The challenges in computer supported conceptual engineering design

Computer Aided Engineering Design (CAED) supports the engineering design process during the detail design, but it is not commonly used in the conceptual design stage. This article explores through literature why this is and how the engineering design research community is responding through the development of new conceptual CAED systems and HCI (Human Computer Interface) prototypes. First the requirements and challenges for future conceptual CAED and HCI solutions to better support conceptual design are explored and categorised. Then the prototypes developed in both areas, since 2000, are discussed. Characteristics already considered and those required for future development of CAED systems and HCIs are proposed and discussed, one of the key ones being experience. The prototypes reviewed offer innovative solutions, but only address selected requirements of conceptual design, and are thus unlikely to not provide a solution which would fit the wider needs of the engineering design industry. More importantly, while the majority of prototypes show promising results they are of low maturity and require further development

Human factors considerations for ultrasound induced mid-air haptic feedback

The engineering design process can be complex and often involves reiteration of design activities in order to improve outcomes. Traditionally, the design process consists of many physical elements, for example, clay/foam modelling and more recently Additive Manufacturing (AM), with an iterative cycle of user testing of these physical prototypes. The time associated with creating physical prototypes can lengthen the time it takes to develop one product, and thus, comes at a burdensome financial and labour cost. Due to the aforementioned constraints of the conventional design process, more research is being conducted into applications of Virtual Reality (VR) to complement stages of the design process that would otherwise take and cost a significant amount of time and money. VR enables users to create 3D virtual designs and prototypes for evaluation, thus facilitating the rapid correction of design and usability issues. However, VR is not without its pitfalls, for example, it often only facilitates an audio-visual simulation, thus hindering evaluation of the tactile element of design, which is critical to the success of many products. This issue already has a wide body of research associated with it, which explores applications of haptic (tactile) feedback to VR to create a more realistic and accurate virtual experience. However, current haptic technologies can be expensive, cumbersome, hard to integrate with existing design tools, and have limited sensorial output (for example, vibrotactile feedback). Ultrasound Haptic Feedback (UsHF) appears to be a promising technology that offers affordable, unencumbered, integrable and versatile use. The technology achieves this by using ultrasound to create mid-air haptic feedback which users can feel without being attached to a device. However, due to the novel nature of the technology, there is little to no literature dedicated to investigating how users perceive and interpret UsHF stimuli, and how their perception affects the user experience. The research presented in this thesis concerns the human factors of UsHF for engineering design applications. The PhD was borne out of interest from Ultraleap (previously Ultrahaptics), an SME technology developer, on how their mid-air haptic feedback device could be used within the field of engineering. Six studies (five experimental and one qualitative) were conducted in order to explore the human factors of UsHF, with a view of understanding its viability for use in engineering design. This was achieved by exploring the tactile ability of users in mid-air object size discrimination, absolute tactile thresholds, perception of intensity differences, and normalisation of UsHF intensity. These measures were also tested against individual differences in age, gender and fingertip/hand size during the early stages, with latter stages focussing on the same measures when UsHF was compared to 2D multimodal and physical environments. The findings demonstrated no evidence of individual differences in UsHF tactile acuity and perception of UsHF stimuli. However, the results did highlight clear limitations in object size discrimination and absolute tactile thresholds. Interestingly, the results also demonstrated psychophysical variation in the perception of UsHF intensity differences, with intensity differences having a significant effect on how object size is perceived. Comparisons between multimodal UsHF and physical size discrimination were also conducted and found size discrimination accuracy of physical objects to be better than visuo-haptic (UsHF) size discrimination. Qualitative studies revealed an optimistic attitude towards VR for engineering design applications, particularly within the design, review, and prototyping stages, with many suggesting the addition of haptic feedback could be beneficial to the process. This thesis offers a novel contribution to the field of human factors for mid-air haptics, and in particular for the use of this technology as part of the engineering design process. The results indicate that UsHF in its current state could not offer a replacement for all physical prototypes within the design process; however, UsHF may still have a place in the virtual design process where haptic feedback is required but is less reliant on the accurate portrayal of virtual objects, for example, during early stage evaluations supplemented by later physical prototypes, simply to indicate contact with virtual objects, or when sharing designs with stakeholders and multidisciplinary teams

Human factors considerations for ultrasound induced mid-air haptic feedback

The engineering design process can be complex and often involves reiteration of design activities in order to improve outcomes. Traditionally, the design process consists of many physical elements, for example, clay/foam modelling and more recently Additive Manufacturing (AM), with an iterative cycle of user testing of these physical prototypes. The time associated with creating physical prototypes can lengthen the time it takes to develop one product, and thus, comes at a burdensome financial and labour cost. Due to the aforementioned constraints of the conventional design process, more research is being conducted into applications of Virtual Reality (VR) to complement stages of the design process that would otherwise take and cost a significant amount of time and money. VR enables users to create 3D virtual designs and prototypes for evaluation, thus facilitating the rapid correction of design and usability issues. However, VR is not without its pitfalls, for example, it often only facilitates an audio-visual simulation, thus hindering evaluation of the tactile element of design, which is critical to the success of many products. This issue already has a wide body of research associated with it, which explores applications of haptic (tactile) feedback to VR to create a more realistic and accurate virtual experience. However, current haptic technologies can be expensive, cumbersome, hard to integrate with existing design tools, and have limited sensorial output (for example, vibrotactile feedback). Ultrasound Haptic Feedback (UsHF) appears to be a promising technology that offers affordable, unencumbered, integrable and versatile use. The technology achieves this by using ultrasound to create mid-air haptic feedback which users can feel without being attached to a device. However, due to the novel nature of the technology, there is little to no literature dedicated to investigating how users perceive and interpret UsHF stimuli, and how their perception affects the user experience. The research presented in this thesis concerns the human factors of UsHF for engineering design applications. The PhD was borne out of interest from Ultraleap (previously Ultrahaptics), an SME technology developer, on how their mid-air haptic feedback device could be used within the field of engineering. Six studies (five experimental and one qualitative) were conducted in order to explore the human factors of UsHF, with a view of understanding its viability for use in engineering design. This was achieved by exploring the tactile ability of users in mid-air object size discrimination, absolute tactile thresholds, perception of intensity differences, and normalisation of UsHF intensity. These measures were also tested against individual differences in age, gender and fingertip/hand size during the early stages, with latter stages focussing on the same measures when UsHF was compared to 2D multimodal and physical environments. The findings demonstrated no evidence of individual differences in UsHF tactile acuity and perception of UsHF stimuli. However, the results did highlight clear limitations in object size discrimination and absolute tactile thresholds. Interestingly, the results also demonstrated psychophysical variation in the perception of UsHF intensity differences, with intensity differences having a significant effect on how object size is perceived. Comparisons between multimodal UsHF and physical size discrimination were also conducted and found size discrimination accuracy of physical objects to be better than visuo-haptic (UsHF) size discrimination. Qualitative studies revealed an optimistic attitude towards VR for engineering design applications, particularly within the design, review, and prototyping stages, with many suggesting the addition of haptic feedback could be beneficial to the process. This thesis offers a novel contribution to the field of human factors for mid-air haptics, and in particular for the use of this technology as part of the engineering design process. The results indicate that UsHF in its current state could not offer a replacement for all physical prototypes within the design process; however, UsHF may still have a place in the virtual design process where haptic feedback is required but is less reliant on the accurate portrayal of virtual objects, for example, during early stage evaluations supplemented by later physical prototypes, simply to indicate contact with virtual objects, or when sharing designs with stakeholders and multidisciplinary teams

Material Visualisation for Virtual Reality: The Perceptual Investigations

Material representation plays a significant role in design visualisation and evaluation. On one hand, the simulated material properties determine the appearance of product prototypes in digitally rendered scenes. On the other hand, those properties are perceived by the viewers in order to make important design decisions. As an approach to simulate a more realistic environment, Virtual Reality (VR) provides users a vivid impression of depth and embodies them into an immersive environment. However, the scientific understanding of material perception and its applications in VR is still fairly limited. This leads to this thesis’s research question on whether the material perception in VR is different from that in traditional 2D displays, as well as the potential of using VR as a design tool to facilitate material evaluation.       This thesis is initiated from studying the perceptual difference of rendered materials between VR and traditional 2D viewing modes. Firstly, through a pilot study, it is confirmed that users have different perceptual experiences of the same material in the two viewing modes. Following that initial finding, the research investigates in more details the perceptual difference with psychophysics methods, which help in quantifying the users’ perceptual responses. Using the perceptual scale as a measuring means, the research analyses the users’ judgment and recognition of the material properties under VR and traditional 2D display environments. In addition, the research also elicits the perceptual evaluation criteria to analyse the emotional aspects of materials. The six perceptual criteria are in semantic forms, including rigidity, formality, fineness, softness, modernity, and irregularity.       The results showed that VR could support users in making a more refined judgment of material properties. That is to say, the users perceive better the minute changes of material properties under immersive viewing conditions. In terms of emotional aspects, VR is advantageous in signifying the effects induced by visual textures, while the 2D viewing mode is more effective for expressing the characteristics of plain surfaces. This thesis has contributed to the deeper understanding of users’ perception of material appearances in Virtual Reality, which is critical in achieving an effective design visualisation using such a display medium

User-based gesture vocabulary for form creation during a product design process

There are inconsistencies between the nature of the conceptual design and the functionalities of the computational systems supporting it, which disrupt the designers’ process, focusing on technology rather than designers’ needs. A need for elicitation of hand gestures appropriate for the requirements of the conceptual design, rather than those arbitrarily chosen or focusing on ease of implementation was identified.The aim of this thesis is to identify natural and intuitive hand gestures for conceptual design, performed by designers (3rd, 4th year product design engineering students and recent graduates) working on their own, without instruction and without limitations imposed by the facilitating technology. This was done via a user centred study including 44 participants. 1785 gestures were collected. Gestures were explored as a sole mean for shape creation and manipulation in virtual 3D space. Gestures were identified, described in writing, sketched, coded based on the taxonomy used, categorised based on hand form and the path travelled and variants identified. Then they were statistically analysed to ascertain agreement rates between the participants, significance of the agreement and the likelihood of number of repetitions for each category occurring by chance. The most frequently used and statistically significant gestures formed the consensus set of vocabulary for conceptual design. The effect of the shape of the manipulated object on the gesture performed, and if the sequence of the gestures participants proposed was different from the established CAD solid modelling practices were also observed.Vocabulary was evaluated by non-designer participants, and the outcomes have shown that the majority of gestures were appropriate and easy to perform. Evaluation was performed theoretically and in the VR environment. Participants selected their preferred gestures for each activity, and a variant of the vocabulary for conceptual design was created as an outcome, that aims to ensure that extensive training is not required, extending the ability to design beyond trained designers only.There are inconsistencies between the nature of the conceptual design and the functionalities of the computational systems supporting it, which disrupt the designers’ process, focusing on technology rather than designers’ needs. A need for elicitation of hand gestures appropriate for the requirements of the conceptual design, rather than those arbitrarily chosen or focusing on ease of implementation was identified.The aim of this thesis is to identify natural and intuitive hand gestures for conceptual design, performed by designers (3rd, 4th year product design engineering students and recent graduates) working on their own, without instruction and without limitations imposed by the facilitating technology. This was done via a user centred study including 44 participants. 1785 gestures were collected. Gestures were explored as a sole mean for shape creation and manipulation in virtual 3D space. Gestures were identified, described in writing, sketched, coded based on the taxonomy used, categorised based on hand form and the path travelled and variants identified. Then they were statistically analysed to ascertain agreement rates between the participants, significance of the agreement and the likelihood of number of repetitions for each category occurring by chance. The most frequently used and statistically significant gestures formed the consensus set of vocabulary for conceptual design. The effect of the shape of the manipulated object on the gesture performed, and if the sequence of the gestures participants proposed was different from the established CAD solid modelling practices were also observed.Vocabulary was evaluated by non-designer participants, and the outcomes have shown that the majority of gestures were appropriate and easy to perform. Evaluation was performed theoretically and in the VR environment. Participants selected their preferred gestures for each activity, and a variant of the vocabulary for conceptual design was created as an outcome, that aims to ensure that extensive training is not required, extending the ability to design beyond trained designers only