面向苹果硬度检测仪的声振信号激励与采集系统设计

Design of excitation and acquisition system of acoustic vibration signal for apple hardness tester

本文设计了基于声振法的苹果硬度检测仪,该检测设备主要由信号激励装置和信号采集系统2部分组成。在信号激励装置中,基于对击打钢板的摆角、弯曲角和可调高度的设计,使大多数苹果都可以被敲击到;通过控制电磁铁和电磁阀的工作状态以实现对苹果的自由敲击,从而满足流水线自动作业需求。在信号采集系统中,使用EAROBE SuperLav麦克风和MPU6050振动传感器收集声音和振动信号,并使用MATLAB软件对收集的数据进行分析。结果表明:使用所设计的检测设备,绝大多数苹果都可以被无损敲击,并且不同硬度苹果的声振信号图差异明显。说明利用声振法能够实现在流水线上对苹果进行无损检测并分级。

An apple hardness tester was designed based on acoustic pulse method.The detection equipment was mainly composed of signal excitation device and signal acquisition system.Most apples could be knocked in this signal excitation system,because of proper designs of the swing angle,the bending angle and the adjustable height of the striking steel plate.Apple could be knocked freely to meet the requirements of automatic detection on assembly line by controlling the work of electromagnet and solenoid valve.In the signal acquisition system,the EAROBE SuperLav microphone and MPU6050 vibration sensor were used to collect acoustic vibration signals,and the collected data were analyzed using MATLAB software.The results showed that,using the designed detection equipment,most of the apples could be hit non-destructively,and the acoustics and vibration signal patterns of apples with different hardnesses were obviously different.It is indicated that the nondestructive testing and grading of apple can be realized on assembly line by acoustic pulse method.