Jonathan C. Borg

Scribbles to vectors: preparation of scribble drawings for CAD interpretation

This paper describes the work carried out on off-line paper based scribbles such that they can be incorporated into a sketch-based interface without forcing designers to change their natural drawing habits. In this work, the scribbled drawings are converted into a vectorial format which can be recognized by a CAD system. This is achieved by using pattern analysis techniques, namely the Gabor filter to simplify the scribbled drawing. Vector line are then extracted from the resulting drawing by means of Kalman filtering.

A knowledge-based tool for designing cyber physical production systems

Changing production systems and product requirements can trace their origin in volatile customer behaviour and evolving product requirements. This dynamic nature of customer requirements has been described as a constantly moving target, thus presenting a significant challenge for several aspects of product development. To deal with this constant and sometimes unpredictable product evolution, cyber physical production systems (CPPS) that employ condition monitoring, self-awareness and reconfigurability principles, have to be designed and implemented. This research contributes a CPPS design approach that proactively provides the required CPPS design knowledge. This approach aims to minimise or avoids future consequences and disruptions on the CPPS. This knowledge needs to be provided at the right time whilst not being intrusive to the production system designers cognitive activity. To effectively deal with the complexity of the cyber physical production system design activity with a manual method would lead to a time consuming, and complex support tool which is hard to implement, and difficult to use. The CPPS design approach has therefore been implemented in a prototype digital factory tool. This paper describes in detail the system requirements and system architecture for this tool. In order to establish the effectiveness of the proposed approach for designing cyber physical production systems, the prototype digital factory tool has been evaluated with a case study and a number of semi-structured interviews with both industrial and scientific stakeholders. The encouraging results obtained from this research evaluation have shown that such an approach for supporting the CPPS design activity makes stakeholders aware of their decision consequences and is useful in practice. This result can lead the way for the development and integration of such knowledge-based decision-making approaches within state-of-the-art digital factory and Computer Aided Engineering Design (CAED) tools.

Line tracking algorithm for scribbled drawings

This paper describes a line tracking algorithm that may be used to extract lines from paper based scribbles. The proposed algorithm improves the performance of existing sparse-pixel line tracking techniques that are used in vectorization by introducing perceptual saliency and Kalman filtering concepts to the line tracking. Furthermore, an adaptive sampling size is used such that it is possible to adjust the size of the tracking step to reflect the stroke curvature.

Adaptation of Brensen's thresholding algorithm for sketched line drawings

Image binarisation is one of the first image processing techniques within a sketched line drawing interpretation system. In order to achieve an automated system, it is necessary to have a single algorithmwhich may be used for all image types. This is difficult to obtain if the parameters required by an algorithm are set manually, however, the adaptive evaluation of parameters form image properties is a step towards this goal. This paper discusses the methods by which the parameters required for Brensens Algorithm may be evaluated adaptively form the image properties.

A language for representing and extracting 3D geometry semantics from paper-based sketches

Every product that exists, ranging from a toothbrush to a car, has first been conceived as a mental concept. Due to its efficacy in rapidly externalizing concepts, paper-based sketching is still extensively used by practising designers to gradually develop the three-dimensional (3D) geometric form of a concept. It is a common practice that form concepts are sketched on paper prior to generating 3D virtual models in commercial Computer-Aided Design (CAD) systems. However, the user-interface of such systems does not support automatic generation of 3D models from sketches. Furthermore, the inherent characteristics of form sketching (e.g. idiosyncrasy) pose a challenge to computer-based understanding of the form concept semantics expressed on paper. To address these issues, this paper is therefore concerned with the development of a visual language that is prescribed and to be used by product designers to annotate paper-based sketches such that the form geometry semantics can be formally represented; parsing the annotated sketch allows for the automatic generation of 3D virtual models in CAD. Inspired by re-usable 3D CAD modelling functions and the related environmental constraints and requirements, a prescribed sketching language, PSL, has been developed to annotate paper-based form sketches. The framework architecture which parses the annotated sketch and subsequently extracts the form concept semantics is described. Based on this framework, a prototype computer tool has been implemented and evaluated. Evaluation results provide a degree of evidence, first on the suitability of PSL in representing the semantics of a range of forms, and secondly on the designers? acceptance of taking up this annotated sketching approach in practice. The key contribution is a visual language to formally represent form geometry semantics on paper.Parsing the language allows for the automatic generation of 3D virtual models.A proof-of-concept prototype tool was implemented.The language is capable to roughly model forms with linear topological ordering.Evaluation results show that practising designers would use the language.

A modular, reconfigurable end effector for the plastics industry

Purpose – The purpose of this paper is to address a problem that is commonly faced by manufacturing companies in the plastics industry, where large and different batches of freshly produced units need to be unloaded from the injection‐moulding machines and relocated, using automation.Design/methodology/approach – The new solution is reached through a formal design approach, including a function analysis, a product design specification, a quality function deployment exercise, the generation of a number of conceptual solutions, and concept evaluation using morphological charts, failure mode and effect analysis and a decision matrix.Findings – A single modular end effector that can be easily reconfigured for a large variety of moulds has been developed. The results are also extrapolated to more general applications where an end effector is required to carry out simultaneously several different but well‐defined functions in the presence of high variety.Research limitations/implications – The critical decision...

A sketching alphabet for paper-based collaborative design

Despite the importance of the early design phase, designers still lack computer support in rapidly modelling their form concepts in Computer-Aided Design (CAD) systems due to the rigid User-Interface. Owing to its efficacy in instantly capturing ideas, traditional pen-and-paper sketching is still very popular amongst designers to record their concepts not only inside but also outside their office. This paper reports the ongoing research aimed at developing a portable, sketch-based tool allowing designers to obtain and share 3D CAD models on cameraphones directly from paper sketches. More specifically, the focus is on a prescribed sketching alphabet required to create a seamless link between sketching and CAD. Results of semi-structured interviews carried out with various design practitioners contribute important insights into the alphabet suitability. Further, the results and an implemented tool indicate that a sketching language based on this alphabet will be beneficial for designers, especially in a collaborative design environment.

A new sketch based interface using the gray-level co-occurrence matrix for perceptual simplification of paper based scribbles

The sketching activity has an important role in conceptual design and a variety of tools exist which help designers to facilitate the generation of 3D models form sketched drawings. This paper describes a new sketch-to-3D tool, which uses annotations to aid the interpretation of the drawing. Over-traced lines present in the designers scribbles provide an interpretation challenge, which must be resolved in order to obtain 3D models from these sketches. Perceptual grouping techniques used to interpret such images require that the drawing is represented as vectors. These are generally obtained through thinning or edge detection. However, we show that processing scribbles using these techniques result in a large number of vectors which do not provide a faithful representation of the drawing. This paper investigates the use of the co-occurrence matrix to perceptually simplify these drawings, thus obtaining a smaller number of vectors which describe the drawing more faithfully.

Mobile Knowledge Management for Product Life-Cycle Design

As products become more complex, a significant amount of design knowledge support is required by designers during the design process. However, given that the design process is not only confined within a design office, knowledge support must be provided to designers even when they are away from their usual workplace. This provision of knowledge is essential for designers to take sound decisions that span through the whole product life-cycle, from the conceptual design stage to the disposal phase. Hence, designers require design tools that support them at considering the consequences based on these decisions. With the ever-increasing popularity of mobile devices (such as PDAs, smartphones and pocket PCs), access to such knowledge can be greatly facilitated. The contribution of this paper consists in the presentation of a mobile Knowledge Management (mKM) system architecture that provides distributed engineering designers situated in mobile work settings with design knowledge support in the form of ‘life-cycle consequences’ during the design process.

Exploiting Integrated 'Product' & 'Life-Phase' Features

Increasing competition requires more and more effort in delivering new products with better prices, good quality and environment savings. In this scenario, since most of the cost and product characteristics are dependent on commitments taken at the early design stages, designers require tools supporting them at considering the consequences of their decisions on the whole product life-cycle, starting from the conceptual design stage to the disposal phase. The adoption of such tools may enforce the exploration of different alternatives thus increasing the possibility of identifying the most convenient and innovative solution. Form features have been recognized as shape-oriented elements for associating geometry with engineering meaning, thus helping in reasoning on products in functional terms. However as argued in this paper, information on shape alone is insufficient for meaningful evaluation and forecast of life-cycle product consequences. The paper presents an approach for considering ‘life-cycle consequences’ during the design decision process, by taking into account both artefact features and the characteristics of the involved life-cycle systems.