scholarly journals Development of robotic polishing/fettling system on ceramic pots

2021 ◽  
Vol 18 (3) ◽  
pp. 172988142110128
Author(s):  
Zhangguo Yu ◽  
Hsien-I Lin
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Force Sensor ◽  
Ball Screw ◽  
Force Response ◽  
Geometric Models ◽  
Six Degrees Of Freedom ◽  
Robot Trajectory ◽  
Polishing Force ◽  
Aided Design

Current robot polishing techniques are available for objects with computer-aided design geometric models but not for objects without geometric models such as ceramic or clay pots. In this study, we developed a robotic polishing/fettling system to polish the molding defects of ceramic objects. The polishing force on the object surfaces is required to be constant to obtain better results. Thus, the proposed robotic polishing system was designed with a stepper motor, ball screw, and force sensor. The proposed system acquired a rough robot polishing/fettling trajectory and adopted a fuzzy proportional–integral–derivative controller to regulate the trajectory to maintain the desired contact force response from a ceramic object. We developed the temporary desired value technique to make the polishing force response close to the desired one. We validated the system on a six-degrees-of-freedom Staubli TX 40L robotic arm. Experiments were performed to test the effectiveness of the system. The robot trajectory responses showed that the proposed system performed well in tracking the desired force in the polishing/fettling process. We used a 3D microscope to verify that the molding defect of the ceramic pot was significantly removed to evaluate the polishing/fettling quality.

Vision-force guided precise robotic assembly for 2.5D components in a semistructured environment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Boyoung Kim ◽  
Minyong Choi ◽  
Seung-Woo Son ◽  
Deokwon Yun ◽  
Sukjune Yoon
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Printed Circuit Board ◽  
Force Sensor ◽  
Circuit Board ◽  
Robotic Assembly ◽  
Ccd Cameras ◽  
Content Type ◽  
3 Dimensional ◽  
Aided Design

Purpose Many manufacturing sites require precision assembly. Particularly, similar to cell phones, assembly at the sub-mm scale is not easy, even for humans. In addition, the system should assemble each part with adequate force and avoid breaking the circuits with excessive force. The purpose of this study is to assemble high precision components with relatively reasonable vision devices compared to previous studies. Design/methodology/approach This paper presents a vision-force guided precise assembly system using a force sensor and two charge coupled device (CCD) cameras without an expensive 3-dimensional (3D) sensor or computer-aided design model. The system accurately estimates 6 degrees-of-freedom (DOF) poses from a 2D image in real time and assembles parts with the proper force. Findings In this experiment, three connectors are assembled on a printed circuit board. This system obtains high accuracy under 1 mm and 1 degree error, which shows that this system is effective. Originality/value This is a new method for sub-mm assembly using only two CCD cameras and one force sensor.

A NUMERICAL SIMULATION INVESTIGATION OF THE HYDRODYNAMIC MOTIONS OF A SHIP ADVANCING IN WAVES

2021 ◽  
Vol 156 (A4) ◽  
Author(s):  
D C Lo ◽  
D T Su ◽  
J T Lin
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Fluid Dynamic ◽  
Wave Interaction ◽  
Six Degrees Of Freedom ◽  
Ship Model ◽  
Computer Aided ◽  
Cad Tool ◽  
Aided Design ◽  
Wave Incidence

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.

Solving reachable workspace of some parallel manipulators by computer-aided design variation geometry

2008 ◽  
Vol 222 (9) ◽  
pp. 1773-1781 ◽  
Author(s):  
Y Lu ◽  
Y Shi ◽  
B Hu
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Six Degrees Of Freedom ◽  
Reachable Workspace ◽  
Spline Curves ◽  
Computer Aided ◽  
Design Variation ◽  
Aided Design ◽  
The Given

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.

Determination of the Workspace of a Three-Degrees-of-Freedom Parallel Manipulator Using a Three-Dimensional Computer-Aided-Design Software Package and the Concept of Virtual Chains1

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Andrew Johnson ◽  
Xianwen Kong ◽  
James Ritchie
Keyword(s):  
Computer Aided Design ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Graphical Representation ◽  
Three Dimensional ◽  
Parallel Manipulators ◽  
Workspace Analysis ◽  
Computer Aided ◽  
Aided Design

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.

scholarly journals Analog Circuit Design Automation Tool Using Genetic Algorithms

1970 ◽  
Vol 1 (1) ◽  
Author(s):  
Y. M. A. Khalifa ◽  
D. H. Horrocks
Keyword(s):  
Genetic Algorithms ◽  
Circuit Design ◽  
Analog Circuits ◽  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Analog Circuit ◽  
Search Space ◽  
Design Stage ◽  
Specific Frequency ◽  
Aided Design

An investigation into the application of Genetic Algorithms (GA) for the design of electronic analog circuits is presented in this paper. In this paper an investigation of the use of genetic algorithms into the problem of analog circuits design is presented. In a single design stage, circuits are produced that satisfy specific frequency response specifications using circuit structures that are unrestricted and with component values that are chosen from a set of preferred values. The extra degrees of freedom resulting from unbounded circuit structures create a huge search space. It is shown in this paper that Genetic Algorithms can be successfully used to search this space. The application chosen is a LC all pass ladder filter circuit design.Key Words: Computer-Aided Design, Analog Circuits, Artificial Intelligence.

Computer-Aided Design of Planar Parallel Robots for Optimal Workspace and Dexterity

2010 ◽  
Author(s):  
Ming Z. Huang
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Design Method ◽  
Strong Dependence ◽  
Simplex Algorithm ◽  
Parallel Robots ◽  
Optimal Designs ◽  
Parallel Structure ◽  
Design Problems ◽  
Aided Design

Parallel robots exhibit salient merits over their serial counterparts in applications where both accuracy and dynamic response are required. However, due to the strong dependence of geometric parameters and their performances, the corresponding design problems for the parallel robots are much more complex and the adequacy and effectiveness of the design method become more critical. In this paper, a study in the design optimization for a class of planar parallel robots is presented. The robots feature an in-parallel structure with two degrees of freedom. Dimension synthesis is performed through maximization of two key performance characteristics, addressing not only workspace but also dexterity of the robots under consideration. Optimal designs are attained using both parametric study and simplex algorithm. Results are shown by way of computer simulations aided with graphic visualizations.

Analysis and Design of Cam-Driven Mechanisms With Nonlinearities

1973 ◽  
Vol 95 (3) ◽  
pp. 685-694 ◽  
Author(s):  
F. Y. Chen
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Lumped Parameter Model ◽  
Analysis Tool ◽  
Analysis And Design ◽  
Lumped Parameter ◽  
Method Of Solution ◽  
Parametric Studies ◽  
Rational Procedure ◽  
Aided Design

The cam-and-follower mechanism is represented by a lumped parameter model of finite degrees of freedom, in which nonlinear system parameters may be taken into account. An approximate dynamic analysis of the system excited by either functional or numerical form of the base motion of a cam is obtained. The method of solution which uses an interpolating polynomial for approximating the excitation function and mechanical quadrature for evaluating the convolution integral is well suited for computer programming. A digital computer program for analysis based on this scheme is developed. In order to utilize the analysis tool for design purposes, parametric studies are conducted, design stratagems are presented and a rational procedure of closed loop computer-aided design is outlined and discussed.

Mechanical/Naval Design of an Underwater Remotely Operated Vehicle (ROV) for Surveillance and Inspection of Port Facilities

2007 ◽  
Author(s):  
Juan A. Rami´rez ◽  
Rafael E. Va´squez ◽  
Luis B. Gutie´rrez ◽  
Diego A. Flo´rez
Keyword(s):  
Visual Information ◽  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Remotely Operated Vehicle ◽  
Port Facilities ◽  
Computer Aided ◽  
Computational Fluid Dynamics Cfd ◽  
High Level ◽  
Aided Design ◽  
And Control

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.

Sign in / Sign up

Export Citation Format

Share Document