ROBUST PARALLEL ALGORITHMS FOR SOLUTION OF RICCATI EQUATION

Robust and efficient parallel-vector algorithms are presented for the solution of the Riccati equations encountered in optimal control probl ems on shared-memory multiprocessor machines, The algorithms have been implemented on a Gray YMP 8/8128 and applied to three large problems resulting from a continuous bridge structure, a 21-story space truss s tructure, and a 12-story space moment-resisting building structure. Ef ficiency of the algorithms is presented in terms of millions of floati ng point operations per second (MFLOPS) and the speedup, The MFLOPS fo r the largest example resulting from the 12-story space frame structur e is a high 206.0. The speedup due to parallel processing only (for th e same example), using seven processors, is 6.33. When vectorization i s combined with parallel processing a very significant speedup of 54.4 is obtained using seven processors. The algorithms developed in this research find applications in the complex integrated control/structura l optimization problem. Further, the writers are currently using them to develop large adaptive/smart structures.