100, 200) over the volume of the block (100, 200).

8. The method according to claim 7, wherein the diameter of the remaining portion of the block (200) is defined to correspond to a diameter at which the density distribution over the volume of the block in the remaining portion of the block (200) meets at least one density reference value.

9. The method according to any of the preceding claims, wherein the generation of the peeling program at least comprises defining an operating speed of the first lathe (110) and the second lathe (210).

10. The method according to any of the preceding claims, wherein the determination of the size of the remaining portion of the block (200) comprises a definition of at least one waste portion in the veneer ribbon (220) peelable from the remaining portion of the block (200).11 . The method according to any or the preceding claims, the peeling system further comprising a round-up lathe (510) arranged to operate prior to the first lathe (110) and the second lathe (210), the method further comprises:generating a peeling program to the round-up lathe (510) for performing a rounding up operation to a raw block received in the peeling system to generate the block (100) for the first lathe (110).

12. A control system (600) of a peeling system for determining a peeling program for a block (100, 200) to be peeled with the peeling system comprising at least two lathes (110, 210), wherein the block (100) is first peeled with a first lathe (110) and a remaining portion of the block (200) after peeled with the first lathe (110) is peeled with the second lathe (210), the control system (600) is configured to carry out the method according to any of the claims 1 to 11 .

13. A computer program comprising instructions, when the program is executed by a control system (600) of claim 12, cause the computer to carry out the method according to claim 1 .

14. A peeling system comprising: a first lathe (110), a second lathe (210), and the control system according to claim 12.

15. The peeling system according to claim 14, wherein the peeling system further comprising: a round-up lathe (510) for pre-processing of a raw block (100, 200) for the first lathe (110).

Images