Moreno-Ramírez Ciro, Iniesta Carmen, González Alejandro, Olazagoitia José Luis
Industrial Engineering and Automotive Department, Universidad Antonio de Nebrija, Pirineos 55, 28040 Madrid, Spain.
Sensors (Basel). 2020 Nov 20;20(22):6663. doi: 10.3390/s20226663.
Existing acoustic test benches are usually costly devices based on proprietary designs, sensors, and acquisition devices. In this paper, a low-cost test bench for acoustic purposes is introduced. The design of the test bench takes into account not only the low-cost mechanical design, but also uses low-cost sensors and control boards. This test bench has been designed for a range of signals compatible with those used by thermoacoustic engines, but it can be useful for applications with similar requirements. Taking advantage of an auxiliary pressure reference, low-cost unidirectional differential pressure sensors can be used to significantly increase the accuracy of the sampling system. The acoustic and mechanical design and development are presented along with the sampling system and the sensors arrangement implemented. Both the sensor and sampling system are evaluated by comparison with a high-fidelity sound acquisition system. An unexpected effect on the time error values distribution of the low-cost acquisition system is found and described. Finally, the errors introduced by the system and the sensors in terms of time and pressure sampling are characterized. As a result, the low-cost system's accuracy has been satisfactory assessed and validated for the conditions expected in thermoacoustic experiments in terms of frequency and dynamic pressure.
现有的声学测试台通常是基于专有设计、传感器和采集设备的昂贵装置。本文介绍了一种用于声学目的的低成本测试台。该测试台的设计不仅考虑了低成本的机械设计，还使用了低成本的传感器和控制板。此测试台设计用于一系列与热声发动机所使用信号兼容的信号，但对于具有类似要求的应用也可能有用。利用辅助压力参考，可以使用低成本的单向差压传感器来显著提高采样系统的精度。文中介绍了声学和机械设计与开发，以及所实施的采样系统和传感器布置。通过与高保真声音采集系统进行比较，对传感器和采样系统进行了评估。发现并描述了低成本采集系统对时间误差值分布的意外影响。最后，对系统和传感器在时间和压力采样方面引入的误差进行了表征。结果，就频率和动态压力而言，已对低成本系统在热声实验预期条件下的精度进行了令人满意的评估和验证。
