Development and Evaluation of Miniaturized 6-DOF Parallel Link Manipulator

2012 ◽  
Vol 523-524 ◽  
pp. 756-761
Author(s):  
Ryujiro Kobayashi ◽  
Ryo Tsuboi ◽  
Shinya Sasaki

Recently, compact machine tools have witnessed increased demand in the manufacture of small parts with high accuracy. However, miniaturization of these machines poses problems such as decrease in the accuracy and the range of motion. We focused on miniaturizing a parallel link manipulator, which is known to have high rigidity and accuracy. A non-cylindrical link was adopted in the designed manipulator for avoiding collisions among links with an impact drive actuator attached to their side. We confirmed through repeatability measurements that the developed manipulator had sufficient accuracy for handling small electronic parts.

2019 ◽  
Vol 109 (05) ◽  
pp. 312-318
Author(s):  
T. Engelberth ◽  
A. Verl

Zahnstange-Ritzel-Antriebe werden vorwiegend in großen Werkzeugmaschinen eingesetzt. Um die hohen Genauigkeitsanforderungen moderner Produktionsanlagen zu erreichen, werden diese Antriebe elektrisch verspannt. Die Verspannung ist konstant. Dieser Beitrag beschreibt eine neuartige Methode, die sogenannte adaptive Verspannung. Ziel ist es, den Energiebedarf und die Belastung des Antriebssystems durch Anpassung der Verspannung während des Betriebs zu reduzieren, ohne die Genauigkeit zu beeinflussen.   Rack-and-pinion-drives are mostly used in large machine tools. To achieve the high accuracy specifications of modern production facilities, these drives are electrically preloaded. The preload is constant. This article describes a new method of so-called adaptive preloading. The aim is to reduce energy demand and wear of the drive system by adjusting the preload during operation without affecting the accuracy.


2021 ◽  
Vol 111 (01-02) ◽  
pp. 82-87
Author(s):  
Felix Brenner ◽  
Armin Lechler ◽  
Alexander Verl

Zahnstange-Ritzel-Antriebe werden überwiegend bei großen Werkzeugmaschinen eingesetzt und häufig mit indirekter Lageregelung betrieben. Hieraus resultiert eine geringe Positioniergenauigkeit und ein unzureichendes dynamisches Nachgiebigkeitsverhalten. Um den hohen Genauigkeitsanforderungen moderner Werkzeugmaschinen gerecht zu werden, wird in diesem Beitrag eine beschleunigungsbasierte Störgrößenkompensation vorgestellt. Experimentelle Ergebnisse belegen eine Verbesserung des Störverhaltens.   Rack-and-pinion drives are mainly used in large machine tools and controlled by indirect position control. This leads to low positioning accuracy as well as an insufficient dynamic compliance. To meet the high accuracy requirements of modern machine tools, this paper presents an acceleration-based disturbance compensation. Experimental results prove a considerable improvement of the disturbance behavior.


2010 ◽  
Vol 447-448 ◽  
pp. 826-830 ◽  
Author(s):  
Tomohisa Tanaka ◽  
Masahiro Komori ◽  
Jiang Zhu ◽  
Yoshio Saito

Parallel mechanism has many advantages, such as high stiffness, high accuracy, high degree of freedom (DOF), etc. These fine features are suitable for work table of machine tools for production of recent complicated designs. In this study, six axes linear-actuated parallel mechanism was chosen as the basic design for work table. First, geometrical parameters of the table were designed to satisfy the required movable range with minimum cutting load. Then, the work table was actually constructed and its performance was evaluated. From positioning accuracy measurement, it was found that the table is suitable to be used for machining of complicated products. On the other hand, from actual cutting tests of primitive shapes using chemical wood and measurement of the machined shapes, potential of the table for real cutting application was confirmed.


Author(s):  
Akio Hayashi ◽  
Masato Ueki ◽  
Keisuke Nagao ◽  
Hiroto Tanaka ◽  
Yoshitaka Morimoto ◽  
...  

Abstract Robot type machine tools with parallel link mechanism are characterized by the performance to change tool posture and machine wider range than conventional machine tools. It is realized by simultaneous multi-axis control of parallel link mechanism. However, there are some problems, it is difficult to identify and adjust alignment error. In addition, the machining performance is unidentified due to the rigidity is different from conventional machine tools. In this research, a geometric model is described and the forward kinematics model is derived based on the geometric model. Then, the machining tests were carried out to evaluate the machining accuracy by measured machined surface and the simulated motion of tool cutting edge based on proposed forward kinematics model.


2015 ◽  
Vol 32 (7) ◽  
pp. 1364-1371
Author(s):  
Pavel I. Ionov ◽  
Andrew K. Mollner

AbstractHigh-accuracy measurement of aerosol optical thickness (AOT) τa with an elevation-scanning lidar is demonstrated and the results are compared with a collocated Cimel 318 sun photometer. Linear regression of the time-coincident data from a 2-week measurement campaign with the two instruments is found to be τalidar = (1.00 ± 0.17)τaphot + (0.025 ± 0.019) (1σ). The method proved to have sufficient accuracy to measure AOTs of 0.1–0.2 commonly seen in relatively clear atmosphere. The measurement is absolute and thus does not depend on any external calibration standards.


2015 ◽  
Vol 794 ◽  
pp. 379-386 ◽  
Author(s):  
Bernd Kauschinger ◽  
Steffen Schroeder

The measures taken to improve the thermal behaviour of machine tools are based on thermal models. The models are applied to support the design process and to correct the machine tool operation in a control-based way. Especially the models for correction purposes include uncertain parameters that cannot be estimated with sufficient accuracy. Thus these parameters have to be adjusted by means of measurements. During the adjustment process, a broad diversity of machine behaviour and model characteristics has to be taken in to account. Therefore, substantial time, effort and expert knowledge are required. To identify the key expenses, a generalized and systematic analysis of the adjustment process was carried out. First, the typical design of the models, the parameters of the sub models and the current adjustment procedure were investigated. Based on the results of the analysis, support requirements were identified. Afterwards first methods and software tools for efficient support were developed. This strategy is demonstrated using the example of a hexapod strut model.


2017 ◽  
Vol 11 (2) ◽  
pp. 139-139
Author(s):  
Keiichi Nakamoto ◽  

Machine tools using numerical control (NC) devices are typical mechatronics products, and introducing them is a powerful way to automate plant production. NC machine tools in workshops meet the requirements of high accuracy and efficiency in the machining of a variety of parts and mold dies. Turning centers and machining centers are typical examples of such machine tools. Various cutting processes have been integrated in them to cope with the increase in machine parts that not only have complicated geometries but also must be made with high accuracy, in small quantities, and in a short machining time. In addition, turning and machining centers have been given multitasking capabilities, and the number of control axes has been increased so that complex products may be manufactured efficiently. Given that the strong attention and interest in multiaxis control and multitasking machine tools are rapidly increasing, it is fitting that the current state of the art of these tools and their practical and applicable technologies be presented. This special issue features 16 research articles – one review and 15 papers – related to the latest research results and practical case studies in multiaxis control and multitasking machining. Their subjects cover various advances in machine control, motion accuracy evaluation, machining error analysis, chatter vibration monitoring or suppression, trouble-free tool path generation, process planning, and new applications of the machine tools. We thank the authors for their contributions to this special issue, and we are sure that both non-specialists and specialists alike will find the information the authors provide both interesting and informative. Moreover, we deeply appreciate the reviewers for their incisive efforts. Without these contributions, this special issue could not have been realized. We truly hope that this special issue will trigger further research on multiaxis control and multitasking machining.


2016 ◽  
Vol 2016 (3) ◽  
pp. 202-209
Author(s):  
Олеся Аникеева ◽  
Olesya Anikeeva

Machinetools belong to the basic technological equipment in mechanical engineering ensuring the creation of other machines with high accuracy and productivity unattainable in coming decades on the basis of additive techniques. Machining accuracy on machinetools is an integral index of quality and despite the diversity of approaches to the identification of correla-tions, computations and estimates of machining accuracy, the value of a general error seems to be as a sum of partial errors. A significant part in the formation of a general error of machining cause machinetools them-selves. Besides, a significant role in assurance of guaranties for machinetools users (operators) the standards for their geometrical accuracy play. A significant problem having scientific and practical meaning is the absence of a single approach substantiated scientifically to the formation of a system of such standards both for machine-tools of new types, and for the revision of the system with actual standards on geometrical accuracy of machinetools. In the paper there are offered methodological fundamentals for the parameters standardization of machine-tools geometrical accuracy on the basis of revealed interrelations between accuracy of units and parts surfaces machined at the use of a variational method for the computation of machines accuracy. The practical use of the approach offered requires both the development of the variational method itself for the computation of machines accuracy in the field of obtaining corresponding estimates of accuracy of various surfaces machined, for example, deviations from parallelism of two faces and others, and thorough investigations of the structure of relationship equations themselves.


2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Eko Budiyanto ◽  
Lukito Dwi Yuono ◽  
Fatku Rohman

The world of manufacturing technology is currently developing rapidly. Computerization carried out on manufacturing equipment makes it very easy for an industry, especially industries with a large production scale or mass production with a high number of orders in a short time. Manufacturing technology for machine tools usually uses a CNC (Computer Numeric Control) machine. Where the operation of this machine uses a program controlled by a computer and the programmer. This machine can produce products with high accuracy, even for very complicated manufacturing work. Product errors due to operator negligence can be reduced, as contact between the operator and the machine is minimal. However, if there is an error in the material or improper feed, the operator tends not to know because everything has been executed with the program that has been made. Observations were made at the 3 axis prismatic machine section, PT. Dirgantara Indonesia (DI). The milling machine used was the QUASER MV 185 type machine. Part material used in this study was Aluminum alloy 7010. The results of observations and calculations obtained that the average machining efficiency was 13%. Keywords: CNC, production process, efficiency.


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