Bus explosions have been attributed to poorly maintained mechanical systems, and PHM (Prognostic & Health Management) technology in mechanical engineering could be an effective solution to prevent such incidents. PHM can detect and prevent mechanical system failures at an early stage and provide benefits such as cost savings and improved safety. Currently, PHM research in Korea is limited, but the demand is expected to grow in the future.
Many years ago, a terrible accident occurred in downtown Seoul, South Korea. A bus that was traveling suddenly exploded, killing 17 people, including the driver and passengers. What’s even more horrifying is that many of the buses in Seoul are the same model as the bus that exploded, making them “street time bombs”. The cause of the accident was found to be poor maintenance and inspection of the buses, but the Seoul Metropolitan Government has not made any significant improvements. Is there any effective technology that can prevent such accidents? PHM, a branch of mechanical engineering, could be the solution to this problem.
Mechanical engineering is an academic discipline that is fundamental to industry and deals with the technology required to design, process, produce, and automate mechanical systems. In other words, it’s the overall technology of mechanical systems, such as airplanes. PHM, a sub-discipline of mechanical engineering, is an acronym for Prognostic & Health Management. It studies techniques for early detection of signs of failure in mechanical systems and effective initial response through appropriate decision-making to prevent failure.
At first glance, you might think that PHM is a discipline that belongs to medicine. In fact, the concept of PHM is very similar to that of preventive medicine. General medicine basically treats diseases when they appear. However, preventive medicine goes one step further and tries to keep people healthy by preventing diseases from occurring in the first place. If you think of mechanical systems as people, the role of PHM is the same as that of preventive medicine. PHM prevents mechanical system failures before they occur and keeps the system in a healthy state. Just as we need to understand our bodies to prevent diseases, we need to understand our mechanical systems. PHM is based on mechanics because it is important to analyze the forces acting on a mechanical system. It also uses statistics to predict the future state of the system based on the current state of the system.
There are a number of advantages to implementing PHM technology in your system to prevent system failures based on mechanics and statistics. The first is cost savings. PHM maintains and manages the system according to the state of the system. As a result, you can reduce system maintenance costs by implementing management optimized for the state of the system. For example, consider managing the health of a car’s engine oil with a PHM. The PHM detects the condition of the engine oil in real time, predicts the future condition, and sets the replacement time, so the engine oil can be replaced at the right time. This reduces the cost of replacing the oil early or late.
Second is safety. Safety is very important in mechanical systems. The city bus explosion mentioned above was caused by the lack of safety in the mechanical system. The bus explosion could have been prevented if the CNG fuel container, which was found to be the cause of the explosion, had been equipped with PHM technology. PHM could have predicted the explosive potential of the fuel through information such as the temperature and pressure of the fuel container and automatically lowered the temperature of the fuel or stopped the bus from running. PHM is superior in terms of safety because it is difficult to predict the likelihood of accidents in different driving conditions at different times with conventional periodic inspections. In addition to these advantages, PHM has many other benefits, such as reducing the failure rate of mechanical systems, increasing the cost of product sales, and improving the reliability of the system.
PHM technology has been recognized as a necessity and is already being actively researched in advanced countries such as the United States and the United Kingdom, and it is being eyed as a field that will grow in the future. However, PHM research in Korea is still underdeveloped. There are not enough universities and manpower to conduct PHM research, and it is still unfamiliar to mechanical engineering majors in Korea. However, the demand for PHM technology in Korea is expected to increase. In Korea, the number of mechanical systems has increased rapidly due to rapid industrial development over the past 50 years. And as the industry is entering a period of maturity after rapid development, the maintenance and management of existing systems is more important than the development of new systems. As a result, the market for PHMs that manage mechanical systems will continue to grow. It is expected that research in the PHM field in Korea will continue to grow.
