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Full-Text Articles in Engineering
Discrete Cosine Transform Based Shift Estimation For Fringe Pattern Profilometry Using Generalized Analysis Model, Jose F. Chicharo, Jiangtao Xi, Yingsong Hu, Zongkai Yang, Enbang Li
Discrete Cosine Transform Based Shift Estimation For Fringe Pattern Profilometry Using Generalized Analysis Model, Jose F. Chicharo, Jiangtao Xi, Yingsong Hu, Zongkai Yang, Enbang Li
Faculty of Engineering - Papers (Archive)
This paper presents a new analysis algorithm to carry out profile measure- ment with low computational complexity and less noise-sensitivity. Firstly, a discrete cosine transform (DCT) based representation method is introduced to express the height distribution of the three-dimensional surface. Then, a novel shift estimation algorithm, called DCT based shift estimation (DCT-SE) is presented to reconstruct three-dimensional object surfaces by using the proposed expression and the generalized analysis model. The advantage of DCT-SE is that without loss of measurement precise it provides lower computational complexity to implement three-dimensional reconstruction from distorted fringe patterns and at the same time survives from …
A Robotic Gripper Based On Conducting Polymer Actuators, Gursel Alici, Nam N. Huynh
A Robotic Gripper Based On Conducting Polymer Actuators, Gursel Alici, Nam N. Huynh
Faculty of Engineering - Papers (Archive)
Conducting polymer actuators or as widely known as artificial muscles have many promising features such as being biocompatible and suitable to open loop control, and having high force to weight ratio. If properly engineered, they can be employed as actuators plus joints like active flexure joints articulating monolithic structures. Such structures or systems not containing any sliding and/or rolling components potentially have high positioning accuracy, which is crucial for micro/nano manipulation applications. In this paper, we employ a bending type polymer actuator to articulate two separate rigid links made up of carbon fibre such that a two-finger gripper is formed. …
Three-Dimensional Profilometry Based On Shift Estimation Of Projected Fringe Patterns, Jose F. Chicharo, Jiangtao Xi, Yingsong Hu, Zongkai Yang, Enbang Li
Three-Dimensional Profilometry Based On Shift Estimation Of Projected Fringe Patterns, Jose F. Chicharo, Jiangtao Xi, Yingsong Hu, Zongkai Yang, Enbang Li
Faculty of Engineering - Papers (Archive)
This paper presents a new approach to fringe pattern profilometry. In this paper, a generalized model for describing the relationship between the projected fringe pattern and deformed fringe pattern is derived, where the projected fringe pattern can be arbitrary rather than being limited to be sinusoidal as those for the conventional approaches. Based on this model, a new approach is proposed to reconstruct the three-dimensional object surface by estimating the shift between the projected and deformed fringe patterns. Additionally, theoretical analysis and computer simulation results are presented, both of which show the proposed approach can significantly improve the measurement accuracy, …
Blind Source Separation Based On Time-Domain Optimization Of A Frequency-Domain Independence Criterion, Tiemin Mei, Jiangtao Xi, Fuliang Yin, A. Mertins, Jose F. Chicharo
Blind Source Separation Based On Time-Domain Optimization Of A Frequency-Domain Independence Criterion, Tiemin Mei, Jiangtao Xi, Fuliang Yin, A. Mertins, Jose F. Chicharo
Faculty of Engineering - Papers (Archive)
A new technique for the blind separation of convolutive mixtures is proposed in this paper. Inspired by the works of Amari, Sabala , and Rahbar, we firstly start from the application of Kullback-Leibler divergence in frequency domain, and then we integrate Kullback-Leibler divergence over the whole frequency range of interest to yield a new objective function which turns out to be time-domain variable dependent. In other words, the objective function is derived in frequency domain which can be optimized with respect to time domain variables. The proposed technique has the advantages of frequency domain approaches and is suitable for very …
Contact State Determination For Robotic-Based Cylindrical Pair Height Adjustment Under Dynamic Conditions, Prasan I. De Waas Tilakaratna, Bijan Shirinzadeh, Gursel Alici
Contact State Determination For Robotic-Based Cylindrical Pair Height Adjustment Under Dynamic Conditions, Prasan I. De Waas Tilakaratna, Bijan Shirinzadeh, Gursel Alici
Faculty of Engineering - Papers (Archive)
This paper investigates fine motion strategies associated with the height adjustment manipulations of a cylindrical pair which can be utilised in dynamic assembly and reconfigurable workholding systems. The outer link of the cylindrical pair is held by the end-effector of a 6DOF serial articulated robot. The environment which holds the inner link can be dynamic. Formulations capable of identifying the type of contact between the links and parameters vital for control purposes based on the force and torque data provided by a wrist mounted F/T sensor are established for a generic spatial case. Experimental results indicate that the established methodology …
Cellular Neural Network Based Deformation Simulation With Haptic Force Feedback, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith
Cellular Neural Network Based Deformation Simulation With Haptic Force Feedback, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith
Faculty of Engineering - Papers (Archive)
This paper presents a new methodology for deformable object modelling by drawing an analogy between cellular neural network (CNN) and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by the non-linear CNN activity. An improved CNN model is developed for propagating the energy generated by the external force on the object surface in the natural manner of Poisson equation. The proposed methodology models non-linear materials with nonlinear CNN rather than geometric non-linearity in the most existing deformation methods. It can not only …
Fiber-Optic Temperature Sensor Based On Interference Of Selective Higher-Order Modes, Enbang Li, X L Wang, Chao Zhang
Fiber-Optic Temperature Sensor Based On Interference Of Selective Higher-Order Modes, Enbang Li, X L Wang, Chao Zhang
Faculty of Engineering - Papers (Archive)
A fiber-optic temperature sensor based on the interference of selective higher-order modes in circular optical fibers is described. The authors demonstrate that by coupling the LP01 mode in a standard single-mode fiber to the LP0m modes in a multimode fiber, and utilizing the interference of the higher-order modes, a fiber-optic temperature sensor which has an extremely simple structure and is suitable for high-temperature measurements can be constructed. The sensing principle, temperature measurement experiments, and results are presented.
Thermal Stability And Crystallization Kinetics Of Mechanically Alloyed Tic/Ti-Based Metallic Glass Matrix Composite, Laichang Zhang, J. Xu, J Eckert
Thermal Stability And Crystallization Kinetics Of Mechanically Alloyed Tic/Ti-Based Metallic Glass Matrix Composite, Laichang Zhang, J. Xu, J Eckert
Faculty of Engineering - Papers (Archive)
A Ti-based metallic glass matrix composite with 10vol% TiC is synthesized by mechanical alloying. The thermal stability and crystallization kinetics of the metallic glass and compositepowders are investigated by differential scanning calorimetry in the mode of isochronal heating and isothermal annealing. The isothermal transformation kinetics is analyzed by the Kolmogorov-Johnson-Mehl-Avrami equation. The values of the Avrami exponent calculated for low crystallization volume fractions imply that the crystallization of both types of powders is governed by diffusion-controlled three-dimensional growth. The mean activation energy of crystallization for the composite is slightly lower than that of the Ti-based metallic glass. The addition of …