In this blog post, we’ll explore the principles, history, and future role of control engineering, which powers various sectors of modern industry, ranging from smartphones to robots, semiconductors, artificial organs, and smart grids.
A man wearing a black turtleneck and jeans steps onto the stage. He soon pulls out a simple, futuristic-looking device and holds it up for the audience to see. When he touches the screen, it responds exactly as his finger moves; when he rotates the device, the screen rotates accordingly. Furthermore, when placed in a bright area, the screen’s brightness adjusts to the surrounding environment, and when he speaks into the device, it automatically recognizes his voice and begins a search. As everyone can guess, the features described above are the ones Steve Jobs demonstrated when he unveiled the iPhone. While the iPhone is famous for the “App Store,” which allows users to access smartphone applications in one place, the various sensors built into the iPhone have also become key elements in providing users with a diverse range of experiences. Since then, smartphones have come standard with a variety of sensors—such as touchscreens, accelerometers, motion sensors, proximity sensors, ambient light sensors, compasses, and GPS—along with the control and signal processing technologies that utilize them. These features would have been difficult to implement without advancements in sensor miniaturization, mass production, digital signal processing, and control systems. While the field of control engineering within electrical engineering is very broad, broadly speaking, it involves designing and adjusting inputs so that the state or output of a machine or system exhibits the characteristics intended by the designer. To set a machine’s output according to the designer’s specifications, it is essential to use sensors that detect the machine’s current state and provide feedback—that is, information about the current output—to the system, thereby adjusting the input so that the output moves in the desired direction. Control engineering develops various control devices and algorithms to perform this process; these act as the “brain” that controls the entire system. A control system can be viewed as functioning similarly to the process by which our bodies receive external information through the senses, and the brain issues appropriate commands to the motor system based on that information. Furthermore, control engineering is closely linked to the field of signal processing, which not only handles signals such as speech but also removes noise generated during various electrical and electronic processing steps or isolates only the desired signals. Simply put, control engineering is the field of designing systems that enable machines and computers to automatically perform tasks—such as measurement, recording, transmission, comparison, and adjustment—that were previously carried out manually by people.
The origins of control engineering can be traced back to the invention of the steam engine. One of the earliest control devices was the centrifugal governor, which regulated the rotational speed of the steam engine. This device worked by attaching a weight to the rotating part of the steam engine, which was connected to the fuel or steam supply system, thereby automatically regulating the rotational speed. If the steam engine rotated too fast, the weight would move outward due to centrifugal force, reducing the supply of fuel or steam and thereby slowing the engine’s speed. Conversely, if the steam engine’s rotation slowed too much, the weights would move inward, increasing the fuel or steam supply and causing the engine’s speed to increase again. Through this principle of feedback—detecting the current state and adjusting the input accordingly—the speed of the steam engine could be maintained at a constant level. Although it was a very simple device, this principle became a crucial starting point for automatic control, which has since evolved into modern control engineering.
Modern control engineering has moved beyond the intuitive interpretive methods of its early days and now analyzes system characteristics and stability using various mathematical theories, such as differential equations, linear algebra, probability, and statistics. Several scholars have made significant contributions to the development of control engineering. In particular, Aleksandr Lyapunov developed theories for the mathematical analysis of system stability, while Harry Nyquist proposed an important method for analyzing the stability of feedback systems in the frequency domain. Today’s control systems actively utilize digital technologies, such as computers, in addition to traditional analog signal analysis. For example, the accelerometer used in smartphones detects acceleration along the x, y, and z axes, measures it as an electrical signal, and processes it into digital data. By utilizing this signal, it is possible to implement features such as rotating the screen when the smartphone is rotated, or making a die displayed on the screen roll around within the screen in response to the user holding and shaking the smartphone. This process—in which a sensor measures the surrounding environment or the device’s state, a computer processes that information, and the system then performs an appropriate action—can be considered a prime example of a modern control system.
With the advancement of digital systems such as computers, control engineering has once again entered a new era. Today, control engineering serves as a foundational technology in various fields, including video and audio signal processing, robotics—which deals with the movement and behavior of robots—autonomous systems, smart manufacturing, semiconductor process control, drones, and autonomous driving systems. Furthermore, control and signal processing technologies are being utilized in the field of biomedical engineering, including medical devices such as artificial hearts, medical imaging systems, and the processing of various biosignals. In particular, the importance of intelligent control combined with artificial intelligence, autonomous systems, and robotics technology has been growing significantly in recent years. Control engineering is expanding beyond the mere regulation of machine motion to become a core technology that enables complex systems to perceive and assess their surroundings and achieve desired objectives. The School of Electrical and Computer Engineering at Seoul National University also currently treats robotics, automation, and control systems as one of its major areas of education and research, conducting broad-ranging research that integrates electrical, electronic, and computer technologies with control engineering.
The history of control engineering in South Korea is relatively short. At Seoul National University, the Department of Instrumentation and Control Engineering was established in 1978 and reorganized into the Department of Control and Instrumentation Engineering in 1982. Subsequently, in 1992, these programs were integrated into the Electrical, Electronic, and Control Engineering Division, and the current School of Electrical and Computer Engineering was launched through the merger of the Department of Electrical Engineering, the Department of Electronic Engineering, and the Department of Control and Instrumentation Engineering. These events—the establishment of the Department of Instrumentation and Control Engineering in 1978 and its reorganization into the Department of Control and Instrumentation Engineering in 1982—are also documented in Seoul National University’s official history. Furthermore, in 1988, the Joint Research Institute for Automation Systems was established, expanding the research infrastructure in the fields of automation and control. Although control engineering has only relatively recently begun to establish itself as a full-fledged field of education and research in South Korea, its subsequent pace of development has been remarkably rapid. Today, the need for control engineering is growing even more in various fields—including the semiconductor industry, which plays a major role in South Korea’s economy, as well as robotics, smart manufacturing, autonomous systems, smart grids, and biomedical engineering. In particular, as industrial sites become automated and machines and computers are connected via networks, the importance of control technology—which measures and analyzes the status of various devices in real time to ensure optimal operation—is increasing significantly. As new technologies—such as artificial intelligence, robotics, autonomous driving, smart manufacturing, and advanced medical devices—continue to advance, control engineering will expand its role as a core enabling technology that ensures these technologies operate reliably in real-world environments. This is why there is growing anticipation about how control engineering—often referred to as the “brain” of modern industry—will combine with other technologies to create new industries in the future.
