RBE Masters Thesis Presentation: Kohmei Kadoya | Improving the User Experience and Features of PMKS+: A Web-Based Linkage Analysis Tool for Education

Thursday, April 20, 2023
9:00 am to 11:00 am
Floor/Room #

RBE Robot Lineup

RBE Masters Thesis Presentation

Kohmei Kadoya

Improving the User Experience and Features of PMKS+: A Web-Based Linkage Analysis Tool for Education

Thursday, April 20th

9:00 AM - 11:00 AM

Higgins Labs 102

Abstract: Planar Mechanism Kinematic Simulator Plus (PMKS+) is a web-based tool for the analysis of planar linkages with revolute and grounded prismatic joints. Developed as a classroom and assignment assistance tool with many features and capabilities, PMKS+ is used in different Mechanical and Robotics Engineering courses at WPI.

   The objectives of this thesis were to critically assess and enhance the application's user interface so that its built-in features are easily accessible and intuitive for users, thereby expanding the user base of PMKS+. Comprehensive studies involving the application's primary users were conducted and journey maps were developed to discover key pain points. One key issue identified was the difficulty in accurately recreating the linkage users wanted to analyze. If the linkage is specified in the form of joint coordinates, then it could be easily created within PMKS+ but not when the linkage is specified in terms of link lengths and angles. Users also had trouble locating features such as plots and equations that could be used to verify or troubleshoot errors in different assignments. Besides, the existing library of link shapes had limited adjustability.

   To address these concerns, a complete redesign of the application was undertaken, with a primary focus on improving the user experience for the existing feature set in PMKS+. The user interface was modernized by following modern material design guidelines. General conventions were extracted from other engineering applications used by our users to allow an easier transition to PMKS+. High-fidelity interface designs were generated and rigorously reviewed by advisors and users at various stages of the development process. In conjunction with front-end improvements, significant backend modifications were implemented to decouple analyses modules from user-interface components. Major features introduced include specifying linkages using link lengths and angles, three-position synthesis, and an innovative method for altering link shapes through weldments.

   Working prototypes of the redesigned application were evaluated by different groups of students at various stages. The results revealed a significant improvement in user experience with a high satisfaction score.


Professor Pradeep Radhakrishnan, Worcester Polytechnic Institute (WPI)


Professor  Alireza Ebadi, Worcester Polytechnic Institute (WPI)

Professor  David C. Brown, Worcester Polytechnic Institute (WPI)

Professor  Nicholas Bertozzi, Worcester Polytechnic Institute (WPI)



Robotics Engineering