Ergonomic Evaluation with the RULA Method in Real Working Conditions through Kinect V2.

Abstract

Nowadays, there are several methods, mostly observational, to assess exposure to ergonomic risk factors, of which the RULA method is one of the most used. The disadvantage of the RULA and the observational methods in general, is that the data collection is very subjective and is based on estimations of angles projected on photos and/or videos, which induces variations according to the criteria of each evaluator. It is thus, that the use of the Kinect V2 sensor is proposed, as a tool for ergonomic assessment in real workplace conditions in industry. The Kinect V2 is a sensor-less or marker-less motion capture system, which is able to detect the human body and get information of its main positions and joints with the help of its RGB and depth camera, which is known as skeleton tracking. From this information, the planes, angles and positions of the worker are obtained, which the RULA method needs to determine the existence of ergonomic risks. The application of the system with Kinect V2 was carried out in a metalworking industry during working hours and a particular task which presents ergonomic risk was selected together with the Occupational Safety and Health Department of this company. The RULA score obtained by the implemented system is compared with the professional criteria of an expert, where both evaluations agree that the analyzed task must be redesigned. The results obtained are very promising and we will discuss which are the best positioning conditions of the sensor and what are its limitations for this application.