KR20160118678A

KR20160118678A - Workload estimation and job rotation scheduling for Work-related Musculoskeletal Disorders prevention

Info

Publication number: KR20160118678A
Application number: KR1020150047153A
Authority: KR
Inventors: 윤상영
Original assignee: 윤상영
Priority date: 2015-04-03
Filing date: 2015-04-03
Publication date: 2016-10-12

Abstract

Provided is a methodology which measures a workload per a body portion of a worker and prevents a muscular skeletal disease when work rotation is performed. The present invention comprises: a sensor unit configured to measure a posture by using a gyro sensor to measure a workload per each body portion; a wireless communication transceiving unit configured to transfer a signal, measured in the sensor unit, to an analysis system; a workload evaluation unit configured to evaluate a workload per each body portion; and a system configured to determine a work rotation method to prevent a workload from being accumulated in a specific body portion so as to prevent a muscular skeletal disease.

Description

[0001] Workload estimation and job rotation scheduling for Work-related Musculoskeletal Disorders [

The present invention relates to a technique for determining a work cycle order in consideration of a workload of a body part of an operator in order to prevent a musculoskeletal disease.

Musculoskeletal disorders have a close relationship with worker characteristics, work types performed by workers, and work environment. As technology develops, much of the work shifts to a mechanized, automated production system, and the worker at the production and assembly site takes a lot of time to perform simple, repetitive tasks. Problems that persist in simple, repetitive tasks are that workers feel psychologically bored and physically can be a source of work-related musculoskeletal disorders.

Work-related musculoskeletal disorders require a lot of cost and time to treat, and the risk of reoccurrence even after returning to work. Therefore, musculoskeletal disorders require prevention of musculoskeletal disorders before treatment.

Although work circulation is a typical preventive measure to prevent musculoskeletal diseases, it is difficult to measure accurate worker workload and there is no method to determine effective work cycle order to prevent musculoskeletal diseases.

A typical method for measuring the workload of a worker on the spot is to evaluate based on the work posture. However, it is a reality to directly evaluate all work postures because it takes a lot of time and manpower to measure workload by selecting representative work posture.

Motion capture technology enables real-time acquisition and evaluation of the worker's work posture. Therefore, it is possible to calculate the workload for all the operations of the worker that was previously impossible, and more accurately determine the workload of the worker.

Work circulation not only reduces work-related musculoskeletal disorders, but also has various advantages such as multifunctionality, monotony of work, reduction of boredom, and reduction of work stress. In order to maximize these advantages, it is necessary to accurately measure and evaluate the load received from the worker when establishing the work cycle plan, and establish it based on this.

However, in many industrial settings, it is often the case that a task recurrence plan is set up arbitrarily without specific rules or regulations, and thus it has not been effective in preventing musculoskeletal diseases. Therefore, it is effective to establish the scope of the work cycle and the work cycle plan considering the characteristics of the worker as well as the characteristics of the worker.

When performing line balancing using optimization techniques in the field of production planning, line balancing is carried out by considering worker workload as a constraint factor and considering industry field more realistic. The work cycle planning using the optimization technique is to prevent the harmful factors of the musculoskeletal diseases from concentrating on the specific worker by modeling the change and diversity of the work.

This paper presents a mathematical method for establishing a work cycle plan that can effectively prevent musculoskeletal diseases in industrial settings.

In the present invention, the worker's work posture is measured in real time through the sensor composed of the MEMS sensor, and the work cycle order for preventing musculoskeletal diseases is determined based on the result of evaluating the accurate work load.

In this specification, a method for determining a work cycle order for effectively preventing a musculoskeletal disease,

Attaching a MEMS sensor to a selected body part to measure a worker's posture and transmitting the measurement result to an analysis system;

Analyzing the transmitted worker work attitude data and evaluating the work load of the worker; And

Based on the evaluated worker workload, it consists of determining the work cycle sequence so that the workload is not accumulated in the body part to prevent musculoskeletal disorders.

In one embodiment, measuring an operator work posture comprises:

Determining a position of the measurement sensor by dividing each body part to measure the work posture of the worker;

Attaching a 9-axis MEMS sensor including the wireless transmission module to each body part of a worker; And

And inputting the worker's work attitude information transmitted from the attached sensor to the database.

In one embodiment, evaluating the workload comprises:

Evaluating the workload of the worker on the weight of the neck, waist, leg, and heavy object according to the REBA evaluation method by inputting the worker work posture data and defining the posture score A;

Evaluating the workload of the worker on the shoulder, elbow, wrist, and knob according to the REBA evaluation method by inputting the worker work posture data and defining the posture score B; And

And evaluating the worker's workload by evaluating the worker's activity score in the posture score A and the posture score B,

In one embodiment, the step of determining a work cycle order comprises:

Establishing an objective equation of the work cycle;

Establishing a constraint condition equation of the work cycle;

And determining a work cycle order through an optimization technique including integer programming based on the objective equation and constraint conditions.

The present invention can determine an effective circulation order for preventing musculoskeletal diseases occurring at industrial sites in Korea and overseas.

The present invention relates to a system and method for preventing musculoskeletal diseases by performing a work cycle so that all workers can perform work with the same level of work load during a day while minimizing the cumulative workload for workers, Establish a model. The optimization work cycle model uses a workload evaluation result based on the work posture to establish a work cycle plan so that different body parts are exposed to the work load between the preceding process and the subsequent process, . Also, it suggests a work cycle model that minimizes the deviation between work processes and allows the worker to perform work at a certain workload level.

The present invention can be utilized in an industrial field having difficulty in establishing a systematic work cycle plan, and it is possible to reduce the possibility of musculoskeletal diseases caused by repeated work through a systematic work cycle. In the workplace where technological improvement has been made to eliminate musculoskeletal harmful factors, or where economic improvement is difficult and immediate engineering improvement is difficult, the optimization work cycle model helps prevent musculoskeletal disorders from appearing continuously in certain workers. .

1 is a conceptual diagram illustrating a worker workload evaluation method according to an embodiment of the present invention.
FIG. 2 is a conceptual diagram illustrating a procedure for evaluating posture score A, posture score B, and worker workload in order to evaluate a workload of a worker's body part according to an embodiment of the present invention.
Figure 3 is a workload evaluation sheet illustrating evaluation of an operator workload according to Figure 2;
Figure 4 illustrates the accumulation of workloads in the same body part when performing a sequential work cycle.
Figure 5 illustrates that when performing the work cycle of the present invention, no workload is accumulated in the same body part.
Figure 6 illustrates changes in worker cumulative workload per work cycle, including work cycle of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, Is provided to fully inform the user.

The object of the present invention is to prevent the accumulation of workload of a worker on a specific body part, and to avoid using a REBA to allocate a work process with a high workload of the same body part. In order to do this, it is necessary to identify the high-risk parts of the body of the preceding process and the subsequent process, and allocate the work process.

Means that the worker i is responsible for the work process s at the work cycle time p. When the worker i takes charge of the work process s at the work cycle time p

Is a binary variable with a value of 1, and a value of 0 otherwise. The workload of each work process s is

, And the total workload of the work process performed by the worker i for one day is

. The posture score A and the posture score B of the work process s are

Wow

. The median values were used to assess the relative workload risk of attitude score A and posture score B and the median values of attitude score A and posture score B were

Wow

, And when the posture score A and the posture score B of the work process s are relatively high in the risk of workload

Wow

Is a binary variable with a value of 1, and otherwise a value of zero.

The symbols used in the model presented in the present invention are summarized in Table 1.

The purpose of the work cycle presented in the present invention is to minimize the variance of the REBA score sum of work processes performed by a worker during a day so that the total work load of the work processes performed by all the workers during a day is similar. Therefore, the objective equation of the work cycle model is expressed as Equation (1) as minimizing the dispersion of the sum of the REBA scores of the processes performed during each day of each worker.

Equation 1

The worker of the assembly line performs the work continuously without moving in one work process for a predetermined work time. Therefore, as in Equation (2), the worker i only takes one process s at the work time p. In each work process, only one worker is placed during the same work time is expressed by Equation (3). Since the work cycle model proposed in the present invention is intended to prevent workload accumulation of the same body part of the worker, one worker restricts the repetition of the same work. Therefore, as shown in Equation (4), the worker i does not take the same process twice during the day. In order to restrict the use of the same body part between the preceding process and the subsequent process when the work cycle is performed, a body part having a high postural score of the preceding process must be assigned a process having a low postural score in the posterior process, Equation (6) limits the same body part between the preceding process and the subsequent process not to be responsible for the work process of the higher workload.

Equation 2

Equation 3

Equation 4

Equation 5

Equation 6

Claims

A database in which the body part of the worker is represented by a plurality of independent variables including the neck, waist, and leg parts and the work load of the shoulder, arm, and wrist parts and the work cycle order as dependent variables, Inputting from a sensor unit;
Measuring an attitude of an operator performing each task s with respect to the given independent variable values, calculating attitude score A and attitude score B, and evaluating an operator workload;
Determining a work cycle order for minimizing accumulation of workloads with respect to a day total worker workload of worker i rated with the given independent variable values.

The method of claim 1,
A sensor unit for measuring angles, angular velocities, and angular velocities of a human body joint;
Attaching a sensor part to each body part by dividing a body part of a person; And
Transferring from the sensor to the database.

The method of claim 1,
An evaluation step of posture score A in consideration of the work load of the neck, waist, and legs and the weight of the heavy object; And
Assessment stage of posture score B taking into account the workload of the shoulder, elbow, and wrist and the shape of the heavy handle.

The method according to claim 1,
Establishing an objective formula that minimizes a workload of a task in charge of the task cycle;
Distinguishing between high risk work and low risk work;
Determining a constraint item when performing a work cycle for preventing a musculoskeletal disease; And
A calculation step to determine the order of work cycles.

The sensor unit according to any one of claims 1 to 2, wherein the sensor unit for measuring angles, angular velocities, and angular velocities of the human body joints,
The sensor unit consists of a 9-axis MEMS sensor (3-axis gyro sensor, 3-axis acceleration sensor, 3-axis geomagnetic sensor) and a transmitter to transmit the measured data to a computer for measuring angle, angular velocity and angular velocity of each joint.

The method of any one of claims 1 to 2, wherein attaching the sensor portion
Positioning the sensor section at a plurality of predetermined positions of the entire body section;
And fixing the sensor unit to the body part.

The method according to any one of claims 1 to 3,
A method of evaluating the scores of neck, waist, and legs in body parts according to REBA, and then calculating scores based on the weight of the weight to determine attitude score A.

The method according to any one of claims 1 to 3, wherein the calculation of the posture score (B)
A method of evaluating the scores of shoulder, elbow, and wrist parts of the body according to REBA, and then calculating scores based on the handle form of the weight and determining the posture score B.

The method of claim 1,
Based on the results of claims 7 and 8, the worker workload is evaluated according to REBA's criteria.

The method according to any one of claims 1 to 4, wherein establishing an objective expression for minimizing a workload of a task in charge of the task cycle,
By minimizing the variance of the worker workload of all the work performed by the worker through the work cycle during the day, the total workload of all the workers during the day is similar, and each individual worker workload is minimized.

The method of any one of claims 1 to 4, wherein distinguishing the high risk work from the low risk work,
To calculate the relative workload risk of posture score A of claim 7 and posture score B of claim 8, the median value of posture score A, posture score B, and worker workload is calculated,
Define a job that exceeds the median value of job attitude A as job attitude A, a high risk job, define a job below the median value of job attitude A as job attitude A,
Defining a task that exceeds the median of the work attitude B as a work attitude B high risk task, defining a work below the median of the work attitude B as a work attitude B low risk task, and
Define tasks that exceed the median of the worker workload as high risk tasks, and define tasks below the median of the worker workload as low risk tasks.

The method according to any one of claims 1 to 4, wherein, when performing the task cycle for preventing musculoskeletal disorders,
A worker may be prevented from simultaneously performing two or more operations at the same time,
Limiting the same work to prevent two or more workers from being assigned at the same time,
Restricting one operator from performing the same operation more than once during a day, and
Restricting the predecessor task and the subsequent task to not perform the posture score A high risk task or the posture score B high risk task consecutively when carrying out the task cycle.

The work cycle order for minimizing the accumulation of workloads with respect to a day total worker workload of worker i evaluated as independent variable values in claim 1,
The task recurrence order satisfying the objective formula and the constraint condition derived in claim 10, claim 11, and claim 12 is derived through an optimization technique.