A new neural-network-based control algorithm has been developed and te
sted in the computer simulation of active control of a three-story fra
me structure subjected to ground excitations. First, an emulator neura
l network has been trained to forecast the future response of the stru
cture from the immediate history of the system's response, which consi
sts of the structure plus an actuator. The trained emulator has been u
sed in predicting the future responses and in evaluating the sensitivi
ties of the control signal with respect to those responses. At each ti
me step of the simulation, the control signal has been adjusted to ind
uce the required control force in the actuator based in a control crit
erion. A controller neural network has been trained to learn the relat
ion between the immediate history of response of the structure and act
uator, and the adjusted control signals. The trained neurocontroller h
as been used in controlling the structure for different dynamic loadin
g conditions. Results of this initial study indicate that the neural-n
etwork-based control algorithms have the promise of evolving into powe
rful adaptive controllers after further research.