EME152 Computer-Aided Mechanism Design, Project Description
(200 points for a single student project)
Project Due Thursday at 11:59pm, December 17
Project: Computer-Aided Design and Analysis of
a Mechanism
Design and implement a software package for the computer-aided design and analysis of a mechanism
shown in Figure 1.
Figure 1: The Whitworth quick return mechanism.
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The software package should be usable by engineers to solve practical problems related to the mechanism.
It can also be used by students to understand the working principle of the mechanism. The important
point is that the software package is designed for others to use.
The software package shall be general and flexible. It shall be readable and easy to maintain. It should
include both on-line and off-line documentation. The software shall include the following components.
• The software shall allow a user to input the parameters for the mechanism. A user can input parameters
in either US Customary or SI units.
• The package shall be able to perform position, velocity, acceleration analysis.
• The package shall be able to perform animation of the mechanism.
Follow the implementation of the class CFourbar for analysis and design of fourbar linkages as an example.
Read its off-line documentation in Chapter 2, and Appendices A and B in Ch Mechanism Toolkit User’s
Guide. The source code for class CFourbar is located in C:/ch/toolkit/include/linkage.h,
C:/ch/toolkit/include/fourbar.h, C:/ch/toolkit/lib/mechanism/CFourbar.chf. Demonstration programs for using
class CFourbar is located in directories C:/ch/toolkit/demos/mechanism/chapters/fourbar and
C:/ch/toolkit/demos/mechanism/appendix/CFourbar. You may implement the software package as a class
called CMechanism with a header file mechanism.h, which includes the header file linkage.h, and class
member function file CMechanism.chf. The class may contain, at the minimum, the following member
functions with proper arguments.
All these member functions should be tested and documented somewhere in the document. There are multiple
geometrical inversions for a given position for the input link 2. Your software only give the solution for
the geometrical inversion shown in Figure 1.
For testing purposes and the ability to check the status of your program with other teams, initialize your
parameters with the values provided in the following table. With these values set as default, users should be
able to use your software package without having to input any data.
The length for each link of a crank-rocker four-bar linkage is r1 = 5.5cm, r2 = 1.0cm, r3 = 3.0cm, r4 =
4.5cm and the phase angle for link 1 is θ1 = 10◦
. THe length r5 for link 5 is 8 cm, the distance of B0 to the
vertical wall on the right side is 3 cm.
Assume that the input link 2 is the driving link that rotates at a constant cw angular velocity ω2 =
15radian/s and that θ2 = 0 when t=0.
Write a program to use the developed class to calculate the position, velocity, acceleration of the slider
when θ2 for the input link is 45◦
Write a program to use the developed class for animation.
Note:
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- A sample project report and source code are available at
http://iel.ucdavis.edu/projec… - For those who would like to use LaTeX for writing project report, you may download the template
from http://iel.ucdavis.edu/course… More information
about LaTeX can be found at http://iel.ucdavis.edu/course/
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EME-152 Project Report Organization
Fall 2018, Dr. Harry H. Cheng
A. Title Page
Include title, authors, and class.
B. Table of Contents
Write your report with pager numbers.
C. Abstract
Summary of the project report.
1: Introduction
Describe the need and outline design specifications.
2: Kinematic analysis of the Whitworth Quick Return Mechanism - Details of position, velocity, and acceleration analysis.
- Sample code with output in numerical data and plotting for
posistion, velocity, and acceleration. - Sample code with animation snapshot.
3: Description of the Software Package - Describe how to use the software package with examples.
- Kinematic analysis and dynamic analysis.
- Plotting of position, velocity, and acceletation.
- Conclusions
Highlight contributions and outstanding features. Discuss the significance of the software package. - Bibliography
- Appendix
Details of Mechanism class. Detailed description of each member functions.
Details of CMechanism class.
Describes details of each member function of class CMechanism.