During the design and creation of linkage-type mechanisms, visualization of linkage motion is extremely important. However, there does not appear to be a commercially available computer package for accomplishing visualization interactively. Most linkage design packages allow animation of linkage motion only after tedious part description (and debug) using cryptic input codes. The main thrust of this work has been the development of a prototype interactive graphics (CAD) system aimed at visualizing the motion and mobility of linkage-type mechanisms. The program is called the Linkage Kinematics Sketchpad (LKSP). It is a 2-D color graphics program which allows the user to describe a limited set of linkages (limited by a simplified kinematics analysis procedure) and interactively drive the linkage through its inherent motion cycle (or parts thereof) to visualize mobility . First, a theoretical investigation of previous work in motion analysis and display of animation is presented. This is followed by a description of the LKSP program and an evaluation of the software by this author and others more familiar with linkage design. The system design appears to be adequate, and the software is correct with linkage motions as required. As a result of this work the usefulness of this approach has been determined, and a reasonable methodology has been established. Also, problem areas have been defined, and potentially fruitful areas for future work have been identified. LKSP offers a unique approach to planar linkage design with the most desirable features being the interactive user-computer interface, the ability to create linkages with ease, and the ability to observe linkage motion and potential interference. The most commonly cited shortcoming was the limited set of linkage components which LKSP can handle. Also, there were some aspects of the motion animation which were improved as a result of the user evaluations. Suggestions for future extensions include more user control over the motion animation and more precise input of linkage dimensions.
Library of Congress Subject Headings
CAD/CAM systems--Design; Links and link-motion--Data processing; Computer graphics--Design
Department, Program, or Center
Computer Science (GCCIS)
St. Jacques, Michael, "Linkage kinematics sketchpad" (1986). Thesis. Rochester Institute of Technology. Accessed from
RIT – Main Campus