Integrated Tool Condition Monitoring Systems and Their Applications: A Comprehensive Review

Abstract

In conventional metal cutting, different tool wear modes, and their individual deterioration rates play vital roles in overall production performance. For a given tool (i.e., geometry or materials), many shop floors still follow a standard rule by pre-setting a tool life, which is conservative but not realistic. Premature failure of a tool can cause unexpected machine downtime and material losses, while another tool could serve beyond that pre-set life. As a result, optimized tool life and productivity cannot be achieved. Moreover, nowadays, there is an increased demand of process monitoring and optimization on the unmanned and the semi-automated shop floors.Tool condition monitoring (TCM) systems for process improvement and optimization have been in research for several decades. Both offline and online TCM systems are invented and discussed. A wide range of original publications are reported focusing on different sub-topics, e.g., specific machining process-based TCM methods, measurement or signal acquisition methods, processing methods, and classifiers. With the recent evolution of smart sensors in the era of Industry 4.0, development of online TCM systems received much attention to the researchers. Accordingly, research on some sub-topics also gets motivated into different directions, such as, feasibility of power or current sensors, machine vision technique, and combination of multi-sensors. Thus, from the industrial viewpoint, the current state of implementation of the proposed TCM systems for (near) real-time process monitoring and control needs to be clear. This paper presents the state-of-the-art of the TCM systems covering three major machining operations, discusses their application feasibility in industry environments, and states some current TCMS implementations. Challenges being faced by the industry are concluded, along with direction and suggestions for future researches.