Let’s consider the general constrained optimization problem as
Minimize
Subject to 
where, 
and functions 
, 
and 
are continuous and their second
derivatives are continuous. In general, the function we call be objective, be equality constraints and be inequality constraints.
RecurDyn/AutoDesign uses the augmented Lagrange multiplier (ALM) method to solve the approximate optimization problem. Next, we will explain the basic concept of ALM.