Max A. González-Palacios

SnAM: a simulation software on serial manipulators

The solution of kinematics problems for serial manipulators is fundamental for their synthesis, analysis, simulation, and computer control; for this reason, this paper introduces a public domain package and open software called SnAM (Serial n-Axis Manipulators), which is developed under the ADEFID (ADvanced Engineering soFtware for Industrial Development) framework, where the manipulator is conceptualized as a derived class from CRobokin, CMachine and CIpiSModel, which are fundamental ADEFID classes. SnAM has been developed with efficient algorithms in a closed-loop solution to solve direct kinematics, whereas for the case of inverse kinematics, matrix formulation, elimination and numerical methods are implemented. Furthermore, for the architecture definition, the user is able to display a dialog box in which the design parameters are set based on the Denavit–Hartenberg convention with the aid of sliding bars, while the solid model is updated simultaneously showing the actual configuration. Since ADEFID provides tools to graphical interface with embedded control components SnAM adopt them to not only simulate virtually, but also with an adaptive prototype designed for this purpose. Furthermore, SnAM assists the user in tasks related to trajectory planning, collision-avoidance and three-dimension objects scanning.

Design of a Novel MEMS Microgripper with Rotatory Electrostatic Comb-Drive Actuators for Biomedical Applications

Primary tumors of patients can release circulating tumor cells (CTCs) to flow inside of their blood. The CTCs have different mechanical properties in comparison with red and white blood cells, and their detection may be employed to study the efficiency of medical treatments against cancer. We present the design of a novel MEMS microgripper with rotatory electrostatic comb-drive actuators for mechanical properties characterization of cells. The microgripper has a compact structural configuration of four polysilicon layers and a simple performance that control the opening and closing displacements of the microgripper tips. The microgripper has a mobile arm, a fixed arm, two different actuators and two serpentine springs, which are designed based on the SUMMiT V surface micromachining process from Sandia National Laboratories. The proposed microgripper operates at its first rotational resonant frequency and its mobile arm has a controlled displacement of 40 µm at both opening and closing directions using dc and ac bias voltages. Analytical models are developed to predict the stiffness, damping forces and first torsional resonant frequency of the microgripper. In addition, finite element method (FEM) models are obtained to estimate the mechanical behavior of the microgripper. The results of the analytical models agree very well respect to FEM simulations. The microgripper has a first rotational resonant frequency of 463.8 Hz without gripped cell and it can operate up to with maximum dc and ac voltages of 23.4 V and 129.2 V, respectively. Based on the results of the analytical and FEM models about the performance of the proposed microgripper, it could be used as a dispositive for mechanical properties characterization of circulating tumor cells (CTCs).

OptimPlot3D: A Novel and Interactive Software Package for Analysis of Three Dimensional Surfaces

An innovate software package for navigation and analysis of three dimensional surfaces is introduced in this paper. The graphical tools developed, allows plotting surfaces and finding optima values by the application of numerical optimization procedures. The platform considered for its development, facilitates the visualization of the results in a quick and interactive form.

SnAP: A Comprehensive Software Package for the Simulation of Serial Manipulators

The solution of kinematics problem for serial manipulators is fundamental for their analysis, simulation and computer control, for this reason, this paper introduces the software package called SnAP (Serial n-Axes Manipulators), which is developed under the ADEFID framework [1], where the manipulator is conceptualized as a derived class from CRobokin, CMachine and CIpiSModel, which are fundamental ADEFID classes. SnAP has been developed with efficient algorithms in a closed-loop solution to solve direct kinematics, whereas for the case of inverse kinematics, matrix formulation, elimination and numerical methods are implemented. Furthermore, for the architecture definition, the user is able to display a dialog box in which the design parameters are set while the solid model is updated simultaneously showing the actual configuration. Since ADEFID provides tools to graphical interface with embedded control components, SnAP adopted them to not only simulate virtually, but also with a parametric prototype designed for this purpose.Copyright

Design and Modeling of a MEMS Dual-Backplate Capacitive Microphone with Spring-Supported Diaphragm for Mobile Device Applications

New mobile devices need microphones with a small size, low noise level, reduced cost and high stability respect to variations of temperature and humidity. These characteristics can be obtained using Microelectromechanical Systems (MEMS) microphones, which are substituting for conventional electret condenser microphones (ECM). We present the design and modeling of a capacitive dual-backplate MEMS microphone with a novel circular diaphragm (600 µm diameter and 2.25 µm thickness) supported by fifteen polysilicon springs (2.25 µm thickness). These springs increase the effective area (86.85% of the total area), the linearity and sensitivity of the diaphragm. This design is based on the SUMMiT V fabrication process from Sandia National Laboratories. A lumped element model is obtained to predict the electrical and mechanical behavior of the microphone as a function of the diaphragm dimensions. In addition, models of the finite element method (FEM) are implemented to estimate the resonance frequencies, deflections, and stresses of the diaphragm. The results of the analytical models agree well with those of the FEM models. Applying a bias voltage of 3 V, the designed microphone has a bandwidth from 31 Hz to 27 kHz with 3 dB sensitivity variation, a sensitivity of 34.4 mV/Pa, a pull-in voltage of 6.17 V and a signal to noise ratio of 62 dBA. The results of the proposed microphone performance are suitable for mobile device applications.

Workspace Analysis of a Delta-Like Robot Using an Alternative Approach

This paper treats the workspace analysis of a delta-like robot using a different placement of the actuators to improve the overall reachable workspace. Instead of having the actuators separated 120° between each other, it is proposed to provide different separations to create a greatly improved workspace suitable for custom applications. The general analysis of inverse and direct kinematics is explained and implemented in a software created to analyse this type of robot. Finally a comparison to prove the advantages of changing the angles between legs is shown.

A Novel Numerical Method to Solve the Inverse Kinematics of 3R Manipulators

A new numerical method to solve the inverse kinematics solution problem of serial manipulators is developed in this paper. The proposed method is known as Differential Evolution (DE), a novel and efficient numerical method which has been adapted to solve the inverse kinematics solution of 3R serial manipulator of general geometry. Besides, the paper contains the complete structuring for the implementation of this new case in SnAP, a comprehensive software package for synthesis, analysis and simulation of serial manipulators. The DE method is stable since it converges to the solution with any initial values, and it is not sensitive to the singular configurations of serial manipulators. Simulation results are presented to show the performance benefits of the proposed algorithm. Computational efficiency of the method is shown based on the results, as well as in comparison with traditional methods used in this problem.Copyright