Design and Compensation
11.1 NECESSITY OF COMPENSATION
It has often been observed that the performance of a control system does not satisfy the given specifications in terms of accuracy, stability, and so on. After design and testing if the system does not perform satisfactorily some changes may need to be introduced to achieve the desired results. The changes could be in the form of adjustment of forward path gain or insertion of a compensating device in the control system.
To reduce steady-state error, gain can be increased. However, it results in an oscillatory transient response or even instability. Under such circumstances, it may be necessary to introduce some kind of corrective sub-systems to force the chosen plant (system) to meet ...