In this blog post, we will look at how PHM technology, which predicts and prevents mechanical system failures, will change the future of mechanical engineering.
A long time ago, there was a terrible accident in downtown Seoul, South Korea. A bus suddenly exploded while in operation, seriously injuring 17 people, including the driver and passengers. What is even more frightening is that many of the buses in downtown Seoul are of the same model as the bus that crashed, making them nothing less than “time bombs on the streets.” The cause of the accident was found to be poor maintenance and inspection of the buses, but the Seoul city government has not come up with any clear improvement measures. Is there any effective technology that can prevent such accidents? A field of mechanical engineering called PHM may be the solution to this problem.
Mechanical engineering is a fundamental academic field that deals with the technologies necessary for designing, processing, producing, and automating mechanical systems. In simple terms, it can be said that it deals with the overall technology of mechanical systems such as airplanes. PHM, a subfield of mechanical engineering, stands for “Prognostic & Health Management.” It studies technologies for detecting signs of machine system failure at an early stage and performing effective initial responses through appropriate decision-making to prevent failure.
At first glance, preventive and health management may seem to belong to the field of 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 than treating diseases by preventing them from occurring in the first place to maintain human health. If we think of machine systems in PHM as humans, the role of PHM is the same as that of preventive medicine. PHM prevents machine systems from breaking down before they do, keeping them in a healthy state. Just as it is important to understand the human body in order to prevent disease, it is also important to understand machine systems in PHM. In order to analyze machine systems, it is important to understand the forces acting on the system, which is why PHM is based on mechanics. Statistics are also used to predict the future state of the system based on information about its current state.
There are many advantages to introducing PHM technology, which prevents system failures based on mechanics and statistics, into a system. The first advantage is cost reduction. PHM maintains and manages the system according to its condition. This enables maintenance optimized for the condition of the system, thereby reducing system maintenance costs. Consider, for example, the use of PHM to monitor the health of a car engine oil. PHM detects the condition of the engine oil in real time, predicts its future condition, and determines when it needs to be replaced, enabling the engine oil to be replaced at the right time. This reduces the costs associated with replacing the engine oil too early or too late.
The second advantage is safety. Safety is extremely important in machine systems. The city bus explosion mentioned above was caused by a failure to ensure the safety of the machine system. If PHM technology had been introduced for the CNG fuel tanks, which were found to be the cause of the bus explosion, the accident could have been prevented. PHM could have prevented the accident by predicting the possibility of fuel explosion based on information such as the temperature and pressure of the fuel tanks and automatically lowering the fuel temperature or stopping the bus. PHM is superior in terms of safety because it is difficult to predict the possibility of accidents in real-time driving situations with conventional regular inspections. In addition to these advantages, PHM has several other advantages, such as reducing the failure rate of mechanical systems, increasing product sales costs, and improving system reliability.
Recognizing the necessity of PHM technology, advanced countries such as the United States and the United Kingdom are already actively conducting research in this field, which is attracting attention as a growth area in the future. However, PHM research in Korea is still in its infancy. There is a lack of universities and human resources conducting PHM research, and even mechanical engineering majors in Korea are still unfamiliar with this field of study. Nevertheless, the demand for PHM technology in Korea is expected to increase. In Korea, the number of mechanical systems has increased rapidly over the past 50 years due to rapid industrial development. As the industry has undergone rapid development and is now entering a period of maturity, the maintenance and management of existing systems is becoming more important than the development of new systems. Accordingly, the market for PHM, which manages mechanical systems, will continue to grow. The future of PHM research in Korea will be closely watched.
