Creating Design Machines for Machine Design

1. Creating Design Machines for Machine Design Linda C. Schmidt Mechanical Engineering Department Institute for Systems Research University of Maryland December 1, 2000

2. THE DATLab MissionThe Designer Assistance Tool Laboratory at the University of Maryland provides state-of-the-art fundamental research and implementation strategies to improve the quality of design processes and outcomes. Vision Our current research emphasis focuses applying grammar-based generative design strategies to design tasks, from concept generation to optimization of detailed designs. Values DATLab researchers operate with enthusiasm, professionalism, and a spirit of innovation.

3. Accomplishment We seek a unified grammar-based approach to generating alternatives from functional descriptions of designs. Prior work demonstrates the Assembler Current work explores the HTN planning approach Significance / Impact Designers can benefit from techniques and tools that generate feasible design solutions. Key People Involved Linda C. Schmidt and Hai Shi References Schmidt, L., Shi, H. and Sameer, K., “The “Generation Gap”: A CSP Approach Linking Function to Form Grammar Generation”, To appear in Journal of Mechanical Design, 2000. Shi, H. and Schmidt, L., “Comparing HTN Planning Method with Grammar-Based Approach in Generative Design”, Submitted to Design Automation Conference, 2000 t1,3 t2,3 t1,2 t2,2 t3,2 t3,1 t3,1 t3,1 t15,1 t17,1 Generative Designer Assistance Tools: Automated Function to Form Design Generation

4. Results of the Assembler

5. Modeling Generative Design As HTN Planning Problem • Methods (refining rules) are design principles and special field knowledge from experienced designers. They tell the HTN planner how to decompose functions, which means how a function (task) can be accomplished by a certain set of lower level sub-functions (task network) • The task set consists of the hierarchical functions that include basic functions (primitive tasks) and non-basic functions (non-primitive tasks) • -A primitive task is a final solution concept of a basic function in the different levels that can be accomplished directly • -A non-primitive task is a function that can not be accomplished directly and need to be decomposed into lower level sub-functions

6. Accomplishment grammar-based graph generation engine other is the functional schematic sketching module. Significance / Impact This designer assistance tool helps designers to generate concepts of EGT structure during the conceptual design phase an initial exploration of using grammar-based design to build a practical designer assistance tool Key People Involved Linda C. Schmidt and Xin Li References Li, X., Schmidt, L., "Grammar-based Designer Assistance Tool for Epicyclic Gear Train", Presented at DETC 2000, Baltimore, MD. Chang, E., Li, X, Schmidt, L. MS Thesis, December 2000 Grammar-based Designer Assistance Tool For Epicyclic Gear Trains: An Overview

7. Sub-task and Procedures Structural Synthesis based on graph-grammar Functional Schematic Sketching Concept selection Three dimensional drawing Behavior Model Proxy Grammar-based Designer Assistance Tool For Epicyclic Gear Trains

8. Grammar-based Designer Assistance Tool For Epicyclic Gear Trains: Interface and Results One-degree-of-freedom EGT up to 6 links can be generated by this system Area 1- User inputs design requirements Area 2- Functional schematic is sketched automatically Area 3- Text output will appear Area 4- User can select and view different design

9. The Need for Behavior-based Representation Systems in Design Diagram of the design process emphasizing the role of form, function, and behavior Modified Design Process