In order to develop a high-resolution piezoelectric walking actuator with a long stroke for the wafer probe station, this work presents a design of a piezoelectric walking actuator with two auxiliary clamping feet elastically attached to major clamping feet. Its construction was introduced and its operating principle was analyzed. Structure design details were discussed and a prototype was proposed. The prototype was fabricated and tested. The experimental results show that the proposed actuator can operate stably along a 20 mm guider. The proposed design is suitable for precision motion control applications.

The application of high-speed real-time data acquisition is becoming increasingly wide spread in industrial field, and its measurement accuracy is also increasing. The closed-loop test system of sine wave signal is constructed by the RIGOL’s DG1022 dual-channel signal source, DS1102C oscilloscope and PCI7489 multifunctional data acquisition card. Three kinds of timing methods, such as Visual Basics (VB) Timer control, multimedia timer function timing and query performance frequency function timing method, were carried out a series of comparative experiments. This paper analyzes the correlation characteristics of the measured voltage peak data, which includes mean value, variance, standard deviation, range, mutation system, deviation, kurtosis and so on, and then finds out the influence rules of software timing error on data acquisition and measurement accuracy. In the high-speed data acquisition, the repeatability error can be reduced from 84.22% to 0.62%, which provides scientific basis and reference for selecting software timing method in different test environment.

Currently, most buildings are constructed using prefabricated concrete slabs supported by a steel skeleton that is generally tied and welded manually. However, if the overall size of the skeleton is incorrect and this error is not noticed before the concrete is poured, then a huge waste is incurred by having to scrap all the prefabricated slabs. Therefore, we propose an automatic system for measuring the frame size needed for prefabricated slabs made of reinforced concrete using LabVIEW and the NI Vision library of machine-vision functions to perform image processing and machine-vision detection. A charge-coupled device camera obtained an overall image, and then, LabVIEW processed the image and extracted its features. The system compared the measured size with the design size and issued a warning if the two differ by more than 0.5 cm. From experimental comparison and verification, the maximum measurement error between the test results and the actual size was 2.7% and the root mean square error was 0.66%. This meets the requirements of actual site construction and provides a scientific reference for realizing the automatic detection of the skeleton size for reinforced-concrete precast slabs.