Juan-Manuel Ramos-Arreguin

A Profilometric Approach for 3D Reconstruction Using Fourier and Wavelet Transforms

In this research, an improved method for three-dimensional shape measurement by fringe projection is presented. The use of Fourier and Wavelet transform based analysis to extract the 3D information from the objects is proposed. The method requires a single image which contains a sinusoidal white light fringe pattern projected on it. This fringe pattern has a known spatial frequency and this information is used to avoid the discontinuities in the fringes with high frequency. Several computer simulations and experiments have been carried out to verify the analysis. The comparison between numerical simulations and experiments has proved the validity of this proposed method.

A 3D Sensor Based on a Profilometrical Approach

An improved method which considers the use of Fourier and wavelet transform based analysis to infer and extract 3D information from an object by fringe projection on it is presented. This method requires a single image which contains a sinusoidal white light fringe pattern projected on it, and this pattern has a known spatial frequency and its information is used to avoid any discontinuities in the fringes with high frequency. Several computer simulations and experiments have been carried out to verify the analysis. The comparison between numerical simulations and experiments has proved the validity of this proposed method.

Fuzzy logic hardware implementation for pneumatic control of one DOF pneumatic robot

The pneumatic actuators can be a useful way to control the position of a manipulator robot, instead of an electrical actuator. The major problem with pneumatic actuators is the compressibility of the air, due to the fact that the mathematical model is a system formed by a set of highly non-linear equations then a simple PID control is not enough to control the robot position, and fuzzy logic is a good option. This work is focused on the hardware implementation of Fuzzy logic algorithm into FPGA system. This paper also presents a methodology to implement a pneumatic control using fuzzy logic, into a FPGA device, which is the main contribution of this work. The air flow is controlled with a pulse width modulation, applied to the pneumatic electro- valve, with 25 ms of period.

Simulation Methodology for Mechatronic Applications using Multilanguage Techniques

Abstract This paper presents a simulation methodology proposal, applying a multilanguage technique to simulate a mechatronic system. Firstly, a way to interact between two programming languages is presented, by taking advantage of each language to facilitate the development of a complex simulation tool. Later, the mechanical structure is obtained in VRML format. Next, special software is used to compute the mathematical model for kinematics and dynamic behavior. The results are showed by graphical simulation with Graphic Libraries support. Finally, the methodology is applied to flexible manipulator with one degree of freedom as study case, and the graphical simulation is presented.

Alignment of the Measurement Scale Mark during Immersion Hydrometer Calibration Using an Image Processing System

The present work presents an improved method to align the measurement scale mark in an immersion hydrometer calibration system of CENAM, the National Metrology Institute (NMI) of Mexico, The proposed method uses a vision system to align the scale mark of the hydrometer to the surface of the liquid where it is immersed by implementing image processing algorithms. This approach reduces the variability in the apparent mass determination during the hydrostatic weighing in the calibration process, therefore decreasing the relative uncertainty of calibration.

Image dehazing using morphological opening, dilation and Gaussian filtering

Image pre-processing is a critical stage in computer vision systems, with greater relevance when the input images are captured in outdoor environments because the pictures could contain low contrast and modified colors. A common condition present in outdoor images is haze. In this work, a new dehazing algorithm based on dark channel prior mathematical morphology operations (opening and dilation), and a Gaussian filter, is proposed. Moreover, the proposed algorithm performance is compared qualitatively and quantitatively against previously reported algorithms. Obtained results show that the proposed algorithm requires less processing time providing higher quality dehazing results than other state-of-the-art approaches.

Simulation of a two DOF pneumatic manipulator robot using control based on back propagation neural network

Although pneumatic actuators have a good power-weight ratio, there is a reduced number of works that consider them to be applied in manipulator robots, mainly because they present difficulties to be controlled, and nonlinearities that make them complicated to obtain a mathematical model which describes their behavior in specific conditions. Control techniques can be implemented in this kind of actuators, and they can be complemented with path tracking to follow trajectories established by the user. This paper proposes software implementation of a back propagation artificial neural network to control a two DOF pneumatic manipulator and compares this method against PID control decreasing processing time and oscillations by self tuning parameters of the controller. Path tracking is realized using an algorithm of cubic splines interpoation and the movement of the pneumatic robot is presented in a graphic simulator developed in C++ using OpenGL libraries.

Four DOF pneumatic robot design and hardware interface

The industrial robot applications are very important for global industry. Major of the robots are using an electrical actuator, due its high precision. The advantage of electrical actuators is the low power-weight rate. The pneumatic actuators are used for industrial applications, but its precision is very low. The major problem with pneumatic actuators is the highly nonlinear behavior of the air, due the expansibility and compressibility properties. This work is focused in design a pneumatic robot with 4 degree of freedom, including the hardware interface to control the pneumatic actuators, and some test are developed with a Texas DSP Delfino C2000. The results show a pneumatic robot design including electronic hardware and an algorithm control.

New Strategy to Approach the Inverse Kinematics Model for Manipulators with Rotational Joints

The chapter describes a new strategy to approach the solution of the inverse kinematics problem for robot manipulators. A method to determine a polynomial model approximation for the joints positions is described by applying the divided differences with a new point of view for lineal path in the end-effector of the robot manipulator. Results of the mathematical approach are analysed by obtaining the kinematics inverse model and the approximate model for lineal trajectories of a manipulator for three degrees of freedom. Finally, future research approaches are commented.

A Novel Approach for Face Authentication Using Speeded Up Robust Features Algorithm

In this paper, we propose a modified face authentication method based on the image preprocessing (histogram equalization, HE) and with SURF algorithm (Speeded Up Robust Features) in the feature extraction step. In particular, our methodology aims at determining a person’s authenticity when he/she has a few facial expressions, different backgrounds or a variance in lighting. We evaluated the performance of this method using public face databases like The Extended Cohn-Kanade Dataset (CK+) and Caltech Faces. We made some test using sixty images (thirty per database), Equal (E) or Different (D) and according to the match between images (for example Image 1 and Image 2) and a defined threshold, our method determines if a person is authenticated or not. The results showed that with the database CK+ was obtained 93% and with Caltech Faces 86% of accuracy in the authentication process, these results were compared with those obtained by some algorithms like LDA, PCA, SIFT and SURF (without preprocessing) and we can conclude that the authentication rate was improved.