Requirements for a transportation system based on ultrasonic traveling waves using the measurement of spatial phase difference

Having good control over the speed and direction of non-contact transportation is critical in industry today, especially in areas such as the manufacturing of flat panel displays, silicon wafers of semi-silicon and a number of other electronic devices. In a dual transducer-type ultrasonic levitation-based transportation system, it is well known that the vibrating plate length and the wavelength of the flexural vibration should satisfy a strict relationship, i.e. one given by the spatial phase difference, cp, so that the transportation process could be as fast as possible and therefore most effective for industry. However, it is difficult to obtain the value of cp through calculation, or through making adjustments during the operation of the transportation process. In this paper, the relationship across the temporal phase shift, 0, the spatial phase difference, cp, and the Standing Wave Ratio (SWR), which directly controls the speed and direction of the transportation system, was derived by the authors for the first time. Subsequently, experimental solutions for the measurement of cp were obtained in this work, using a Laser Doppler Vibrometerbased approach (LDV) and as a result, the research has been successful in giving results for cp, through the series of experiments carried out and reported.

Automated summary

This study derived the relationship between the Standing Wave Ratio (SWR), temporal phase shift, and spatial phase difference, which directly control the speed and direction of a dual transducer-type ultrasonic levitation-based transportation system. Experimental solutions for measuring the spatial phase difference were obtained using a Laser Doppler Vibrometer-based approach.