Marcus Bengtsson

Fault Diagnosis of Industrial Robots Using Acoustic Signals and Case-Based Reasoning

In industrial manufacturing rigorous testing is used to ensure that the delivered products meet their specifications. Mechanical maladjustment or faults often show their presence through abnormal acoustic signals. This is the same case in robot assembly – the application domain addressed in this paper. Manual diagnosis based on sound requires extensive experience, and usually such experience is acquired at the cost of reduced production efficiency or degraded product quality due to mistakes in judgments. The acquired experience is also difficult to preserve and transfer and it often gets lost if the corresponding personnel leave the task of testing. We propose herein a Case-Based Reasoning approach to collect, preserve and reuse the available experience for robot diagnosis. This solution enables fast experience transfer and more reliable and informed testing. Sounds from normal and faulty robots are recorded and stored in a case library together with their diagnosis results. Given an unclassified sound signal, the relevant cases are retrieved from the case library as reference for deciding the fault class of the new case. Adding new classified sound profiles to the case library improves the system’s performance. So far the developed system has been applied to the testing environment for industrial robots. The preliminary results demonstrate that our system is valuable in this application scenario in that it can preserve and transfer the related experience among technicians and shortens the overall testing time.

The potential in strategic maintenance development

Abstract Purpose - The purpose of this paper is to exemplify and discuss the potential in strategic maintenance development. Design/methodology/approach - This paper is based on a three-year indust ...

Supporting Implementation of Condition Based Maintenance: Highlighting the Interplay between Technical Constituents and Human and Organizational Factors

This article presents two case studies and theory on the topic of implementing a condition based maintenance approach. It visualizes that condition based maintenance, within the Swedish industry, i ...

Cost effectiveness of condition based maintenance in manufacturing

This paper presents a proposed guide for analysis of the costs and benefits of implementing Condition Based Maintenance (CBM) in manufacturing industry. The guide will be exemplified with results from a case study performed in a real CBM implementation in hardening and machining processes in a large manufacturing facility. The result indicates factors that ought to be taken into consideration in order to evaluate both the cost of implementing CBM and its benefits. These factors indicate the benefits of CBM mostly by reducing the losses due to damage in the production equipment, including capital loss, production loss, quality loss, environmental loss, safety loss etc. By analyzing the empirical data, the most potential savings by implementing CBM are presented as; reducing the probability of having maximal damage in the production equipment and, reducing production losses particularly in high production volumes.

Implementation of Condition Based Maintenance in manufacturing industry - A pilot case study

This paper presents a guide for implementation of Condition Based Maintenance (CBM) in a manufacturing industry, considering the technical constituents and organizational aspects when implementing CBM. The empirical base for the study is a case study from a major manufacturing site in Sweden. The data was collected during a pilot project to implement CBM at the case company. The purpose of the pilot study at the company was to implement online condition monitoring on some of the critical components in the hardening process. Hereby, two of the main online condition monitoring techniques namely vibration analysis and Shock Pulse Method (SPM) have been implemented and tested on electric motors to monitor bearing conditions. The paper presents the process of implementation and the elements included in this process. Some of the main elements in the implementation process are selection of the components to be monitored, techniques and technologies as well as installation of the technologies and finally how to analyze the results from the condition monitoring. The data from online condition monitoring on the electric motors, driving the furnace fans, are recorded and presented in the paper including breakdown data on two objects. This information is leading to useful and reliable knowledge for maintenance work to be cost effective and be able to increase the overall equipment availability (OEA). In addition to this, the result indicates to what extent advanced CBM practices are applicable in the hardening environment in the manufacturing company and it provides guidance for further research and development in this area. The paper concludes with a discussion on possible future trends and research areas, needed to increase the effective and efficient use of CBM.

Requirements and Needs—A Foundation for Reducing Maintenance-Related Waste

The objective of this paper is to discuss and elaborate on requirements of maintenance and the resulting maintenance needs in order to maintain said requirements without introducing waste while doing so, taking into account both external and internal wastes. The paper will present, and elaborate on, conceptual models that can be utilized in maintenance operations in order to increase awareness of the importance of well-founded customer/stakeholder requirements in order to articulate appropriate maintenance needs in order to balance effectiveness and efficiency as well as to reduce or eliminate maintenance-related waste.

Applying Multi-factorial Pareto Analysis in Prioritizing Maintenance Improvement Initiatives

One practical solution in prioritizing which maintenance improvement initiative to undertake is by using Pareto analysis. This has also been advocated for, as one tool (of many), to use within maintenance by many maintenance research practitioners. However, there are some drawbacks and potential sources of errors if not being cautious. The main objective of this research is to develop and test a tool to be utilized for prioritization purposes of maintenance improvement initiatives. The purpose of the paper is to exemplify, from an industrial case, some of the strengths and weaknesses of this approach.

Hinder och möjligheter i handledningssituationen - en recension av två forskarhandledningsböcker

Vi har last och diskuterat Asa Bergenheim och Karin Agrens Forskarhandledarens robusta rad samt Monika Appel och Asa Bergenheims Ref lekterande forskarhandledning i syfte att ref lektera over hur och av vem de kan anvandas i forskarhandledningssituationer. Det ska redan inledningsvis sagas att aven om Bergenheim ar medforfattare till bada titlarna, har bockerna skilda fokus och kan darfor aven komma till anvandning pa olika vis. Forskarhandledarens robusta rad ar en antologi, dar de skilda bidragen har ambitionen att fokusera pa konkreta rad. I Ref lekterande forskarhandledning ger forfattarna en elementar bakgrund och ram till forskarhandledningssituationen. Bockerna kompletterar darmed varandra val. Vi ska ocksa se att de kanske anvands bast av olika aktorer i handledningssituationen.