scholarly journals Multi-objective Optimization of a Mechatronic Solar Tracking Mechanisms

Author(s):  
Cătălin Alexandru ◽  

In this work, the multi-objective optimization of a dual-axis solar tracker is carried out by using a virtual prototyping software platform that integrates CAD (Computer Aided Design) – CATIA, MBS (Multi-Body Systems) – ADAMS and DFC (Design for Control) – EASY5 computer aided engineering programs. The solar tracking mechanism performs the bi-axial orientation of a PV panel, with the purpose to increase of the amount of incident solar radiation captured by the conversion system, thus improving its energy output. The optimization study aims to determine the optimal arrangement of the linear actuators that control the two degrees of freedom of the system (i.e. the diurnal and elevation movements of the PV panel) and the optimal tuning of their control elements (controllers), so that to minimize the energy consumption for performing the tracking and the tracking errors (relative to the imposed orientation program), while complying with the functional and constructive requirements/constraints coming from the type of actuator used in the application (which is a real/existing one). The tracking mechanism is approached/designed in mechatronic concept (i.e. concurrent engineering), by integrating the mechanical and control subsystems at the virtual prototype level.

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Andrew Johnson ◽  
Xianwen Kong ◽  
James Ritchie

The determination of workspace is an essential step in the development of parallel manipulators. By extending the virtual-chain (VC) approach to the type synthesis of parallel manipulators, this technical brief proposes a VC approach to the workspace analysis of parallel manipulators. This method is first outlined before being illustrated by the production of a three-dimensional (3D) computer-aided-design (CAD) model of a 3-RPS parallel manipulator and evaluating it for the workspace of the manipulator. Here, R, P and S denote revolute, prismatic and spherical joints respectively. The VC represents the motion capability of moving platform of a manipulator and is shown to be very useful in the production of a graphical representation of the workspace. Using this approach, the link interferences and certain transmission indices can be easily taken into consideration in determining the workspace of a parallel manipulator.


Author(s):  
Abolfazl Seifi ◽  
Reza Hassannejad ◽  
Mohammad Ali Hamed

In this study, a new method to improve ride comfort, vehicle handling, and workspace was presented in multi-objective optimization using nonlinear asymmetrical dampers. The main aim of this research was to provide suitable passive suspension based on more efficiency and the low cost of the mentioned dampers. Using the model with five degrees of freedom, suspension system parameters were optimized under sinusoidal road excitation. The main functions of the suspension system were chosen as objective functions. In order to better illustrate the impact of each objective functions on the suspension parameters, at first two-objective and finally five-objective were considered in the optimization problem. The obtained results indicated that the optimized viscous coefficients for five-objective optimization lead to 3.58% increase in ride comfort, 0.74% in vehicle handling ability, and 2.20% in workspace changes for the average of forward and rear suspension.


Author(s):  
Lothar Birk

The paper reports on the continuous development of an automated optimization procedure for the design of offshore structure hulls. Advanced parametric design algorithms, numerical analysis of wave-body interaction and formal multi-objective optimization are integrated into a computer aided design system that produces hull shapes with superior seakeeping qualities. By allowing multiple objectives in the procedure naval architects may pursue concurrent design objectives, e.g. minimizing heave motion while simultaneously maximizing deck load. The system develops a Pareto frontier of the best design alternatives for the user to choose from. Constraints are directly considered within the optimization algorithm thus eliminating infeasible or unfit designs. The paper summarizes the new developments in the shape generation, illustrates the optimization procedure and presents results of the multi-objective hull shape optimization.


2021 ◽  
Vol 156 (A4) ◽  
Author(s):  
D C Lo ◽  
D T Su ◽  
J T Lin

This study establishes a relationship diagram of the ship-wave interaction under a ship advancing in waves. A finite difference method based on volume of fluid (VOF) principles was used to simulate the hydrodynamic motions of a ship advancing in waves. A ship model was constructed using a computer aided design (CAD) tool. The computational fluid dynamic (CFD) technique was used to calculate the hydrodynamic motions effect of a ship sailing in waves at varying angles of incidence. This study investigates a number of significant related parameters, such as the speed of the ship model, the various wave incidence angles, the wave height, and the navigation time. A chart is also used to show the flow field, and changes in the six degrees of freedom motion and continually compare changes in the drag force.


2013 ◽  
Vol 347-350 ◽  
pp. 1525-1529
Author(s):  
Jie Shi ◽  
Jun Shi ◽  
Lin Lin Yang ◽  
Xiu Ying Tang ◽  
Yi Jie Zhang

With the increasingly serious crisis of the energy problem, all around the world, the application of solar energy has become an approach of solving the problem undoubtedly. In recent years, due to the rapid development of Chinese photovoltaic (PV) industry, the emergence of PV buildings is more and more widely in the domestic. The current trend is to apply Computer-Aided Design (CAD) software to realize the design of Building Integrated Photovoltaic (BIPV). The core problem of CAD is to obtain the best solution to a laying scheme of PV cell. In this paper, the design problem of PV building is concerned about. Through the research on the multi-objective optimization theory, it is to establish the model of multi-objective optimization that can meet these two objectives of the largest total annual solar photovoltaic power generation, yet the smallest possible the unit cost of power generation. The model can be solved by MATLAB using ideal point method. In order to detail explain the application of model and verify it, the design of PV cabin, in Datong area of Shanxi Province, is as an example. The study has laid the foundation for the development of CAD in the future.


Author(s):  
Y Lu ◽  
Y Shi ◽  
B Hu

To shape the workspace of some novel parallel manipulators (PMs) is significant. A novel computer-aided design (CAD) variation geometry approach is proposed to shape and solve the reachable workspace of some PMs with three to six degrees of freedom (DOFs). Some basic techniques are described for designing the simulation mechanism and solving the reachable workspace. The simulation mechanisms of some PMs with three to six DOFs are created. When varying the driving dimensions of the active legs in the given extent, the simulation mechanisms vary correspondingly, and the position components of the moving platform are solved automatically. By transferring the position solutions into spatial spline curves in the simulation mechanism, all the boundary surfaces of the workspace can be created and visualized dynamically. Comparing with analytic approaches for solving workspace, the CAD variation geometry approach is simple, straightforward, accurate, and repeatable.


Author(s):  
Juan A. Rami´rez ◽  
Rafael E. Va´squez ◽  
Luis B. Gutie´rrez ◽  
Diego A. Flo´rez

This paper presents the mechanical/naval design process of an underwater remotely operated vehicle (ROV), required to obtain reliable visual information, used for surveillance and maintenance of ship shells and underwater structures of Colombian port facilities. The design was divided into four main subsystems: mechanical/naval, hardware, software and guidance, navigation and control. The most relevant design constraints were evaluated considering environmental conditions, dimensional restrictions, hydrostatics, hydrodynamics, degrees of freedom and the availability of instrumentation and control hardware. The mechanical/naval design was performed through an iterative process by using computational tools, including Computer Aided Design CAD, Computer Aided Engineering CAE, Computational Fluid Dynamics CFD and a high level programming environment. The obtained design ensures that the reliable operation of the robot will be achieved by using a consistent construction process. The new ROV constitutes an innovative product in Colombia, and it will be used for surveillance and oceanographic research tasks.


2010 ◽  
Vol 132 (8) ◽  
Author(s):  
J. Hamel ◽  
M. Li ◽  
S. Azarm

Uncertainty in the input parameters to an engineering system may not only degrade the system’s performance but may also cause failure or infeasibility. This paper presents a new sensitivity analysis based approach called design improvement by sensitivity analysis (DISA). DISA analyzes the interval uncertainty of input parameters and using multi-objective optimization, determines an optimal combination of design improvements that will ensure a minimal variation in the objective functions of the system, while also ensuring the feasibility. The approach provides a designer with options for both uncertainty reduction and, more importantly, slight design adjustments. A two-stage sequential framework is used that can employ either the original analysis functions or their metamodels to greatly increase the computational efficiency of the approach. This new approach has been applied to two engineering examples of varying difficulty to demonstrate its applicability and effectiveness. The results produced by these examples show the ability of the approach to ensure the feasibility of a preexisting design under interval uncertainty by effectively adjusting available degrees of freedom in the system without the need to completely redesign the system.


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