Abstract
Generation of altered nonlinear characteristic block using Matlab-Simulink is presented. These blocks can be added to the block library and be used to replace the corresponding nonlinear element for applying dual-input describing function in simulation. This will help teaching and understanding the concept and applications of dual-input describing function. This is a way of incorporating computer aided control systems design into education, particularly in subject such as nonlinear control theory. Examples are given to show that software such as Matlab-Simulink can be very useful in teaching and studying.