工业机器人并联机床操作外文原文.doc

资料内容仅供您学习参考，如有不当或者侵权，请联系改正或者删除。 Industrial Robots for Manipulation with ParallelKinematic MachinesZdenk Kolbal Brno University of Technology, Faculty of Mechanical Engineering, Technicka 2, 616 69 Brno, Czech Republic, e-mail: Abstract: The presented article analyses structures of kinematic chains in industrial robots, i.e. their positioning and orientation mechanisms with respect to positioning of end - effectors within the workspace of parallel kinematic machine and in its vicinity with the aim to facilitate a selection of appropriate industrial robot for automatic in between operational manipulation in the periphery of such a machine or production systems. Keywords: Industrial robot, kinematic chain, linkage, arrangement, machining centre, parallel kinematic I INTRODUCTION adaptation in terms of morphology (architecture number of degrees of freedom), in of kinematic chain, With development of control systems and computer technology, the terms of purpose (selection of construction of production machines, and machining centres in particular, has witnessed a revival of the so called Steward platform positioned in space as a plane suspended evenly in three or six points by means of linear actuators. The same principle forms the basis of the industrial robot with this parallel kinematics of its basic kinematic chain - TRICEPT HP1. appropriate end effectors, if possible automatically replaceable) and in terms of control 3. If, however, the machining centre is not equipped with another manipulation peripheral device, as can be seen e.g. in Fig. 1, the industrial robot has to directly encompass the work space of the serviced machining centre and a flow of material (semi - products and work pieces) is written in two columns. One of the advantages of so designed machining centres is a relative ease of building them into the running work units. Here the use of industrial robots seems to be an appropriate form of in between operational manipulations. However, the selection of robots cannot be casual; there has to be an all sided adaptation of the robot to the construction and handling possibilities of parallel kinematic machines, i.e. accomplished industrial robot. directly by this Figure 1aMachining centre of company INGERSOLL taken into account for the selection of industrial robots. Figure 1bMachining centre of company Kearney &TreckerIn the case of periphery from Fig. 1, it is evident that a pertinent industrial Figure 2bMachining centre of company GIDDING &LEWISrobot to be used for further manipulation is not significantly limited in terms of mainly its morphology selection (kinematic structure); therefore these cases are not a subject of the present work. A completely different is the case when a direct robotic manipulation is required for the machining centre with parallel kinematic, which is designed in terms of current trends, i.e. the components and mechanisms of the Figure 2cMachining centre of company INGERSOLLcentre virtually encompass its workspace (see Fig. 2). II BASIC AND DERIVED TYPES OF INDUSTRIAL ROBOTS As stated in most of the existing publications, basic types of industrial robots can be those described in Fig. 3: Figure 2aMachining centre of FhI ChemnitzCurrent parallel kinematics (see Fig. 2) can, in terms machining centres with Figure 3aCartesian type (K) with linkage of kinematicpairs TTTof industrial robot direct serviceability, rank among production machines with space limited serviceability; therefore this should be therefore proved theory that sets for n - degrees of freedom the number of possible linkages of kinematic pairs T and R: m = 2n(1) where n is natural number. Figure 3bCylindrical type (C) with linkage of kinematicpairs RTTFigure 4Scheme of basic kinematic chain ofindustrial robots UM-160 and GE-ROBOFor the practical and commonly used number of degrees of freedom n = 3, the basic so analysed number of linkages is extended in total up to m =23 = 8 groups: TTT, RTT, TRT, TTR, RRT, RTR, TRR, RRR. Figure 3cSpherical type (S) with linkage of kinematicpairs RRTThis set of linkages has already encompassed the above - mentioned structure of robot from Fig. 4; it is therefore possible to refer to a derived structure of the basic kinematic chain of this robot by virtue of its kinematic pairs. Each of kinematic pairs, employed in the basic kinematic chain, can however be further located in one of the three different directions given by the Cartesian system of coordinates x,y,z as follows: translation (T) in the direction of coordinates X,Y,Z, rotation (R) around these coordinates A,B,C, Figure 3dAnthropomorphous (angular, torus) type (A)with linkage of kinematic pairs RRRFurther practical use and monitoring of development revealed the robots occurrence of industrial robots with a structure of kinematic pairs linkage different from that corresponding to basic workspaces as e.g. with the industrial robot UM-160 or GE-ROBO; their structure ZKR can be expressed, as seen in Fig. 4, by a kinematic pairs linkage TRR. Practice wherefrom within the respective linkages, further possible different arrangements originate, e.g.Tx,Ty,Tz in contrast to Tx,Tz,Ty, etc. The Institute of Production Machines, (basic and derived) and also provides Systems and Robotics of FME BUT us with premises for building up new has been paying a long-time attention constructions, e.g. the following to the study of arrangements of designs of robot configurations to positioning mechanisms. The use of service machining centres with parallel kinematics. the so called combinatorial algorithms mathematical morphological constructional evaluation enabled us to assess the arrangements in all eight linkages and to state that - out of 165 1, 2, expression analysis 5, their and with III SELECTION AND DEVELOPMENT OF INDUSTRIAL ROBOTS SUITABLE TO SERVICE MACHINING CENTRES WITH PARALLEL KINEMATICS theoretically possible arrangements - From configuration structures of basic 47 solutions constructional some of the workspaces thus obtain the so called ”shell” character. So far 13 arrangements have been used in practice as can be seen from the following evaluation: various can non be isomorphous types of industrial robots in Fig. 3 it is evident that the type ”A” in particular is not suitable to service machining centres in Fig. 2. Questionable is also the above - described type ”K”(linkage used for practice. However, TTT, arrangement xszsy), whose locomotion in the basic direction (x s) is accomplished on the base that will undoubtedly form an inconvenient barrier in front of the machining centre. The above described types ”K”, ”C” (linkage RTT, arrangement CZX) and also type ”S” (linkage RRT, arrangement CAY) seem to be more convenient for the required servicing because they have as an end member of the basic kinematic chain a protruding arm and types ”K” and ”C” (linkage RTT, arrangement CZX) even have a horizontal arm that can appropriately encompass the workspace of the machining centre 4. The most suitable solution to meet these requirements is a portal design in the linkage of type ”K” (TTT) with a subsequent vertical member in a sliding shoe design (z) and a horizontal member (y) at the end of the basic kinematic chain. This is therefore the arrangement XYZ but in a modified form xportalzy (see Fig. 5). In total 3+4+5+6+6+10+7+6 = 47 arrangements, out of these 8 ”shell”. A performed theoretical analysis enables us to classify various types of IRaM within a set of possible types further modified types of industrial robots. One of the possibilities could be the use of shell structure with arrangement CAX (CBY) as seen in Fig. 6a, which could be convenient for machining centres with an external peripheral device (feeder), or a suspension modification of type SCARA with arrangement AAX (BBY), as seen in Fig. 6b, enabling a further member of the basic kinematic chain sufficiently long second Figure 5awith single horizontal armto rotate by 180 outside the machining centre. Figure 6aarrangement CAX (CBY)Figure 5bwith rotary dual arm to accelerate amanipulation cycleThe locomotion of the horizontal arm of the industrial robot is however linked with certain problems related to its possible further rotation. The locomotion of end effectors of the basic kinematic chain, as seen in Fig. 5, is actually performed in front of and behind the robot base so that a complete rotation of the machining centre is in fact impossible. A possible dual arm (Fig. 5b) can form an angle of maximum 90. A more suitable solution would be if the robot could drive a little forward from the machining centre or if it were not situated in the middle of the machining centre. Figure 6barrangement AAX (BBY)Conclusion The presented selection and proposals for development of robotic systems to service machining centres with parallel kinematics are based on a long time research of morphology of mobile robotic systems and industrial robots, respecting thus a relatively difficult For these reasons, on the basis of morphological analysis, it will be presumably necessary to develop access to workspace machining centres. A set of proposed of these types is far from being complete; it 5 Kolbal, Z.: The theory of basic rather strives to make a contribution to the specification of this problem and to the search for possible solutions. kinematic chain structures and its effect on their application in the design of industrial robot positioning mechanisms. CERM Akademick nakladatelstv, s.r.o. Brno, , ISBN 80-7204-196-7, p. 71 References 1 Blohoubek, P., Kolbal, Z.: The knowledge from the Research in the Field of Robotics at UT Brno, Czech Republic. In: Automazione/Automation 1993, BIAS, Milano, Italy, November 23-25, 1993, pp. 723-726 2 Kolbal,Z.: The Theory of the Structures of Basic Kinematic Chains in Industrial Robots and this Effect on their Practical Application. In: 8 International thWorkshop on Robotics in Alpe-Adria-Danube Region RAAD 1999, Edited by Franz Freyberger and Gnter Schmidt, Mnchen, June 17-19, 1999, Technische Universitt Mnchen, Germany, 1999, ISBN 3-00-004482-5, pp. 127-132 3 Knoflek, R.- Marek, J.: Obrbc centra a prmyslov roboty s paraleln kinematickou strukturou. In: Strojrensk vroba, ronk 45, 1997, .1-2, ISBN 0039-24567, pp. 9-11 4 Kolbal, Z.- Blohoubek, P.: Die Analyse der geeigneten Gestaltung des Industrie-roboters fr die Handhabung bei den Bearbeitungszentren mit In:. paralleler Kinematik. Tagungsband des 2.Chemnitzer Parallelkinematik-Seminar Arbeits-genauigkeit Parallelkinematiken”, von 12/13. April , Verlag Wissenschaftliche Scripten, Zwickau, Germany, ISBN: 3-928921-54-1, pp. 441-455