A LOW-Cost Multi-Frequency Testing Platform for Non-Contact Vibration Measurement

The machine vision-based non-contact vibration measurement is currently one of the hottest research topics in the instrumentation and measurement field. Single-frequency experiments are usually used to evaluate the non-contact measurement quality; however, in reality, it is difficult/impossible to quantify the non-contact vibration measurement using a single-frequency excitation. To bridge this research gap, this work designs and tests a low-cost platform to produce multi-frequency vibrations for evaluating the non-contact vibration measurement. In this platform, a double-rail sliding mechanism is designed to convert the circular motion of a servo motor into linear motion. The pulse+ direction control method is applied to the servo motor to produce multi-frequency and multi-amplitude vibration excitations. Thanks to the simplicity of the sliding mechanism, common and inexpensive mechanical and instrumentation devices can be used to construct the testing platform, and the low-cost feature of the developed platform make it ubiquitously applicable for practice. Lastly, the vibration characteristics of the platform are analyzed, and three sets of vibration tests using different frequency bands are performed. The experimental results verify that the vibration responses of the platform are well consistent with the theoretical results, which can be used as a new solution that allows non-contact vibration quantification.