الفهرس 
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Abstract
In this thesis a design for a new method for DC-motor controller is developed ,the method is called Error weighing method,. The aim of this method is to have a robust DC-motor performance at the presence of disturbance or undesired changes in the main parameters that affect the motor performance such as; sudden change in the load torque, motor characteristics, or abrupt change in reference. By using the new method the motor should maintain -in the event of disturbances- in a sufficiently stable performance till the termination of the external disturbance.
This was done by changing the parameters of the controller’s speed and current loops, the loop gain and time constant, in accordance to the changes in the system due to the effect of disturbance, i.e. each loop will be partially active.
The designed controller uses the advanced parallel speed and current loops instead of the conventional cascade configuration. The parallel scheme has the advantages of faster response and easier to set the loop parameters. The implementation of the controller was done with a new technique , where its completely implemented using software instead of a hardware design. The advantage of this technique is to make it easy to change the controller’ parameters and configuration. The controller’s software was programmed using the Programmable Logic Controller (PLC) which is dominant in nowadays industries.
The choice of using the PLC is for its powerful capabilities, and is easy to be programmed. The thesis also includes a survey for the most advanced techniques in the
field of controlling the DC-motor using the cascade scheme to be
compared with the developed method.
Chapter 1 includes an introduction to the DC-motor characteristics, drives and control, Chapter 2 represents the control of DC-motor using the
cascade two-loop scheme consisting of a current-regulating loop enclosed
within a speed-control loop. Tow technique based on this scheme are examined, the first one a controller was designed to operate in tow modes, one applicable when the motor armature current is continuous, the other when it is discontinuous. The second technique improves the speed response by using a fast-response current controller for the intemalloop.
Chapter 3 represents other systems which are not using the cascade scheme, the first one is the Interventionist system, which normally operates in the speed control mode, the current limiter taking control only after the armature current has exceeded a threshold value. The second is the parallel loop scheme, in this scheme the operation of the two loops is independent and only one loop operates at any given time. It also offers a shorter computation and execution times.
Chapter 4 is an introduction for the PLC, demonstrating its application, structure ,addressing and capabilities. In this chapter is also an explanation for the programming concepts and language of the PLC
Chapter 5 introduce the developed controller using the Error Weighing method .It includes an introduction to the general concept of the model reference adaptive control it also includes includes the representation for the concept of dividing the current error into a weighted levels, each level has a different values assigned to the controller parameters.
The chapter is followed with a case study in which a simulation for a DC¬motor ,used in a Rubber factory, contr~lled by the developed controller is presented. The simulation was done using the TUTSIM computer simulation package, the results showed the superiority of the suggested controller.