Physical Prototype Research Articles

Methodology for the Formation of a Digital Model of the Life Cycle of an Offshore Oil and Gas Platform

This article systematizes scientific views on the problems associated with the conditions and patterns of creating a digital model of a sophisticated engineering and technical complex. The main elements of a digital model of the life cycle of an offshore oil and gas platform are considered. An interdisciplinary approach to the study of the essence of the subject space of the life cycle of an offshore oil and gas platform is substantiated on the basis of modeling the subject space of the life cycle of an offshore oil and gas platform using alternative graphs and information technologies. New concepts have been introduced into scientific circulation that reveal the essence of a digital model of the life cycle of an offshore oil and gas platform: life cycle cost, life cycle duration, and the scientific and technical level of the offshore oil and gas platform. The main provisions of the concept of the virtual life cycle of an offshore oil and gas platform are considered. Based on modeling the subject area of the life cycle of an offshore oil and gas platform by alternative graphs, is shown the relationship between the stages of the life cycle. The technology of model-based design of the virtual life cycle of an offshore oil and gas platform is proposed. The developed model of the life cycle of an offshore oil and gas platform based on the display of the life cycle by alternative graphs makes it possible to choose solutions for each stage based on criteria common to the life cycle of an offshore oil and gas platform. A cyclic procedure for managing a virtual life cycle model of an offshore oil and gas platform has been developed. The digital model of the life cycle of an offshore oil and gas platform is constantly updated following the change in physical prototypes, which increases the accuracy of decisions based on it. The application of the model in practice will significantly reduce the number of full-scale tests of everything related to the manufacture of the real material part of a platform.

Beyond Chainmail: Computational Modeling of Discrete Interlocking Materials

We present a method for computational modeling, mechanical characterization, and macro-scale simulation of discrete interlocking materials (DIM)---3D-printed chainmail fabrics made of quasi-rigid interlocking elements. Unlike conventional elastic materials for which deformation and restoring force are directly coupled, the mechanics of DIM are governed by contacts between individual elements that give rise to anisotropic deformation constraints. To model the mechanical behavior of these materials, we propose a computational approach that builds on three key components. ( a ): we explore the space of feasible deformations using native-scale simulations at the per-element level. ( b ): based on this simulation data, we introduce the concept of strain-space boundaries to represent deformation limits for in- and out-of-plane deformations, and ( c ): we use the strain-space boundaries to drive an efficient macro-scale simulation model based on homogenized deformation constraints. We evaluate our method on a set of representative discrete interlocking materials and validate our findings against measurements on physical prototypes.

The Impact Modeling and Experimental Verification of a Launch Vehicle with Crushing-Type Landing Gear

In order to investigate the landing process of a vertical landing reusable vehicle, a dynamic model with a complex nonlinear dissipative element is established based on the discrete impulse step approach, which includes a three-dimensional multi-impact model considering friction and material compliance, and a multistage aluminum honeycomb theoretical model. The normal two-stiffness spring model is adopted in the foot–ground impact model, two motion patterns (stick and slip) are considered on the tangential plane and the structural changes caused by buffering behavior are included, and the energy conversion during the impact follows the law of conservation of energy. The state transition method is used to solve the dynamic stability convergence problem of the vehicle under the coupling effect of impact and buffering deformation in the primary impulse space. Landing experiments on a scaled physical reusable vehicle prototype are conducted to demonstrate that the theoretical results exhibit good agreement with the experimental data.

An Exploration of Conceptual Prototype of an Artistic Handcraft Wallet (AHW) Design

The exploration of a conceptual prototype of an Artistic Handcraft Wallet (AHW) design is a studio practice study that engages the experience of both virtual and real physical prototyping. This article is method based .i.e. it unfolds the method used in the design of AHW. It involves the use of 5H + 1H for design thinking. Simulation of AHW involves CorelDraw X5 and Adobe Photoshop CS5 for motif, surface pattern and object transformation. The real physical prototyping involves studio experiment on textile decoration to produce AHW. The significance of this exploration is to fulfil of one of the objectives of Industrial Design Department, Federal University of Technology, Akure, Ondo State, Nigeria. That is, students have to develop creative, aesthetic and industrial skills needed for product design. The findings show that design thinking is important for insightful design. Art and design making like AHW can bring up analogy that are useful for social design. Moreover, the findings show that it is enjoyable to use CAD during conceptual prototyping depending on the designers’ optimum proficiency in the use of CAD software application. Finding as well reveals that the satisfactory level of virtual and real physical prototyping are different in terms of process and end product/finishing/design outcome. It is also noticed that there are challenges tackling the translation of CAD virtual prototype to real tangible physical products. It is also realized that suitable learning environment is needed for the proper psyche to initiate good designs.

Integrated Modelling and Control of Linear Actuator Based Automatic Pedal Pressing Mechanism for Low-Speed Driving in a Road Traffic Delay

Sitting in traffic congestion for hours in a posture that requires recurrent actions of manually pressing the pedal and braking excessively can result in fatigue, especially on the driver's leg and back. This fatigue can have long-term implications and adversely affect the driver's health. Thus, this paper aims to model and develop a control system that utilizes a linear actuator to replace the leg activities involved in pressing and releasing the brake pedal. This approach, combined with the implementation of a PID controller, offers a novel solution to control the vehicle speed by integration with the linear actuator that focus on low-speed driving condition. The design process begins with creating a 3D model using SolidWorks to visualize the movement of the linear actuator and Pedal subsystem. This model is then connected to Matlab-Simulink, where a PID controller is implemented and integrated into the electrical circuit to control the actuator's movement. Integration with the vehicle dynamic model enables a comprehensive analysis of the system's behavior on the vehicle dynamics. This research compares the trial and error method with the Matlab tuner for implementing the PID controller. The performance of the system will be evaluated based on the steady state error, overshoot, rise time, and settling time. The results demonstrate that the Matlab tuner outperforms trial and error method by achieving a faster response and significantly reducing steady state error during robustness testing. With the integration of the linear actuator, the system is capable of tracking the desired speed and has the potential to replace the leg activities involved in pressing and releasing the brake pedal. For future work, validating the proposed mechanism with a physical prototype of the linear actuator and pedal using hardware-in-the-loop techniques poses a challenge, as hardware constraints may vary with different environments.

Using eHMI, acoustic signal, and pitch motion to communicate the intention of automated vehicles to pedestrians: A Wizard of Oz study

Communication between automated vehicles (AVs) and pedestrians is crucial to coordinate traffic maneuvers and hence maintain road safety. Automated driving changes the driver’s role to that of a mere passenger, who can perform non-driving related tasks and therefore may not interact with other road users. In this novel traffic environment, both explicit and implicit cues might contribute to an effective communication between AVs and pedestrians by providing relevant information.So far, physical prototypes of AV communication have rarely been evaluated under real world conditions. The few studies managed to do so used a Wizard of Oz technique, where a human operator simulates the behavior of an AV. To measure the communication effectiveness, these studies instructed participants to explicitly state their crossing decision, but not to cross. While safety is assured, the generalizability of the results to pedestrians’ actual crossing behavior is unclear. We established a more realistic experimental setup for a Wizard of Oz study that allows pedestrians to actually start crossing while a of simulated AV is approaching.In a Wizard of Oz study, participants (N = 35) interacted with a simulated AV and had to infer its intention. In a fully factorial design, the effects of three different communication cues were explored: an external human-machine interface (eHMI, absent vs. present), an acoustic signal (absent vs. present), and pitch motion (active, normal, or none). The eHMI and acoustic signal were considered as explicit and the pitch motion as implicit cues. Participants were asked to exhibit natural crossing behavior which was captured by two optical tracking systems.Consistently to previous work, explicit AV communication showed a positive effect on pedestrians’ crossing behavior and safety feeling. Pedestrians initiated their crossings earlier and reported to feel safer when approaching an AV with an eHMI or an acoustic signal, compared to only having only a pitch motion. There was no main effect of pitch motion on crossing behavior and safety feeling. Nevertheless, there was an interaction between eHMI and active pitch motion. The effect of eHMI on crossing initiation time (CIT) was smaller in combination with an active pitch motion compared to normal pitch conditions. These results underline the importance of implementing appropriate AV communication.

Development of a Digital Twin for a Hydraulic, Active Seat Suspension System

The vibrations induced by the soil irregularities and other equivalent disturbances on agricultural tractors represent a major cause of disease for tractor drivers. The reduction of vibration exposure of operators is a topic of interest for the (Italian) National Institute for Insurance against Accidents at Work (INAIL). Several passive, semi-active, and active solutions are commercially available for the seat or the cabin suspension to isolate the driver from the vibrations. A prototype of a hydraulic active suspension system for the operator seat has been developed in the laboratories of INAIL. In this paper, nonlinear multi-physics modeling of the prototype has been carried after an experimental identification of the actuation system and specifically of the control valve parameters. The model is adjusted to retrace the system’s response and is used as a digital twin of the physical prototype to develop and optimize the control system. An equivalent simplified model is obtained to design a proper control strategy for the active suspension system. Finally, the controller is tested on the digital twin of the system to assess its performance in isolating vibrations.

Mechanical Performance of 5-speed Manual Transmission Gearshift Bracket

The main purposes of a gear shift bracket for manual transmission are to hold the gear shift cables and acts as pivot during the gear shifting process. During the gear shifting process, the bracket experiences push and pull reciprocating forces which applied by the driver while selecting or shifting gears. This study presents the development of a simulation model to analyze the mechanical performance of a specific manual transmission gearshift bracket. Based on the simulation results, an optimized bracket design was proposed. Commercial CAD software and Finite Element (FE) Method software were used to perform the simulation. Boundary and initial conditions were applied to the FE model which was based on the real-life mechanical movement of the bracket during gear shifting process. The boundary and initial conditions included fixed position, displacement and both select and shifting loads by following actual test requirements which replicated the movement of the actual model during gear shifting process. Specific mechanical ratio formula was used to obtain the magnitude of loads that was experienced by the gear shift bracket in both select and shifting gears action. The simulation of the gearshift bracket provided outcome parameters such as total deformation, maximum stress and safety factor value. Based on the safety factor value, the model was eligible for topology optimization process and it was modified to gain the optimized model. Then, the same simulation setup was used for the optimized model. The modified design bracket was able to provide a 7% reduction in mass, a 25.15% increase in maximum deformation, a 46,78% increase in maximum stress and, a 36.74% decrease in safety factor value by comparing it to the original model. Although the modified model has lower strength, but its safety factor value is still within the minimum requirements. This concludes that the simulation model allows the manufacturer to undertake design iteration and analyze its performance without producing any physical prototypes and conduct any actual test, thus saving development cost and time.

PUF-Based Mutual Authentication and Key Exchange Protocol for Peer-to-Peer IoT Applications

Peer to Peer (P2P) or direct connection IoT has become increasingly popular owing to its lower latency and higher privacy compared to database-driven or server-based IoT. However, wireless vulnerabilities raise severe concerns on IoT device-to-device communication. This is further aggravated by the challenge to achieve lightweight direct mutual authentication and secure key exchange between IoT peer nodes in P2P IoT applications. Physical unclonable function (PUF) is a key enabler to lightweight, low-power and secure authentication of resource-constrained devices in IoT. Nevertheless, current PUF-enabled authentication protocols, with or without the challenge-response pairs (CRPs) of each of its interlocutors stored in the verifier's side, are incompatible for P2P IoT scenarios due to the security, storage and computing power limitations of IoT devices. To solve this problem, a new lightweight PUF-based mutual authentication and key exchange protocol is proposed. It allows two resource-constrained PUF embedded endpoint devices to authenticate each other directly without the need for local storage of CRPs or any private secrets, and simultaneously establish the session key for secure data exchange without resorting to the public-key algorithm. The proposed protocol is evaluated using the game-based formal security analysis method as well as the automatic security analysis tool ProVerif to corroborate its mutual authenticity, secrecy, and resistance against replay and man-in-the-middle (MITM) attacks. Using two Avnet Ultra96-V2 boards to emulate the two IoT endpoint devices, a physical prototype system is also constructed to demonstrate and validate the feasibility of the proposed secure P2P connection scheme. A comparative analysis shows that the proposed protocol outperforms related protocols in terms of security features, computational complexity as well as communication and storage costs.

Domotic House: Domotic

The main goal of this project is to develop a smart home that can be controlled through a mobile application built on Flutter, enabling cross-platform functionality. Various technologies were employed, including the AWS (Amazon Web Services) broker, with the MQTT protocol facilitating real-time communication between the Raspberry controller and the mobile device. The Raspberry PI 4 controller, along with multiple sensors and actuators, were utilized to enable interaction. To accomplish this project, it was necessary to use the SCRUM methodology, which allows identifying each stage of the product through a sprint. This work was carried out in 4 stages: In stage 1, called Requirements Analysis: the needs and objectives of the project were determined. A detailed analysis of the functionalities required in the software, the AI and the physical prototype was carried out. In stage 2. System design: the design of the home automation system and the AWS server were developed. The necessary hardware and software components were defined, as well as the system architecture and the integration with artificial intelligence was planned. In stage 3 Software development: the necessary software was developed to control all the components of the house and the implementation of the AWS server with MQTT. In the last stage: 4. Integration of hardware and software and AI: the integration tests of the home component of hardware, software and the integration and training of the AI with the life patterns of the inhabitants of the house were carried out

A Closed-Loop Dynamic Controller for Active Vibration Isolation Working on A Parallel Wheel-Legged Robot

Serving the Stewart mechanism as a wheel-legged structure, the most outstanding superiority of the proposed wheel-legged hybrid robot (WLHR) is the active vibration isolation function during rolling on rugged terrain. However, it is difficult to obtain its precise dynamic model, because of the nonlinearity and uncertainty of the heavy robot. This paper presents a dynamic control framework with a decentralized structure for single wheel-leg, position tracking based on model predictive control (MPC) and adaptive impedance module from inside to outside. Through the Newton-Euler dynamic model of the Stewart mechanism, the controller first creates a predictive model by combining Newton-Raphson iteration of forward kinematic and inverse kinematic calculation of Stewart. The actuating force naturally enables each strut to stretch and retract, thereby realizing six degrees-of-freedom (6-DOFs) position-tracking for Stewart wheel-leg. The adaptive impedance control in the outermost loop adjusts environmental impedance parameters by current position and force feedback of wheel-leg along Z-axis. This adjustment allows the robot to adequately control the desired support force tracking, isolating the robot body from vibration that is generated from unknown terrain. The availability of the proposed control methodology on a physical prototype is demonstrated by tracking a Bezier curve and active vibration isolation while the robot is rolling on decelerate strips. By comparing the proportional and integral (PI) and constant impedance controllers, better performance of the proposed algorithm was operated and evaluated through displacement and force sensors internally-installed in each cylinder, as well as an inertial measurement unit (IMU) mounted on the robot body. The proposed algorithm structure significantly enhances the control accuracy and vibration isolation capacity of parallel wheel-legged robot.

Smooth Trajectory Planning for a Cable Driven Parallel Waist Rehabilitation Robot Based on Rehabilitation Evaluation Factors

Rehabilitation robots can help physiatrists to assist patients in improving their movement ability. Due to the interaction between rehabilitation robots and patients, the robots need to complete rehabilitation training on a safe basis. This paper presents an approach for smooth trajectory planning for a cable-driven parallel waist rehabilitation robot (CDPWRR) based on the rehabilitation evaluation factors. First, motion capture technology is used to collect the motion data of several volunteers in waist twisting. Considering the impact of motion variability, the feature points at the center of the human pelvis are obtained after eliminating unreasonable data through rationality judgments. Then, point-to-point waist training trajectory planning based on quintic polynomial and cycloid functions, and multipoint waist training trajectory planning based on quintic B-spline functions are carried out. The corresponding planned curves and kinematics characteristics using three methods are compared and analyzed. Subsequently, the rehabilitation evaluation factors are introduced to conduct smooth trajectory planning for waist training, and the waist trajectory with better compliance is obtained based on the safety and feasibility of waist motion. Finally, the physical prototype of the CDPWRR is built, and the feasibility and effectiveness of the proposed smooth trajectory planning method are proved by numerical analysis and experiments.

IN SEARCH FOR SHARED CHARACTERISTICS OF PHYSICAL AND VIRTUAL PROTOTYPES

AbstractPrototyping is essential for knowledge acquisition and, thus, for informed decision-making in product development. The gold standard is still the use of physical prototypes. However, with the increase in computing capacity, it is becoming easier also to use virtual prototypes.The selection of prototyping approaches often starts with the distinction between physical and virtual prototypes and therefore excluding a broad range of possibilities early on.This paper explains why a selection of prototypes based on the distinction between physical and virtual is not necessarily the best solution and suggests a selection approach based on characteristics which offer the possibility to avoid this limitation. Therefore the characteristics of physical prototypes commonly used in literature are analysed and reduced to a generally valid selection. Examples of virtual prototypes are selected and analysed regarding their characteristics. All elaborated characteristics are then tested for their applicability to the examples of virtual prototypes.

VISUAL BEHAVIOUR IN THE EVALUATION OF PHYSICAL AND VIRTUAL PROTOTYPES

AbstractProduct development stages are typically characterized by different forms of representations and degrees of specification, which potentially affect user's perception and evaluation. These effects are worth investigating more closely also because of the growing relevance of new technologies such as Virtual Reality (VR) in the design field. The objective of this paper is to elucidate the mutual relations between forms of representation, visual behaviour, and people's evaluations. The focus is on differences between virtual and physical prototypes. In the illustrated experiment, participants visited a tiny house in an immersive VR (360° images acquisition). The results were compared with a past experiment where the physical prototype of the same product was similarly evaluated. The dwell times on Areas of Interest (AOIs) pertaining to the tiny house were compared and correlated to variables concerning subjective evaluations. The results show just a few similarities of visual exploration in terms of gazed AOIs. Substantial differences in terms of how the duration of gazing affects evaluations have been found too. The larger number of significant correlations between observations and evaluations in the virtual exploration emerged.

INVESTIGATING THE PROCESS, DESIGN OUTPUTS AND NEUROCOGNITIVE DIFFERENCES BETWEEN PROTOTYPING ACTIVITIES WITH PHYSICAL AND DIGITAL LEGO

AbstractDesign neurocognition is an emerging research area that can provide insights into the black box of designers’ cognitive processes. However, work to date has focused on neurocognition on its own, without integrating this with other design measures. This paper presents the results of a pilot study which brings together designer neurocognition with design output and assessment of the design process followed in a constrained prototyping activity comparing use of physical and digital Lego. This was achieved via EEG data capture, a TLX survey and measures of design output variance. Differences between physical and digital prototyping methods were found with respect to Task Related Powers of EEG signals and the design process followed with digital prototyping methods found to take longer, require more effort and cause more frustration. No differences were found with regard to design output. Whilst the sample size used (n=12) was small, future studies will use large sample sizes to increase their statistical power and will consider alternative EEG or fNIRS to capture brain activity due to challenges with the headset used in this study.

VIRTUALLY HOSTED HACKATHONS FOR DESIGN RESEARCH: LESSONS LEARNED FROM THE INTERNATIONAL DESIGN ENGINEERING ANNUAL (IDEA) CHALLENGE 2022

AbstractThe International Design Engineering Annual (IDEA) Challenge is a virtually hosted hackathon for Engineering Design researchers with aims of: i) generating open access datasets; ii) fostering community between researchers; and, iii) applying great design minds to develop solutions to real design problems. This paper presents the 2022 IDEA challenge and elements of the captured dataset with the aim of providing insights into prototyping behaviours at virtually hosted hackathons, comparing it with the 2021 challenge dataset and providing reflections and learnings from two years of running the challenge. The dataset is shown to provide valuable insights into how designers spend their time at hackathon events and how, why and when prototypes are used during their design processes. The dataset also corroborates the findings from the 2021 dataset, demonstrating the complementarity of physical and sketch prototypes. With this paper, we also invite the wider community to contribute to the IDEA Challenge in future years, either as participants or in using the platform to run their own design studies.

A CRITICAL APPRAISAL OF MIXED REALITY PROTOTYPING TO SUPPORT STUDIO DESIGN EDUCATION

AbstractMixed Reality (MR) technologies are widely available and applied in a variety of design and engineering applications. MR prototypes capture the respective benefits of physical and digital prototypes by merging these domains saving the time and resources required to create them. This advantage is compelling in the context of design education where tight time and resource constraints exist. However, it is known that new digital prototyping tools can cause problems for students applying appropriate prototyping tools during practice-based studio design projects. Our paper contributes a systematic appraisal of MR prototyping's proposed dimensions value against constraints and issues in design studio education. This highlights MR Visualisation and Knowledge Management dimensions as most readily realised in education. Recommendations are then reflected on via an illustrative case study into the implementation of MR prototyping via these dimensions. Reflections corroborate the value proposition, but also highlight a need for further research exploring activities to scaffold MR prototyping to further support reflective design thinking.

PROTOTYPING FOR CHILDREN: UNDERSTANDING HOW FIDELITY AFFECTS CHILDREN'S COMPREHENSION OF PROTOTYPES

AbstractTesting prototypes with intended end users is critical to the design process. There is limited research on testing prototypes with certain types of end users, specifically children for toy products. Additionally, prototypes evolve in fidelity throughout a project, adding to the complexity in developing best practices for prototype testing. This paper analyzes children's understanding of physical prototypes at various levels of fidelity throughout a university semester-long design project developing wooden toys. Through analyzing students’ feedback on their prototype testing sessions, aspects of the prototypes that aid or inhibit children from understanding both form and function are uncovered. These aspects relate to Norman's principles of interaction and their inclusion in prototypes, specifically mental models, signifiers, and affordances. This paper suggests to include these principles in prototypes early in development to guide the user during testing. The goal of this research is to be a resource for those developing products for children, as well as adding knowledge around prototyping testing at various levels of fidelity.

FROM HAPTIC INTERACTION TO DESIGN INSIGHT: AN EMPIRICAL COMPARISON OF COMMERCIAL HAND-TRACKING TECHNOLOGY

AbstractAdvancements in prototyping technologies – haptics and extended reality – are creating exciting new environments to enhance stakeholder and user interaction with design concepts. These interactions can now occur earlier in the design process, transforming feedback mechanisms resulting in greater and faster iterations. This is essential for bringing right-first-time products to market as quickly as possible.While existing feedback tools, such as speak-aloud, surveys and/or questionnaires, are a useful means for capturing user feedback and reflections on interactions, there is a desire to explicitly map user feedback to their physical prototype interaction. Over the past decade, several hand-tracking tools have been developed that can, in principle, capture product user interaction.In this paper, we explore the capability of the LeapMotion Controller, MediaPipe and Manus Prime X Haptic gloves to capture user interaction with prototypes. A broad perspective of capability is adopted, including accuracy as well as the practical aspects of knowledge, skills, and ease of use. In this study, challenges in accuracy, occlusion and data processing were elicited in the capture and translation of user interaction into design insights.

DEVELOPMENT OF A CLASSIFIER AND A SIMULATOR TO SUPPORT THE DESIGN OF AN ANTI-DECUBITUS ACTIVE MATTRESS

AbstractApproximately 10% of hospitalized patients develops decubitus ulcers that quickly degenerates into chronic illness that reduces the quality of life and requires expensive clinical management. The use of an anti-decubitus active mattress, that automatically redistributes the pressure loads, reduces the occurrence of new lesions and promotes the healing of the pre-existing ones.The aim of this work is to design and develop two tools to support the design of an anti-decubitus active mattress. Almost all the systems found in literature are based on the classification of pressure maps through machine learning and are difficultly usable in the design context.This work proposes a pressure map Classifier and an Interactive Simulator of the mattress, based on a simpler logic, by integrating image processing techniques and functioning simulations. The Classifier can recognize the patient's pressure maps and classify them according to six reference sleep postures. The Interactive Simulator allows to understand the operating mechanisms of the mattress and to test the controller and the various control logics in the absence of a physical prototype.