Search

EP-4739091-A1 - METHOD AND CONTROL SYSTEM FOR CONTROLLING OPERATION OF WOOD PROCESSING DEVICE OF FOREST WORK MACHINE

EP4739091A1EP 4739091 A1EP4739091 A1EP 4739091A1EP-4739091-A1

Abstract

A method for processing a tree (9) in a wood processing device (10) of a forest work machine (1). In the method, the tree is fed in the wood processing device by means of feeding means (12) of the wood processing device pressable against the trunk of the tree and delimbing means (14a, 14b) of the wood processing device are pressed against the tree trunk to remove branches from the tree trunk. In the method, at least one of the following details is determined: at least one detail describing the feeding of the tree in the wood processing device or at least one detail describing the efficiency of the delimbing and, based on at least one determined detail, at least one of the following is adjusted: a pressing force of the delimbing means against the tree trunk or a pressing force of the feeding means against the tree trunk. Furthermore, a control system (20) for controlling the operation of a wood processing device (10) of a forest work machine (1).

Inventors

  • OINONEN, Mikko

Assignees

  • Ponsse Oyj

Dates

Publication Date
20260513
Application Date
20240705

Claims (8)

  1. 1. A method for processing a tree (9) in a wood processing device (10) of a forest work machine (1), in which method feeding the tree (9) in the wood processing device (10) by means of feeding means (12) of the wood processing device (10) pressable against the trunk of the tree (9) and pressing delimbing means (14a, 14b) of the wood processing device (10) against the trunk of the tree (9) for removing branches from the trunk of the tree (9), characterized by determining at least one detail describing the efficiency of the delimbing of the tree (9), wherein at least one detail describing the efficiency of the delimbing is at least one of the following: a height of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9), or a number of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9), and adjusting based on at least one determined detail at least one of the following: a pressing force of the delimbing means (14a, 14b) against the trunk of the tree (9) or a pressing force of the feeding means (12) against the trunk of the tree [9).
  2. 2. A method according to claim 1, characterized by measuring a thickness of the trunk of the tree (9) when feeding the tree (9) in the wood processing device (10), determining from the measured thickness of the trunk of the tree (9) at least one of the following details: a height of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9) or a number of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9), comparing the height and/or number of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9) with a limit value set for the detail in question, and increasing the pressing force of the delimbing means (14a, 14b) against the trunk of the tree (9) and/or the pressing force of the feeding means (12) against the trunk of the tree (9) when the height and/or the number of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9) exceed the limit value set for the detail in question.
  3. 3. A method according to any one of the preceding claims, characterized by that at least one detail describing the feeding of the tree (9) in the wood processing device (10) is at least one of the following: a feeding speed of the tree (9) or its part when feeding the tree (9) in the wood processing device (10), or a feeding acceleration of the tree (9) or its part when feeding the tree (9) in the wood processing device (10), and determining the feeding speed and/or feeding acceleration of the tree (9) or its part when feeding the tree (9) in the wood processing device (10) and adjusting the pressing force of the delimbing means (14a, 14b) against the trunk of the tree (9) and/or the pressing force of the feeding means (12) against the trunk of the tree (9) based on the determined feeding speed and/or feeding acceleration of the tree (9) or its part.
  4. 4. A method according to claim 2 or 3, characterized by storing at least one detail describing the thickness of the trunk of the tree (9) processed in the wood processing device (10) and at least one detail describing the feeding of the tree (9) in the wood processing device (10) and/or at least one detail describing the efficiency of the delimbing the tree (9) as well as at least the pressing force of the feeding means (12) and the pressing force of the delimbing means (14a, 14b) used for delimbing the tree (9) or its part as a part of a dataset designated for a tree species corresponding the processed tree (9), measuring for delimbing at least one detail describing the thickness of the trunk of the tree (9) to be processed in the wood processing device (10), comparing the determined at least one detail describing the thickness of the trunk of the tree (9) to be processed with at least one corresponding detail of trunks or their parts of trees (9) previously processed, stored in the dataset designated for the same tree species at least for the part of the detail describing the thickness in order to find a record of a previously processed tree (9) substantially corresponding to the tree (9) to be processed, the height or number of branch stubs or branch lumps remaining on the trunk or a part of the trunk of the tree (9) is smaller or equals the limit value set for the height and/or number of branch stubs or branch lumps, and adjusting the pressing force of the feeding means (12) and/or the pressing force of the delimbing means (14a, 14b) used for delimbing the tree (9) to be processed according to the pressing force of the feeding means (12) and/or the pressing force of the delimbing means (14a, 14b) of the previous processed tree [9).
  5. 5. A control system (20) for controlling the operation of the wood processing device (10) of a forest work machine (1), which control system (20) is configured to control feeding of a tree (9) in the wood processing device (10) by means of feeding means (12) of the wood processing device (10) pressable against the trunk of the tree (9) and pressing delimbing means (14a, 14b) of the wood processing device (10) against the trunk of the tree (9) for removing branches from the trunk of the tree (9), characterized in that the control system (20) is further configured to determine at least one detail describing the efficiency of the delimbing of the tree (9), wherein at least one detail describing the efficiency of the delimbing is at least one of the following: a height of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9), or a number of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9), and adjust based on said at least one determined detail at least one of the following: a pressing force of the delimbing means (14a, 14b) against the trunk of the tree (9) or a pressing force of the feeding means (14a, 14b) against the trunk of the tree (9).
  6. 6. A control system according to claim 5, characterized in that the control system (20) comprises means for measuring the thickness of the trunk of the tree (9) and that the control system (20) is configured to measure the thickness of the trunk of the tree (9) when feeding the tree (9) in the wood processing device (10), determine from the measured thickness of the trunk of the tree (9) at least one of the following details describing the efficiency of the delimbing: a height of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9) or a number of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9), compare the height and/or number of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9) with a limit value set for the detail in question, and increase the pressing force of the delimbing means (14a, 14b) against the trunk of the tree (9) and/or the pressing force of the feeding means (12) against the trunk of the tree (9) when the height and/or the number of branch stubs or branch lumps remaining in the trunk or a part of the trunk of the tree (9) exceed the limit value set for the detail in question.
  7. 7. A control system according to claim 5 or 6, characterized in that the control system (20) comprises means for determining at least one of the following details describing the feeding of the tree (9) in the wood processing device (10): a feeding speed of the tree (9) or its part when feeding the tree (9) in the wood processing device (10), or a feeding acceleration of the tree (9) or its part when feeding the tree (9) in the wood processing device (10), and that the control system (20) is configured to determine the feeding speed and/or feeding acceleration of the tree (9) or its part when feeding the tree (9) in the wood processing device (10) and adjust the pressing force of the delimbing means (14a, 14b) against the trunk of the tree (9) and/or the pressing force of the feeding means (12) against the trunk of the tree (9) based on the determined feeding speed and/or feeding acceleration of the tree (9) or its part.
  8. 8. A control system according to claim 6 or 7, characterized in that the control system (20) comprises at least one database (22) which comprises tree- species-specific datasets and that the control system (20) is configured to store to the database (22) at least one detail describing the thickness of the trunk of the tree (9) processed in the wood processing device (10) and at least one detail describing the feeding of the tree (9) in the wood processing device (10) and/or at least one detail describing the efficiency of the delimbing the tree (9) as well as at least the pressing force of the feeding means (12) and the pressing force of the delimbing means (14a, 14b) used for delimbing the tree (9) or its part as a part of a dataset designated for a tree species corresponding the processed tree (9), measure for delimbing at least one detail describing the thickness of the trunk of the tree (9) to be processed in the wood processing device (10), compare the determined at least one detail describing the thickness of the trunk of the tree (9) to be processed with at least one corresponding detail of trunks or their parts of trees (9) previously processed, stored in the dataset designated for the same tree species at least for the part of the detail describing the thickness in order to find a record of a previously processed tree (9) substantially corresponding to the tree (9) to be processed, the height or number of branch stubs or branch lumps remaining on the trunk or a part of the trunk of the tree (9) is smaller or equals the limit value set for the height and/or number of branch stubs or branch lumps, and adjust the pressing force of the feeding means (12) and/or the pressing force of the delimbing means (14a, 14b) used for delimbing the tree (9) to be pro- cessed according to the pressing force of the feeding means (12) and/or the pressing force of the delimbing means (14a, 14b) of the previous processed tree (9).

Description

Method and control system for controlling operation of wood processing device of forest work machine Background of the invention The invention relates to wood harvesting and particularly to a method and control system for controlling the operation of a wood processing device of a forest work machine for delimbing a tree being processed in the wood processing device of the forest work machine. When harvesting wood by a forest work machine, the wood is processed i.e. worked in the wood processing device of the forest work machine. Said wood processing typically comprises felling of a tree, removing branches from the felled tree i.e. delimbing, and cross-cutting the trunk of the felled tree into parts of preferred length. For delimbing the felled tree, the felled tree is fed by means of feeding means pressable against the tree trunk in the wood processing device and, at the same time, delimbing means used for removing the branches are pressed against the tree trunk in the wood processing device for removing the branches from the tree trunk. After this, such a section of the tree trunk of which branches have been removed is cross-cut into a part of preferred length. During delimbing, the tree being processed in the wood processing device is held up by said feeding means and said delimbing means at the same time as the tree being processed is fed by said feeding means forward in the wood processing device. If the pressing force of said delimbing means against the tree trunk is too low, the delimbing result is weak, that is, branch stubs or branch lumps remain on the surface of the tree trunk. Furthermore, the support of the tree against the bottom of the wood processing device is weakened. On the other hand, the too high pressing force of said delimbing means against the tree trunk increases resistance for tree feeding in the wood processing device, which in turn increases power required for the wood processing and its energy consumption. If the pressing force of said feeding means against the tree trunk is too low, the feed of the tree in the wood processing device is weakened, whereby, if the feeding means include e.g. feeding rolls, said feeding rolls spin more easily, which slows down wood processing and thus decreases productivity. If the pressing force of said feeding means against the tree trunk is in turn too high, unnecessarily much power is used for holding up, supporting and feeding the tree trunk, which unnecessarily increases energy consumption of wood processing. Additionally, said feeding means, particularly feeding rolls, might damage the surface of the tree. Brief description of the invention The object of the invention is to provide a new kind of method and control system for delimbing a tree being processed in a wood processing device of a forest work machine. The solution according to the invention is characterised by what is disclosed in the independent claims. In the solution according to the invention, at least one of the following details is determined: at least one detail describing the feeding of the tree in the harvester head or at least one detail describing the efficiency of the delimbing of the tree and, based on said at least one determined detail, the pressing force of the delimbing means against the tree trunk and/or the pressing force of the feeding means against the tree trunk is adjusted, that is, based on said at least one determined detail, at least one of the following is adjusted: pressing force of the delimbing means against the tree trunk or pressing force of the feeding means against the tree trunk. Due to the solution according to the invention, the pressing force of the feeding means of the wood processing device of the forest work machine against the tree trunk and/or the pressing force of the delimbing means of the wood processing device against the tree trunk can be adjusted based on at least one detail describing the efficiency of the delimbing and/or at least one detail describing the feeding of the tree in the harvester head to control the delimbing efficiently such that no branch stubs or branch lumps remain on the surface of the tree trunk, that is, the pressing force of the delimbing means and the pressing force of the feeding means against the tree trunk is sufficient but not unnecessarily high. Then, wood processing for at least the part of the delimbing occurs efficiently without too high pressing force of the delimbing means and feeding means and unnecessarily high energy consumption of wood processing caused by it. Some embodiments of the invention are presented in the dependent claims. Brief description of the drawings The invention will now be described in greater detail by means of preferred embodiments and with reference to the attached drawings, in which: Figure 1 is a schematic side view of a forest work machine, Figure 2 is a schematic diagonal top view of a wood processing device of a forest work machine, Figure 3 is a schematic view of a co