Download or read book Smooth Trajectory Generation and Precision Control of 5 axis CNC Machine Tools written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents experimentally verified optimal feedrate generation and high performance precision control algorithms developed for 5-axis machine tools. A feedrate scheduling algorithm has been introduced to minimize the cycle time for 5-axis machining of curved tool-paths. The variation of the feed along the tool-path is expressed in a cubic B-spline form as a function of the arc displacement. The velocity, acceleration and jerk limits of the five axis drives are considered in finding the most optimal feed along the tool-path to ensure smooth and linear operation of the servo drives with minimal tracking error. Improvement in the productivity and linear operation of the drives are demonstrated through 5-axis experiments. In an effort to design an accurate contour controller, analytical models are developed to estimate the contour errors during simultaneous 5-axis machining. Two types of contouring errors are defined by considering the normal deviation of tool tip from the reference path, and the normal deviation of the tool axis orientation from the reference orientation trajectory. A novel multi-input-multi-output sliding mode controller is introduced to directly minimize the tool tip and tool orientation errors, i.e. the contouring errors, along the 5-axis tool-paths. The stability of the control scheme is proven analytically, and the effectiveness of this new control strategy has been demonstrated experimentally. An identification technique for identifying the closed loop transfer function of machine tool feed drives has been introduced. The drive system is identified in closed loop, including the feed drive mechanism, motor amplifier, and the control law. A short Numerical Control Program is used for exciting the axis dynamics without interfering with the servo control loop. A generalized drive model is utilized to capture the key dynamics of the drive systems, while guaranteeing the stability of the identified model dynamics by solving a constrained opti.

Download or read book Smooth Trajectory Generation for 5 axis CNC Machine Tools written by Robert Ward and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Smooth and Time optimal Trajectory Generation for High Speed Machine Tools written by Michele Mei-Ting Heng and published by . This book was released on 2008 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: In machining complex dies, molds, aerospace and automotive parts, or biomedical components, it is crucial to minimize the cycle time, which reduces costs, while preserving the quality and tolerance integrity of the part being produced. To meet the demands for high quality finishes and low production costs in machining parts with complex geometry, computer numerical control (CNC) machine tools must be equipped with spline interpolation, feedrate modulation, and feedrate optimization capabilities. This thesis presents the development of novel trajectory generation algorithms for Non Uniform Rational B-Spline (NURBS) toolpaths that can be implemented on new low-cost CNC's, as well as, in conjunction with existing CNC's. In order to minimize feedrate fluctuations during the interpolation of NURBS toolpaths, the concept of the feed correction polynomial is applied. Feedrate fluctuations are reduced from around 40 % for natural interpolation to 0.1 % for interpolation with feed correction. Excessive acceleration and jerk in the axes are also avoided. To generate jerk-limited feed motion profiles for long segmented toolpaths, a generalized framework for feedrate modulation, based on the S-curve function, is presented. Kinematic compatibility conditions are derived to ensure that the position, velocity, and acceleration profiles are continuous and that the jerk is limited in all axes. This framework serves as the foundation for the proposed heuristic feedrate optimization strategy in this thesis. Using analytically derived kinematic compatibility equations and an efficient bisection search algorithm, the command feedrate for each segment is maximized. Feasible solutions must satisfy the optimization constraints on the velocity, control signal (i.e. actuation torque), and jerk in each axis throughout the trajectory. The maximized feedrates are used to generate near-optimal feed profiles that have shorter cycle times, approximately 13-26% faster than the feed profiles obtained using the worst-case curvature approach, which is widely used in industrial CNC interpolators. The effectiveness of the NURBS interpolation, feedrate modulation and feedrate optimization techniques has been verified in 3-axis machining experiments of a biomedical implant.

Download or read book Advanced Mobile Robotics written by DaeEun Kim and published by MDPI. This book was released on 2020-03-06 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mobile robotics is a challenging field with great potential. It covers disciplines including electrical engineering, mechanical engineering, computer science, cognitive science, and social science. It is essential to the design of automated robots, in combination with artificial intelligence, vision, and sensor technologies. Mobile robots are widely used for surveillance, guidance, transportation and entertainment tasks, as well as medical applications. This Special Issue intends to concentrate on recent developments concerning mobile robots and the research surrounding them to enhance studies on the fundamental problems observed in the robots. Various multidisciplinary approaches and integrative contributions including navigation, learning and adaptation, networked system, biologically inspired robots and cognitive methods are welcome contributions to this Special Issue, both from a research and an application perspective.

Download or read book Information Computing And Automation In 3 Volumes Proceedings Of The International Conference written by Jian Ping Li and published by World Scientific. This book was released on 2008-04-25 with total page 1645 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wavelet analysis and its applications have become one of the fastest growing research areas in the past several years. Wavelet theory has been employed in many fields and applications, such as signal and image processing, communication systems, biomedical imaging, radar, air acoustics, and endless other areas. Active media technology is concerned with the development of autonomous computational or physical entities capable of perceiving, reasoning, adapting, learning, cooperating, and delegating in a dynamic environment.This book consists of carefully selected and received papers presented at the conference, and is an attempt to capture the essence of the current state-of-the-art in wavelet analysis and active media technology. Invited papers included in this proceedings includes contributions from Prof P Zhang, T D Bui, and C Y Suen from Concordia University, Canada; Prof N A Strelkov and V L Dol'nikov from Yaroslavl State University, Russia; Prof Chin-Chen Chang and Ching-Yun Chang from Taiwan; Prof S S Pandey from R D University, India; and Prof I L Bloshanskii from Moscow State Regional University, Russia.

Download or read book A New Approach for Trajectory Generation in 5 axis Machining written by Matthias Müller and published by . This book was released on 2002 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Secrets of 5 axis Machining written by Karlo Apro and published by Industrial Press Inc.. This book was released on 2008 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book explains 5-axis machining in simple terms most people in the field will appreciate and quickly understand. The colorful graphics are nothing short of amazing and generously sprinkled throughout the book with incredible detail. Dozens of machining applications are illustrated and explained while taking much of the fear out of driving these complex machine tools. Anyone associated with 5-axis machine tools has much to gain by reading this book." Mark Summers, President CNC Software Inc. ..". this great book will allow operators, NC programmers and anybody interested in multiaxis machining to learn and understand the reality of 5-axis machining. The crystal clear wording and perfect overview make this book easy to read and simple to understand for everyone, from beginner to expert." Yavuz Murtezaoglu, Managing Director ModuleWorks GmbH Up to now, the best way to get information on 5-axis machining has been by talking to experienced peers in the industry, in hopes that they will share what they learned. Visiting industrial tradeshows and talking to machine tool and Cad/Cam vendors is another option, only these people will all give you their point of view and will undoubtedly promote their machine or solution. This unbiased, no-nonsense, to-the-point description of 5-axis machining presents information that was gathered during the author's 30 years of hands-on experience in the manufacturing industry, bridging countries and continents, multiple languages - both human and G-Code. As the only book of its kind, Secrets of 5-Axis Machining will demystify the subject and bring it within the reach of anyone who is interested in using this technology to its full potential, and is not specific to one particular CAD/CAM system. It is sure to empower readers to confidently enter this field, and by doing so, become better equipped to compete in the global market. Features full-color illustrations through that help to explain the theories and principals. Includes a CD containing avi files, high quality illustrations, and sample parts.

Download or read book Computer Control of Manufacturing Systems written by Yoram Koren and published by . This book was released on 1983 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Minimum Error Tool Path Generation Method and an Interpolator Design Technique for Ultra precision Multiaxis CNC Machining written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conferences 2005 written by and published by . This book was released on 2005 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research in Intelligent and Computing in Engineering written by Raghvendra Kumar and published by Springer Nature. This book was released on 2021-01-04 with total page 975 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises select peer-reviewed proceedings of the international conference on Research in Intelligent and Computing in Engineering (RICE 2020) held at Thu Dau Mot University, Vietnam. The volume primarily focuses on latest research and advances in various computing models such as centralized, distributed, cluster, grid, and cloud computing. Practical examples and real-life applications of wireless sensor networks, mobile ad hoc networks, and internet of things, data mining and machine learning are also covered in the book. The contents aim to enable researchers and professionals to tackle the rapidly growing needs of network applications and the various complexities associated with them.

Download or read book Parallel Kinematics written by Xin-Jun Liu and published by Springer Science & Business Media. This book was released on 2013-08-15 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Parallel Kinematics- Type, Kinematics, and Optimal Design presents the results of 15 year's research on parallel mechanisms and parallel kinematics machines. This book covers the systematic classification of parallel mechanisms (PMs) as well as providing a large number of mechanical architectures of PMs available for use in practical applications. It focuses on the kinematic design of parallel robots. One successful application of parallel mechanisms in the field of machine tools, which is also called parallel kinematics machines, has been the emerging trend in advanced machine tools. The book describes not only the main aspects and important topics in parallel kinematics, but also references novel concepts and approaches, i.e. type synthesis based on evolution, performance evaluation and optimization based on screw theory, singularity model taking into account motion and force transmissibility, and others. This book is intended for researchers, scientists, engineers and postgraduates or above with interests in robotics and advanced machine tools technology such as parallel kinematics machines (PKMs). Xinjun Liu and Jinsong Wang, professors, work at The Institute of Manufacturing Engineering, Department of Precision Instruments and Mechanology, Tsinghua University.

Download or read book Dynamic Model Identification and Trajectory Correction for Virtual Process Planning in Multi axis Machine Tools written by Mustafa Hakan Turhan and published by . This book was released on 2019 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: In today's industry, the capability to effectively reduce production time and cost gives a manufacturer a vital advantage against its competitors. Specifically, in the machining industry, the ability to simulate the dynamic performance of machine tools, and the physics of cutting processes, is critical to taking corrective actions, achieving process and productivity improvements, thereby enhancing competitiveness. In this context, being able to estimate mathematical models which describe the dynamic response of machine tools to commanded tool trajectories and external disturbance forces plays a key role in establishing virtual and intelligent manufacturing capability. These models can also be used in virtual simulations for process improvement, such as compensating for dynamic positioning errors by making small corrections to the commanded trajectory. This, in turn, can facilitate further productivity improvement and part quality in multi-axis manufacturing operations, such as machining. This thesis presents new methods for identifying the positioning response and friction characteristics of machine tool servo drives in a nonintrusive manner, and an approach for enhancing dynamic positioning accuracy through commanded trajectory correction via Iterative Learning Control (ILC). As the first contribution, the linear transfer functions correlating the positioning response to the commanded trajectory and friction disturbance inputs are identified using a new pole search method in conjunction with least squares (LS) projection. It is validated that this approach can work with in-process collected data, and demonstrates superior convergence and numerical characteristics, and model prediction accuracy, compared to an earlier 'rapid identification' approach based on the application of classical Least Squares for the full model. Effectiveness of the new method is demonstrated in simulations, and in experimental case studies for planar motion on two different machine tools, a gear grinding machine and a 5-axis machining center. Compared to the earlier approach, which could predict servo errors with 10-68% closeness, the new method improves the prediction accuracy to 0.5-2%. In the simulation of feed drives used in multi-axis machines, high fidelity prediction of the nonlinear stick-slip friction plays an important role. Specifically, time-dependent (i.e., dynamic) friction models help to improve the accuracy of virtual predictions. While many elaborate models have been proposed for this purpose, such as the generalized Maxwell-slip (GMS) model, their parameters can be numerous and difficult to identify from limited field data. In this thesis, as the second contribution, a new and highly efficient method of parameterizing the pre-sliding (hysteretic) portion of the GMS friction model is presented. This approach drastically reduces the number of unknown variables to identify, by estimating only the affective breakaway force, breakaway displacement, and 'shape factor' describing the shape of the pre-sliding virgin curve. Reduction in the number of unknowns enables this 'reduced parameter' GMS model to be identified much more easily from in-process data, compared to the fully parameterized GMS model, and the time-dependent friction dynamics can still be simulated accurately. Having improved the positioning response transfer function estimation and friction modeling, as the third contribution of this thesis, these two elements are combined together in a 3-step process. First, the servo response is estimated considering simplified Coulomb friction dynamics. Then, the friction model is replaced and identified as a reduced parameter GMS model. In the third step, the transfer function poles and zeros, and the reduced parameter GMS model, are concurrently optimized to replicate the observed experimental response with even greater fidelity. This improvement has been quantified as 12-44% in RMS and 28-54% in MAX values. This approach is successful in servo systems with predominantly rigid body behavior. However, its extension to a servo system with vibratory dynamics did not produce an immediately observed improvement. This is attributed to the dominance of vibrations in response to the commanded trajectory, and further investigation is recommended for future research. Having an accurate model of a multi-axis machine's feed drive response allows for the dynamic positioning errors, which can lead to workpiece inaccuracy or defects, to be predicted and corrected ahead of time. For this purpose, ILC has been investigated. It is shown that through ILC, 1-2 orders of magnitude reduction in the servo errors is possible. While ILC is already available in certain commercial CNC systems, its training cycle (which is performed during the operation of the machine tool) can lead to part defects and wasted productive machining time. The new idea proposed in this thesis is to perform ILC on a virtual model, which is continuously updated via real-time production data using the identification methods developed in this work. This would minimize the amount of trial and error correction needed on the actual machine. In the course of this thesis research, after validating the effectiveness of ILC in simulations, to reliably and safely migrate the virtual modeling and trajectory correction results into industry (such as on a gear grinding machine tool), the author initiated and led the design and fabrication of an industry-scale testing platform, comprising a Siemens 840D SolutionLine CNC with a multi-axis feed drive setup. Majority of this implementation has been completed, and in near future work, the dynamic accuracy and productivity improvements facilitated with 'virtually' tuned ILC are expected to be demonstrated experimentally and tested in industry.

Download or read book Real time Surface Interpolars for Multi axis CNC Machine Tools written by Rong-Shine Lin and published by . This book was released on 1994 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Manufacturing Automation written by Yusuf Altintas and published by Cambridge University Press. This book was released on 2012-01-16 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal cutting is widely used in producing manufactured products. The technology has advanced considerably along with new materials, computers and sensors. This new edition considers the scientific principles of metal cutting and their practical application to manufacturing problems. It begins with metal cutting mechanics, principles of vibration and experimental modal analysis applied to solving shop floor problems. There is in-depth coverage of chatter vibrations, a problem experienced daily by manufacturing engineers. Programming, design and automation of CNC (computer numerical control) machine tools, NC (numerical control) programming and CAD/CAM technology are discussed. The text also covers the selection of drive actuators, feedback sensors, modelling and control of feed drives, the design of real time trajectory generation and interpolation algorithms and CNC-oriented error analysis in detail. Each chapter includes examples drawn from industry, design projects and homework problems. This is ideal for advanced undergraduate and graduate students and also practising engineers.

Download or read book Trajectory Planning for Automatic Machines and Robots written by Luigi Biagiotti and published by Springer Science & Business Media. This book was released on 2008-10-23 with total page 515 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the problems related to planning motion laws and t- jectories for the actuation system of automatic machines, in particular for those based on electric drives, and robots. The problem of planning suitable trajectories is relevant not only for the proper use of these machines, in order to avoid undesired e?ects such as vibrations or even damages on the mech- ical structure, but also in some phases of their design and in the choice and sizing of the actuators. This is particularly true now that the concept of “el- tronic cams” has replaced, in the design of automatic machines, the classical approach based on “mechanical cams”. The choice of a particular trajectory has direct and relevant implications on several aspects of the design and use of an automatic machine, like the dimensioning of the actuators and of the reduction gears, the vibrations and e?orts generated on the machine and on the load, the tracking errors during the motion execution. For these reasons, in order to understand and appreciate the peculiarities of the di?erent techniques available for trajectory planning, besides the ma- ematical aspects of their implementation also a detailed analysis in the time and frequency domains, a comparison of their main properties under di?erent points of view, and general considerations related to their practical use are reported.

Download or read book Enabling Manufacturing Competitiveness and Economic Sustainability written by Michael F. Zaeh and published by Springer Science & Business Media. This book was released on 2013-09-12 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: The changing manufacturing environment requires more responsive and adaptable manufacturing systems. The theme of the 5th International Conference on Changeable, Agile, Reconfigurable and Virtual production (CARV2013) is "Enabling Manufacturing Competitiveness and Economic Sustainability. Leading edge research and best implementation practices and experiences, which address these important issues and challenges, are presented. The proceedings include advances in manufacturing systems design, planning, evaluation, control and evolving paradigms such as mass customization, personalization, changeability, re-configurability and flexibility. New and important concepts such as the dynamic product families and platforms, co-evolution of products and systems, and methods for enhancing manufacturing systems' economic sustainability and prolonging their life to produce more than one product generation are treated. Enablers of change in manufacturing systems, production volume and capability, scalability and managing the volatility of markets, competition among global enterprises and the increasing complexity of products, manufacturing systems and management strategies are discussed. Industry challenges and future directions for research and development needed to help both practitioners and academicians are presented. About the Editor Prof. Dr.-Ing. Michael F. Zaeh, born in 1963, has been and is Professor for and Manufacturing Technology since 2002 and, together with Prof. Dr.-Ing. Gunther Reinhart, Head of the Institute for Machine Tools and Industrial Management (iwb) at the Technische Universitaet Muenchen (TUM). After studying general mechanical engineering, he was doctoral candidate under Prof. Dr.-Ing. Joachim Milberg at TUM from 1990 until 1993 and received his doctorate in 1993. From 1994 to 1995, he was department leader under Prof. Dr.-Ing. Gunther Reinhart. From 1996 to 2002, he worked for a machine tool manufacturer in several positions, most recently as a member of the extended management. Prof. Dr.-Ing. Michael F. Zaeh is an associated member of the CIRP and member of acatech, WGP and WLP. His current researches include among others Joining and Cutting Technologies like Laser Cutting and Welding as well as Friction Stir Welding, Structural Behaviour and Energy Efficiency of Machine Tools and Manufacturing Processes like Additive Manufacturing.