The application of an airplane to explore Mars may become an important research aera due to some distinctive advantages such as the large detection range and good maneuvering characteristics. Also, the resulting works have the strong forward-looking and driving actions which are helpful for mankind to realize the intergrated design dreams concerning aerospace technologies. This paper discusses the complex modeling and sliding control law design issues for Mars airplane. First, the particular features with regard to atmospheric environment on Mars are considered to explain the Martian flight principles as well as to provide the faced new challeges in comparison to the conventional airpalne on Earth. Afterwards, the mathematical model of Mars airplane is established using the isolation methods, and based on this built model the dynamic characteratics are analyzed under the Martian atmospheric environment in order to indicate the importance of the control actions. Furthermore, the sliding control law is proposed to meet the anticipated demands including robust stability and adaptive track response. Finally, a simulation example is given to verify the effectiveness of the proposed modeling and control methods, and the according works will also provide the good theoretical reserve and technical support to independently develop Mars airplane in the future.

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An acoustic black hole (ABH) has been applied in the regulation of structural performance to form the aggregation effect of elastic waves in the local area of the structure, which has been used in energy harvesting in recent years. The piezoelectric vibration energy harvester (VEH) integrated with the beam of a bilateral periodic 1D ABH is proposed in this study. The theoretical model of the proposed VEH is established and analyzed based on the transfer matrix method. The performance of the VEHs is numerically simulated by COMSOL Multiphysics. The simulation results show that the performance of the bilateral ABH beam is higher than its traditional counterpart. Finally, the performance of the proposed VEH is validated in an experimental system. The experimental results show that the peak output voltage of the VEH Model 3 can reach 169.16 V, which is 1.9 times that of the traditional one. In the optimal impedance matching, the output power of the third bilateral VEH is 2.7 times that of the traditional ABH, which can reach 91.52 mW.

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In this paper, a piezoelectric energy harvester based on periodic one-dimensional acoustic black holes (ABH) is proposed to improve efficiency. The harvesting performance of the energy harvester with different ABH-structures was numerically simulated through the commercial software, COMSOL Multiphysics. Finally, an experimental platform was set up to test several energy harvester samples. The results show that the energy aggregation effect of the bilateral ABH beam is better than that of the traditional ABH beam. In the optimal impedance matching, the maximum output power of the energy harvester with bilateral ABH type 3 is 112 mW, which is 2.8 times that of the energy harvester with traditional ABH. The simulation and experimental results show that the energy harvesting efficiency of the proposed ABH is much higher than that of the energy harvester with traditional ABH. It is expected to make some contributions to the further development of lightweight wireless sensors, equipment service life, bearing fault diagnosis, and so on.