A framework for flexible integration in robotics and its applications for calibration and error compensation

Robotics has been considered as a viable automation solution for the aerospace industry to address manufacturing cost. Many of the existing robot systems augmented with guidance from a large volume metrology system have proved to meet the high dimensional accuracy requirements in aero-structure assembly. However, they have been mainly deployed as costly and dedicated systems, which might not be ideal for aerospace manufacturing having low production rate and long cycle time. The work described in this thesis is to provide technical solutions to improve the flexibility and cost-efficiency of such metrology-integrated robot systems. To address the flexibility, a software framework that supports reconfigurable system integration is developed. The framework provides a design methodology to compose distributed software components which can be integrated dynamically at runtime. This provides the potential for the automation devices (robots, metrology, actuators etc.) controlled by these software components to be assembled on demand for various assembly applications. To reduce the cost of deployment, this thesis proposes a two-stage error compensation scheme for industrial robots that requires only intermittent metrology input, thus allowing for one expensive metrology system to be used by a number of robots. Robot calibration is employed in the first stage to reduce the majority of robot inaccuracy then the metrology will correct the residual errors. In this work, a new calibration model for serial robots having a parallelogram linkage is developed that takes into account both geometric errors and joint deflections induced by link masses and weight of the end-effectors. Experiments are conducted to evaluate the two pieces of work presented above. The proposed framework is adopted to create a distributed control system that implements calibration and error compensation for a large industrial robot having a parallelogram linkage. The control system is formed by hot-plugging the control applications of the robot and metrology used together. Experimental results show that the developed error model was able to improve the 3 positional accuracy of the loaded robot from several millimetres to less than one millimetre and reduce half of the time previously required to correct the errors by using only the metrology. The experiments also demonstrate the capability of sharing one metrology system to more than one robot

Design of multifunctional paired robots engaged across a thin plate for aircraft manufacturing and maintenance

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 77-78).The aircraft industry lacks an automated system for wing box manufacturing and maintenance. Currently workers assemble and inspect thousands of fasteners in the wing structure by hand. This manufacturing process consumes valuable time and resources. Mobile robots capable of navigating on the interior and exterior of the wing have the potential to perform the wing structure manufacturing tasks. This thesis describes the design, analysis, and implementation of paired robots engaged across a thin plate. Two robots, each capable of carrying an end effector, are engaged using strong magnets attracting each other and thereby supporting each body against gravity. The robots must move across the surface of the box, while avoiding interference with obstacles fixed to the surface. The multifunctional paired robots navigate the surface with three different operations. The paired robots are automatically loaded and unloaded from the confined box through a small entry hole using the "Flipping" operation. The "Drive and Slide" operation is used on horizontal surfaces. The robots "Step" over obstacles while securely holding each body against gravity. Parametric models of the robots are developed, and the conditions for the successful multifunctional operations are analyzed. The two primary failure modes are tipping of the robots on either side of the thin panel. An optimal trajectory that minimizes the peak tipping moments, while also minimizing how close the robots are to failure is designed to meet the many challenges of the stepping operation. The trajectory ensures that the failure modes are avoided during the disengagement of the strong permanent magnets in the stepping operation. The position trajectories are parameterized using cubic splines with the bounds being the start and end robot configurations. Prototype paired robots are constructed and experimentally tested. The prototype robots performed their multifunctional operation modes on a mock wing structure, validating the design and analysis.by Geoffrey Ian Karasic.S.M

Design of an instrumented multifunctional foot for application to a heavy duty mobile robot manufacturing system

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 56-57).The design of a multifunctional foot for application to a mobile robotic system for heavy duty manufacturing is presented. The requirements for a target manufacturing task are presented and translated into requirements for the mobile robotic system, and specifically for the feet of this system. This includes: the ability of the feet to change frictional properties, the ability of the foot to operate without a direct power source, and load bearing requirements for heavy duty tooling. The mechanical design to meet these requirements for these feet is presented. Stability analysis is shown, and it is used to determine several design parameters to meet the goals of the project. The development of a series of iterations of prototypes is discussed. Manufacturing techniques, choice of materials, alignment strategies and assembly practices are explained. Appendices include information about several of the important design milestones. A sensing methodology is introduced. Computer simulations of magnetic fields to estimate the effectiveness of this methodology are performed. Experimental results are shown to match the simulations. A final functional prototype is shown. Testing is performed on this prototype to verify that it meets the functional requirements desired for the system.by Manas Chandran Menon.S.M

Design and control of a gravity-assisted underactuated snake robot with application to aircraft wing assembly

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (p. 108-111).We present the design and control of a hyper-articulated robot arm comprising just a few active joints driving a multitude of passive joints. This underactuated arm design was motivated by the need for a compact snake-like robot for assembly operations inside an aircraft wing. The interior of the wing is accessible only through small access portholes distributed along the length. Currently, such assembly operations are performed by human operators who crawl into the wing through its access portholes. The working conditions are ergonomically challenging and result in frequent injuries. The conflicting requirements of small form factor and high payload carrying capacity have been the primary bottlenecks in the development of assembly robots. We propose a nested-channel serial linkage structure for the hyper-articulated arm. When fully contracted, the arm is extremely compact and can access the interior of the wing through its access porthole. Once inside the wing, the arm may be expanded to access distal assembly locations. However, it is impossible to package current actuator technology to meet the payload requirements within the limited size of the robot arm. The joints of the hyper-articulated arm have no dedicated actuators. Instead, they are deployed by modulating gravitational torques. By tilting the base link appropriately, the gravitational torque drives each unactuated link to a desired angular position. With simple, compact locking mechanisms, the arm can change its configuration using the actuated base placed outside the wing. We analyze the system dynamics to gain physical insight into the interaction between the actuated and unactuated degrees of freedom. We make important approximations to capture the dominant effects in the system dynamics so as to facilitate control design.(cont.) The dynamics (actual, as well as approximate) of the unactuated links are essentially 2nd order non-holonomic constraints, for which there are no general control techniques. We present several motion planning algorithms for sequential positioning of the free joints of the robot arm. The motion planning algorithms are formulated as parameterized non-linear two point boundary value problems. These algorithms demonstrate reasonable performance in the absence of disturbances. However, the end-effecter requires accurate positioning to perform assembly operations. To address this issue, we present a sequential closed-loop control algorithm for accurate positioning of the free joints. We synthesize a Lyapunov function to prove the convergence of this control scheme and to generate estimates of the domain of convergence. For faster deployment of the robot arm, multiple free links must move concurrently. We also present several motion planning algorithms to address this problem. We built two prototypes to illustrate the design and actuation concepts. The first prototype has 3 links and has a fixed axis of tilt in the horizontal plane. The second prototype has 4 links and may be tilted about an arbitrary axis in the horizontal plane. The motion planning and closed-loop control algorithms were implemented on both prototypes. The experimental results indicate the efficacy of such control schemes.by Binayak Roy.Ph.D

A novel positioning system for accurate tracking in indoor environments

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (p. 91-93).Precise positioning is crucial to many applications involving autonomous robots in indoor environments. Current solutions to the indoor localization problem are either both highly unreliable and inaccurate (like GPS based systems), or hugely expensive (such as the iGPS system). In this thesis we propose, design and build a low-cost, robust and highly accurate indoor localization system using laser light sources. The system is composed of three transmitting laser modules arranged in a straight line and a receiver module mounted on the mobile robot. The system calculates the coordinates of the mobile robot by using triangulation algorithms which require precisely measured values of the angles of the receiver with respect to the three laser emitters. Results from practical testing of the system in an aircraft wing assembly set-up have been found to be extremely encouraging. Using our system, the mobile robotic arm could be localized accurately within error margins defined approximately by Gaussian distributions centered at the object's true coordinate values and with standard deviations of 0.1778 mm, 0.1016 mm and 0.3352 mm in the x, y and z coordinate directions respectively. The system is also used to detect height drop in the arm due to its weight as it extends to perform fitting operations on the skin of the wing. Feedback from the laser localization system is used to adjust the position of the tip of the robotic arm in order to perform a sequence of high precision docking tasks within the aircraft wing.by Srujan Linga.S.M

Small business innovation research. Abstracts of completed 1987 phase 1 projects

Non-proprietary summaries of Phase 1 Small Business Innovation Research (SBIR) projects supported by NASA in the 1987 program year are given. Work in the areas of aeronautical propulsion, aerodynamics, acoustics, aircraft systems, materials and structures, teleoperators and robotics, computer sciences, information systems, spacecraft systems, spacecraft power supplies, spacecraft propulsion, bioastronautics, satellite communication, and space processing are covered

Conference on Intelligent Robotics in Field, Factory, Service, and Space (CIRFFSS 1994), volume 1

The AIAA/NASA Conference on Intelligent Robotics in Field, Factory, Service, and Space (CIRFFSS '94) was originally proposed because of the strong belief that America's problems of global economic competitiveness and job creation and preservation can partly be solved by the use of intelligent robotics, which are also required for human space exploration missions. Individual sessions addressed nuclear industry, agile manufacturing, security/building monitoring, on-orbit applications, vision and sensing technologies, situated control and low-level control, robotic systems architecture, environmental restoration and waste management, robotic remanufacturing, and healthcare applications

Flexible Automation and Intelligent Manufacturing: The Human-Data-Technology Nexus

This is an open access book. It gathers the first volume of the proceedings of the 31st edition of the International Conference on Flexible Automation and Intelligent Manufacturing, FAIM 2022, held on June 19 – 23, 2022, in Detroit, Michigan, USA. Covering four thematic areas including Manufacturing Processes, Machine Tools, Manufacturing Systems, and Enabling Technologies, it reports on advanced manufacturing processes, and innovative materials for 3D printing, applications of machine learning, artificial intelligence and mixed reality in various production sectors, as well as important issues in human-robot collaboration, including methods for improving safety. Contributions also cover strategies to improve quality control, supply chain management and training in the manufacturing industry, and methods supporting circular supply chain and sustainable manufacturing. All in all, this book provides academicians, engineers and professionals with extensive information on both scientific and industrial advances in the converging fields of manufacturing, production, and automation