Engineering of automated assembly of beam-shaping optics

CAD/Tolerancing integration: Mechanical assembly with form defects

The use of PDM systems is especially in the late phases of product development state of the art. In fact, it is possible to integrate requirements for future products in the meaning of product lifecycle management into a PDM system. The following steps of product development like initial design sketches are almost not represented yet. Early design work is currently done without computer assistance. An integration of handcrafted sketches in PDM systems is in the case of digitalization possible, but further use is strongly limited. Concluding, in the early phases of product development a gap does still exist in computer assistance. 3D sketching in Virtual Reality (VR) helps to close this gap. Certainly, PDM systems are not prepared for integrating such content in present structures and processes. An approach to integrate these sketches into PDM systems is the main key to establish 3D sketches in product development. To evaluate the use of 3D sketches, a demonstrator in VR has been developed. 27 test subjects worked on two different tasks within this tool. An analysis of the working process and the created solutions shows that sketching in VR could be a possible assistance. In order to cater to these results, a process to handle sketches in PDM has been developed. This process allows preparing sketches with further information and preparing them for further use. The objective is to reach a traceability for the product from requirements via sketches to CAD models to complete the product lifecycle management approach in companies.

In mechanical assemblies, the performance, quality, cost and assemblability of the product are significantly affected by the geometric errors of the parts. This paper develops the statistical error analysis approach for dimensional control in automotive body multi-station assembly process. In this method, the homogeneous transformation matrices are used to describe the location and orientation of part and assembly features and the small homogeneous transformation matrices are used to model the errors. In this approach, the effective errors in automotive body assembly process are classified in three categories: manufacturing errors (dimensional and geometric tolerances), locating errors (fixture errors) and process errors (joining errors). In a mechanical assembly, small variations due the errors propagate according to a complex mechanism that in this approach it formulated in error analysis procedure. The propagation chain of geometric errors is described based on CAD models. The estimation of the error accumulation and the percent contributions of individual errors are based on the statistical model (root-sum-square method). The application of the proposed method is illustrated through presenting an example problem.

A novel multi-focusing curved microlens array (MLA), inspired by compound eyes, was fabricated using a homebuilt mold in this paper. By gas-assist deformation, and using the PDMS film as the template, MLA with variable focal length were fabricated through the different apertures of the micro-stomatas attached on the mold. Fabricated in one step, without reverse mould process, makes the whole fabrication process simple, cost-effective and deformation less. The ultraviolet curing adhesive NOA81, which was cured in seconds, has excellent optical performance and a wide operating temperature range. The optical performances of the MLA were demonstrated by optical experiments and simulation.

The increasing product complexity emerges digitalization of product manufacturers to meet the challenges, such as uncertainties with technological and business settings. The customers are looking for innovative solutions to understand better the product features rather than the complexity associated with its functionality. From the manufacturers’ perspective, developing complex and smart products requires huge amount of data to be collected, assessed, processed, and enhanced based on the usage and requirement. Internet of Things (IoT) will be the most beneficial technology when integrated in every phase of design and development of a product. The IoT, when integrated with the product development become a comprehensive and a practical approach. This chapter aims to present the transformation of conventional manufacturing to modern manufacturing called Industry 4.0, and the insights on how IoT integration helps the manufacturers to digitalize the development and production activities. Also, the challenges related to the implementation of IoT in product development phases are discussed. This chapter will provide the needs, key learning, and guidance to the product development people and practicing managers to know how IoT can be linked to the product development activities.

Abstract. The focus towards multi-material and lightweight assemblies, driven by legal requirements on reducing emissions and energy consumptions, reveals important drawbacks and disadvantages of established joining processes, such as welding. In this context, mechanical joining technologies, such as clinching, are becoming more and more relevant especially in the automotive industry. However, the availability of only few standards and almost none systematic design methods causes a still very time- and cost-intensive assembly development process considering mainly expert knowledge and a considerable amount of experimental studies. Motivated by this, the presented work introduces a novel approach for the methodical design and dimensioning of mechanically clinched assemblies. Therefore, the utilization of regression models, such as machine learning algorithms, combined with manufacturing knowledge ensures a reliable estimation of individual clinched joint characteristics. In addition, the implementation of an engineering workbench enables the following data-driven and knowledge-based generation of high-quality initial assembly designs already in early product development phases. In a subsequent analysis and adjustment, these designs are being improved while guaranteeing joining safety and loading conformity. The presented results indicate that the methodological approach can pave the way to a more systematic design process of mechanical joining assemblies, which can significantly shorten the required number of iteration loops and therefore the product development time.

The article presents application of the FreeCAD software and generative artificial intelligence (AI) in the design process regarding exemplary mechanical engineering-related assemblies. Authors have studied how to support a product development and computer-aided (CAD) design phase by the use of generative pre-trained transformer (GPT). Prompting process, that lead to Python language-based code creation in the ChatGPTTM by OpenAI company, was studied from the perspective of 3D assemblies generation in the FreeCAD software. Moreover, authors studied how to improve the basic 3D models by the use of text-based prompts and CAD user improvements of the solid models and discussed the general effectiveness of this approach. It was also separately studied how to automate creation of many parts of the same type by the use of the AI, and apply such CAD libraries in the developed assemblies. The performed research presented selected possibilities of AI-based design process, challenges of the design process and future areas of investigation of AI-based assembly development resulting from the usage of existing GPTs.

Research and development activities on high efficiency separation process technologies for carbon dioxide removal from industrial sources at University of Regina, Canada

Corrosion impacts the value, safety, and readiness of many assets in almost all industries. The cost of maintaining and repairing runs into astronomical numbers. The current approach to evaluate susceptibility to galvanic corrosion is by determining the relative position of metals in the galvanic series table valid for a given environment. However the potential difference between metals provides no information on the kinetics of galvanic or bimetallic corrosion. Additionally, there is a wide range of factors which affect the corrosion severity like surface area ratio, flow rate, temperature, dry-wetting cycle, inhibiting effects, etc. Moreover, in most mechanical assemblies the overall effect of multiple material components and the complexity of the geometry make corrosion prediction difficult. In this article a unique 3D simulation technology to predict galvanic corrosion will be presented. Potential distributions and corrosion rates are calculated based on electrochemical characterization of the different materials in lab conditions. Corroded areas are visualized by the software tool and are compared with real-life observations on assemblies. The examples show cases where engineers select different material combinations of complex assemblies in a virtual environment during the design process and assess the corrosion behavior of the complete system under various environmental conditions. The technology provides quantitative information on the corrosion risk as well as the corrosion rate. Thus, ensuring target performance and safe operation.

One design of the state-of-the-art laser scanner systems in automotive applications is based on oscillating mirror modules. The requirement of a large mirror surface for eye-safe transmission beams and long measurement distances is a major drawback for fast and reproducible scanning. Tolerances of angular positioning, position sensing, and vibrational perturbations limit the position accuracy of such a mirror and, thus, the accuracy of the transmission spot position in the field of view (FoV). Our approach for a scanner module with maximum transmission beam diameter combines a microlens array with an objective lens for generating one optical telescope assembly for each angular scan position exclusively. Aperture stops define the beam positions in the FoV and avoid positioning errors caused by angle deviations of the scanner mirror. This increases the reliability of the angular position accuracy of the scanner module significantly. To minimize the shadings between adjacent scan spots in the target distance, created by beam cutoffs at the aperture stop of the objective lens, an array of optimized microwedge prisms is provided in combination with the microlens array. Therefore, we can increase the throughput of transmission power into the FoV and improve the measurement distance, especially at large scan angles.

The proposed method includes generation of a “common data model” (CDM) containing all the required parametric information for both CAD and CAE analysis. CDM stores and supplies the associative data to both CAD and CAE models and thus maintaining the associative dependencies between them. As the common data model gets modified according to designer's intent, the changes in it are consistently reflected in both CAD and CAE models through regeneration and analysis iteration. The same data model can be used to work with different CAD and CAE packages since it is totally independent from the software tools used. The data model is reusable and the whole process can be automated so that the embedded expertise in the cycles of the adaptive design and manufacturing can be consistently applied iteratively during product development processes.

Many high-technology products currently manufactured are affected adversely if contamination is deposited in or on the product during manufacture or use. Contamination can be defined as any condition, material, process, or effect that can degrade quality, performance, or yield for any product. The product can be an electronic device, an optical or mechanical assembly, a pharmaceutical product or device, or essentially any modern “high-technology” product. The product can also be a simple system, such as a food item or plant that can be affected adversely by airborne bacteria. A contaminant can be a particulate or a gaseous material; it can be a harmful electric field or an excessive vibration level. It can be the condition of excessive moisture (relative humidity) in an assembly area, or it can be a high light flux at harmful wavelengths in a lithographic operation. It can be an excess of lubricant in a precise mechanical device, or it can be a condition of inadequate lubrication. An examination of an ultralarge-scale integrated (ULSI) semiconductor device manufacturing requirement might result in the conclusion that the entire manufacturing operation must use ultraclean technology (Ohmi 1988). As a strong example, regarding the design and operation of present-day logic and memory devices used in computers, it can be concluded that contamination control is a vital necessity, without which no computer or any of the many microprocessor-controlled devices in our modern world would be operating today. The dimensions of the circuitry used in these devices simply does not allow operation if the particulate contaminants found in “normal” air were to deposit upon these devices during the manufacturing process. The manufacturer must not only control particulate and vapor contamination but also control exposure to high-energy conditions and excessively variable thermal conditions, ensure freedom from vibration, and eliminate excessive process variations. These precautions are required during the manufacturing operation, during storage, and, in many cases, during product operation.

When thermosetting polymers are used to bond or encapsulate electrical, mechanical or optical assemblies, residual stress, which often affects the performance and/or reliability of these devices, develops within the structure. The Thin-Disk-on-Cylinder structural response test is demonstrated as a powerful tool to design epoxy encapsulant cure schedules to reduce residual stress, even when all the details of the material evolution during cure are not explicitly known. The test's ability to (1) distinguish between cohesive and adhesive failure modes and (2) demonstrate methodologies to eliminate failure and reduce residual stress, make choices of cure schedules that optimize stress in the encapsulant unambiguous. For the 828/DEA/GMB material in the Thin-Disk-on-Cylinder geometry, the stress associated with cure is significant and outweighs that associated with cool down from the final cure temperature to room temperature (for measured lid strain, IεcureI > IεthermalI). The difference between the final cure temperature and the temperature at which the material gels, Tf-Tgel, was demonstrated to be a primary factor in determining the residual stress associated with cure. Increasing Tf-Tgel leads to a reduction in cure stress that is described as being associated with balancing some of the 828/DEA/GMB cure shrinkage with thermal expansion. The ability to tune residual stress associated with cure by controlling Tf-Tgel would be anticipated to translate to other thermosetting encapsulation materials, but the times and temperatures appropriate for a given material may vary widely.

Developing complex systems usually involves many activities that are based on the integration of the designer CAD models: mechanical assemblies, analysis models (CFD, FEA, Thermal, etc.), interface control, tool and jig design data, production models, mass properties, ILS, documentation, and many more. Proper management of the integrated data base can lead to cost and time savings by parallel design, updated interfaces, and minimum integration faults; and can increase the reuse of parts and support the system engineering decisions. On the other hand, improper data managing can lead to major failures in the design process and during the mechanical assembly, which might result in loss of time, money and reputation. In order to assure efficient and accurate management of the mechanical data base, special training is required for designated personnel – the Mechanical Integrator (MI). The Mechanical Integrator ensures the implementation of appropriate working procedures by the sub-systems designers, that the current design is based on approved and released data, the use of generic parts and much more by managing an updated and robustly built data base. The Mechanical Integrator has a major roll in the project, but does he have the necessary knowledge and training? This paper presents the advantages of managing the mechanical data base; focusing on the techniques in use for building and monitoring it properly and explains the training program of the Mechanical Integrator, a person in charge over the mechanical data base and data flow.

For the distribution of consumer and industrial goods, every company is obliged to provide assembly instructions. For the consumer goods market, for example, the German Civil Code defines that defective assembly instructions must be declared as a material defect. However, the creation of comprehensible and defect-free assembly instructions is still a very time-consuming manual process, which must be determined in an extremely time-consuming procedure. Nonetheless, assembly instructions are more than just obligatory documents. They are also required in places where they are not prescribed. For example, assembly instructions are needed in production to pass on assembly knowledge to the assembly operators. Here, it often turns out that this knowledge is either not available or can only be used to a limited extent.The two key elements of an assembly instruction are the assembly sequence and the visual illustrations. Currently, the assembly sequence is determined manually by the designers based on their personal experience, whereas illustrations are generated with costly software tools which are not even able to check the feasibility of the planned instruction. This work presents a novel approach to generate assembly instructions directly and automatically from CAD models of the designers. For this purpose, the commercial CAD software SolidWorks was extended by a macro Tool. All necessary data to generate an assembly instruction are extracted from the CAD model. The extracted data are assembly features, stability and geometric restrictions, subassemblies and assembly directions. Based on these data, the assembly operations are evaluated with a fitness function which includes the attributes like tool changing costs or distances of assembly paths. The whole assembly sequence optimization process was modeled as a Travelling Salesman Problem. After the ideal assembly sequence was found by the macro Tool, this tool also generated matching visualizations of the assembly operations based on the CAD model. The approach was validated by three different models, an assembly benchmark, a single-cylinder engine and a gear box.