Deterioration Judgment Program

Abstract

To provide a technique capable of determining the degree of degradation of a wire rope.SOLUTION: A felling system transports trees by suspending a felling device that holds a felled tree on a main rope and winds up a traverse rope connected to the felling device to move the felling device. A deterioration determining program determines deterioration of a wire rope including at least one of the main rope and the traverse rope. This deterioration determining program has an acquisition function and a determination function which are implemented by the computer. The acquisition function is for acquiring time-series data of the tension applied to the wire rope from a tensiometer. The determination function is for determining that the wire rope is deteriorated when the amount of change from the natural frequency of the period data when the wire rope is not deteriorated is greater than a threshold, where the natural frequency of the period data is time-series data for at least part of the period from felling of a tree in the logging system to completion of transportation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a degradation determination program. [Background technology]

[0002] 2. Description of the Related Art In a felling system for transporting felled trees, a technique for transporting the trees using a wire rope is known, as described in Patent Document 1, for example. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-162456 A Summary of the Invention [Problem to be solved by the invention]

[0004] When using the felling system described in Patent Document 1 for a long period of time, maintenance work for the wire rope is required. In order to perform the maintenance work for the wire rope, a technology that can determine the degree of deterioration of the wire rope is desired. [Means for solving the problem]

[0005] The present disclosure has been made to solve the above-mentioned problems, and can be realized in the following forms.

[0006] According to one embodiment of the present disclosure, in a felling system in which a felling device that grips a felled tree is hung from a main rope and a lateral rope connected to the felling device is wound up to move the felling device and transport the tree, a deterioration determination program is provided for determining deterioration of a wire rope including at least one of the main rope and the lateral rope. The deterioration determination program includes an acquisition function for acquiring time-series data of tension applied to the wire rope from a tension meter, and a period data that is the time-series data for at least a part of the period from felling of the tree to completion of transport in the felling system. is required from Natural frequency of the wire rope when it is not deteriorated It is calculated from the above period data The computer is caused to realize a judgment function of judging that the wire rope is deteriorated when the amount of change from the natural frequency is greater than a threshold value. In this manner, the deterioration of the wire rope can be judged. Also, since the deterioration is judged using time series data of the tension applied to the wire rope during a series of operations of the felling system, the deterioration degree of the wire rope can be judged without increasing the number of complicated operations, compared to the case where the deterioration is judged using time series data of the tension applied to the wire rope measured separately from the series of operations of the felling system.

[0007] The present disclosure can be realized in various forms, for example, as a wire rope deterioration determination device, a wire rope deterioration determination method, etc. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a general configuration of a felling system. [Diagram 2] 11 is a flowchart illustrating an example of a tree cutting process. [Diagram 3] 11 is a graph showing an example of period data. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A. Embodiment: 1 is a schematic diagram showing a schematic configuration of a felling system 100 according to an embodiment of the present disclosure. The felling system 100 includes a felling device 10, a wire rope 20, a winding device 30, a sheave 40, a tension meter 50, a determination unit 60, and a storage unit 70. The felling system 100 is used to lift and transport timber felled in a forest using the wire rope 20 stretched in the air.

[0010] The felling device 10 is a device that cuts down and grips trees. The felling device 10 is connected to a wire rope 20. The felling device 10 has, for example, a cutting unit that cuts trees, a wire for lifting and lowering, and a hook attached to the tip of the wire for lifting and lowering. The cutting unit is, for example, a chainsaw. The hook grips the cut tree. When gripping a tree and when lowering the tree, the felling device 10 winds the wire and moves the hook up and down.

[0011] The wire rope 20 is stretched between a plurality of posts. At least one end of the wire rope 20 is connected to a winding device 30. The wire rope 20 includes a main rope 21 and a cross rope 22. The main rope 21 supports the felling device 10. The cross rope 22 moves the felling device 10.

[0012] The winding device 30 is, for example, an electric winch driven by a motor. The winding device 30 can wind up the wire rope 20 connected thereto. More specifically, the winding device 30 includes a first winding device 31 provided at one end of the main rope 21 and winding the main rope 21, and a second winding device 32 and a third winding device 33 provided at both ends of the lateral rope 22 and winding the lateral rope 22. The first winding device 31 winds up the main rope 21 and applies tension to the main rope 21, thereby causing the main rope 21 to support the felling device 10. The second winding device 32 and the third winding device 33 can move the felling device 10 in a substantially horizontal direction by winding up the lateral rope 22, respectively.

[0013] The sheave 40 is provided on the support. The sheave 40 changes the direction of movement of the wire rope 20 hung thereon.

[0014] The tension meters 50 are attached to the sheaves 40. Each tension meter 50 measures the tension applied to the wire rope 20 hung on the sheave 40 to which it is attached.

[0015] The determination unit 60 is configured as a computer having a CPU, a memory, and an interface circuit to which the above-mentioned components are connected. The CPU executes a deterioration determination program stored in the memory to realize an acquisition function and a determination function, and realizes a determination of whether the wire rope 20 is deteriorated or not. The determination unit 60 realizes an acquisition function of acquiring time series data (hereinafter, simply referred to as "time series data") of the tension applied to the wire rope 20 acquired from the tension meter 50, and a determination function of comparing the natural frequency in the time series data acquired from the tension meter 50 with the natural frequency stored in the storage unit 70 to determine the deterioration of the wire rope 20. More specifically, the determination unit 60 determines that the wire rope 20 is deteriorated when the amount of change in the natural frequency of the period data, which is the time series data for at least a part of the period from felling of a tree in the felling system 100 to the completion of transportation, from the natural frequency of the period data when the wire rope 20 is not deteriorated, is greater than a threshold value. The determination unit 60 performs a deterioration determination for each of the main ropes 21 and the traversing ropes 22. In addition, in the determination unit 60, some or all of these functions may be realized as a hardware circuit.

[0016] The storage unit 70 stores the natural frequency in the time series data of the tension applied to the wire rope 20 when the wire rope 20 is not deteriorated. The storage unit 70 stores, for example, the natural frequency in the period data measured by the tension meter 50 when the wire rope 20 is not deteriorated.

[0017] 2 is a flowchart showing an example of a tree felling process in the tree felling system 100 according to this embodiment. The tree felling process is a process in which the tree felling device 10 fells and transports trees.

[0018] In step S100, the felling machine 10 moves to the location of the tree to be felled.

[0019] In step S110, the tree harvesting machine 10 cuts down trees.

[0020] In step S120, the tree harvesting device 10 grips the tree that was harvested in step S110. More specifically, a hook is attached to the tree.

[0021] In step S130, the felling machine 10 transports the tree.

[0022] In step S140, the felling machine 10 releases the tree that was gripped in step S120. More specifically, the tree is removed from the hook.

[0023] FIG. 3 is a graph showing an example of period data. In FIG. 3, the horizontal axis indicates time. The vertical axis indicates the tension of the wire rope 20. FIG. 3 shows time series data of the tension of the wire rope 20 in step S100 (see FIG. 2) in the tree felling process measured by the tension meter 50. In this embodiment, the judgment unit 60 uses the time series data in step S100 as the period data. The time series data in step S100 does not need to take into account the weight or size of the tree, so that the deterioration of the wire rope 20 can be judged more accurately. The judgment unit 60 compares the natural frequency in the period data shown in FIG. 3 with the natural frequency stored in the memory unit 70, and judges that the wire rope 20 is deteriorated when the amount of change is greater than a threshold value.

[0024] The above-described tree-cutting system 100 of the present embodiment can determine the deterioration of the wire rope 20. In addition, since the deterioration is determined using time-series data of the tension applied to the wire rope 20 during a series of operations of the tree-cutting system 100, the deterioration degree of the wire rope 20 can be determined without increasing the number of complicated operations, compared to the case where time-series data of the tension measured by measuring the tension applied to the wire rope 20 is used separately from the series of operations of the tree-cutting system 100.

[0025] B. Other embodiments: (B1) In the above-described embodiment, the determination unit 60 uses the time series data in step S100 (see FIG. 2) in the tree felling process as the period data. However, the determination unit 60 may use time series data in other steps in the tree felling process, or may use a series of time series data from the start to the end of the tree felling process. In this case, it is preferable to correct the natural frequency according to the weight, size, etc. of the tree.

[0026] (B2) In the above-described embodiment, the judgment unit 60 may judge whether the wire rope 20 is deteriorated or not using a model that has learned the relationship between time series data and the degree of deterioration of the wire rope 20 through supervised machine learning.

[0027] (B3) In the above-described embodiment, the storage unit 70 stores the natural frequency in the period data when the wire rope 20 is not deteriorated. Alternatively, the storage unit 70 may store the period data when the wire rope 20 is not deteriorated. In this case, the determination unit 60 obtains the natural frequency in the period data stored in the storage unit 70 when comparing the natural frequency in the period data.

[0028] (B4) In the above-described embodiment, the transverse rope 22 is connected at both ends to the second winding device 32 and the third winding device 33. Instead of this, a winding device 30 may be provided so that the transverse rope 22 circulates.

[0029] (B5) In the above-described embodiment, the determination unit 60 may further realize an output function. For example, the determination unit 60 outputs the determination of whether the wire rope 20 is deteriorated or not to a monitor or the like provided in the felling system 100.

[0030] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in each form described in the Summary of the Invention column can be appropriately replaced or combined in order to solve the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0031] 10... felling device, 20... wire rope, 21... main rope, 22... traverse rope, 30... winding device, 31... first winding device, 32... second winding device, 33... third winding device, 40... sheave, 50... tension meter, 60... determination unit, 70... memory unit, 100... felling system

Claims

[Claim 1] A tree-cutting system in which a cutting machine that holds a cut tree is hung from a main rope and a lateral rope connected to the cutting machine is wound up to move the cutting machine and transport the tree, comprising: a deterioration determination program for determining deterioration of a wire rope including at least one of the main rope and the lateral rope, the deterioration determination program comprising: An acquisition function for acquiring time series data of tension applied to the wire rope from a tension meter; a determination function for determining that the wire rope is deteriorated when a change in a natural frequency calculated from period data, which is the time-series data for at least a portion of the period from felling of the tree in the felling system to the completion of transportation, from a natural frequency calculated from the period data in a case where the wire rope is not deteriorated is greater than a threshold value; A deterioration determination program that enables a computer to carry out the above steps.

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