Antropomorfik Robotların Dinamiği Ve Adaptif Kontrol Uygulamaları: Matlab/simulink Modelleme

Abstract

Robotlar günümüzde bir çok alanda insanların yaşayışlarını ve işlerini kolaylaştırmak için kullanılan mekanizmalardır. İlk zamanlarda basit makineler şeklinde dizayn edilmiş olan robotlar zamanla ilerlemiş ve insanımsı yapılara dönüşmüşlerdir. Robotların tarihteki gelişimi incelendiğinde karşımıza robot alanında ilk çalışmaları yapan ve ilk sibernetikçi kabul edilen Ebul-iz İsmail bin ar-Razzaz el-Cezeri çıkmaktadır. Ebul-iz İsmail bin ar-Razzaz el-Cezeri 1205-1206 yıllarında yazdığı "Kitab-ül'-Camü Beyne'l-İlmi-i ve'l-amelen-Nafi' Fi Sınaati'l-Hiyel" adlı kitabın içinde, 300'e yakın otomatik makine ve sistemleri ile ilgili bilgi verdikten sonra çalışma özelliklerini şemalarla göstermiştir. Sadece suyun kaldırma ve basınç gücünü kullanarak tamamen yeni bir teknik ve sistem kurmuş, çok yönlü otomatik hareketler elde edebilmiştir. Kurmuş olduğu otomatik sistemlerde ses (kuş, davul, zurna, ıslık vs) ya da çığlık çıkması gerektiği anda bu sesleri de sağlayabilmiştir. 17. ve 18. yüzyıllarda Avrupa'da ilkel otomatlar bulunmuştur. 1940’lı yıllardan sonra gelişen teknolojiye bağlı olarak robot teknolojisinde büyük gelişmeler görülür ve endüstriyel robotların üretimi başlar. Günümüzde robotların sanayi robotu, insansı robotlar gibi değişik çeşitleri bulunmaktadır. Bizim incelediğimiz kısım endüstriyel robotlardır. Endüstriyel robot; genel amaçlı, insana benzer özelliklere sahip programlanabilir bir makinedir. Bu robotun insana benzeyen en önemli özelliği onun koludur. Tutma ve yerleştirme işlemlerinde robot kolu kullanılır. Robot kolu, başka bir makineyle birleştirilerek, malzemenin yüklenmesi ve takım değiştirme işlemini yapmaktadır. Kesme, şekil verme, yüzey kaplama, silindirik ve düzlem yüzey taşlama gibi imalat işlemlerini gerçekleştirir. Montaj ve kontrol uygulamalarında kullanılmaktadır. Genellikle hantal ve sabit konumludurlar. Bu çalşımada kullanılan sanayi robotu ABB firmasına ait IRB 140 robotudur. Bu robot üzerinde kullanılan gerçek veriler üzerinden kinematik ve dinamik kontrolleri yapılmıştır. Kontrol sistemleri genel olarak lineer ve lineer olmayan kontrol sistemleri olarak ikiye ayrılmaktadır. 20. yuzyılın ikinci yarısından itibaren lineer kontrol sistemlerinin yetersiz kaldığı bir çok durum meydana çıkmaya başlamıştır. İlk olarak uçaklarda karşılaşılan lineer sistemlerin yetersizliği problemi lineer olmayan yöntemlerin kullanılmaya başlanılmasıyla çözüme kavuşmaya başlamıştır. Ancak şu da belirtilmelidir ki lineer olmayan kontrol sistem tasarımları lineer sistemlere göre daha zordur. Lineer olmayan kontrol sistemleri ile alakalı bir çok yönteme ulaşmak mümkündür. Ancak hem uçaklarda hem de robotlarda kullanılan genel yöntemler olarak gürbüz kontrol, uyarlamalı kontrol gibi sistemler kullanılmaktadır. Bunların yanında robotlarda kullanılan kayma kipli kontrol yöntemi de bulunmaktadır. Bütün eklemlerin bütün verilerinin çok iyi bir şekilde bilindiği durumlarda hesaplanmış tork yöntemi ile sistemi çözmek ve iyi sonuçlara ulaşmak mümkündür ancak sistemin bütün parametreleri hatasız olarak bilebilmek mümkün olmayabilmektedir. Bunun için kullanılan yöntemlerden uyarlamalı kontrol sistemi üzerinde durulmuştur. Uyarlamalı kontrol yönteminde sistemin parametrik hataları giderilebilmiştir. Bu yöntemlerde ve çalışmalarda Denavit-Hartenberg yöntemi ve Matlab kullanılmıştır. Robot hakkındaki bütün bilgiler ABB firmasından alınmıştır.

Nowadays, robots are used to simplify the works and human lives in many areas. In the beginning, simple machines had been designed but with the time, complicated robots as humanoid robots have been structured. When we examine the improvement of robotics in history, we meet with Ebul-iz İsmail bin ar-Razzaz el-Cezeri that made the first robotic labors. He is accepted as the first cybernetic. He has written a book named "Kitab-ül'-Camü Beyne'l-İlmi-i ve'l-amelen-Nafi' Fi Sınaati'l-Hiyel" that contains nearby 300 automatic machines and systems. In the book, all systems have been viewed clearly with diagrams. By the water’s lift force and pressure, he has used a new technic and performed very effective systems. Besides, in the automatic systems he could provide some voices like birds, timpani, clarions, whistles and screams. In the seventeenth and eighteenth centuries, primary automatic systems have been found in Europe. Barely with the developing technologies by 1940, there have been big developments in robot technology and industrial robots started to be produced. Now there are types of robots like industrial, humanoid etc. We are interested in industrial robotics. Industrial robots are used for general purposes and can behave like human. Industrial robots generally designed as an arm. All the works have been done with that arm. Those arms can work with each other and can some works like loading material, changing tools, cutting, forming, coating and grinding cylindrical and plane surface. Those arms are generally cumbersome and fixed. Robotic systems that being used in the industry have a rising line that any machine in industry can only be used for a purpose. A robot can be used for several purposes like human. The robots can be serial or parallel. The serial robots like human and can do many things like human and can have some solutions for barriers. However, the parallel robots cannot behave like the serials. They cannot move like human but if you need very big resolution and powers in a restricted area, you must use parallel. Generally, in industry, serial robots are being used and our work is about serial robots. When you start to work in the field of robotics, you must coordinate the robotic systems. There are simple diversity between plane and robots that was shown in thesis. There are mainly two methods to find equations as spatial operator algebra (SOA) and Denavit Hartenberg (DH). In this thesis, Denavit Hartenberg has been used and examined in detail. DH is a simple method to learn and to use so DH is being used in many robotic systems continuously. In the main idea in DH robot needs to a main coordinate axis and depending on the main axis other axes being determined. In DH, you need coordinate axes for every link and all of the axes must be related to previous one. How to determine all the axes have shown in thesis. In thesis, there are mainly two problems that kinematic and dynamic. Kinematic system has two titles that forward and inverse kinematics. Forward kinematic works from links to tip point namely you know the link’s angle and location values and so you can find the tip point. Inverse kinematic determine the link’s values from tip points. Inverse kinematic must be calculated to work in robotic area. Kinematic systems have been examined in second and third chapters. Dynamic systems have the same situations like kinematic systems that are forward dynamic and inverse dynamics. In forward dynamics, we have the torque values for every links, we find acceleration values for each links, and so we can find acceleration and so velocity, location at any moment. In the inverse dynamics, we have the link’s location, velocity and acceleration values at any moment so we get the torque values for every links. Each of these systems are nonlinear and so control system must be nonlinear but when we put the inverse and forward dynamics one after another we have inputs as location, velocity and acceleration and have outputs as acceleration, velocity and location. There are some types of controllers for systems like robots. Generally, there are two ways to solve the control problems as linear and nonlinear systems. Linear systems are simple and easily applicable and so in first times generally used but linear control systems was not enough for some systems. Because some systems are so complicated and have nonlinear differential equations. Firstly, airplane systems needed to nonlinear control systems. The nonlinear systems were successful so they were used in the other systems like robots. The dynamics systems are nonlinear systems and control systems must be nonlinear. In this thesis some control mechanism has been dealt like computed torque, robust and adaptive. Computed torque gives fast and good results. It works both forward and inverse dynamic systems. If there is not any parametric fault, the system works very good and systems become like linear. However, if there are some parametric errors the computed torque cannot tolerate the error. Robust control systems tolerate the error that comes from outside but dynamic model must be very good. In adaptive control systems dynamic model does not have to be perfect that adaptive control system tolerates the errors that come from model as link mass, length and any others, besides tolerate the faults from outer region like robust do. In mathematical equations adaptive are similar to computed torque but we have some addition on it. Namely, the dynamic equation is accepted as combination of two equations as regression matrix and parameter faults. When you study on that terminology, you reach to a control equation that related to parametric faults. This mathematical structure has been shown in thesis. In this thesis, adaptive control systems have been used. Firstly, some parameters accepted with errors and afterwards the system was run. Adaptive control system has tolerated the error but computed torque was not any effect on the error. All results have been showed and explained in detail. Besides simulation has been done with virtual reality toolbox in Matlab. The robot that used in the thesis was IRB 140 that belongs to ABB firm. All the knowledge and drawing folders has been taken from them like measures of link, some other specific values. That studied robot is a currently used robot that is controlled again with the real data. All the results have been given and compared each other. Besides, some addition to system has been done and the results were compared.