In recent years DC motors are used in high performance drive system because of its advantages. A DC servo motor which is usually a DC motor of low power rating is used as an actuator to drive a load. It is having high ratio of starting torque to inertia and faster dynamic response. Because of their high reliability, flexibility and low cost, DC servo motors are widely used in industrial applications, robot manipulators and home appliances where speed and position control of motor are required [1-4]. It is a common actuator in control system, it is directly provides the rotary and transitional motion. In this paper permanent magnet DC motor is preferred. Here the field excitation is by permanent magnet and remains constant under all operating conditions. DC servo drive systems normally use the full four quadrant operations which allow bidirectional speed control with regenerative braking capabilities [5-8]. This paper demonstrates the position control based drive by conventional and fuzzy PI controller. The conventional methods have the following difficulties, it depends on the accuracy of the mathematical model of the system and the expected performance is not met due to the load disturbances. The classical linear control shows good performance only at one operating speeds. Fuzzy logic is a technique to embody human like thinking into a control system [9-12]. Fuzzy control has been primarily applied to the control of processes through fuzzy linguistic performances. The fuzzy controller gives the better dynamic performance as well as error reduction.
The first section gives the introduction and importance about the paper. The second section of the paper discuss about the DC position servo drive concept. Design of speed/position controller with conventional and fuzzy technique is discussed in the third section of the paper. The fourth section deal with the simulation work carried through MATLAB environment. The fifth section explains the experimental implementation. The sixth section is about the results and discussions. The final section present in this paper is the conclusion.