System, device, and method for processing a length of material

Abstract

A system, device, and method for processing a length of material are provided. A material-working device has first and second cutting devices, each having different cutting capacities. Data relating to the length and diameter at a plurality of points of the material is received, and used to determine at least one cutting position along its length. The diameter of the length of material at the cutting position is determined, and used to select either the first cutting device or second cutting device for use in performing a cut at the cutting position based on the cutting capacity of each cutting device.

Claims

1. A system for processing a stem of a tree, comprising: a material-working device, comprising: a frame having a feed axis; a first cutting device having a first cutting capacity, wherein the first cutting device is attached to the frame and is configured to be controlled to perform a cross-cut at a first position along the feed axis; a second cutting device having a second cutting capacity, wherein the second cutting device is attached to the frame and is configured to be controlled to perform a cross-cut at a second position along the feed axis; a drive mechanism configured to drive the stem along the feed axis of the frame; at least one distance measuring device configured to measure a length of the stem as the stem is driven by the drive mechanism; and at least one diameter measuring device configured to measure a diameter of the stem; and at least one processor configured to: receive data relating to the length of the stem from the distance measuring device; receive data relating to the diameter of the stem at a plurality of points along the length of the stem from the diameter measuring device; set a plurality of cutting positions along the length of the stem based on at least the length of the stem; determine, for each of the plurality of cutting positions, a cutting position diameter of the stem at the cutting position using at least the data relating to the diameters of the stem at the plurality of points along its length; and select either the first cutting device or the second cutting device for use in cross-cutting the stem at each of the cutting positions based at least in part on the cutting capacity of each cutting device and the cutting position diameter of the stem at the cutting position, wherein the selection of either the first cutting device or second cutting device for use in cross-cutting the stem at each of the cutting positions is also based at least in part on minimizing a total distance the stem travels when driven along the feed axis to align each of the cutting positions with one of the first cutting device or the second cutting device.

2. A system as claimed in claim 1, wherein setting at least one of the plurality of cutting positions comprises receiving a manual input from an operator.

3. A system as claimed in claim 1, wherein setting the plurality of cutting positions comprises the processor determining each of the cutting positions along the length of the stem using at least the data relating to the length of the stem.

4. A system as claimed in claim 1, wherein the processor is configured to determine the plurality of cutting positions as part of a value optimisation process for the stem.

5. A system as claimed in claim 1, wherein the processor is configured to determine the cutting positions such that an end of the stem having a larger diameter is prioritised over the other end.

6. A system as claimed in claim 1, wherein the processor is configured to determine the order in which the cutting positions are to be cut.

7. A system as claimed in claim 6, wherein the processor is configured to determine the order in which the cutting positions are to be cut based at least in part on distance the material-working device would be required to travel relative to the stem.

8. A system as claimed in claim 6, wherein the processor is configured to determine the order in which the cutting positions are to be cut based in part on a requirement that the stem remain held by the material-working device until a final cutting position has been cut.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the present disclosure may be better understood with reference to the following description and accompanying drawings, which are given by way of example only:

(2) FIG. 1A is a side view of an exemplary material-working system comprising an exemplary material-working device in the form of a forestry head;

(3) FIG. 1B is an elevated view of the forestry head;

(4) FIG. 2A is a diagrammatic view of an exemplary control system for the exemplary material-working system;

(5) FIG. 2B illustrates an exemplary display device as part of the exemplary control system;

(6) FIG. 3 is a flowchart illustrating an exemplary method for processing a length of material such as a tree stem using the exemplary system;

(7) FIG. 4A illustrates a exemplary stem to be processed according to an exemplary method of the present disclosure, and

(8) FIG. 4B illustrates a cutting solution for the stem according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

(9) FIG. 1A illustrates a timber-working system comprising a carrier 1 for use in forest harvesting. The carrier 1 comprises an operator cab 2 from which an operator (not shown) controls the carrier 1. The carrier 1 further comprises a boom assembly 3, to which a timber-working device in the form of a forestry head 4 is connected.

(10) Connection of the head 4 to the boom assembly 3 comprises a rotator 5, configured to rotate the head 4 about the generally vertical axis of rotation marked by dashed line 6. A tilt bracket 7 further allows rotation of the head 4 between a prone position (as illustrated) and a standing position.

(11) Referring to FIG. 1B, the head 4 comprises a frame 8 to which the tilt bracket 7 of FIG. 1 is pivotally attached. Right hand (RH) and left hand (LH) delimb arms 9a and 9b are pivotally attached to the frame 8, as are opposing RH and LH feed arms 10a and 10b. RH and LH feed wheels 11a and 11b are attached to RH and LH drive arms 10a and 10b respectively, which together with a frame-mounted feed wheel 12 may be controlled to feed one or more stems (not illustrated) along feed axis 13 of the head 4. Feed wheels 11a, 11b, 12 are driven by hydraulic motors, and may collectively be referred to as the feed mechanism. The displacement of the delimbing arms 9a or 9b and/or feed arms 10a or 10b may be used to determine the diameter of the stem at that point.

(12) A measuring wheel 14 may be used to measure the length of stems processed by the head 4. The measuring wheel 14 may be selectively raised and lowered into contact with the stems as desired. Alternatively, rotation or runtime of the feed wheels 11a or 11b, may be used to measure the length of the stem as it is driven relative to the head 4.

(13) A main chainsaw 15, and a topping chainsaw 16, are attached to the frame 8. The main saw 15 is typically used to fell a tree when the head 4 is in a harvesting position, and to buck stems into logs in the processing position of the head 4 (as seen in FIG. 1A). The topping saw 16 may be used to cut off a small-diameter top portion of the stem(s) to maximize the value recovery of the trees. The main saw 15 has a greater cutting capacity in terms of the diameter of stem it is capable of sawing through than the topping saw 16.

(14) An optical sensor 17 is positioned at the end of the head 4 next to the main saw 15. The optical sensor 17 may be used to locate an end of a stem as it is driven through the head 4.

(15) The various operations of the head 4 may be controlled by the operator using hand and foot controls as known in the art. Further, certain automated functions of the harvester head 4 may be controlled by an electronic control system 20 as shown by FIG. 2A and FIG. 2B.

(16) The control system 20 comprises one or more electronic controllers, each controller comprising a processor and memory having stored therein instructions which, when executed by the processor, causes the processor to perform the various operations of the controller.

(17) For example, the control system 20 comprises a first controller 21 on board the carrier 1 and a second controller 22 on board the head 4. The controllers 21 and 22 are connected to one another via a communications bus 23 (e.g., a CAN bus).

(18) A human operator operates an operator input device 24, for example hand and foot controls, located at the operator's cab 2 of the carrier 1 to control the head 4. Details of operation are output to an output device 25for example a display device. Certain automated functions may be controlled by first controller 21 and/or second controller 22.

(19) The head 4 has a number of valves 26 arranged, for example, in a valve block and coupled electrically to the second controller 22 so as to be under its control. The valves 26 comprise, for example, drive valves 27 configured to control operation of the motors associated with the RH and LH feed wheel 11a and 11b, and frame-mounted feed wheel 12a.

(20) The valves 26 further comprise delimb drive valves 28 for controlling operation of the delimb arms 9a and 9b, main saw drive valve 29 and topping saw drive valve 30 for controlling operation of the saws 15 and 16 respectively, and measuring wheel valves 31 for controlling the transfer of the measuring wheel 14 between its extended and retracted positions.

(21) FIG. 2B illustrates an exemplary display device 25 on which details of the operations of the head 4 may be displayed. For example, information regarding the current log to be cut from the stem may be presented in the central area 32. The next logs in the sequence may be displayed in a queuing area 33. The currently selected saw may be displayed in an icon 34.

(22) Referring to FIG. 3, the control system 20 is configured to implement exemplary method 300, which will be described with reference to FIG. 1A, FIG. 1B, FIG. 2A, and FIG. 2B.

(23) At step 301, an end of the stem is found using the optical sensor 17preferably the Large End Diameter. The stem is delimbed by a human operator operating the input device 24 to cause the first controller 21 to broadcast a command on bus 23 to feed the stem, which is in turn received by the second controller 22 which outputs control signals to drive valves 27 causing the wheels 11a, 11b, and 12 to feed the stem in the desired direction through the delimb arms 9a and 9b.

(24) In step 302, while the stem is being fed through, the second controller 22 receives signals from the distance measuring wheel 14 indicating the distance travelled. Diameter measurements are also taken at 100 millimeter intervals using deflection of the delimb arms 9a or 9b and/or feed arms 10a or 10b. These measurements are transmitted to the first controller 21 over the bus 23.

(25) At step 303 the other end of the stem is identifiedwhether through determination that a minimum diameter has been reached, or on manual designation by the operator via input device 24.

(26) In step 304, the first controller 21 uses the measured length and diameters to determine at least one cutting position along the length of the stem such that the value of the resulting logs is optimized.

(27) These are displayed to the operator on display device 25 in step 305, who can choose to make changes in step 306for example changing the grade of the stem. Those changes may require re-optimization of the cutting solution by the first controller 21.

(28) If the operator approves the cutting solution, then the first controller 21 determines the diameter of the stem at the cutting positions at step 307.

(29) At step 308 the first controller 21 then determines the order in which the cutting positions are to be cut based on the minimum distance the head 4 will be required to travel relative to the stem while maintaining control of the stem using the feed rollers 11a, 11b, and 12. This comprises selecting either the main saw 15 or top saw 16 to make each cut based on the cutting capacity of the saws and the diameter of the stem at each cutting position.

(30) At step 309 the first controller 21 broadcasts control signals for carrying out the cutting solution on the bus 23. The second controller 22 receives the control signals, and controls the drive valves 27 to cause feed wheels 11a, 11b, and 12 to drive the stem to each cutting position, where the second controller 22 awaits activation of the selected saw 15 or 16 by the operator before executing the cut and proceeding to the next cutting position. In another embodiment the second controller 22 may cause the saw 15 or 16 to be automatically activated at each position unless overridden by the operator.

(31) FIG. 4A and FIG. 4B illustrates an exemplary cutting solution for optimizing value of a stem and reducing processing time for same. FIG. 4A illustrates a stem 400 having a measured length of 13.1 m.

(32) Exemplary values of various log lengths are outlined in the following Table 1:

(33) TABLE-US-00001 TABLE 1 Log length (m) Value ($) 4.0 500 4.5 550 5.0 400 5.5 450 6.0 500 6.5 550 7.0 600 12.0 950
For ease of illustration the value of logs are determined based solely on length, without factoring diameter into the equation.

(34) Table 2 outlines exemplary calculated cutting priorities for the stem 400 based on the values shown in Table 1:

(35) TABLE-US-00002 TABLE 2 Priority Value ($) Log Composition Total Length (m) 1 1600 2 4.5 m; 1 4.0 m 13.0 2 1550 1 4.5 m; 2 4.0 m 12.5 3 1500 3 4.0 m 12.0

(36) In FIG. 4B it may be seen that in addition to logs 401a, 401b and 401c, a waste portion 402 is produced by cutting solution priority 1. Cutting positions 403a, 403b and 403c are also marked.

(37) Using standard prior art control techniques, the stem 400 would be driven from a position in which the top saw 16 was substantially aligned with the Small End Diameter (SED) to a position in which the main saw 15 was substantially aligned with the Large End Diameter (LED). The stem would then be driven to align the main saw 15 with cutting position 403a, and log 401a cut. The stem would then be driven to align the main saw 15 with cutting position 403b, and log 401b cut. The stem would then be driven to align the top saw 16 with cutting position 403c, and log 401c cut.

(38) Designating the distance between the main saw 15 and the top saw 16 on the harvester head 4 as X, the total distance travelled (d) using the prior art technique in this example may be calculated as:
d=(13.1 mX)+4.5 m+4.5 m+(4.0 mX)=26.1 m2X.

(39) In turn, using the exemplary control method 300 the diameter (D) of the stem at cutting positions 403a, 403b and 403c is compared with the cutting capacity of the top saw 15 (CCT). In this example, it is determined that the diameter of the stem at cutting positions 403b and 403c is less than the cutting capacity of the top saw 15. Only cutting position 403a requires cutting using the main saw 16.

(40) Starting from the same position as the example discussed above, the stem 400 would be driven from a position in which the top saw 15 was substantially aligned with the SED to a position in which the top saw 15 aligned with cutting position 403c, and the waste portion 402 cut. The stem would then be driven to align the top saw 15 with cutting position 403b, and log 401c cut. The stem would then be driven to align the main saw 16 with cutting position 403a, and logs 401a and 401b cut.

(41) The total distance travelled (d) using the exemplary method 300 may be calculated as:
d=0.1 m+4.0 m+(4.5 mX)=8.6 mX.

(42) Using the present disclosure, in this example the harvester travels 17.5 m (less the distance between saws) less than previously required.

(43) Aspects of the present disclosure have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.