To raise the calculation precision of active structural control, the closed-loop and closed-open-
loop control algorithms for instantaneous structural optimizationwere improved based on the active structural
control strategy and the precise integration method (PIM). Different from the traditional solutions of
structural control equations, it is not required for this improved algorithm to solve the characteristic vector
and the eigenvalues of a dynamic state matrix. As a result, the precision of instantaneous structural control
can be raised. As an example, this algorithm was used for the control simulation of two structures. The
results showthat the algorithm is convergent and not sensitive to time-step, and its calculation precision can
be controlled easily.