Active tuned mass damper (ATMD) is widely adopted as a reliable active device to protect tall buildings subjected to earthquake excitations from severe seismic damages. Soil-structure interaction (SSI) phenomena effects on the free vibration characteristics and the seismic responses of tall structures. This study presents the design of an adaptive sliding sector controller (ASSC) for the active control of tall buildings equipped with an ATMD system considering the SSI effects. The ASSC technique is designed based on the hyper-surface of the sliding mode which is surrounded by a sector and can consider the uncertainty of system parameters. To validate the efficiency of the ASSC technique, its design is first implemented for a 40-story building equipped with an ATMD system under an artificial earthquake excitation for different soil types. Then, the performance of the designed ASSC technique is evaluated in mitigating the seismic responses of the structure subjected to five real earthquake excitations considering the SSI effects. In addition, the efficiency of the designed ASSC strategy is compared against that of the two controller techniques including proportional-integral-derivative (PID) and linear-quadratic regulator (LQR). Comparative results demonstrate the efficiency of the ASSC strategy for the reduction of the structural responses under real earthquake excitations.

Scientific explorations have shown that the lunar water-ice exists only in the bottom of craters of lunar South and North pole, where is permanently dark and as cold as 40K This paper presents the concept of increase the temperature of water-ice by reflecting the sunlight to a certain area using polar orbit satellite formation, such that the water-ice is more detectable. The orbit of spacecraft is designed and the expected attitude is derived based on the relative motion between the spacecraft and the water-ice. The objective is to keep the reflected light from spacecraft point to the water-ice during the process so that the water-ice can be heated by solar radiation. A nonlinear adaptive controller is developed. Numerical simulations demonstrate the effectiveness of the control algorithm.