Hans-Joachim Franke

Passive and Adaptive Joints for Parallel Robots

In order to take advantage of parallel kinematic structures, the development of specific and optimized structure components (rods, passive joints) is becoming increasingly necessary. Accordingly, in this chapter the development and implementation of novel joint concepts for parallel structures is discussed. The focus lies on two different joint types: firstly, conventional passive joints and secondly, adaptive joints with integrated piezo-actuators. Based on the specific design methodology, different joint prototypes are developed and tested. By drawing on the test results, it is shown how the novel joints influence performance of the whole robot system.

Adaptronic Revolute Joints for Parallel Robots Based on Simultaneous Quasi-Statical Axial and Radial Clearance Adjustment

Robots based on parallel kinematics feature low moved masses, allowing for better dynamic performance compared to serial mechanisms. Otherwise, the known drawbacks, like occurrence of singularities or bad radio of work space to installation area, hinder their fully industrial establishment. In order to overcome some of these drawbacks, development of specific and optimized robot components, like rods or joints, becomes necessary. Development of joints for parallel robots is determined by numerous contradictory requirements which cause different goal conflicts. In this work, possibilities for dissolving of such goal conflicts by means of adaptronic joints (joints with integrated piezo-actuators) are discussed. To deal with these complex issues this paper focuses on three major areas: firstly, conventional joint concepts, including their main flaws; secondly, new, adaptronic joint concepts based on quasi-statical clearance adjustment with two laboratory prototypes and their improvements over the old solutions; thirdly and finally, some of possible consequences of the new joint concepts for the overall performance of parallel robots. By drawing on experimental results derived from laboratory tests, it is possible to show how implementation of the developed joint prototypes could influence friction characteristic of the whole robot system.Copyright

Design decisions derived from product requirements

An adapted and detailed analysis of product requirements, followed by the generation of a requirement structure seems to be an appropriate way for the early identification of potential solutions and features of solutions within the process of design. This strategy allows the use of information contained in requirements for the different tasks in the process of solving problems: complete clarification of the task, search and assessment of solutions.

Design and Implementation of New Sensors and Their Integration in Joints

Taking full advantage of the structural capabilities of parallel kinematics demands additional machine-oriented control tasks, e.g. self-calibration and workspace monitoring. A promising strategy to simplify the corresponding algorithms is the integration of lightweight angular position sensors in passive joints. Due to the rough environment, contactless working sensors are required. In this section, two different inductive sensors manufactured by means of microtechnology are presented. The incremental sensor consists of microcoils, whose inductance changes during the rotation of a microscale on the joint shaft. The absolute sensor combines a vectorial magnetometer with a permanent magnet changing its magnetic orientation during joint movement.

Knowledge-Based Design Principles and Tools for Parallel Robots

Complex products such as parallel robots need sophisticated management of knowledge and an integrated use of different tools during the whole product development process.

Highly-integrative lightweight car body concept

The car body concept “Functional high integration”, developed within the scope of the joint project of the Volkswagen AG Group Research and the Technical University of Braunschweig, describes a cost-effective integrative lightweight car body. In this paper the approach for laying the new car body structure concerning its stiffness will be explained, along with presenting the component and function integration on the basis of the floor pan components.

Hochintegratives Leichtbau-Karosseriekonzept

Das Karosseriekonzept „Funktionale Hochintegration“, das im Rahmen eines Gemeinschafts-projekts der Volkswagen AG Konzernforschung und der Technischen Universitat Braunschweig entwickelt wurde, beschreibt eine kostenattraktive Leichtbaukarosserie in Integralbauweise. Im vorliegenden Beitrag wird neben der Darstellung der Bauteil- und Funktionsintegration anhand der Bodengruppe weiterhin die Vorgehensweise zur Auslegung der neuen Karosseriestruktur hinsichtlich ihrer Steifigkeit erlautert.

Demand-Driven Development of Parallel Robots with Adaptronic Components by a Modular System

Parallel robots provide high stiffness, accelerations and accuracy. They are relatively complex products that are specialized to a specific problem. Normally a new robot is designed for every new task. This paper shows an approach that makes it possible to configure parallel robots by demand and therefore to use adaptronic components in a reasonable context.

Hilfsmittel zum Auffinden einer ersten Gestalt beim methodischen Konstruieren: Gestaltbeeinflussung durch die Verwendung physikalischer Effekte

ZusammenfassungZiel des Teilvorhabens, über das hier berichtet wird, was es, für eine Auswahl von physikalischen Effekten eine Zuordnung von gestaltbeeinflussenden Merkmalen auf sehr abstrakter Ebene zu erreichen und damit eine nähere Charakterisierung der Wirkflächen und Wirkräume zu erreichen die zur Umsetzung eines physikalischen Effektes notwendig sind. Die hieraus resultierenden Ergebnisse sind dem Abschlußbericht zu entnehmen [1]. Weiterführende Themen, die basierend auf den vorliegenden Erkenntnissen bearbeitet werden, haben zum Ziel, die wesentlichen und entscheidenden Parameter einer Konstruktionsaufgabe zu erkennen und zukünftig zielgerichtet Lösungsvarianten zu erstellen, um somit für eine Neukonstruktion sinnvolle Lösungsfelder sehr frühzeitig abzugrenzen.