• A system has a steady state error when the actual output during steady states deviates from the desired output. This error should be as low as possible to increase the accuracy of the system.

Static error coefficients :

Static velocity error coefficient

:

Static acceleration error coefficient

Routh-Hurwitz Criterion:

• It is a method where we determine the location of poles of a polynomial with constant real coefficients.
• For applying this method, it is required that no powers of s in the characteristic equation should be absent otherwise the system confirms instability by inspection.
• All roots of equation must lie in the left half of s-plane.
• The difficulties while carrying Hurwitz Criterion occur when the first element in any single row of the Routh tabulation is zero, while the elements are not & when the elements in one row of Routh tabulation are all zero.