The object of the invention is a method for determining the volume of a pulp wood or timber stack, wherein in the first step of the method, the pulp wood or timber stack is taken to a measurement station comprising measuring instruments.

Methods for determining the volume of individual timbers applicable in chopping machines directly at the cutting site are previously known. These measurements are based on information received from measuring instruments arranged in the chop- ping machine, which information is obtained e.g. at the timber pruning step when the tree trunk is moved with the pruning means of the chopping machine. Further, methods intended for determining the volume of pulp wood or timber stacks stacked at the cutting site based at least partially on estimation are known, wherein the end results depend on the estimator, and are thus not accurate.

Further, volumes are measured in connection with individual pulp wood or timber logs, for example, in factories utilizing pulp wood or timber using various imaging methods. Such processes often involve time-consuming sorting of the pulp wood or timber instead of volume measurement performed at the factory (or at any equiva- lent plant).

Systems for determining the volume of pulp wood or timber stacks carried by pulp wood or timber trucks have also been developed. One such solution is implemented by Vi si systems Oy under the trade name Taljari, wherein a truck carrying a pulp wood or timber load drives past a measuring frame fitted with laser scanners for scanning the surface of the load, after which the calculated volume of the wood load is determined. However, this is designed for determining the volume of dense loads, such as wood chips, and is not suitable for direct and accurate measurement of the solid volume of a pulp wood or timber stack. This type of an arrangement is not suitable for measuring the volume of a pulp wood or timber stack separate from a vehicle, as the measurement is entirely dependent on the movement of the pulp wood or timber stack, i.e. the movement of the vehicle.

Nowadays, a commonly used method for measuring the volume of pulp wood or timber stacks, e.g. at the factory, is submersion measurement applying the Archimedes' principle, which is a method known to a person skilled in the art. Alt hough this method is relatively accurate per se, submersion measurement utilizes water, typically in an outdoor submersion pool, which renders measuring in winter conditions difficult or impossible. In addition, the submersion pool requires repeated maintenance because of the accumulation of dirt.

The purpose of the present invention is to provide a new method for determining the volume of a pulp wood or timber stack, which method is more accurate and reli able than previously known methods, and with which additional information relating to the measured pulp wood or timber stack can also be provided for the final pro duction site, such as the factory, even information on an individual pulp wood or timber log, for the purposes of further processing. One of the purposes of the in vention is thereby to provide a method replacing submersion measurement for measuring the volume, which method is reliable and accurate also in cold condi tions.

In order to achieve the above-mentioned purpose, the method of the present inven tion is characterized by comprising steps wherein: a) both ends of pulp wood or tim ber logs of a pulp wood or timber stack taken to a measurement station are illumi nated using lighting devices; b) the solid volume of the pulp wood or timber stack is determined using a measuring module comprising measuring instruments, the measuring module comprising: imaging devices arranged at each end of the pulp wood or timber stack for determining the diameter of each end of individual pulp wood or timber logs, and distance measuring devices arranged at each end of the pulp wood or timber stack for determining the lengths of individual pulp wood or timber logs of a pulp wood or timber stack and the proportion of empty space be tween them, and by c) calculating the solid volume of the pulp wood or timber stack on the basis of the information determined with the measuring instruments.

The present invention provides a simple and fast way for measuring the solid vol ume of a pulp wood or timber stack at the factory or at an equivalent production plant where pulp wood or timber is used as raw material. The present invention does not limit the measurement to be performed in a vehicle like many correspond ing prior art solutions do. The solution of the invention enables imaging of the pulp wood or timber stack to be measured using measuring instruments in optimal lighting conditions so that the proportion of empty space between the pulp wood or timber logs can be determined using the measuring instruments, and no calculated assumptions associated with the prior art are required. The optimal lighting condi tions also enable determining additional properties of an individual pulp wood or timber log according to a preferred embodiment of the invention.

Next, the invention is described in more detail by reference to the accompanying di agrammatic drawings, in which: Figure 1 shows a diagrammatic side view of a measurement station applying the method according to a preferred embodiment of the invention,

Figure 2 shows a top view of the measurement station according to figure 1, Figure 3 shows a pulp wood or timber stack viewed from the end thereof in the grapple of a material handler according to figure 1,

Figure 4 shows a diagrammatic side view of a measurement station applying the method according to another preferred embodiment of the inven tion, wherein the pulp wood or timber stack has been positioned in a cradle, and

Figure 5 shows a diagrammatic side view of a measurement station applying the method according to another preferred embodiment of the inven- tion, wherein the measuring instruments have been arranged on a movable mount.

Figures 1 and 2 thus present a preferred embodiment of the measurement station 1 applying the method according to the invention. The measurement station 1 herein includes a space into which the pulp wood or timber stack indicated by reference number 2 can be placed. The placement can be done using e.g. the grapple 6 of the material handler shown in figures 1 and 2 in such a manner that the individual pulp wood or timber logs 3 of the pulp wood or timber stack 2 are arranged parallel or at least essentially parallel to one another. Both ends of the pulp wood or timber stack 2 and the end surfaces 3a and 3b of individual pulp wood or timber logs 3 thereof are illuminated using lighting devices 4a and 5a. The lighting can be carried out using e.g. a necessary number of led and/or xenon lights, and/or to provide the lighting power required.

The measurement station applying the present method comprises a measuring module comprising imaging devices 4c and 5c arranged at each end of the pulp wood or timber stack 2. The first imaging device 4c has preferably been arranged in such a position in the above-mentioned space that it faces the first end of the pulp wood or timber stack 2 (and the end surfaces 3a of individual pulp wood or timber logs 3 thereof) from a distance. Correspondingly, the second imaging device 5c has preferably been arranged in such a position in the above-mentioned space on the opposite side of the pulp wood or timber stack 2 that it faces the second end of the pulp wood or timber stack 2 (and the second end surfaces 3b of individual pulp wood or timber logs 3 thereof) from a distance. The purpose of these at least two imaging devices 4c and 5c is to at least determine the diameter of each end 3a and 3b of individual pulp wood or timber logs 3. The imaging devices can be, but not limited to, for example, color line scan and/or color matrix cameras.

In addition, the measuring module comprises distance measuring devices 4b and 5b arranged at each end of the pulp wood or timber stack 2. The first distance measur ing device 4b has been arranged similarly to the first imaging device 4c preferably in such a position in the above-mentioned space that it faces the first end of the pulp wood or timber stack 2 (and the end surfaces 3a of individual pulp wood or timber logs 3 thereof) from a distance. Correspondingly, the second distance measuring device 5b has been arranged similarly to the second imaging device 5c preferably in such a position in the above-mentioned space on the opposite side of the pulp wood or timber stack 2 that it faces the second end of the pulp wood or timber stack 2 (and the second end surfaces 3b of individual pulp wood or timber logs 3 thereof) from a distance. The purpose of these at least two distance measuring devices 4b and 5b is to determine the lengths of individual pulp wood or timber logs 3 of a pulp wood or timber stack 2. Further, the purpose of the distance measuring devices 4b and 5b is to determine the proportion of empty space 3c between individual pulp wood or timber logs 3. The distance measuring devices can be, but not limited to, for example, laser fans. In a preferred embodiment of the invention, the first imaging device 4c and the first distance measuring device 4b have been arranged in connection with a first upright post 4 arranged at the edge of the space. The upright post 4 is in turn fitted with guideways 4' in which the first imaging device 4c and the first distance measuring device 4b have been arranged to move in the vertical direction. Correspondingly, a second imaging device 5c and a second distance measuring device 5b have been ar ranged on the opposite edge of the space, on the other side of the pulp wood or timber stack 2 in connection with the guideways 5' of a second upright post 5. To gether, they form the measuring module of the invention. In addition, lighting de- vices 4a and 5a can be positioned in connection with the upright posts 4 and 5 as part of the measuring module. The upright posts 4 and 5 are mounted on the ground or the floor, whereby the above-mentioned space remains between them, into which space the timber stack 2 can be placed. Instead of upright posts, other types of means for moving the measuring instruments 4b, 4c, 5b, 5c can be used.

In the case shown in figures 1 and 2, the pulp wood or timber stack 2 placed in the measurement station 1 can be arranged to move in relation to the measuring instru ments 4b, 4c; 5b, 5c. In this case, the pulp wood or timber stack 2 is moved in the grapple of a material handler 6 either automatically or manually, for example by an operator of the material handler, whereby the measuring instruments 4b, 4c; 5b, 5c can be kept in place during the determination of the solid volume.

Figure 4 shows an arrangement corresponding per se to the one shown in figures 1 and 2, but with the pulp wood or timber stack 2 taken to a space in a cradle 6' wherein the solid volume of the timber stack 2 is determined. In this embodiment, the cradle 6' can be lowered during the determination onto the ground or onto the floor between the upright posts 4 and 5.

Figure 5 shows an arrangement corresponding per se to the one shown in figures 1 and 2, but with the measuring module and hence, the measuring instruments ar ranged on a movable mount 7. For moving, the movable mount 7 can be fitted with e.g. wheels 7a, used and controlled using power transmission means known per se and not shown herein. Thus, the measurement station 1 consist of a measuring module arranged on a movable mount 7. A common characteristic of these above-mentioned embodiments is that the pulp wood or timber stack 2 and the measuring instruments 4b, 4c; 5b, 5c move in rela tion to each other during the determination of the solid volume of the pulp wood or timber stack 2. This characteristic enables a preferred embodiment of the invention for accurately determining the solid volume, wherein a plane passing through the ends 3a; 3b of individual pulp wood or timber logs 3 of a pulp wood or timber stack 2 is essentially perpendicular to a measuring plane M of the measuring instruments 4b, 4c; 5b, 5c. In this way, when the measuring plane M is longitudinal or at least essentially longitudinal to the pulp wood and timber logs, the distance measuring devices 4b and 5b are able to form a determination of the empty space 3c between individual pulp wood or timber logs 3 (in addition to their length) based on an actual observation. This empty space 3c has been shown by way of example in figure 3 depicting the pulp wood or timber stack 2 viewed from the end thereof.

In the figures, the plane M of the measuring beam is shown to be horizontal, but it can be in another plane, for example in a vertical plane. In this case, the posts 4 and 5 must be fitted with means (not shown), with which the measuring instru ments or at least the distance measuring devices 4b and 5b can be moved in the vertical direction in order to bring the plane M of the measuring beam past the end surfaces 3a and 3b. A corresponding arrangement can naturally be implemented for the imaging devices 4c and 5c. The movement of the measuring instruments, as well as the movement of the grapple of the material handler 6, can be carried out using electric, hydraulic and/or pneumatic movement means.

Once the information required for calculating the solid volume of the pulp wood or timber stack 2 has been determined with the measuring module comprising the measuring instruments 4b, 4c; 5b, 5c with means applying the above-mentioned method, the solid volume of the pulp wood or timber stack 2 is calculated on the basis of the information determined with the measuring instruments 4b, 4c; 5b, 5c. According to a preferred embodiment of the present invention, this calculation can be performed with a data processing unit 8, which is, for example, a computer or another smart device. The data processing unit 8 is in turn fitted with receiving means with which the information determined using the measuring instruments 4b, 4c; 5b, 5c obtained from the measuring instruments 4b, 4c, 5b, 5c via electronic data carriers SI, S2, SI' S2' can be electronically transferred to the data processing unit 8. Further, the data processing unit 8 is equipped with a program or another corresponding application for calculating and indicating the solid volume of the pulp wood or timber stack 2 on the basis of the above-mentioned information. It is also advantageous to equip the data processing unit with a screen, or to arrange a screen in connection therewith, from which screen the final outcome of the calcula tion can be read and/or seen for indicating the final outcome of the calculation.

Naturally, the calculated and indicated information on the solid volume can be used as a part of other information on the pulp wood or timber stack 2. For example, once the weight of the pulp wood or timber stack 2 is known, the density corre sponding to the solid volume of the pulp wood or timber stack 2 can be calculated.

In a preferred embodiment of the invention, the purpose of the two imaging devices 4c and 5c is to determine other properties of the pulp wood or timber in addition to the diameter of the ends 3a and 3b of individual pulp wood or timber logs 3, such as the tree species and/or quality of an individual pulp wood or timber log 3. This can be carried out, for example, by determination with color analysis from the RGB signals of a color line scan camera or by means of a neural network or another arti ficial intelligence-based system. Thereby, in addition to measuring the distance, the right lighting achieved with the lighting devices 4a and 5a is an important aspect in carrying out the method according to the invention and obtaining correct results from the measuring instruments.

The present invention is not limited to the embodiments presented, but can be ap plied in many ways within the scope of protection defined by the claims.