强化现象启发的随机振动能量收集器优化设计

Strengthening phenomenon-inspirited optimum design of random vibration energy harvester

为了使宽带振动能量收集器件的平均输出功率最大,以压电型随机振动能量收集器件为研究对象,系统讨论优化设计问题.通过建立器件随机响应与输出功率统计量的解析表达式,证实了平均输出功率的局部强化现象.讨论给定激励点位置时,压电片布置位置和压电片尺寸的优化,讨论最优尺寸随激励作用点和激励带宽的变化关系.研究表明:激励作用点及对称位置是布置压电片的较好位置,压电片的最优、次优、最差、次差位置相隔很近;为了得到最大的输出功率,压电片尺寸应略大于最优尺寸.

The optimum design of piezoelectric-type random vibration energy harvester was investigated to acquire the maximum mean output power.The analytical formula for the statistics of random responses and output power were established.Then the local strengthening phenomenon of mean output power were verified.For given excitation locations,the optimal locations and optimal length of piezoelectric patch were derived,and the relations of the optimal length to the excitation location and excitation bandwidth were discussed.Results show that the excitation and its symmetry location are good places for piezoelectric patch.The optimal,sub-optimal,worst and sub-worst locations of piezoelectric patch are very close.The length of piezoelectric patch should be slightly larger than the optimal design value in order to obtain the maximum output power.