Selasa, 08 November 2016

English Article

History of Control Engineering

Automatic control systems were first developed over two thousand years ago. The first feedback control device on record is thought to be the ancient Ktesibios's water clock in Alexandria, Egypt around the third century B.C. It kept time by regulating the water level in a vessel and, therefore, the water flow from that vessel. This certainly was a successful device as water clocks of similar design were still being made in Baghdad when the
Mongols captured the city in 1258 A.D. A variety of automatic devices have been used over the centuries to accomplish useful tasks or simply to just entertain. The latter includes the automata, popular in Europe in the 17th and 18th centuries, featuring dancing figures that would repeat the same task over and over again; these automata are examples of open-loop control. Milestones among feedback, or "closed-loop" automatic control devices, include the temperature regulator of a furnace attributed to Drebbel, circa 1620, and the centrifugal fly ball governor used for regulating the speed of steam engines by James Watt in 1788.
In his 1868 paper "On Governors", James Clerk Maxwell was able to explain instabilities exhibited by the flyball governor using differential equations to describe the control system. This demonstrated the importance and usefulness of mathematical models and methods in understanding complex phenomena, and signaled the beginning of mathematical control and systems theory. Elements of control theory had appeared earlier but not as dramatically and convincingly as in Maxwell's analysis.
Control theory made significant strides in the next 100 years. New mathematical techniques made it possible to control, more accurately, significantly more complex dynamical systems than the original flyball governor. These techniques include developments in optimal control in the 1950s and 1960s, followed by progress in stochastic, robust, adaptive and optimal control methods in the 1970s and 1980s. Applications of control methodology have helped make possible space travel and communication satellites, safer and more efficient aircraft, cleaner auto engines, cleaner and more efficient chemical processes.
Before it emerged as a unique discipline, control engineering was practiced as a part of mechanical engineering and control theory was studied as a part of electrical engineering since electrical circuits can often be easily described using control theory techniques. In the very first control relationships, a current output was represented with a voltage control input. However, not having proper technology to implement electrical control systems, designers left with the option of less efficient and slow responding mechanical systems. A very effective mechanical controller that is still widely used in some hydro plants is the governor. Later on, previous to modern power electronics, process control systems for industrial applications were devised by mechanical engineers using pneumatic and hydraulic control devices, many of which are still in use today.

Source : https://en.wikipedia.org/wiki/Control_engineering


sejarah teknik control

sistem kontrol otomatis pertama kali dikembangkan lebih dari dua ribu tahun yang lalu. Perangkat kontrol umpan balik pertama pada catatan dianggap jam kuno Ktesibios ini air di Alexandria, Mesir sekitar SM abad ketiga Itu terus waktu dengan mengatur tingkat air di kapal dan, oleh karena itu, aliran air dari kapal itu. Hal ini tentu merupakan perangkat yang sukses sebagai jam air desain serupa masih dibuat di Baghdad ketika Mongol merebut kota pada tahun 1258 Masehi Berbagai perangkat otomatis telah digunakan selama berabad-abad untuk menyelesaikan tugas-tugas yang berguna atau hanya untuk sekedar menghibur. Yang terakhir termasuk automata, populer di Eropa pada abad ke-17 dan ke-18, menampilkan tokoh menari yang akan mengulangi tugas yang sama berulang-ulang; automata ini adalah contoh dari kontrol loop terbuka. Milestones antara umpan balik, atau "loop tertutup" perangkat kontrol otomatis, termasuk regulator suhu tungku dikaitkan dengan Drebbel, sekitar tahun 1620, dan Gubernur terbang bola sentrifugal yang digunakan untuk mengatur kecepatan mesin uap oleh James Watt pada tahun 1788.

Pada tahun 1868 makalahnya "On Gubernur", James Clerk Maxwell mampu menjelaskan ketidakstabilan yang dipamerkan oleh gubernur flyball menggunakan persamaan diferensial untuk menggambarkan sistem kontrol. Ini menunjukkan pentingnya dan kegunaan model matematika dan metode dalam memahami fenomena yang kompleks, dan menandai awal dari kontrol matematika dan teori sistem. Elemen teori kontrol telah muncul sebelumnya tapi tidak dramatis dan meyakinkan seperti dalam analisis Maxwell. teori kontrol membuat langkah signifikan dalam 100 tahun ke depan. teknik matematika baru memungkinkan untuk mengontrol, lebih akurat, sistem dinamis secara signifikan lebih kompleks daripada gubernur flyball asli. Teknik-teknik ini termasuk perkembangan di kontrol optimal pada 1950-an dan 1960-an, diikuti oleh kemajuan dalam stokastik, kuat, adaptif dan metode kontrol optimal pada 1970-an dan 1980-an. Aplikasi metodologi kontrol telah membantu membuat perjalanan ruang angkasa dan komunikasi satelit mungkin, lebih aman dan lebih efisien pesawat, mesin auto bersih, bersih dan proses kimia yang lebih efisien.
Sebelum itu muncul sebagai suatu disiplin unik, teknik kontrol dipraktekkan sebagai bagian dari teknik mesin dan kontrol teori dipelajari sebagai bagian dari teknik listrik sejak sirkuit listrik sering bisa dengan mudah dijelaskan dengan menggunakan teknik teori kontrol. Dalam hubungan kontrol pertama, arus keluaran diwakili dengan masukan kontrol tegangan. Namun, tidak memiliki teknologi yang tepat untuk menerapkan sistem kontrol listrik, desainer kiri dengan pilihan sistem mekanik menanggapi kurang efisien dan lambat. Sebuah controller mekanik yang sangat efektif yang masih banyak digunakan di beberapa tanaman hidro adalah gubernur. Kemudian, sebelumnya untuk elektronika daya modern, sistem kontrol proses untuk aplikasi industri yang dirancang oleh insinyur mekanik menggunakan perangkat kontrol pneumatik dan hidrolik, banyak yang masih digunakan sampai sekarang.

Sumber : https://en.wikipedia.org/wiki/Control_engineering

Build 5W+1H sentences

1.  What is the application who can help to make space travel more safety called?
      Answer : Applications of control methodology
2.  When did the first time automatic control system develop ?
      Answer : Automatic control systems were first developed over two thousand years ago
3.  Where was the automata popularize?
      Answer : Automata popular in Europe in the 17th and 18th centuries
4.  Who was able to explain instabilities exhibited by the flyball governor using diferential equations  to describe the control system ?
      Answer : James Clerk Maxwell

5.  Why was the automatic system control created?
      Answer : to solve some useful duty and it can be just for fun
6.  How  was mathematic used to make the automatic control system ?
      Answer : Because Maxwell can explain about the thing related to the automatic control system


List verbal and nominal sentences

v List Verbal
      Automatic control systems were first developed over two thousand years ago
      It kept time by regulating the water level in a vessel
      Mongols captured the city in 1258 A.D
      A variety of automatic devices have been used over the centuries to accomplish useful tasks or simply to just entertain
      James Clerk Maxwell was able to explain instabilities exhibited by the flyball governor using differential equations to describe the control system
      The first feedback control device on record is thought to be the ancient Ktesibios's water clock in Alexandria



v List Nominal
      The latter includes the automata, popular in Europe in the 17th and 18th centuries

Identify tenses

v Simple Past Tense
      James Clerk Maxwell was able to explain
                   S                            P
instabilities exhibited by the flyball governor
                                                                  O
Reason : Because the Sentence tell the event in the past

      It kept time by regulating the water level in a
S              P                               O         
    vessel
                    K
Reason : Because the sentence tell the event in the past


v Past Perfect Tense
      Elements of control theory had appeared earlier
                         S                                P              K
Reason : Because the sentence tell an action who has finished before another action in the past

Conclusion

v So we know from the article that we must learn all history about science in order to more knowledge about science development from the past so we won’t repeat the mistakes from the past so we can develop science better

Change sentences active to passive and conversely

v Mongols was captured the city in 1258 A.D (Active)
v in 1258 A.D the city captured by Mongols (Passive)

v James Clerk Maxwell was able to explain instabilities (Active)
v instabilities was able to be explained  by James Clerk Maxwel (Passive)