WO2012052549A1

WO2012052549A1 - Arrangement and method for marking a log end surface

Info

Publication number: WO2012052549A1
Application number: PCT/EP2011/068445
Authority: WO
Inventors: Björn MÖLLER; Mikael Hellgren; Jan Wikander
Original assignee: Moeller Bjoern; Mikael Hellgren; Jan Wikander
Priority date: 2010-10-22
Filing date: 2011-10-21
Publication date: 2012-04-26

Abstract

The invention relates to an arrangement (1) for marking a log end surface (4a) with a marking code during cutting of a log (4) and amethod for marking a log end surface (4a)with a marking code. The arrangement (1) is connected to a saw bar (3) comprising a plurality offluid distributing nozzles(6) in communication with a fluid container (16). The arrangement (1) further comprises acontrol unit (CU) arranged to control the flow of fluid through eachnozzle (6)based on log-related identification code. The invention is characterised in thatthe flow of fluid through eachnozzle (6)is controlled based on the movement of the saw bar (3) relative to the log in a cutting direction.

Description

ARRANGEMENT AND METHOD FOR MARKING A LOG END SURFACE

Technical field

[0001 ] The present invention relates generally to an arrangement for marking a log end surface during cutting. The cutting is preferably performed by a harvesting machine. The invention is also related to a method for marking a log end surface.

Background art

[0002] In forest industry today, trees are already in the forest cut into one or more logs by a harvesting machine. The method can be called "cut to length method". The length of each log is based on the length and quality wanted from the sawmill to which the raw material is intended. This is to a large extent automatically handled by the harvester's control system .

[0003] Every log produced is measured by the harvester; length and diameter along the stem . This data together with location, operator, machine type, temperature etc. is stored in the harvester for each log. When the log later ends up at the sawmill it is measured again to be placed in certain piles depending on its dimension and quality. There is a problem to link and compare the data produced in the forest and at the sawmill. If a unique code is applied to each log and stored with the log data, it would be traceable if the code is detected at the sawmill.

[0004] No automatic log marking/reading equipment used for individual log traceability between the forest and the sawmill is in operation today. On the market today is a simpler paint marking system that can hold four different identities. Two nozzles and pumps applies red and/or blue paint on the log end surface during the cutting procedure. The nozzles are located beside the saw bar and spray paint on the saw bar surface prior to cutting hence the saw bar smears the paint on the log surface during cutting. This marking is mainly used to separate logs meant for board manufacturing or for the pulp industry. [0005] However, patents in this field do exist. For example, patent

US5 1 43 1 3 1 A discloses a specially designed saw bar to be used in a harvesting machine where a code pattern can be applied to the log end surface during the cutting procedure. Pressurized fluid is supplied to an elongated chamber in the saw bar from a pump inside the harvester aggregate. Evenly spaced fluid emitting holes are drilled from at least one side of the saw bar into the chamber. Inside the chamber, a slide bar with a predefined drilled pattern controls the fluid flow out through the emitting holes. The slide bar position is controlled by an actuator to facilitate different patterns to be applied on the log end surface. A microcontroller controls the slide bar actuator and a pattern is created based on data, such as log length and diameter, sent from the harvester computer to the microcontroller.

[0006] This patent has a limited code structure due to the sliding bar. Thus, it is impossible to adapt this machine to create a pattern containing enough information to trace individual logs on a large market.

[0007] The Swedish patent SE469974B discloses a saw bar with two or more fluid channels providing nozzles with fluid to spray on to the log surface during the cutting procedure. Each nozzle is individually controlled by a valve supplied with a pressurized fluid from a container. Several fluid containers with different types of fluids can be connected to the valves, to facilitate different types of line marks on the log end surface.

[0008] A major difference between patent SE46997 4B and the inventive log marker described in this application is the complexity of the code and its function. With SE469974B it is not possible to open and close valves with accuracy at certain angles to apply complex code structures such as two dimensional data matrix codes.

[0009] Patent EP 1 252992B 1 relates to a simple application of fluid to the log end surface during cutting. Holes in the saw bar allow pressurized fluid to be sprayed on to the log end surface via the holes. No alteration of the "code" is possible.

[001 0] This patent has restricted code possibilities and is far from the concept described in this patent application .

Summary of invention

[001 1 ] An object of the present invention is to provide an apparatus which is adapted to apply a code mark on the log end surface simply and with no time loss.

The invention relates to an arrangement for marking a log end surface with a marking code during cutting of the log. The arrangement is connected to a saw bar comprising a plurality of fluid distributing nozzle in communication with a fluid container. The arrangement further comprises a control unit arranged to control the flow of fluid through each nozzle based on a log-related identification code. The invention is characterised in that the flow of fluid through each nozzle is also controlled based on the movement of the saw bar relative to the log in a cutting direction .

When controlling the flow of fluid based also on the movement of the saw bar in the cutting direction it is possible to create a clear and easily readable marking code on the log end surface, preferably a two-dimensional code. A two-dimensional code can comprise a larger code size than a one dimensional code, but it is difficult to create well defined dots and lines to visualize the code. Especially when the code is applied at the same time as the log is cut. A log has very rarely the same density and hardness throughout the entire log diameter and when the saw bar reaches a location with a different hardness, the velocity of the saw bar movement is changed. When measuring the movement of the saw bar it is possible to control when and how much fluid each valve emits during this movement. This leads to a more well defined application of the marking code calculated by the control unit. The movement of the saw bar can be based upon the measurement of an output signal from a sensor.

In embodiments of the invention the sensor to measure the saw bar movement is any one of; a position sensor, an angle sensor, a velocity sensor or a virtual sensor. It is possible to measure the movement of the saw bar with different types of sensors. The most applicable sensors are the ones stated above, however other sensor types are of course also possible. The sensors may be located in the vicinity of the saw bar and it is also possible to use sensors already mounted on the harvesting machine. It is also possible to use a virtual sensor if the saw bar has constant speed. A virtual sensor does not measure a position, instead the position is calculated from time and a constant speed.

In another embodiment of the invention each nozzle is arranged to be individually controlled by at least one controllable valve at specific positions or at specific angles.

By using the different sensor types it is possible to control the fluid flow through each nozzle. This is preferably done by changing the state of controllable valves from opened to closed and vise versa at specific positions or saw bar angles. The positions and/or angles are measured in relation to a predefined zero-level, this level is preferably defined when the saw bar is in its starting position before a cut is made, as can be seen in figure 2a. If instead the velocity of the saw bar is measured, the position when the valve is activated can be calculated by the control unit.

In further embodiments, the movement of the saw bar is sampled at a predetermined frequency. Preferably, the sampling rate is between 0, 1 and 5 ms. When collecting information of the position of the saw bar at an interval of maximum 5 ms the code applied is clearly visible and distinct at normal cutting speed . A higher sampling rate of the saw bar position facilitates shorter distances between applied code dots.

In another embodiment the control unit comprises a micro controller which is adapted to control the flow of fluid by adjusting the pressure from a fluid pump connected to an accumulator.

Preferably, a micro controller is used to control the fluid flow. The micro controller can adjust the pressure from a fluid pump by valve activation and pressure sensor readings. When a micro controller also controls the fluid pressure and not only the valve opening the application of the code can be even better controlled.

In one embodiment the control unit is connectable to an external computer unit containing the log-related information.

In another embodiment the control unit is connectable to the data communication bus DCB (see Figure 3) of a harvesting machine and the DCB is delivering the log related identification code to the control unit.

The log related information can be stored in an external computer unit or in the harvesting machine control unit. If an external computer unit is used the information can for example be transferred via Bluetooth, IR or by USB or similar. The control unit, can via the harvester control system, also be connected directly to the saw mill log reception or to the log saw intake at the saw mill.

The invention further relates to a method of marking a log end surface during cutting of the log using an arrangement according to any of the embodiments described above, wherein the method comprises the following steps:

• Receiving a log related identification code to the control unit CU • Calculating a marking code by control unit CU, based on the received log related identification code

• Determining the movement of a saw bar relative to the log in a cutting

direction

• Activating each nozzle on basis of the of the saw bar

• Applying fluid marks according to the calculated marking code In one embodiment of the method further comprises the step:

• Controlling the fluid pressure by the control unit with a fluid pump valve, a fluid pump and a pressure sensor and where the step is performed before the measurement or calculation of the saw bar movement.

In another embodiment the log related identification code is received from a computer unit located on a harvesting machine.

When using this method to mark log end surfaces during cutting, a desired distinct two-dimensional code can be applied to the log end surface.

Brief description of drawings

[001 2] The invention is now described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 discloses a cutting aggregate with the inventive arrangement for marking a log

Fig. 2a and 2b discloses the log marking system before and after a cut through the log is made. Fig. 3 shows a schematic overview of the whole log marking system

Fig. 4 discloses a detail view of one embodiment of a saw bar with the inventive arrangement for marking a log

Description of embodiments

[001 3] The invention is here described more in detail. All examples herein should be seen as part of the general description and therefore possible to combine in any way in general terms.

[001 4] The preferred embodiment of the invention is disclosed in figure 1 which discloses a harvesting machine cutting aggregate 1 on which log handling gripping claws 2 and a saw bar 3 are mounted. The harvesting machine cutting aggregate can be attached to any known type of harvesting machine. The log handling gripping claws 2 are enclosing the log 4 which is about to be cut and marked. Thus, the physical code marking of the logs 4 can be performed in the forest by the harvesting machine while operating. An arrangement for marking the log end surface 4a, comprising the saw bar 3 and the valve bracket 5 , hereafter named the marking unit MU, is preferably mounted with the same attachment as the original saw bar 3, on the harvester cutting aggregate 1 or in a vicinity of the cutting aggregate 1 . Further, the valve bracket 5 is connected to the control unit CU. The control unit CU communicates with the harvester control system HCS (see figure 3) via a data communication interface.

[001 5] The marking unit MU applies a marking code C on the log end 4a while cutting, as illustrated in figure 1 and 2b. After cutting, the remaining part of the stem is fixed by the claws 2 in the harvester cutting aggregate 1 . The cutting aggregate 1 can also include a feeding device (not shown) which moves the remaining part of the log forward a predetermined distance before a new cut and a new mark is made by the marking unit. [001 6] The marking code C is preferably a two-dimensional pattern of dots and /or lines created by a fluid, for example ink or any other type of marking fluid. The pattern represents a dot and/or line code containing log related identification code. The identification code is connected to the processed log and its log data. This log related data can for example be measured by the harvester, such as log length and diameter along the stem. The data can also be the log location, operator, machine type, temperature etc. which preferably is stored in the harvester control system for each log. The marking unit MU can be modular to suit different harvester cutting aggregates.

[001 7] The valve assembly 1 5 (see Figure 3) inside the valve bracket 5 is via at least one fluid line 7 connected to at least one nozzle 6. This at least one fluid line 7 and nozzle 6 are integrated in the saw bar 3 to be able to apply the ink dots and/or lines related to the identification code C. The more advanced identification code used, the more nozzles 6 are needed to apply the code. If for example a 1 0* 1 0 data matrix code is used as identification code, ten nozzles 6 are needed to be integrated in the saw bar 3 to be able to apply this code C with a printed solution. The log related identification code sent from the harvester control system and received by the control unit CU is recalculated to represent a 1 0* 1 0 data matrix code C to be executed by ten valves 1 5. The valves 1 5 can be located inside the valve bracket 5, in or on the saw bar, on the cutting aggregate 1 or in its vicinity.

As the saw bar 3 cuts through the log 4, the movement of the saw bar in the cutting direction is measured by a sensor 9 (only show in figure 3) . If the saw bar has constant speed it is also possible to calculate the movement based on time and the constant speed, i.e. a virtual sensor can be used. The sensor 9 can measure the saw bar 3 angle a, see figure 2b, the position of the saw bar 3 or the velocity of the saw bar 3. The positions and/or angles a are measured in relation to a predefined zero-level. This level is preferably defined when the saw bar is in its starting position before a cut is made, as can been seen in figure 2a. The movement can be read by the sensor 9 continuously or sampled at a certain frequency. At a specific measured movement of the saw bar 3, preferably at a specific angle, the first row in the matrix is executed. Calculations based on the specific movement are performed in the control unit CU. Based on the calculations each row in the matrix code are performed by activated and/or non-activated valves, thus builds up the pattern of the matrix code. The rows are then executed consecutive at an incremental angle increase and the timing of the valve activation and deactivation is decided by the measured movement of the saw bar.

[001 8] Figure 3 shows a schematic overview of the whole system. Actuation and sensor inputs are handled by the microcontroller inside the control unit CU . A data communication interface is present in the microcontroller and connects the control unit with the harvester control system HCS. The lower dotted square comprises the marking unit MU and the middle dotted square a fluid pump assembly.

[001 9] The marking system comprises the main data communication bus DCB, an electrical system ES, a hydraulic system HS and a fluid system FS. The main units are a control unit CU - including main circuit board with microcontroller, transistors, power and a data communication interface, a marking fluid pump 1 1 , fluid pump valve 8, filter 1 2, an accumulator 1 3 and a pressure sensor 1 4. The main units are preferably located inside the harvester aggregate 1 for protection . The marking unit MU with its related valves 1 5, and the saw bar 3 with its nozzles 6 and fluid lines 7, are located on the outside of the harvester cutting aggregate 1 . The valves 1 5 can be mounted in a valve bracket 5 or directly in the fluid lines 7 arranged in the saw bar. The marking system can also include a saw bar movement sensor 9. This sensor 9 can either be an existing sensor where sensor output is delivered by the data communication bus DCB, or the sensor 9 can be added as a separate part to the applicator unit with its sensor output delivered on the internal central unit electrical signal system ES. The two interfaces that need to be adapted to a specific harvester are the data communication and the mechanical attachment to the aggregate 1 mounted on the harvester machine.

[0020] The fluid pump 1 1 can be a hydraulic powered pump already mounted on the harvesting machine and normally used for simpler paint marks. The existing fluid pump 1 1 is controlled by the fluid pump valve 8 via the microcontroller in the control unit CU . To maintain a steady fluid pressure, the accumulator 1 3 is connected to the pressurized fluid. As fluid tanks 1 6, existing containers integrated in the aggregate 1 , can be used. An extra installed filter 1 2 prohibits debris from reaching the valves 1 5 and nozzles 6.

[002 1 ] All parts here mentioned as parts are either already existing in the harvester, or can of course also be included as separate parts in the marking system . However, it is preferred to reduce the amount of components that are mounted on the outside of the aggregate and exposed to the tough environment in which this equipment operates. Thereby the cost of replaceable parts such as valves and saw bar could be reduced to produce a cost effective marking solution .

[0022] The application sequence is preferably as follows:

• A code number is transmitted on the data communication bus DCB from the harvester main control system HCS

• The code is received by the control unit CU via the DCB and the control unit CU calculates a two dimensional code based on the received log related identification code from the harvester main control system HCS

• Fluid pressure is controlled by the control unit CU with the fluid pump valve 8, fluid pump 1 1 and pressure sensor 1 4

• The saw bar angles are read by motion sensor 9. • When the cutting motion starts, the valves 1 5 are activated at a certain angle to let fluid flow to the nozzles 6

• Fluid marks are applied to the log end surface 4a to create a two-dimensional code.

[0023] By reading the saw bar angle a or the saw bar velocity from a sensor 9 it is possible to open and close each valve 1 5 individually at a specific angle. This is extremely time critical in order to create distinct marks. Angles are sampled at an appropriate frequency to be able to execute the valves 1 5 during the cutting procedure. This makes it possible to apply two-dimensional codes such as data matrix codes in full production speed.

[0024] In figure 4 one embodiment of a marking unit MU comprising a saw bar 3 and a valve bracket 5 including the valves 1 5, is disclosed. The saw bar is the component exposed to most stress of the marking components. The fluid has to be fed out to nozzles 6 through the saw bar 3 via fluid lines 7. Each nozzle 6 is connected to a valve 1 5 controlled by the control unit CU . Fluid nozzles and channels are integrated in the saw bar. The fluid lines 7 to the nozzles 6 start at the valve assembly 1 5 and runs through a valve mounting plate 1 7 out to the nozzles 6 in the saw bar 3. To minimize the fluid dynamic influence the fluid line 7 diameter is 1 mm with a length of approximately 300 mm . Relatively stiff channel material such as hard plastic or metal is preferred. The nozzles 6, which can be drilled holes, are placed in a row along the saw bar 3, preferably near one outer edge of the saw bar 3.

[0025] There are several possible versions of saw bar designs, of which two are described below.

[0026] A first version of the saw bar 3 can have inserted copper tubes in fabricated slots in the saw bar. These slots are filled with epoxy and holes are drilled for nozzles and fluid inlet. A second version comprises two components; a specially designed saw bar 3 and a fluid line module insert. The fluid line module includes the fluid lines 7, nozzles 6 and inlet. Its material composition could be plastic or metal. The pre made fluid line module is inserted in a cavity in a specially designed saw bar. The two versions have the nozzle row placed close to the circumference of the saw bar to be able to start the application of a code as soon as possible during cutting. The amount of nozzles can vary from a few to a dozen depending on wanted code size. The second version facilitates saw bar

replacement without replacing the fluid line module. Both saw bar designs facilitate code application on either side of the saw bar depending on which side the nozzle holes are drilled.

[0027] The saw bar bracket 5 attaches the saw bar 3 to the cutting aggregate 1 . The valve assembly 1 5 can however be placed on the other side of the saw bar, inside the saw bar or inside the aggregate 1 . If placed inside the aggregate, the marking liquid must be fed to the saw bar 3 through sealed fluid lines 3a .

[0028] The marking system according to the above is giving added functionality in terms of code marking ability at zero time loss and can be manufactured in a cost effective way. The system is also robust and service friendly, which facilitates maintenance and handling usually performed by the operator of the machine out in the field, in sometimes difficult conditions.

Claims

1 . An arrangement (1 ) for marking a log end surface (4a) with a marking code during cutting of the log (4), wherein the arrangement (1 ) is connected to a saw bar (3) comprising a plurality of fluid distributing nozzles (6) in communication with a fluid container (1 6), the arrangement further comprises a control unit (CU) arranged to control the flow of fluid through each nozzle (6) based on a log-related identification code, characterised in that the flow of fluid through each nozzle (6) is controlled based on the movement of the saw bar (3) relative to the log in a cutting direction .

2. An arrangement according to claim 1 , wherein movement of the saw bar (3) is based upon the measurement of an output signal from a sensor (9) .

3. An arrangement according to claim 2, wherein the sensor (9) is any one of; a position sensor, an angle sensor, a velocity sensor or a virtual sensor.

4. An arrangement according to claim 2 or 3, wherein each nozzle (6) is arranged to be individually controlled by at least one controllable valve (1 5) at specific positions or at specific angles.

5. An arrangement according to any of the above claims, wherein the movement of the saw bar (3) is sampled at a predetermined frequency.

6. An arrangement according to any of the above claims, wherein the control unit (CU) comprises a micro controller adapted to control the flow of fluid by adjusting the pressure from a fluid pump (1 1 ) connected to an accumulator (1 3) .

7. An arrangement according to any of the above claims, wherein the control unit (CU) is connectable to an external computer unit (HCS) containing the log- related information .

8. An arrangement according to any of the above claims, wherein the control unit (CU) is connectable to the data communication bus (DCB) of a harvesting machine.

9. An arrangement according to claim 8, wherein the data communication bus (DCB) is delivering the log related identification code to the control unit (CU) .

1 0. A method of marking a log end surface (4a) during cutting of the log (4) using an arrangement according to any of the above claims, wherein the method comprising the following steps:

• Receiving a log related identification code to the control unit (CU)

• Calculation of a marking code in the control unit (CU), based upon the

received log related identification code

• Determining the movement of a saw bar (3) relative to the log (4) in a cutting direction

• Activating each nozzle (6) on basis of the movement of the saw bar (3)

• Applying fluid marks (C) according to the calculated marking code

1 1 . Method according to claim 1 0, wherein the method further comprises the step:

• Controlling the fluid pressure by the control unit (CU) with a fluid pump valve (8), a fluid pump (1 1 ) and a pressure sensor (1 4) and where the step is performed before the measurement or calculation of the saw bar movement.

1 2. Method according to claim 1 0 or 1 1 , wherein the log related

identification code is received from a computer unit (HSC) is located on a harvesting machine.