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Dawei Zhang

Bio: Dawei Zhang is an academic researcher from Tianjin University. The author has contributed to research in topics: Machine tool & Stiffness. The author has an hindex of 34, co-authored 278 publications receiving 3739 citations. Previous affiliations of Dawei Zhang include Hong Kong University of Science and Technology & Chinese Ministry of Education.


Papers
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Journal ArticleDOI
TL;DR: In this article, the authors proposed a direct approach to derive the inverse PI model directly from experimental data, where no inversion calculation is involved, the proposed direct approach is efficient and the theoretical modeling error can be avoided.
Abstract: The Prandtl-Ishlinskii (PI) model is widely utilized in hysteresis modeling and compensation of piezoelectric actuators For systems with rate-independent hysteresis, the inverse PI model is analytically feasible and it can be adopted as a feedforward compensator for the hysteretic nonlinearity of piezoelectric actuators However, for the rate-dependent PI model, the applicable valid inversion methodology is not yet available Although simply replacing all the rate-independent terms in the conventional inversion law with the rate-dependent terms can achieve acceptable results at very slow trajectories However, a large theoretical modeling error is inevitable at fast trajectories, which is investigated through simulations This paper proposes a new direct approach to derive the inverse PI model directly from experimental data As no inversion calculation is involved, the proposed direct approach is efficient and the theoretical modeling error can be avoided In order to validate the accuracy of the direct approach, a number of experiments have been implemented on a piezo-driven compliant mechanism by utilizing the inverse PI model as a feedforward controller The tracking performance of the mechanism is significantly improved by the direct approach

219 citations

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TL;DR: In this article, a piezo-driven flexure-based Scott-Russell mechanism for nano-manipulations is presented, which is monolithically constructed to provide high positioning accuracy and longterm repeatability.

181 citations

Journal ArticleDOI
TL;DR: In this article, a high performance piezoelectric actuator is used to drive a flexure-based mechanism for ultra-precision turning operation, where a parallel flexure hinge mechanism is utilized to guide the moving platform and to preload the piezel actuator.
Abstract: This paper presents the methodology for modeling and control of a high precision flexure-based mechanism for ultra-precision turning operation. A high performance piezoelectric actuator is used to driven the flexure-based mechanism. A parallel flexure hinge mechanism is utilized to guide the moving platform and to preload the piezoelectric actuator. A high resolution capacitive sensor is used to measure the displacement of the flexure-based mechanism for closed-loop control. With consideration of the driving circuit, the dynamic model of the flexure-based mechanism has been established. The effect of the driving circuit on the dynamic response of the precision mechanism is investigated. Experimental tests have been carried out to verify the established model and the performance of the flexure-based mechanism.

164 citations

Journal ArticleDOI
Fujun Wang1, Cunman Liang1, Yanling Tian1, Xingyu Zhao1, Dawei Zhang1 
TL;DR: In this paper, a micro gripper with a three-stage flexure-based amplification has been designed to achieve large jaw displacements, which can grasp microobjects with the maximum jaw motion stroke of 190μm corresponding to the 100-V applied voltage.
Abstract: This paper presents a novel microgripper mechanism for micromanipulation and assembly. The microgripper is driven by a piezoelectric actuator, and a three-stage flexure-based amplification has been designed to achieve large jaw displacements. The kinematic, static and dynamic models of the microgripper have been established and optimized considering the crucial parameters that determine the characteristics of the microgripper. Finite element analysis was conducted to evaluate the characteristics of the microgripper, and wire electro discharge machining technique was utilized to fabricate the monolithic structure of the microgripper mechanism. Experimental tests were carried out to investigate the performance of the microgripper and the results show that the microgripper can grasp microobjects with the maximum jaw motion stroke of 190 μm corresponding to the 100-V applied voltage. It has an amplification ratio of 22.8 and working mode frequency of 953 Hz.

136 citations

Journal ArticleDOI
TL;DR: In this paper, a flexure-based mechanism with three piezoelectric actuators is proposed to achieve desired displacements in X, Y and θ, where the lever based amplification is used to enhance the displacement of the mechanism.

134 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the state-of-the-art with respect to inspection methodologies compatible with additively manufactured (AM) processes is explored with the intention of identifying new avenues for research and proposing approaches to integration into future generations of AM systems.

1,024 citations

Journal ArticleDOI
TL;DR: The progresses of different modeling and control approaches for piezo-actuated nanopositioning stages are discussed and new opportunities for the extended studies are highlighted.
Abstract: Piezo-actuated stages have become more and more promising in nanopositioning applications due to the excellent advantages of the fast response time, large mechanical force, and extremely fine resolution. Modeling and control are critical to achieve objectives for high-precision motion. However, piezo-actuated stages themselves suffer from the inherent drawbacks produced by the inherent creep and hysteresis nonlinearities and vibration caused by the lightly damped resonant dynamics, which make modeling and control of such systems challenging. To address these challenges, various techniques have been reported in the literature. This paper surveys and discusses the progresses of different modeling and control approaches for piezo-actuated nanopositioning stages and highlights new opportunities for the extended studies.

458 citations

Journal ArticleDOI
TL;DR: In this paper, various mathematical models for hysteresis such as Preisach, Krasnosel’skii-Pokrovskii (KP), Prandtl-Ishlinskii (PI), Maxwell-Slip, Bouc-Wen and Duhem are surveyed in terms of their applications in modeling, control and identification of dynamical systems.

372 citations

Journal ArticleDOI
TL;DR: A critical overview of UVAM is presented, covering different vibration-assisted machining styles, device architectures, and theoretical analysis, and based on the current limitations and challenges, device improvement and theoretical breakthrough play a significant role in future research on UVAM.
Abstract: Compared to conventional machining (CM), ultrasonic vibration-assisted machining (UVAM) with high-frequency and small-amplitude has exhibited good cutting performances for advanced materials. In recent years, advances in ultrasonic generator, ultrasonic transducer, and horn structures have led to the rapid progress in the development of UVAM. Following this trend, numerous new design requirements and theoretical concepts have been proposed and studied successively, however, very few studies have been conducted from a comprehensive perspective. To address this gap in the literature and understanding the development trend of UVAM, a critical overview of UVAM is presented in this study, covering different vibration-assisted machining styles, device architectures, and theoretical analysis. This overview covers the evolution of typical hardware systems used to achieve vibratory motions from the one-dimensional UVAM to three-dimensional UVAM, the discussion of cutting characteristics with periodic separation between the tools and workpiece and the analysis of processing properties. Challenges for UVAM include ultrasonic vibration systems with high power, large amplitude, and high efficiency, as well as theoretical research on the dynamics and cutting characteristics of UVAM. Consequently, based on the current limitations and challenges, device improvement and theoretical breakthrough play a significant role in future research on UVAM.

286 citations

Journal ArticleDOI
TL;DR: In this paper, a comprehensive review on the classification of DED systems, process variables, process physics, modeling efforts, common defects, mechanical properties, and quality control methods is presented.
Abstract: Additive manufacturing (AM) is a new paradigm for the design and production of high-performance components for aerospace, medical, energy, and automotive applications. This review will exclusively cover directed energy deposition (DED)-AM, with a focus on the deposition of powder-feed based metal and alloy systems. This paper provides a comprehensive review on the classification of DED systems, process variables, process physics, modelling efforts, common defects, mechanical properties of DED parts, and quality control methods. To provide a practical framework to print different materials using DED, a process map using the linear heat input and powder feed rate as variables is constructed. Based on the process map, three different areas that are not optimized for DED are identified. These areas correspond to the formation of a lack of fusion, keyholing, and mixed mode porosity in the printed parts. In the final part of the paper, emerging applications of DED from repairing damaged parts to bulk combinatorial alloys design are discussed. This paper concludes with recommendations for future research in order to transform the technology from “form” to “function,” which can provide significant potential benefits to different industries.

273 citations