Ground Robotic Hand Applications for the Space Program study (GRASP)

This document reports on a NASA-STDP effort to address research interests of the NASA Kennedy Space Center (KSC) through a study entitled, Ground Robotic-Hand Applications for the Space Program (GRASP). The primary objective of the GRASP study was to identify beneficial applications of specialized end-effectors and robotic hand devices for automating any ground operations which are performed at the Kennedy Space Center. Thus, operations for expendable vehicles, the Space Shuttle and its components, and all payloads were included in the study. Typical benefits of automating operations, or augmenting human operators performing physical tasks, include: reduced costs; enhanced safety and reliability; and reduced processing turnaround time

Automated freeform assembly of threaded fasteners

Over the past two decades, a major part of the manufacturing and assembly market has been driven by its customer requirements. Increasing customer demand for personalised products create the demand for smaller batch sizes, shorter production times, lower costs, and the flexibility to produce families of products - or different parts - with the same sets of equipment. Consequently, manufacturing companies have deployed various automation systems and production strategies to improve their resource efficiency and move towards right-first-time production. However, many of these automated systems, which are involved with robot-based, repeatable assembly automation, require component- specific fixtures for accurate positioning and extensive robot programming, to achieve flexibility in their production. Threaded fastening operations are widely used in assembly. In high-volume production, the fastening processes are commonly automated using jigs, fixtures, and semi-automated tools. This form of automation delivers reliable assembly results at the expense of flexibility and requires component variability to be adequately controlled. On the other hand, in low- volume, high- value manufacturing, fastening processes are typically carried out manually by skilled workers. This research is aimed at addressing the aforementioned issues by developing a freeform automated threaded fastener assembly system that uses 3D visual guidance. The proof-of-concept system developed focuses on picking up fasteners from clutter, identifying a hole feature in an imprecisely positioned target component and carry out torque-controlled fastening. This approach has achieved flexibility and adaptability without the use of dedicated fixtures and robot programming. This research also investigates and evaluates different 3D imaging technology to identify the suitable technology required for fastener assembly in a non-structured industrial environment. The proposed solution utilises the commercially available technologies to enhance the precision and speed of identification of components for assembly processes, thereby improving and validating the possibility of reliably implementing this solution for industrial applications. As a part of this research, a number of novel algorithms are developed to robustly identify assembly components located in a random environment by enhancing the existing methods and technologies within the domain of the fastening processes. A bolt identification algorithm was developed to identify bolts located in a random clutter by enhancing the existing surface-based matching algorithm. A novel hole feature identification algorithm was developed to detect threaded holes and identify its size and location in 3D. The developed bolt and feature identification algorithms are robust and has sub-millimetre accuracy required to perform successful fastener assembly in industrial conditions. In addition, the processing time required for these identification algorithms - to identify and localise bolts and hole features - is less than a second, thereby increasing the speed of fastener assembly

Design for manufacturability and assembly

This report presents a study of the various concepts of design for manufacturability and assembly with some case studies, and examples. The goal of DFM is reduction of parts and simplifying assembly process. A simple faucet has been studied and attempts have been made at re-designing the same using the techniques of design for manufaturability as postulated by Boothroyd, Dewhurst and Henry Stoll

Implementation of automated assembly

Research has shown that about 60 - 80% wealth producing activities is related to manufacturing in major industrial countries. Increased competition in industry has resulted in a greater emphasis on using automation to improve productivity and quality and also to reduce cost. Most of the manufacturing works such as machining, painting, storage, retrieval, inspection and transportation have changed to automation successfully, except assembly. Manual assembly is predominant over automatic assembly techniques due to inherent assembly problem and the fact that the assembly machines lack the innate intelligence of human operator and lack sufficient flexibility to changeover when product designs and market demands change. With the advent of flexible manufacturing systems, which involve very large capital costs and complex interactions. For the reduction the risk of the investment and analyze the system, simulation is a valuable tool in planning the systems and in analyzing their behavior, and get the best use of them. This thesis applies animation techniques to simulate an automatic assembly system. In chapter 1 to 9, we cover some of the fundamental concepts and principles of automatic assembly and simulation. Some manufacturers put the subject of part orientation first on their list of priorities; but design for assembly (DFA) techniques have proven extremely valuable in developing better assembly techniques and ultimately, better products. We discuss DFA in chapter 1, part feeding and orientation in chapter 2. Chapter 3, 4 and 5 are concerned with assembly process, machines and control system, respectively. Annual sales for industrial robots have been growing at the rate of about 25 percent per year in major industrial countries, we review the robot application in chapter 6. The cost of material handling is a significant portion of the total cost of production, material storage uses valuable space and consumes investment, we cover these two topics in chapter 7 and 8. Chapter 9 is concerned with simulation. In chapter 10, 11,12 and 13, we implement a software package IGRIP to build a model of an automatic assembly system and analyze the result

ARMD Workshop on Materials and Methods for Rapid Manufacturing for Commercial and Urban Aviation

This report documents the goals, organization and outcomes of the NASA Aeronautics Research Mission Directorates (ARMD) Materials and Methods for Rapid Manufacturing for Commercial and Urban Aviation Workshop. The workshop began with a series of plenary presentations by leaders in the field of structures and materials, followed by concurrent symposia focused on forecasting the future of various technologies related to rapid manufacturing of metallic materials and polymeric matrix composites, referred to herein as composites. Shortly after the workshop, questionnaires were sent to key workshop participants from the aerospace industry with requests to rank the importance of a series of potential investment areas identified during the workshop. Outcomes from the workshop and subsequent questionnaires are being used as guidance for NASA investments in this important technology area

Reducing the acquisition cost of the next fighter jet using automation

The acquisition cost of fast-jets has increased exponentially since WWII, placing defence budgets under severe pressure. Fleet sizes are contracting as fewer new aircraft are ordered, and with new programmes few and far between the methods of assembling airframes have hardly changed in fifty-years. Modern airframes rely on traditional welded steel assembly fixtures and high accuracy machine tools, which represent a significant non-recurring cost that cannot be reconfigured for re-use on other programmes. This research investigates the use of automation to reduce the acquisition cost. Its aim is to demonstrate innovations, which will collectively assist in achieving the twin goals of Tempest, to be manufactured 50-percent faster and 50-percent cheaper, through the re-configuration and re-use of automation, creating a flexible factory-of-the-future. Two themes were explored, the UK-MOD’s acquisition process, to position this research in the timeframe of the next generation of fast-jet, and the use of automation in airframe assembly globally, specifically focusing on Measurement Assisted Assembly (MAA), part-to-part methods and predictive processes. A one-to-one scale demonstrator was designed, manufactured and assembled using MAA; and from the measurement data additively manufactured shims for the structure’s joints were produced. The key findings are that; metrology guided robots can position parts relative to one-another, to tolerances normally achieved using welded steel fixtures, maintaining their position for days, and can then be reconfigured to assemble another part of the structure. Drilling the parts during their manufacture on machine tools, using both conventional and angle-head tooling, enables them to be assembled, negating the requirement to use traditional craft-based skills to fit them. During the manufacture of the parts, interface data can be collected using various types of metrology, enabling them to be virtually assembled, creating a Digital Twin, from which any gaps between parts can be modelled and turned into a shim using an additive manufacturing process with the limitation that current AM machines do not produce layers thin enough to fully meet the shimming requirement. The acquisition process requires, a technology to be demonstrated at technology readiness level (TRL) 3 during the concept phase, and have a route-map to achieve TRL 6 in the development phase, following the assessment phase. The novel use of automation presented in this thesis has the potential to enable manufacturing assets to be re-configured and re-used, significantly reducing impacting the acquisition costs of future airframe programmes. Collectively the innovations presented can significantly reduce the estimated 75 percent of touch labour costs and 9 percent of non-recurring costs associated with assembling an airframe. These innovations will help to enable a digital transformation that, together with other Industry 4.0 technologies and methods, can collectively enable the automated manufacture of customised aerospace products in very-low volumes. This is of relevance not only to next generation fighter jets, but also to emerging sectors such as air-taxis

Large volume metrology technologies for the light controlled factory

In the Light Controlled Factory part-to-part assembly and reduced weight will be enabled through the use of predictive fitting processes; low cost high accuracy reconfigurable tooling will be made possible by active compensation; improved control will allow accurate robotic machining; and quality will be improved through the use of traceable uncertainty based quality control throughout the production system. A number of challenges must be overcome before this vision will be realized; 1) controlling industrial robots for accurate machining; 2) compensation of measurements for thermal expansion; 3) Compensation of measurements for refractive index changes; 4) development of Embedded Metrology Tooling for in-tooling measurement and active tooling compensation; and 5) development of Software for the Planning and Control of Integrated Metrology Networks based on Quality Control with Uncertainty Evaluation and control systems for predictive processes. This paper describes how these challenges are being addressed, in particular the central challenge of developing large volume measurement process models within an integrated dimensional variation management (IDVM) system

Intelligent control of an automated adhesive dispensing cell.

Imperial Users onl