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The precise measurement of inner dimensions and contour accuracy is required for deep-hole parts, particularly during the manufacturing process, to monitor quality and obtain real-time error parameters. However, on-machine measurement is challenging due to the limited inner space of deep holes. This study proposes an automatic on-machine measuring apparatus for assessing inner diameter, straightness, and roundness errors. Based on the axial-section measurement principle, an integrated measuring module was designed, including a self-centering mechanism, a diameter measuring sensor, and a positioning reference sensor, all embedded within a control system. On this basis, calculations of the inner diameter, and evaluations of the straightness and roundness errors are presented. Experimental verification is conducted on a blind deep hole with a nominal 100 mm inner diameter and 700 mm depth. Compared with measurements performed on a coordinate measuring machine (CMM), which is limited to a maximum hole depth of 300 mm, the proposed apparatus achieved full-depth on-machine measurements. Meanwhile, the measurement results were consistent with the data obtained by the CMM. The straightness error is considered less than 0.05 mm, and the roundness error is considered less than 0.015 mm. Ultimately, without requiring any additional reference platform, the proposed apparatus shows promise for measuring deep-hole parts on various machine tools, with diameters of no less than 80 mm and theoretically unlimited hole depth. [ABSTRACT FROM AUTHOR]

Dimensional and profile measurements of deep-hole parts are key processes both in manufacturing and product lifecycle management. Due to the particularity of the space conditions of deep-hole parts, the existing measurement instruments and methods exhibit some limitations. Based on the multi-axis, highly precise servo drive system, a novel measuring device is developed. The laser displacement sensors are fed by the flux-switching permanent magnet linear motor, and the part is rotated by the servo motor. On this basis, the assessment methods of roundness, straightness, and cylindricity are proposed by employing the least square method (LSM). Additionally, considering the axial center deviation between the sensors and the part, the rotating center coordinate is optimized by the gradient descent algorithm (GDM). Then, the measurement system is constructed and the experiment study is conducted. The results indicate favorable evaluation error of the LSM fitting and GDM iteration. Compared with the coordinate measuring machine (CMM), the measured results show good consistency. In the error analysis, the angle positioning error of measured point is less than 0.01°, and the axial positioning error is less than 0.05 mm. The proposed system and assessment method are regarded as a feasible and promising solution for deep-hole part measurements. [ABSTRACT FROM AUTHOR]

To elucidate the nonlinear oscillations inherent to dielectric elastomer transducers (DETs), this study delves into the dynamic behaviour exhibited by a one-dimensional asymmetric Duffing oscillator, which may exhibit either hardening or softening stiffness. The investigation utilizes hyperelastic and visco-hyperelastic constitutive models to capture the nonlinear stiffness properties of dielectric elastomers within compliant transducers. The canonical Duffing equation is employed to articulate the oscillator's motion, complemented by both asymptotic and quantitative analyses of unforced vibrations and harmonic excitation. Our results reveal that the distinctive stiffness characteristics observed in DETs arise from the complex interplay among hyperelasticity, rheology and applied electric fields. Contrary to conventional oscillators, Maxwell stress substantially modifies the nonlinear dynamics of DETs, an aspect that has been quantitatively dissected in this study. Furthermore, the influence of additional system parameters on forced oscillation has also been meticulously evaluated. [ABSTRACT FROM AUTHOR]

ABSTRACT A novel study on sensitivity of matching network to load variation is presented in this work. In passive RFID sensor tag, it is desired that a small change in input impedance of tag antenna should yield a significant response, which can be achieved by a matching network with high sensitivity. In this work, network sensitivity is defined and maximum sensitivity matching network is acquired for certain source and load impedances. Several LC and microstrip matching circuits are designed and fabricated to verify the network sensitivity theory. By inserting a sensitive matching network to a temperature sensor tag in literature, three times higher sensitivity is achieved, which proves the merit of the theory. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:232-236, 2017 [ABSTRACT FROM AUTHOR]

ABSTRACT For passive RFID sensor tag, high sensing sensitivity is achieved at the expense of read range reduction with a fixed transmitted power of RFID reader. To maximize sensing sensitivity and ensure satisfied communication performance of tag at meanwhile, the constraint between them can be defined as a multi-objective problem. The MOEA/D-DE (multi-objective evolutionary algorithm based on decomposition combined with differential evolution) is applied for the first time to provide a direct and effective solution to this constraint. For demonstration, an effective permittivity sensor and a temperature sensor are designed with MOEA/D-DE, respectively. Both the simulated and measured results show the feasibility of applying MOEA/D-DE to design high-sensitivity sensor tag with satisfied communication performance. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:83-86, 2017 [ABSTRACT FROM AUTHOR]