Appropriate Assembly Instruction Modes: Factors to Consider

Presented is a literature study into the importance of how information in assembly instructions in manual assembly is presented, more specifically how various factors such as the complexity of the assembly itself, the mental and physical workload of the worker, as well as the experience and skill level of the worker affect the requirements for information presentation. The requirements made by Industry 4.0 on flexibility in production lines and an increased number of variants produced causes increased demands on workers, which leads to more cognitive demands being made on assembly workers. Studies exist around assembly instruction modes, but have in many cases ignored factors such as worker skill level, mental workload, and task complexity and how these affect the requirements for information presentation, which is a major contribution of this study. The findings are that no single solution fits all requirements, but that the aforementioned factors should be taken into account.

OpenWeedLocator (OWL): an open-source, low-cost 1 device for fallow weed detection.

The use of a fallow phase is an important tool for maximizing yield potential in moisture limited environments. There is a focus on ensuring these phases are maintained weed-free as even low weed densities can be detrimental to fallow efficiency. Repeated whole field herbicide treatment to control low-density weed populations is expensive and wasteful. Site-specific application of herbicide treatments to low density fallow weed populations is currently facilitated by sensor-based devices that detect chlorophyll fluorescence from living plant tissue. The use of image-based weed detection technology for fallow weed detection is an opportunity to develop an approach that can be translated for in-crop weed recognition. Here we present the OpenWeedLocator (OWL), an open-source, low-cost image-based approach for fallow weed detection that improves accessibility to this technology for the weed control community. A comprehensive repository, containing all code and assembly instructions, has been developed that will allow for community driven improvement over time. Four different colour-based weed detection algorithms were tested with the OWL system over seven fallow field scenarios under varying light, soil and stubble conditions. Across all scenarios, the four algorithms were similarly effective in detecting fallow weeds with average precision and recall of 79% and 52%, respectively. In individual transects, precision and recall values of up to 92% and 74%, respectively, suggest the potential fallow weed detection performance of the colour-based system. OWL represents an opportunity to redefine the approach to weed detection by enabling community-driven technology development and implementation in the weed control industry.

Novel 3D printable powered air purifying respirator for emergency use during PPE shortage of the COVID-19 pandemic: a study protocol and device safety analysis

ObjectivesTo design a low-cost 3D printable powered air-purifying respirator (PAPR) that meets National Institute for Occupational Safety and Health (NIOSH) standard for flow rate and Occupational Safety and Health Administration (OSHA) standard for particle filtration for loose-fitting PAPRs and that can be made with a 3D printer and widely available materials.DesignDetailed description of components, assembly instructions and testing of a novel PAPR design in an academic laboratory following respective protocols. The assembled PAPR must meet NIOSH standards of flow rate, 170 L/min; OSHA fit factor for particle filtration, ≥250 and maintain positive pressure during regular and deep breathing.Main outcome measuresThe PAPR design was run through a series of tests: air flow (L/min), particle filtration (quantitative and qualitative) and positive pressure measured inside the helmet (mm Hg).ResultsFlow rate was 443.32 L/min (NIOSH standard: minimum 170 L/min) and overall fit factor for particle filtration was 1362 (OSHA pass level: ≥500), n=1. The device passed qualitative particle filtration, n=2, and measured peak pressure of 6mm Hg (>0 mm Hg indicates positive pressure) in the helmet, n=1.ConclusionsThe Hygieia PAPR is a low-cost, easily accessible, just-in-time 3D printable PAPR design that meets minimum NIOSH and OSHA standards for flow-rate and particle filtration for loose-fitting PAPR devices to be made and used when industry-made designs are unavailable.

IDENTIFYING THE FACTORS AFFECTING THE REPLICABILITY OF OPEN SOURCE HARDWARE DESIGNS

Open-source hardware (OSH) development is a new design paradigm from a commercial perspective. Openly sharing designs of technical products is a step towards democratising access to new technologies for the benefit of individuals and communities in society. At the core of the open-source hardware definition lies the freedom for anyone to replicate the hardware based on the design. Thus, enabling this freedom is a step towards developing a successful OSH. Previous research supposes that a bill of materials and assembly instructions are enough for this. In this study, we question this assumption and investigate what other factors may influence replicability of an OSH. Using data from a survey and interviews with OSH practitioners, we identify and describe these factors, which relate to the documentation, the design and the context of the person replicating the hardware. Using these insights, we present a diagram of the replication process along with questions the person replicating the hardware would ask to check whether an OSH is replicable. Finally, we synthesise this information into practical advice for OSH projects to increase the replicability of the designs they produce, and thus the likelihood of their project's success.

Toying With Engineering: Teaching Engineers to Be Entrepreneurial by Developing a Toy

Most engineering design projects focus primarily on the engineering fundamentals. Studying the business case or manufacturability of a design is often left for other courses, if at all. To address this gap, an existing mechanical engineering course project was modified by embedding the interdependent entrepreneurial dimensions. In the past, junior engineering students developed a reciprocating air engines over two semesters. The modified project extended the engineering fundamentals into an entrepreneurial venture. To accomplish this, students were asked to propose an air engine toy for middle schoolers. The proposed toy had to be assembled, provide a learning opportunity, and demonstrate utility. The students had to ensure the product appealed to those interested in the STEM fields. The students, working in groups, created renders of the final product, assembly instructions, and a guided worksheet for the kids to explore the underlying engineering concept. The groups produced a website with a video pitching their toy concepts. This case study exemplifies how any engineering endeavor can be modified to capture a more holistic simulation of the profession.

Augmented Reality Application for Laptop Assembly with Assembly Complexity Study

Augmented Reality (AR) in the assembly process will improve the user's experience by providing interactive instructions in real time. However, no previous application of AR guided assembly for laptops with a high level of assembly complexity has been developed. The research aims to develop an AR guided assembly application to provide instruction on the assembly of a laptop. The assembly complexity of the laptop was also investigated. The development of the AR application involves the creation of model target, 3D models and animations, and the development of user interface. The laptop assembly consists of ten steps. Each step comprises animated 3D models and text detailing the assembly instructions. Speech recognition has been used to navigate the assembly sequence. The AR application has successfully been developed for laptop assembly with an assembly complexity of 6.63. With the developed application, the performance of the laptop assembly can be accelerated.