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This study demonstrates a new approach for constructing a rotary piezoelectric motor that utilizes an asymmetric stator driven by a single-phase signal. An asymmetric stator with four driving feet is proposed on the basis of the idea of generating asymmetric action on the rotor. This new motor consists of one piezoelectric transducer with two anchors and four driving feet placed in a parallelogram and internally connected to a circular rotor. The four feet vibrate asymmetrically to push the rotor into motion in one direction when a preload is applied. The proposed motor is designed, analyzed, and tested by using a finite element method (FEM). The vibration and impedance characteristics of the stator are measured after fabricating a prototype, and the test results are consistent with the FEM analysis results. The typical output of the prototype is a no-load speed of 176.5 rpm and a maximum torque of 29.4 N mm at an excitation voltage of 274 Vp-p.

Resonant-type piezoelectric impact motors can improve the output capability effectively. A new construction of asymmetric inertial masses is proposed to synthesize approximate saw-tooth wave resonant vibration with matched anti-phase and in-phase modes. A prototype is designed, manufactured, and tested. With 40 Vp–p, 400 Hz exciting voltage for the anti-phase mode and 16 Vp–p, 800 Hz exciting voltage for the in-phase mode, the prototype provides a maximum no-load velocity of 17.2 mm/s and a maximum output power of 0.72 mW with 100 mN load. The velocity and output power of the prototype in the proposed resonant state are near three orders of magnitude higher than those in the traditional quasi-static state.

A dual stage tuning fork transducer (DSTFT) is designed as a stator for a resonant-type inertial linear motor. The first- and second-layer resonant frequencies of DSTFT are automatically adjusted with a ratio of 1:2 by using an ANSYS optimization design algorithm, and a resonant-type sawtooth-shaped mechanical waveform is generated by composing the two resonant vibrations of DSTFT. An inertial linear motor prototype is fabricated and tested. Experimental results confirmed the effectiveness of the designed transducer. The no-load maximum speed is 21.5 mm/s with a driving voltage of 67.2 V at a base frequency of 2831 Hz. The linear speed is 10.5 mm/s, and the drag load is 0.02 N at a preload force of 1 N and a driving voltage of 114 V for the base frequency. The movement direction could be reversed by changing the driving voltage phase.

In order to achieve high accuracy and good stability of temperature measurement results, an online vision-based temperature field measurement system for continuous casting billets is developed instead of the conventional single-point radiation pyrometer in this paper. This system is a hybrid temperature measurement system which consists of a monochrome array CCD camera with high resolution and a single spot colorimetric thermometer simultaneously. In this system, a narrow-band spectrum radiation temperature measurement model is established for the optical CCD-based pyrometer system, and the non-uniformity of the temperature field measurement due to the inter-element sensitivity deviations of the CCD-array detector and photometric distortion caused by the vignetting in the optical system is analyzed in detail and compensated. Furthermore, in order to eliminate the temperature fluctuation caused by the stripped iron oxide scale on billets, a temperature field reconstruction approach, which took full advantage of the high resolution characteristic of CCD and the distribution character of the surface temperature field of billets, is introduced in this system. Meanwhile, based on the narrow band spectral thermometry theory, the spot temperature measured by the colorimetric thermometer is used to correct the temperature field measured by the CCD camera on-line so as to reduce the temperature measurement error caused by the inconclusive absolute emissivity of different grades of steel and the interference of industrial dust. Currently, the system has been successfully applied and verified in some continuous casting production lines. Industrial trials indicate that the system could effectively eliminate false temperature variation caused by striped iron oxide scale and provide information about changes of processing parameters in the continuous casting production line in real time.