Demonstrating the Generation of Bond Graphs From 3D Assemblies

Topics in mechanics such as Dynamics, Kinematics and System Modeling are generally taught using many examples. These examples and the associated numerical computations help foster an improved understanding of various important concepts.  There are also several hands-on laboratory activities that are used to reinforce those concepts. Such methods generally work well in the traditional classroom-based transmission model. With increasing focus on online education and flipped teaching models, replicating the successes achieved in the traditional model becomes challenging. This is primarily because a lot of these concepts are delivered through online videos that have no interactive component associated with them. The students watch the videos and redo the problems worked out in those videos. Even if there are interactive aspects to the online lectures, they are primarily passive, in the sense that the students that are part of the online course do not have any means to receive instant feedback for their work. Introducing interactive aspects and active feedback mechanisms to online courses are very important especially in topics such as system modeling.  Not only would these active feedback systems be helpful in online and flipped teaching models, they can be used to complement traditional methods as well.

Therefore, we have been working towards enhancing student understanding in bond graph-based system modeling. The bond graph method provides a generic and a simpler way to compute differential equations for complex mechatronic systems. Prior work in this area [1,2] has led to the development of an automated tool for generating bond graphs and energy states. This paper will illustrate the methods and the grammar rules that are used to automatically generate bond graphs from 3D assemblies created in SolidWorks. The built-in feature recognition system in SolidWorks is used to identify the geometric relationships between different components in the assembly and using grammar rules, a system graph is generated. The system graph is converted to bond graphs using the existing bond graph tool. This tool will benefit students as they can be exposed to various assemblies of mechatronic systems, manually generate bond graphs and then verify their solutions with the help of the automated tool.

References:

[1] Grande D, Mancini F, Radhakrishnan P. An Automated Graph Grammar Based Tool to Automatically Generate System Bond Graphs for Dynamic Analysis. ASME. International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 1B: 36th Computers and Information in Engineering Conference (2016): V01BT02A036. doi:10.1115/DETC2016-59941.

[2] Mancini F, Grande D, Radhakrishnan P. An Automated Virtual Lab for Bond Graph Based Dynamics Modeling Using Graph Grammars and Tree Search. ASME. ASME International Mechanical Engineering Congress and Exposition, Volume 5: Education and Globalization (2016): V005T06A004. doi:10.1115/IMECE2016-66110.