This paper is divided in industrial applications and research at universities and research institutions. According to the last statistics at the end of 1992 approximately 1750 robots were in use in Austria. In the paper a short overview on the research on robotics is given. There are two main directions: More theoretical oriented research in the field of kinematics, kinetics, path planning and control and research mainly emphasized to applications mainly in small and medium sized companies. In the last time research is done in the direction of application of methods of artificial intelligence in form of expert or knowledge based systems as well as in fuzzy control and neuronal networks related to the field of robotics.

To reduce the mass of a robot link having the same deflection by the same length under the same loading, there exist the possibilities of using lighter materials and/or other geometric form, both by obtaining the needed rigidity. Possibilities of minimizing the weight of robot links, which are bending under static and dynamic loadings, by constructive arrangements and suitable form giving are here investigated.

SUMMARYTo derive the equations of motion for a multibody system using the Gibbs-Appell calculus – the partial derivatives of the Gibbs function G = 1/2 ∫ a2 dm with respect to the generalized accelerations equal the generalized forces-shows special advantages. Describing the kinematics with Jacobi matrices and local terms, these equations can be written in such a way that the partial derivations need not be performed explicitly. Kinetic effects of fast rotating driving devices attached to the moving links can be included in a similar way. Though an analytical formulation of the equations of motion is especially desirable with respect to its application for industrial robots, such a formulation becomes too extended and susceptible to errors for systems with more than 3 or 4 bodies. Therefore an approach is developed for tree structured robots with rotational or translational joints for calculating the Jacobi matrices and the local terms without employing any differentiation process. So it is possible to use the Gibbs-Appell method numerically in a recursive way e.g. for calculating the torques of the actuators of a robot with 6 or more degrees of freedom for a given motion.

This survey gives a short introduction to the today robot structure and problems of motion control and some remarks for future aspects of lightweight, high performance robots, that will include parts with non negligible flexibilities. How the modelling of this time variant elastic deformations, a substantial part of any control strategy, can principally be done is shown based on the recent literature. The quasistatic method uses substitutive springs to describe the elastic deformations at special locations. For the dynamic behaviour of vibrating flexible links FE-methods, a vibration mode or shape functions approach or other combined methods may be applied. The characteristics of the FE-methods are their advantage of a realistic modelling of complex shaped links but with the drow back of high evaluation time. The vibration mode methods need a special knowledge to select the right set of functions but lead to short evaluation time. Combined methods are also based on a fracturizing of the deformable elements into smaller units, whose elastic properties can be described more easily. The modelling of the elastic properties and an adequate control will be an essential basis for a future time and energy efficient robot performance.

Industrial robots and handling devices will be of great importance in future. Today robots are used for various purposes in different industries. Main disadvantages of the robots used today are the very heavy construction, the relatively slow speed and the “unintelligence”. Therefore the next generation of robots will be more “intelligent”. Such robots have to be equipped with external sensors giving them additional information about their surroundings. In addition these robots will be faster and therefore they have to be lightweight constructions. The last two features will lead to socalled “flexible” robots which are very complicated to describe mathematically and to control

Approximate equations of motion for tree-structured robots and manipulators can be obtained by neglecting relative rotational inertia effects of the active elements(motors) that drive the links of the system. Starting from these equations the Gibbs-Appell(GA)-calculus is used in this paper in order to determine generalized mass matrices and gyroscopic forces that take care of the dynamics of the active elements in the system.

To determine the equations of notion for robots or manipulators it is often started with a dynamic model consisting of linked rigid bodies where relative rotational effects of active elements are neglected. Using these results and the GIBBS-APPELL-calculus a method is demonstrated which makes it possible to get the complete equations of motion very simply. Only additional terms have to be added to the original equations to take into account that the links are gyrostats carrying axissymnetric rotors. The calculation of the kinetic energy is treated in the same way. This approach is also used to get a comparison of three different ways to describe the motion of a robot. In case A the original equations are used, case B comprises the complete equations including all inertial and gyroscopic effects of the rotors while in case C for calculating the effects of the internal rotors it is assumed that the corresponding links are fixed in an inertial frame. A three link RRR-manipulator is investigated to visualize the influences of the rotational effects upon the controlling torques.

The differential equations describing the dynamic behaviour of a robotic arm lncluding drives and gears are strongly coupled and highly nonlinear especially in case of an articulated arm. In order to allow the application of the well developed theory and control synthesis procedures for linear systems, a low order, coupled, linear and autonomous model is derived by linearization and order reduction which is - at least for nowadays stiff robots equipped with powerful drives - accurate enough for controller design and - if necessary - path prediction. The suggested procedure is simple and allows to estimate the influence of coupling terms as well as an easy updating of the model and/or controller parameters according to the actual working area

The concepts of linearization and order reduction are used to derive low order linear autonomous models for the dynamic behaviour of a robot including drives and gears. As the parameters depend on the actual working point an easy updating of the model and/or the controller parameters is possible if necessary. Further, the influence of coupling terms can be also estimated easily.

The purpose of this contribution should be to give a short introduction to the problems treated in this session of the symposium titled “Kinematics and Kinetics of Robots”. For the description of the geometric relations between the robot coordinates - the relative angles resp.translatorial displacements between the links - and the position and orientation of the gripper in the working space the use of coordinate frames attached to the links will be suitable. This is also advantageous for developing appropriate control algorithms. Based on these geometric relations the kinematic and then the kinetic relations may be derived. From these “drive-equations” the influence of distinct construction parameters on the dynamic behaviour and complexity of control algorithms can be estimated.

The authors have been teaching since 5 years fundamentals of Industrial Robots and Handling Devices for students of Mechanical Engineering, Electrical Engineering as well as Applied Mathematics and Computer Sciences. These fundamentals include mechanics, model building, simulation and control. For the practical education mainly in laboratory courses two personal computers, a little hydraulic driven robot and a hybrid computer system for simulations is available. At a lower level the students solve the kinematic and kinetic equations with the personal computer for different structures of robots. The hybrid computer system is applied for simulations of the controlled robot. The hydraulic driven robot can be controlled by means of a control box with pushbuttons for movements (e.g. up/down, rotate and grip and for start/stop). Another programming possibility for robot movements consists by using a special language which is different for each robot. Both possibilities are little efficient for education at a higher level. Therefore the control box of our robot is replaced by a personal computer for advanced studies. For all laboratory experiments the necessary software packages are written in dialoge form like a CAD system.

Today most of the industrial robots applied in practice are controlled by means of conventional, linear control algorithms which are implemented in the control computer. The development of faster, weight weight robots yields to additional control problems. For this new generation of robots advanced digital control algorithms are necessary and have to be available in the nearest future.

SIND MIT DER LUFTBEWEGUNG WAERMETRANSPORTE VERBUNDEN, KANN KONDENSATION DES IN DER LUFT ENTHALTENEN WASSERDAMPFES EINTRETEN. DIES IST DANN VON BEDEUTUNG, WENN DIE FELSTEMPERATUR VON DER TEMPERATUR DER LUFT WESENTLICH VERSCHIEDEN IST ODER WENN IN DEN BETRACHTETEN RAEUMEN DURCH LEBEWESEN, MASCHINEN ODER FAHRZEUGE WAERME UND/ODER WASSERDAMPF FREIGESETZT WIRD. ES WIRD GEZEIGT, DASS DER MITTLERE JAHRESGANG DER TEMPERATUR DER EINTRETENDEN LUFT IM VEREIN MIT DEM MITTLEREN JAHRESGANG DER BEAUFSCHLAGUNGSMENGE ASYMPTOTISCH ZU EINER ZEITLICH-PERIODISCHEN LOESUNG FUER DIE TEMPERATURVERTEILUNG IM FELS IM NAHBEREICH DES SCHACHTES FUEHRT, DIE DIE URSPRUENGLICH GEOTHERMISCHE TEMPERATURVERTEILUNG IM FELS AUS DIESEM BEREICH VERDRAENGT. ES WURDEN DIE GRUNDLAGEN ZUR BERECHNUNG DIESER TEMPERATURVERTEILUNG UND DAMIT DIE FUER DIE BESTIMMUNG DES DRUCK- UND LEISTUNGSBEDARFES FUER DIESE BEIDEN THERMISCHEN UNTERGRUENDE BEI VERSCHIEDENEN METEOROLOGISCHEN BEDINGUNGEN UND BETRIEBSZUSTAENDEN FUER ZU- UND ABLUFTSCHAECHTE ERARBEITET. DIE NUMERISCHEN AUSWERTUNGEN WERDEN AN BEISPIELEN GEZEIGT, DEREN ERGEBNISSE IN ABBILDUNGEN UND TABELLEN ZUSAMMENGESTELLT UND AUSFUEHRLICH BESPROCHEN (IRRD 700509). (A).