Sound Transmission Control with Intelligent Compound Structure

(1)透声实验装置的研制通过对由扬声器作为声源、导管和固定板的法兰组成的简易实验装置进行改造，研制了一种新的测量宽约40 mm ×长约150 mm智能复合板透声性能的实验装置。(2)智能复合板的研制：研制了两种尺寸均为38mm（宽）× 160mm（长）× 0.6mm（厚）的智能复合板，中间夹有两块0.1mm（厚）的不锈钢板作为增强材料，其表面形成有传感器和执行器的三个部分。在第一次生产中，使用了单晶型压电板，但是复合板没有表现出足够好的板中振动感测。第二种方法是采用单双晶压电片，然后采用复合压电片，使其具有足够好的振动传感性能。(3)智能复合结构的传声实验研究：在第一个产品中，基于三个执行器到三个传感器的传递函数矩阵的辨识，构建了智能复合板的前馈控制系统。由于系统辨识精度不高，控制系统未能达到传声目标。在第二个产品的反馈控制系统的构造后，引入了鲁棒H ∞控制技术，包括系统辨识。该控制系统成功地实现了传声目标。(4)微型压力传感器的开发我们尝试利用MEMS技术开发微型压力传感器，但由于膜电极形成不良，该产品失败。

(1) Development of Sound Transmission Experimental setup;By reforming the readily maid experimental setup consisting of a loud speaker as sound source, duct and flange for securing the plate, we developed the new experimental setup for measuring the sound transmission performance of the intelligent compound plate of about 40 mm (broad) × 150 mm (long).(2) Development of Intelligent Compound Plate;We developed two types of the intelligent compound plate, dimension of both of which is 38 mm (broad) × 160 mm (long) × 0.6 mm (thickness), sandwiched by two sheets of stainless steel plate with 0.1 mm (thickness) for reinforcement, and on the surface of which three portions of sensor and actuators were formed. In the first production mono-morph piezoelectric plates were utilized, but the compound plate did not present good enough sensing of vibration in the plate. In the second production single bi-morph piezoelectric plate was introduced, and then the compound plate presented good enough sensing of vibration.(3) Sound transmission experiment of the intelligent compound structure;In the first production the feed-forward control system using the intelligent compound plate was constructed, based on identification of the transfer function matrix from the three actuators to the three sensors. The control system failed to present the target performance of sound transmission due to poor preciseness of the system identification. In the second production the feed-back control system was constructed after introducing the robust H-infinity control technique including the system identification. This control system proved to be successful in presenting the target performance of sound transmission.(4) Development of micro-pressure sensor;We tried to develop the micro-pressure sensor by utilizing the MEMS technique, but this production failed due to poorly forming the membrane electrode.