The facilitation for human activity is getting more and more real. Along with technology improvement, things that are typically done manually now can be preceded automatically. It is because human creates an automatic and control system. The ability to design and create this automatic and control system is needed to make everything under control and guaranteed. In the end, the efficiency and effectiveness rate in a process of something can be achieved.
There are many types of research related to control system that is conducted to achieve the stability in many uncertain systems. In this research, it specifically discusses how to design a control system of neutral system; a system with delay period, and change of delay period, so it can achieve optimum and stable condition.
Optimum can be defined that cost and time function is efficient and economical, while stable can be explained as follow: even though a system faces uncertainty that is caused by many things, such as disturbance and system physical changes, but control system that is designed can result a strong system reaction to overcome the uncertainty.
The application of this con- trol system can be found in daily life, nowadays. Including the simple one, for example, feed water tank. If it is done manually, it is easy to fill out the tank, only by turning up the faucet, waiting for the water to fulfill the tank, and turning it down after the tank is full. However, this method is considered ineffective, inefficient, and not optimum, since human should continually monitor the tank, whether it is already full or not.
For that reason, control system appears to optimize and ease the human jobs. So, people make a control system for the feed water tank using some instruments that can replace the eye and hand of human; for example by using censor, automatic switch (electronic, mechanic, and hydraulic instruments), and the result is changed to energy that moves motor to turn on and off the faucet. So there are automatic works performed by instruments using a simple algorithm that replaces human brain.
So, water feed using this automatic system can work alone, without human supervision. For example, when water already reaches a given minimum limit, the faucet will turn on and when water already reaches the maximum limit, this faucet will also turn off, automatically.
Initiated from Steam Machine by James Watt
Control system is a set of equipment to control, to order and to arrange a state of system.
There are many methods and algorithms of control system that are applied, starting from simple systems such as automatic feed water tank, to a very complicated system with a huge scale, such as aerospace control systems.
Control system itself started from the invention of steam machine by James Watt. The first work that is very important in control system was centrifugal governor to control the speed of this steam machine made in 18th century.
Another important work in the development of control theory was made by Minorsky, Hazen, Nyquist, et al. In 1922, Minorsky made an automatic controller to drive a ship and he showed how to determine the stability from differential equation that pictured physical system.
In 1943, Hazen intro- duced ReleServomekanis term that responded to changing input. During 1940s decade, frequency method enables the engineer to design linear feedback control that fulfils working requirements. The frequency response method enabled engineers to design linear control system with feedback that fulfilled work- ing requirements. By the end of 1940, until the beginning of 1950, the method of position of root in control design greatly developed and it has been used until now.
Control system actually can be found not only in electronics engineering but also in mechanics area, process chemistry or other areas of knowledge. It is true that control system is dominated by electronics engineering area, considering the easiness of the conversion, storage and process of electrical signal.
The character of this research is fundamental and it is focused on math modeling, and continued by strong control design (robust) for system with uncertainty character. Later on, the outcome of this research is expected to be implemented, for example, in control system of rotation and electrical motor and others.
For that reason, as the continuity of control system research, a research is being conducted in which the outcome is the implementation of control design on reaction wheel that is applied in Nano satellite. Besides that, this research also found important outcomes for teaching activity, i.e. enriching teaching materials of control system, so it will improve lecturers’ and students’ knowledge in control design.
Cited from a research: “Model Guaranteed Cost Pada System Netral Tak Pasti dengan Waktu Tunda yang Berubah Terhadap Waktu: Sistem Kendali dan Penyaringan (Filtering)” by Erwin Susanto, S.T., M.T., Ph.D and Junartho Halomoan,S.T., M.T.
