Exploring a cobot risk assessment approach combining FMEA and PRAT

Abstract

Collaborative robots are an emerging technology falling within the scope of Industry 4.0 and based on the concept of Human-Robot Collaboration (HRC). Unlike traditional industrial robots, collaborative robots are used in shared workspaces with no safety fences. Hence, prospective hazardous contacts need to be avoided or mitigated through a risk assessment. The normative standards such as ISO TS 15066 suggest a list of common hazards, but do not guide the robot system user through the risk assessment process. To address this shortcoming, this paper proposes a practical eight steps risk assessment approach, resulting in a risk priority list. In order to provide an accurate, practical, quantitative and supportive tool for HRC environments, the Failure Mode and Effects Analysis (FMEA) and the Proportional Risk Assessment technique (PRAT) techniques are proposed for risk assessment. The two techniques mentioned above are combined in the suggested new methodology, highlighting both their benefits and disadvantages. The proposed methodology is applied with positive results to a collaborative brick-lifter case study.

Failure analysis of floating offshore wind turbines based on a fuzzy failure mode and effect analysis model

“…(ii) FMEA's focus on known failure modes may hinder its ability to encompass emerging or unforeseen risks, particularly in developing technologies with limited operational experience. 36 (iii) The challenge of identical RPN values arising from distinct failures complicates failure differentiation and introduces an element of uncertainty in risk categorization. The traditional assumption of independence among failures, which forms the basis of many FMEA methodologies, may only sometimes hold, particularly in complex systems such as wind turbines.…”

“…The deterministic nature of FMEA, with single‐point estimates for factors, may not adequately address uncertainties and variations in dynamic environments, limiting its effectiveness over time. (ii) FMEA's focus on known failure modes may hinder its ability to encompass emerging or unforeseen risks, particularly in developing technologies with limited operational experience 36 . (iii) The challenge of identical RPN values arising from distinct failures complicates failure differentiation and introduces an element of uncertainty in risk categorization.…”

Reliability Prediction for New Prefabricated Track Structures Based on the Fuzzy Failure Modes, Effects, and Criticality Analysis Method

“…FMECA is a fundamental task for identifying the weak links and critical items in the reliability of a new prefabricated track structure system. Through FMECA, basic information for evaluating and improving system reliability can be systematically obtained, providing data support for enhancing the overall performance of the track structure [26,27].…”

Fuzzy Method to Improve Products and Processes Considering the Approach of Sustainable Development (FQE-SD Method)

“…In order for enterprises to increase their competitiveness they should implement the effective management of selected elements in the process of product development [1][2][3]. These elements have the potential to satisfy customer expectations and environmental requirements [2,4,5], as well as influence technical requirements, thus leading to the creation of innovative products [6,7] and possibly the development of ideal product alternatives [8][9][10]. The management of the quality of products and processes is recognised as the main element supporting issues of sustainable development [11,12].…”