A semi-active controller for the vibration absorber on the I-35 Walnut Creek Bridge

A simple bi-state Lyapunov controller has been developed for an intelligent stiffener for bridges (ISB). The simple control logic is a reduction from the n/sup th/-order Lyapunov controller used on the first ISB prototype, which requires a complex sensor network (more than 20 sensors of three types in this case). The bi-state controller requires only three local sensors (two pressure sensors and one LVDT). The sensors are installed directly on the semi-active actuator, not the bridge. It forms a completely self-contained control system. The performance is comparable to the complex system. Simulation of the simplified controller yields a 36% peak stress reduction as compared to 42% for the complex control.