Conceptual Design and Artificial Intelligence

This paper introduces new approaches to the conceptual design of electro-mechanical systems from qualitative specifications of behaviour and function. The power of these methods stems from the integration of techniques in qualitative physics, symbolic mathematics , computational geometry and constraint programming. This is illustrated with an effective kinematic synthesis method that integrates reasoning with configuration spaces and constraint-programming techniques. 1 Introduction The broad goal of our research is to derive computational theories of conceptual or pre-parametric design. As manufacturing technologies change, as new materials are developed, as new design constraints emerge (designs with recyclable parts, and designs that assemble and disassemble easily), as products become more complex, as the need to build in continuous improvement into design processes emerges, basic conceptual design procedures for electro mechanical systems require broadening with effective use of computer tools in the early stages of design. Our specific aim is to use methods from artificial intelligence, especially qualitative physics and constraint programming, with techniques from computational geometry and symbolic mathematics to build new computational prototyping tools for conceptual design. 2 A Case Study While the talk will present several case studies of effective tools for conceptual design in a variety of domains, the rest of this paper is devoted to an illustration in the context of mechanism synthesis 1. Mechanisms are an important part of most electro-mechanical systems. They transmit motion from one rigid body to another. Our design system takes as input constraints on the motion of a mechanism in qualitative, mathematical form. As Figure 1: Design of a windshield wiper output, it produces a systematic enumeration of mechanism topologies and geometries that satisfy the given constraints. Tt also performs high-level simulation to demonstrate the feasibility of the design. The conceptual designs produced by our system can be refined and optimized by constraint-solving systems that select candidate designs based on cost, material, manufacturing and assembly constraints. The running example used in this paper is the synthesis of a windshield wiper whose input power is provided by a motor rapidly rotating around the z axis and whose output is an oscillation in the yz plane with low frequency. Note that this a partial description of the input and output motions of this device. The first design enumerated by our system is shown in Figure 1. It employs a worm spur which converts the uniform input rotation around the z axis to one about the x …