Bir matkap için kullanıcı arayüz yazılımı

Abstract

Günümüzde, sayısal elektronikteki gelişmelere paralel olarak kontrol sistemlerinde de sayısal yöntemler kullanıl maya başlanmış ve özellikle motor kontrolünde sıkça uygulama alanı bulmuşlardır. Motor çeşitlerinden, doğru ve alternatif akım motorları yüksek güçlerdeki çalışmalarda kullanılmalarına rağmen, kontrollerinde geri beslemeye ihtiyaç duymaları ve yüksek duyarlılıklarda çalışamamaları gibi bası dezavantajlara sahiptirler. Sayısal işaretlerle doğrudan kontrol edilebilen Adım Motorları, diğer iki tip motorun kullanılamadığı bu tip uygulamalarda sıklıkla kullanılırlar. Maliyetlerinin düşük olması, sürücü devrelerinin basitliği gibi avantajlara sahip olan Adım Motorları, his kontrollerinin dar bir aralıkta yapılabilmesi gibi bir dezavantaja rağmen özellikle xy tablalarında, yazıcı ve çisicilerde sıklıkla kullanılmaktadır. X ve y eksenlerine yerleştirilmiş hibrit adım motorları sayesinde hareket eden bir xy tablası ve sabit matkaptan oluşan sistemimizde, kullanıcı tarafından matkabın deleceği noktaların koordinatları veri olarak girilmekte ve oluşturulan yazılım da bu bilgilerden adım motorlarına attırılacak adım sayılarını hesaplamaktadır. Koordinat bilgileri çeşitli düşenlerde olabileceği gibi işlenecek olan parçada harekete engel olacak bası engeller bulunabilmekte ve xy tablasına buna bağlı olarak belli yörüngeler verilmektedir. Bu amaçla engel etrafından dolaşma algoritması geliştirilmiş ve kullanıcının verdiği parçaya ilişkin bilgilerden, parçanın içindeki işlenebilir alanların yerleri belli bir algoritma ile tespit edilmiştir. Tezde, birçok veri yapısı ve algoritma kullanılmıştır. Grafikle ilgili çeşitli teknikler kullanılmış ve kullanıcıya programı mümkün olduğu kadar kolay kullanma imkanı sağlanmıştır. Yeri girişinin her aşamasında verilerin kontrolü prensibi ön planda tutulmuş ve kullanıcının yapacağı hataların en aza indirilmesi amaçlanmıştır.

The mechanical part of the system mainly consists of two stages which can make linear motion. Step motors are used to make the stages move through screws which convert the rotation of the motor shaft to linear motion of the stages. Accurate positioning is one of the roost important problems in position control systems. As an actuator, DC or AC motors are widely used when the settling points are far from the starting point, but if the positioning requires small movements, conventional motors capabilities fail. Accurate positioning with very small movements has been achieved after the development of the stepping motors. Stepping motors are electromagnetic incremental motion actuators which convert digital pulses to analog output motion. When properly controlled, the output steps of a step motor are always equal in number to input pulses. Each pulse advances the rotor shaft one step increment and latches it magnetically at the precise point to which it is stepped. Although there is a wide range of stepping motor designs, most motors can be identified as a variation of the three basic types; variable reluctance (VR), permanent magnet, or hybrid step motors. VR step motors have magnetic field which is produced solely by the winding currents. For the hybrid motors, the main source of the magnetic flux is a permanent magnet and DC currents flowing in one or more windings direct the flux along alternative paths. In both types of step motors accurate positioning of the rotor is generally achieved by magnetic allignment of the iron teeth on the stationary and rotating parts of the motor. Hybrid Stepper motors are used in our system to provide movement on the axises. - vm - Hybrid motors have a small step length (typically 1.8) which can be great advantage when high resolution angular positioning is required. The torque producing capability of the hybrid motors are generally greater then VH motors and also sufficient for general applications. When the windings of the hybrid motor are unexcited the magnetic flux produces a small detent torque which retains the rotor at the step position. This feature can be useful in some applications where the rotor position must be preserved during a power failure. As I mentioned above, stepping motor systems are popular for many reasons. The summary of these reasons below offers an introduction to various control schemes. - Data are increasingly handled in digital form. Digital integrated circuits are inexpensive anâ if output motion is desired a digital actuator such as a stepping motor provides the ideal solution. - Stepping motors are inherently very reliable because they are simple devices with only two moving bearings. - More controls and processes are being automated because of the availability of inexpensive microprocessors. - Stepping motors are ideal motion control devices because they are digitally controlled. They are easly used in incremental and continous motion control applications. - More powerful stepping motors and more reliable, lower cost, solid state power devices have extended the range of application. - Stepping motors needs simple and lower cost driver circuits comparing with other motors. Stepping motors are often used as output devices for microprocessor based control systems. The essential feature of the systems is that the microprocessor program produces a result and the stepping motor then moves the load to the position corresponding to this result. There are various ways in which the microprocessor can be involved in control of the stepping motor. These are software intensive and hardware intensive. In our system software intensive approach was used. In software intensive approach, microprocessor produces the phase control signals, and the program is responsible for timing and sequencing the signal to move the motor to the r equ i red po s i t i on. ıx - In hardware intensive approach, microprocessor program merely feed the target position information and a start command to hardware controller, which generates the phase control signal for the motor drive circuits and a final signal for the microprocessor when the target is reached. The hardware parts of the developed system consists of control, drive and interfacing circuits. Operating with open- loop control at constant stepping rate is chosen. When the hardware was implemented the software which would control the motors were considered. The characteris tics of the motors were examined and parabolic curve was selected for acceleration. The motor control program was written in assembly language to properly control stepper motor. The main part of the thesis consists of a Pascal program which has about 9000 source lines. It has differ ent data types and algorithms. The data structures saves the data entered by user and the algorithms find the path between two holes specified by the coordinate data given by the users. The program supports mouse and mouse makes the use of the program easy. As I have just mentioned, program have different data types. These data types are dynamic and they are not in memory unless they are used. The examples of this data type used in the thesis are given below: The example structure is one of the dynamic list structure used in the program. This structure is used to save the data about a part in memory. The technical picture of a part is represented as a dynamic list struc ture in memory. Xs, Ys, Xe, and Ye record parts show the starting and end coordinates of a line drawn for describing a part. Dashed boolean record part determines the type of the line. upview describes from where the user looks at the part and the Next part of the record shows where the other records and data are. x - The main structure which holds the coordinate data given by the user, has a dynamic matrix structure. This structure was identified in the program like it is written below: TYPE MainNode = Record Data : Real ; Point : ExtNodePtr; Next : MainNodePtr; end ; ExtNode = Record X, Y, Z S, R, C, T ün, No Link end; MainNodePtr = "MainNode; ExtNodePtr = "ExtNode; Real; Boolean; Byte; ExtNodePtr; This structure expands on two direction. Vertically, and horizontally. The main structure consists of the ExtNodes and when the radius datum of a coordinate isn't in the list then a node which has the radius of this coordi nate is added to the mainnodelist. The procedures of these structures are given at the end of the thesis. The algorithms which deal with the motor motion are also implemented. Some of these algorithms are Kruskal algorithm which find the minimum path between coordinates entered by the user, area line intersection algorithm, DBA line algorithm, dynamic list bubble sort algorithm, quick sort algorithm, orbit according to a part algorithm. These algorithms are given in appendixes. The program consists of some menus and some sub menus. The main menu have six selection. These are coordinate, part, operate, options, initial conditions, and quit. Let's focus our attention, when we will use these selec tions. - Coordinate option is used to enter the coordinate of the data where we will make the xy stage move. The data could be in different format. The data could be absolute or relative. They could be in cartesian or cylindrical coordinate system. In this option, we could see the data we had entered, on the screen or we could print them on a paper by a printer. - xi - - Part option is used to describe the part we examine. Description of the part is made by means of its technical draw. The sections of it that we can see, is drawn as a solid line and the others are as a dashed line. When the draw is completed, the important lengths are asked. -Operate option deals with calculating the step numbers for each axis and send them to the motor control software written in assembly language. The orbit of the motion could be seen by a simulation program. - Options and initial settings submenus provide to change some global variables. Some of them are the radius of the drill, the height of the drill, the sensitivity of the mouse, the coordinate system that we work on, etc. - Quit provides us to quit from the program if we are sure. The performance of the system could be increased by using faster computers or some external devices such as microcontrollers. When such devices are added, these devices are dedicated to control the motors and computer could calculate the results faster and operate more systems.