Fatigue degree estimation system and fatigue degree estimation method

Abstract

The present application provides a fatigue degree estimation system and a fatigue degree estimation method capable of improving the estimation accuracy of the fatigue degree of a worker. The posture acquisition section of the fatigue degree estimation system of the present application acquires a walking posture assumed by a worker during work. The duration acquisition section acquires the duration of the walking posture. The external force information acquisition section acquires external force information received by the worker when assuming the walking posture. The load estimation section estimates the physical load of the worker caused by the walking posture, based on the walking posture and the external force information received by the worker when assuming the walking posture. The fatigue degree estimation section estimates the fatigue degree of the worker in a walking section, which is an interval during which the walking posture is continuously assumed, based on the duration of the walking posture and the physical load of the worker caused by the walking posture.

Description

Technical Field

[0001] This invention relates to a fatigue estimation system and a fatigue estimation method. Background Technology

[0002] Patent Document 1's system calculates the fatigue level of a worker performing work involving walking (i.e., walking work). Specifically, the system in Patent Document 1 calculates the worker's fatigue level based on information about the distance traveled, the mode of movement, the weight of the equipment, and the method of holding it.

[0003] Patent Document 2's system calculates the time-series changes in worker fatigue when performing work that does not involve walking (i.e., non-walking work). Specifically, the system in Patent Document 2 acquires the postures adopted by the worker during non-walking work and uses the physical load and duration at that time to estimate the time-series changes in the worker's fatigue.

[0004] Regarding Non-Patent Document 1 and Non-Patent Document 2, they are described in terms of the manner in which the invention is carried out.

[0005] Patent Document 1: International Publication No. 2020 / 148876

[0006] Patent Document 2: Japanese Patent Application Publication No. 2024-005974

[0007] Non-patent literature 1: Ting Xia, Laura A. Frey Law, “A theoretical approach for modeling peripheral muscle fatigue and recovery”, Journal of Biomechanics, 41 (2008), pp.3046-3052

[0008] Non-patent literature 2: John M. Looft, Nicole Herkert, Laura Frey-Law, "Modification of a three-compartment muscle fatigue model to predict peaktorque decline during intermittent tasks", Journal of Biomechanics, 77 (2018), pp.16-25 Summary of the Invention

[0009] When workers walk while holding objects, they actually adopt various walking postures depending on factors such as the contents or weight of the object and how it is held. Therefore, it is believed that the worker's fatigue level may vary depending on the walking posture adopted.

[0010] However, the technologies involved in Patent Documents 1 and 2 do not calculate the fatigue level of workers based on their walking posture, so there is room for improvement in the accuracy of the estimation of worker fatigue.

[0011] The purpose of this invention is to provide a fatigue estimation system and method that can improve the accuracy of estimating worker fatigue in view of the above-mentioned problems.

[0012] The fatigue estimation system according to one aspect of the present invention comprises:

[0013] The posture acquisition unit acquires the walking posture adopted by the worker during the operation;

[0014] The duration acquisition unit acquires the duration of the walking posture;

[0015] The external force information acquisition unit acquires information about the external forces experienced by the worker when he / she adopts the walking posture.

[0016] The load estimation unit estimates the physical load on the worker caused by the walking posture based on the walking posture and information about the external forces acting on the worker when adopting the walking posture; and

[0017] The fatigue estimation unit estimates the fatigue level of the worker within the interval during which the walking posture is maintained, i.e., the walking interval, based on the duration of the walking posture and the physical load on the worker caused by the walking posture.

[0018] The fatigue estimation system of the present invention, through the above-described structure, can improve the accuracy of estimating the fatigue level of the operator.

[0019] Another aspect of the fatigue estimation system of the present invention further comprises:

[0020] The body characteristic acquisition unit acquires the body characteristics of the worker.

[0021] The load estimation unit estimates the physical load on the worker caused by the walking posture based on the walking posture, the external force information experienced by the worker when adopting the walking posture, and the worker's physical characteristics.

[0022] In another aspect of the fatigue estimation system of the present invention,

[0023] The load estimation unit also uses a pre-stored, learned AI model that takes the walking posture, the external force information experienced by the worker when adopting the walking posture, and the worker's physical characteristics as inputs to estimate the physical load on the worker caused by the walking posture.

[0024] The fatigue estimation system of the present invention, through the above-described structure, can further improve the accuracy of estimating the fatigue level of the operator.

[0025] In another aspect of the fatigue estimation system of the present invention,

[0026] The task includes multiple walking sections.

[0027] The fatigue estimation unit sums up the fatigue of the workers in multiple walking sections and estimates the summed fatigue of the workers as the fatigue of the workers in the operation.

[0028] It is believed that workers adopt various walking postures during operations, and their fatigue levels change accordingly. The fatigue estimation system of this invention, through the aforementioned structure, can further improve the accuracy of worker fatigue estimation.

[0029] In one aspect of the fatigue estimation method of the present invention,

[0030] The computer performs the following processing:

[0031] To obtain the walking posture adopted by the worker during the operation;

[0032] Obtain the duration of the walking posture;

[0033] Obtain information about the external forces acting on the worker when adopting the walking posture;

[0034] Based on the walking posture and the external force information experienced by the worker when adopting the walking posture, estimate the physical load on the worker caused by the walking posture; and

[0035] Based on the duration of the walking posture and the physical load on the worker caused by the walking posture, the worker's fatigue level within the interval of the continuous walking posture, i.e., the walking interval, is estimated.

[0036] The fatigue estimation method of the present invention, through the above-described structure, can improve the accuracy of estimating the fatigue level of the operator.

[0037] Invention Effects

[0038] This invention provides a fatigue estimation system and method that can improve the accuracy of worker fatigue estimation. Attached Figure Description

[0039] Figure 1 This is a block diagram illustrating an example of the structure of the fatigue estimation system according to the first embodiment.

[0040] Figure 2 This is a flowchart illustrating an example of the operation of the fatigue estimation system according to the first embodiment.

[0041] Figure 3 This is a diagram illustrating an example of the estimated results of the time-series changes in the fatigue level of an operator in the fatigue estimation system 10 according to the first embodiment.

[0042] Figure 4 This is a diagram illustrating an example of the estimated results of the time-series changes in the remaining physical strength of an operator in the fatigue estimation system 10 according to the first embodiment. Detailed Implementation

[0043] Hereinafter, specific embodiments of the invention will be described in detail with reference to the accompanying drawings. In the drawings, the same elements are labeled with the same symbols, and repeated descriptions are omitted as needed for clarity.

[0044] (First Embodiment)

[0045] First, use Figure 1 The structure of the fatigue estimation system 10 according to the first embodiment will be described. Figure 1 This is a block diagram illustrating an example of the structure of the fatigue estimation system 10 according to the first embodiment.

[0046] like Figure 1 As shown, the fatigue estimation system 10 is a system for estimating the fatigue level of an operator performing a task. In the following description, the operator, while performing the task, adopts postures accompanied by one or more walking movements (hereinafter referred to as walking postures) and postures not accompanied by one or more walking movements (hereinafter referred to as non-walking postures). Walking postures include, for example, the swinging leg or standing leg posture adopted when performing tasks involving carrying an object. Non-walking postures include, for example, the posture adopted when performing standing tasks, manual tasks, or machine tasks in a designated location.

[0047] The fatigue estimation system 10 includes a posture acquisition unit 11, a duration acquisition unit 12, an external force information acquisition unit 13, a body characteristic acquisition unit 14, a load estimation unit 15, and a fatigue estimation unit 16.

[0048] The posture acquisition unit 11 acquires the prescribed walking posture adopted by the operator during the operation. The acquired walking posture is the posture maintained for a specified duration or longer. Furthermore, the acquired walking posture is the posture with both feet in contact with the ground. Specifically, the posture acquisition unit 11 acquires pre-stored dynamic images or images of the operator. Moreover, the posture acquisition unit 11 uses motion capture or image recognition to acquire the operator's walking posture. This walking posture is represented by the position or angle of various parts of the operator's body (e.g., joints). Alternatively, the posture acquisition unit 11 can also acquire the operator's walking posture from a simulation of the operator walking in a virtual environment.

[0049] The duration acquisition unit 12 acquires the duration of the worker's continuous walking posture (hereinafter referred to as duration). Hereinafter, the interval of continuous walking posture is referred to as walking interval.

[0050] The external force information acquisition unit (13) acquires information about the external forces experienced by the worker when adopting a walking posture. Specifically, the external force information is information about the magnitude or direction of the external force experienced by the worker from the items held by the worker. The external force information acquisition unit 13 uses a pre-stored mechanics simulator to acquire the magnitude or direction of the external forces experienced by the worker. At this time, the magnitude of the external force can be a value calculated based on information such as the type or size of the item. When adopting a walking posture without holding any items, the magnitude of the external force acting on the hand can be set to 0.

[0051] The body characteristic acquisition unit 14 acquires pre-stored body characteristics of the operator. These body characteristics include, for example, the operator's weight and height. Predefined set values ​​or reference values, such as averages, can be used instead of variables; that is, values ​​that are tailored to the individual operator.

[0052] The load estimation unit 15 estimates the worker's body load caused by the walking posture based on the walking posture, the external force information experienced by the worker when adopting the walking posture, and the worker's body characteristics. Specifically, the load estimation unit 15 estimates the worker's body load caused by the walking posture by comparing the walking posture, external force information, and body characteristics with information pre-stored in a database (not shown). Body load is the muscle load acting on various parts of the worker's body (e.g., various joints of the body). The muscle load acting on each part is calculated, for example, as a percentage of maximum voluntary contraction (MVC), i.e., %MVC.

[0053] Furthermore, the load estimation unit 15 can use a model pre-stored with walking posture, external force information, and body characteristics as input to estimate the worker's physical load caused by the walking posture. This model could be, for example, a mechanics simulator or a learned AI model. Additionally, by using this model, the load estimation unit 15 can also estimate the worker's physical load caused by the walking posture in real time.

[0054] Furthermore, the load estimation unit 15 may not use the worker's physical characteristics acquired by the body characteristic acquisition unit 14, but instead estimate the worker's physical load caused by the walking posture based on the walking posture and the external force information experienced by the worker when adopting the walking posture. In this case, the fatigue estimation system 10 may not have the body characteristic acquisition unit 14.

[0055] The fatigue estimation unit 16 estimates the worker's fatigue level within a sustained walking posture interval (walking interval) based on the duration of the walking posture and the physical load caused by the walking posture. Specifically, the fatigue estimation unit 16 estimates the worker's fatigue level at a predetermined time based on the physical load caused by the walking posture. The fatigue estimation unit 16 accumulates the worker's fatigue level caused by the walking posture at each time point from the beginning to the end of the walking interval (i.e., the duration of the walking posture). Thus, the fatigue estimation unit 16 estimates the time-series change in the worker's fatigue level within the walking interval. Furthermore, this estimation result can be the worker's fatigue level at each time point within the walking interval.

[0056] Furthermore, the fatigue estimation unit 16 estimates the remaining physical strength of the workers in the walking section based on the workers' remaining physical strength at the beginning of the walking section and the workers' fatigue level in the walking section. Specifically, the fatigue estimation unit 16 estimates the workers' remaining physical strength at a specified time by subtracting the workers' fatigue level at the specified time from the workers' remaining physical strength at the time preceding the specified time. The fatigue estimation unit 16 estimates the workers' remaining physical strength at each time from the beginning to the end of the walking posture (i.e., the duration of the walking posture). Thus, the fatigue estimation unit 16 estimates the time-series change of the workers' remaining physical strength in the walking section. In addition, this estimation result can be the workers' remaining physical strength at each time within the walking section.

[0057] For example, the fatigue estimation unit 16 uses a muscle fatigue model to estimate at least one of the worker's fatigue level or the worker's remaining physical strength at each time point. This muscle fatigue model is disclosed in Patent Document 2, Non-Patent Document 1, and Non-Patent Document 2.

[0058] Next, use Figure 2 The operation of the fatigue estimation system 10 according to the first embodiment will be explained. Figure 2This is a flowchart illustrating an example of the operation of the fatigue estimation system 10 according to the first embodiment.

[0059] like Figure 2 As shown, in step S101, the posture acquisition unit 11 of the fatigue estimation system 10 acquires the walking posture adopted by the worker during the operation.

[0060] Next, in step S102, the duration acquisition unit 12 acquires the duration of the walking posture.

[0061] Next, in step S103, the external force information acquisition unit 13 acquires the external force information experienced by the worker when adopting a walking posture.

[0062] Next, in step S104, the body characteristic acquisition unit 14 acquires the worker's body characteristics.

[0063] Next, in step S105, the load estimation unit 15 estimates the physical load on the worker caused by the walking posture based on the worker's walking posture, the external force information received by the worker when adopting the walking posture, and the worker's physical characteristics.

[0064] Next, in step S106, the fatigue estimation unit 16 estimates the fatigue level of the worker in the interval of the continuous walking posture (walking interval) based on the duration of the walking posture and the physical load caused by the walking posture.

[0065] Next, in step S107, the fatigue estimation unit 16 estimates the remaining physical strength of the worker in the walking section based on the worker's remaining physical strength at the beginning of the walking section and the worker's fatigue level in the walking section.

[0066] Furthermore, it is believed that workers adopt various walking postures during work, and their fatigue levels change accordingly. When a worker adopts multiple walking postures during work—in other words, when the work includes multiple continuous walking posture intervals (walking intervals)—the fatigue estimation system 10 can repeatedly perform the processes described in steps S101 to S107 to estimate the worker's fatigue level for each of the multiple walking intervals. Moreover, the fatigue estimation unit 16 of the fatigue estimation system 10 can sum the worker's fatigue levels across the multiple walking intervals and estimate the summed fatigue level as the worker's fatigue level during the work. Therefore, the fatigue estimation system 10 can improve the accuracy of worker fatigue estimation.

[0067] Furthermore, the fatigue estimation system 10 can acquire the prescribed non-walking posture adopted by the worker during the operation and estimate the worker's fatigue level during the interval of continuous non-walking posture (non-walking interval). Moreover, the fatigue estimation system 10 can estimate the worker's remaining physical strength at the end of the non-walking interval based on the worker's remaining physical strength at the beginning of the non-walking interval and the worker's fatigue level during the non-walking interval. In this case, the "walking posture" and "walking interval" processed in steps S101 to S107 are replaced with "non-walking posture" and "non-walking interval," respectively. Furthermore, when the operation includes multiple non-walking intervals, the fatigue estimation system 10 can estimate the fatigue level of the worker in each of the multiple non-walking intervals.

[0068] Next, use Figure 3 The estimation results of the time series changes in the fatigue of the operator in the fatigue estimation system 10 according to the first embodiment will be explained.

[0069] Figure 3 This is a graph illustrating an example of the estimated results of the time-series changes in worker fatigue in the fatigue estimation system 10 according to the first embodiment. Figure 3 In one example, suppose the worker takes walking posture A1, non-walking posture B1, walking posture A2 and non-walking posture B2 in sequence while performing the task.

[0070] Fatigue estimation system 10 estimates the time-series changes in worker fatigue levels within each of the following intervals: continuous walking posture A1 (walking interval a1), continuous non-walking posture B1 (non-walking interval b1), continuous walking posture A2 (walking interval a2), and continuous non-walking posture B2 (non-walking interval b2). The estimation results are derived from... Figure 3 The solid line (thick) represents the solid line.

[0071] Furthermore, as a comparative example of the present invention, Figure 3 The solid line (thin) represents the result of using the system described in Patent Document 1 to estimate the time series changes in worker fatigue in the above interval. Figure 3 The dashed (thin) line represents the result of using the system described in Patent Document 2 to estimate the time series changes in worker fatigue during the above interval.

[0072] In the system described in Patent Document 1, when determining the fatigue level of a worker performing work accompanied by walking (walking work), the fatigue level is calculated based on information such as the distance traveled, the mode of movement, the weight of the equipment, and the method of holding it, but the fatigue level caused by walking posture is not calculated. Therefore, in the system described in Patent Document 1, the accuracy of the estimated fatigue level of workers in walking intervals a1 and a2 can be improved, and the estimated results differ from those of the fatigue estimation system 10. Furthermore, the system described in Patent Document 1 lacks a structure for estimating the fatigue level of workers performing work not accompanied by walking (non-walking work) caused by non-walking posture. Therefore, in the system described in Patent Document 1, the fatigue level of workers in non-walking intervals b1 and b2 cannot be estimated.

[0073] The system described in Patent Document 2 calculates the fatigue level of workers caused by non-walking postures when performing non-walking tasks, but does not estimate the fatigue level caused by walking postures. Therefore, in the system described in Patent Document 2, it is impossible to estimate the time-series changes in the fatigue level of workers in walking intervals a1 and a2.

[0074] Based on the above, the fatigue estimation system 10 can estimate the fatigue level of workers based on their walking posture, thus improving the accuracy of fatigue estimation for workers in operations including walking.

[0075] Next, use Figure 4 The estimation results of the time series changes in the remaining physical strength of the worker in the fatigue estimation system 10 according to the first embodiment will be explained.

[0076] Figure 4 This is a graph illustrating an example of the estimated results of the time-series changes in the remaining physical strength of an operator in the fatigue estimation system 10 according to the first embodiment. Figure 4 In one example, with Figure 3 Similarly, suppose that the worker takes walking posture A1, non-walking posture B1, walking posture A2 and non-walking posture B2 in sequence while performing the task.

[0077] If used Figure 3 The fatigue estimation system 10 estimates the time series changes in the fatigue of the operator in each of the intervals of continuous walking posture A1 (walking interval a1), continuous non-walking posture B1 (non-walking interval b1), continuous walking posture A2 (walking interval a2), and continuous non-walking posture B2 (non-walking interval b2).

[0078] like Figure 4As shown, the fatigue estimation system 10 estimates the time-series changes in the remaining physical strength of the worker in each of the walking intervals a1, non-walking intervals b1, walking intervals a2, and non-walking intervals b2 by subtracting the worker's fatigue level from their physical strength over time. Here, in Figure 4 In one example, at the beginning of walking interval a1, since it is the start of the task, the worker's total strength is 100%. This is presumed by... Figure 4 The solid line (thick) represents the solid line.

[0079] Furthermore, as a comparative example of the present invention, Figure 4 The solid line (thin) represents the result of using the system described in Patent Document 1 to estimate the time series changes in the remaining physical strength of the workers in the above interval. Figure 4 The dashed line represents the result of using the system described in Patent Document 2 to estimate the time-series changes in the remaining physical strength of the workers in the above-mentioned interval.

[0080] The fatigue estimation system 10 can improve the estimation accuracy of the fatigue of workers in operations including walking operations, and therefore can also improve the estimation accuracy of the worker's remaining physical strength.

[0081] <Hardware Structure>

[0082] Each structure of the fatigue estimation system 10 in the above embodiments is composed of hardware or software or both. It can be composed of one piece of hardware or software or multiple pieces of hardware or software.

[0083] For example, each structure of the fatigue estimation system 10 in the above embodiments is composed of a computer equipped with a processor and memory. The processor may be, for example, a microprocessor, a microprocessor unit (MPU), or a central processing unit (CPU). Multiple processors may be included. The memory consists of a combination of volatile and non-volatile memory. The memory may include storage devices configured separately from the processor. In this case, the processor can access the memory through an I / O interface not shown. The processor executes one or more programs to enable the computer to perform the algorithms illustrated in the accompanying drawings.

[0084] When the program is read into a computer, it includes a set of commands (or software code) for causing the computer to perform one or more functions (fatigue estimation methods) described in the embodiments. The program may be stored on a non-transitory computer-readable medium or a physical storage medium. By way of example, and not limitation, a computer-readable medium or a physical storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technologies, CD-ROM, digital versatile disc (DVD), Blu-ray disc (registered trademark) or other optical disc storage devices, magnetic tape, magnetic tape, disk storage devices, or other magnetic storage devices. The program may be transmitted on a temporary computer-readable medium or a communication medium. By way of example, and not limitation, a temporary computer-readable medium or a communication medium includes electrical, optical, acoustic, or other forms of propagation signals.

[0085] The present invention has been described above with reference to the embodiments described above, but the present invention is not limited to the above embodiments. Various modifications that can be understood by those skilled in the art can be made to the structure or details of the present invention within the scope of the present invention. Furthermore, each embodiment can be appropriately combined with other embodiments.

[0086] The accompanying drawings are merely illustrative examples of one or more embodiments. Each drawing may be associated not only with a specific embodiment but also with one or more other embodiments. To enable those skilled in the art to understand, various features or steps described with reference to any of the drawings can be combined with features or steps shown in one or more other drawings to create embodiments, for example, not explicitly illustrated or described. For the purpose of illustrating illustrative embodiments, not all features or steps shown in any of the drawings are essential, and some features or steps may be omitted. The order of steps described in any of the drawings may be appropriately changed.

[0087] Symbol Explanation

[0088] 10-Fatigue estimation system, 11-Posture acquisition unit, 12-Duration acquisition unit, 13-External force information acquisition unit, 14-Body characteristic acquisition unit, 15-Load estimation unit, 16-Fatigue estimation unit.

Claims

1. A fatigue estimation system, characterized in that, have: The posture acquisition unit acquires the walking posture adopted by the worker during the operation; The duration acquisition unit acquires the duration of the walking posture; The external force information acquisition unit acquires information about the external forces experienced by the worker when he / she adopts the walking posture. The load estimation unit estimates the physical load on the worker caused by the walking posture based on the walking posture and the external force information experienced by the worker when adopting the walking posture. and The fatigue estimation unit estimates the fatigue level of the worker within the interval during which the walking posture is maintained, i.e., the walking interval, based on the duration of the walking posture and the physical load on the worker caused by the walking posture.

2. The fatigue estimation system according to claim 1, characterized in that, It also has: The body characteristic acquisition unit acquires the body characteristics of the worker. The load estimation unit estimates the physical load on the worker caused by the walking posture based on the walking posture, the external force information experienced by the worker when adopting the walking posture, and the worker's physical characteristics.

3. The fatigue estimation system according to claim 1, characterized in that, The task includes multiple walking sections. The fatigue estimation unit sums up the fatigue of the workers in multiple walking sections and estimates the summed fatigue of the workers as the fatigue of the workers in the operation.

4. The fatigue estimation system according to claim 2, characterized in that, The load estimation unit uses a pre-stored, learned AI model that takes the walking posture, the external force information experienced by the worker when adopting the walking posture, and the worker's physical characteristics as input to estimate the physical load on the worker caused by the walking posture.

5. A method for estimating fatigue degree, characterized in that, The computer performs the following processing: To obtain the walking posture adopted by the worker during the operation; Obtain the duration of the walking posture; Obtain information about the external forces acting on the worker when adopting the walking posture; Based on the walking posture and the external force information experienced by the worker when adopting the walking posture, the physical load on the worker caused by the walking posture is estimated; and Based on the duration of the walking posture and the physical load on the worker caused by the walking posture, the worker's fatigue level within the interval of the continuous walking posture, i.e., the walking interval, is estimated.

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