Position Control with Speed Feedbac
Position Control with Speed Feedback When the gain is raised in a position control system to minimize the deadband effect, the closed loop system responded with an overshoot which resulted in undesired system oscillation. One way to mitigate oscillation is to add a brake which is proportional to the speed to the output shaft. The brake method may produce a satisfactory result. However, it consumes a significant power and makes acceleration of the load difficult. Better way of preventing oscillation is to add a speed control loop to the position control loop. The speed control loop provides a negative feedback signal from the output of the Tachogenerator which is proportional to the speed of the motor. The effect of adding a speed loop is illustrated in Figure 1 (a), (b), and (c). An optimum control of the speed feedback loop produces a system response as shown in (b). Figure 1 : Effect of a speed feedback loop...