2^N type algorithm for constrained control system

The present paper, starting from the definition of mixed-energy, goes further to make it applicable when constraint is present. The author develops further the embryonic idea. It is believed to be clear that the key to the other analogy is the two correspondences of the one-dimensional coordinate and the substructure in structural mechanics to the time coordinate and the time-interval in optimal control respectively. So the dynamic problems in optimal control can be treated by the methods in structural static mechanics. 2^N type algorithm is a special method in multi-level substructural method, and can be naturally transplanted to the optimal control problem.