Swee M. Mok

Media searching on mobile devices

Mobile devices such as cellular phones are now capable of storing a significant amount of multimedia files and personal data. However these devices still use traditional directory browsing which offers little in terms of usability for searching and retrieving specific files. In this paper we design and implement a prototype media search engine for a mobile phone. We use modified versions of open source search and metadata extraction libraries along with scrollable instant search results and an auto-fill feature. The prototype has acceptable performance in terms of resource requirement and execution speed. Potential applications may include multimedia file searching in distributed mobile computing and peer-to-peer file sharing environments.

Automatic generation of assembly instructions using STEP

An automatic method for generating assembly instructions using CAD files is presented. Algorithms for extracting geometrical information of objects stored in a non-proprietary format, ISO-10303, STEP-CAD data file are explained. The developed algorithms form an important link between design and manufacturing. In our previous work, (Mok et al., 2000, 1999, Wu and Kim, 1994, and Kim and Wu, 1990) we designed a hierarchical assembly model that allows designers to evaluate products for manufacturing cost using a structured assembly coding system (SACS). Each SACS code represents a sequence of assembling/disassembling operations for mating two parts. The developed algorithms in this paper generate the required SACS codes based on the geometrical and topological information extracted from the STEP files of a product in a CAD environment. Based on the generated SACS codes, the proper assembly operations can then be derived for assembling the designed product. An example of assembly with simple parts is presented to verify the method.

Modeling automatic assembly and disassembly operations for virtual manufacturing

A system for evaluating products in their design phase has been developed for virtual manufacturing. It is integrated into a CAD/CAM environment to calculate the cost for assembling and disassembling parts. In our earlier work, a generic assembly and disassembly model was developed to represent operations required for product manufacturing and de-manufacturing. To be useful, the model requires a method for translating high-level instructions from product designers into low-level assembly and disassembly instructions. This paper presents a set of rules for accomplishing this task. The developed rules are used for manipulating strings representing parts and handlers in binary assembly and disassembly operations. A telephone assembly and disassembly simulation is used to illustrate the developed system.

A system for analyzing automatic assembly and disassembly operations

A system for evaluating products in their design phase has been developed. It is integrated into a CAD/CAM environment to calculate cost for assembling and disassembling parts. In previous work, a generic assembly and disassembly model was developed to represent operations required for product manufacturing and demanufacturing. To be useful, the model requires a method for translating high-level instructions from product designers into low-level assembly and disassembly instructions. This paper presents a set of rules for accomplishing this task. The developed rules are used for manipulating strings representing parts and handlers in binary assembly and disassembly operations. A telephone assembly and disassembly simulation is used to illustrate the developed system.

Evolutionary Path Planning With Subpath Constraints

We develop an evolutionary method of planning paths that are subject to subpath constraints. These constraints can include subpaths that must be incorporated into the solution path, path intersection restrictions, and obstacle avoidance. Our method involves two stages. In the first stage, a global solution is found without consideration of any obstacles. In the second stage, local planning is performed to modify the global path to avoid obstacles. Stage one involves a fixed-length chromosome formulation of a genetic algorithm that utilizes existing operators and a new subpath reversal operator. Stage two involves a graph search process. Our algorithm is applicable to the field of printed electronics where continuous-spray processes are used to deposit electrically functional material onto flexible substrates. These processes give rise to the kinds of subpath constraints we have investigated. We evaluate our algorithm by applying it to a representative problem in the printed electronics field.

A hierarchical workcell model for intelligent assembly and disassembly

An intelligent virtual assembly and disassembly (VIRAD) system that can be integrated into a CAD/CAM environment is developed for designers to evaluate products for assembly and disassembly efficiencies during the design process. The VIRAD system uses a hierarchical model of a generic assembly and disassembly (GENAD) workcell to generate merging trees for simulating assembly and disassembly processes. In a GENAD workcell, every object is either a part for making a product or a handler to facilitate the workcell operations. Each workcell operation is associated with a cost for product assembly and disassembly. The estimated cost is used for representing a products manufacturability, providing important feedback for the designer. This paper presents details of the GENAD workcell model and its inner representation.

Linking product design in CAD with assembly operations in CAM for virtual product assembly

Purpose – Virtual product design has become a key technology in reducing costly design errors that are often difficult to detect manually. In order to evaluate product assembly in a virtual environment, it is important to link a products design in CAD with the constrained complexity of assembly operations in CAM so that the design can be evaluated and modified in a virtual environment before production begins. The paper aims to focus on this.Design/methodology/approach – The proposed virtual system includes the following components: a product assembly coding model, named Open Structured Assembly Coding System (OSACS), that codes part‐mating operations for assembling any two parts in CAM; a rule‐based code extractor that identifies OSACS codes for assembling product from the part‐mating information encoded in Standard for the Exchange of Product Model Data AP‐203 CAD data; and an assembly‐sequence generator that generates a binary assembly‐tree for the designed product coded with OSACS assembly codes, rep...

Automation integration with UPnP modules

A method for leveraging a communication protocol called Universal Plug and Play (UPnP) for workcell automation and integration is presented. By leveraging UPnP for automation equipment, a workcell can potentially be built in a modular manner whereby the modules can be easily replaced, reused, or upgraded over time with minimal re-engineering of a workcell. UPnP devices can be automatically discovered and their services can be activated remotely via a communication network. However, the UPnP protocol is relatively new and it was designed primarily for connecting home entertainment devices for serving and playing movies and songs. This paper will present preliminary investigative work required to integrate typical automation equipment such as a robot and its vision system in a simple pick and place workcell.

Structured product coding system (SPCS) for product cost evaluation in a CAE/CAD/CAM Product (C3P) environment

Virtual design and manufacturing has become a key technology in reducing both design errors and manufacturing cost. In order to have a realistic evaluation, the cost of assembling, disassembling, and manufacturing a product has to be realized. A products design and its manufacturability will give an overall manufacturing efficiency and production cost. To eliminate future production failure and control the cost, management has to be able to foresee and evaluate the whole process from design to production, easily and wisely. In recognizing the importance of this capability, a CAE/CAD/CAM Product (C3P) management tool based on a structured product coding system (SPCS) is developed for the process of virtual design and manufacturing.