J. Ottnad

Upper Body of a new Humanoid Robot - the Design of ARMAR III

The development of a humanoid robot platform within the scope of the collaborative research centre 588 has the objective of creating a machine that closely cooperates with humans. This development area presents a new challenge to designers. In contrast to industrial robots - for which mechanical rigidity, precision and high velocities are primary requirements - the key aspects here are prevention of hazards to users, a motion space that corresponds to that of human beings and a lightweight design. In order to meet these requirements, the robot must have humanlike appearance, motion space and dexterity. Additionally, its kinematics should be familiar to the user, its motions predictable, so as to encourage inexperienced persons to interact with the machine. This article gives insight into the design of the mechatronic components of the upper body of the humanoid robot ARMAR III. Due to the special boundary conditions for the design of such a humanoid robot and complex interaction between system elements, the design process is very challenging. The robot has a modular structure. The modules for neck, torso and arms were designed and built at the Institute of Product Development (IPEK) at the University of Karlsruhe (TH). The design of these modules of the upper body and the problems solved by these designs are presented in this article

Integrated Structural and Controller Optimization in Dynamic Mechatronic Systems

In order to take into account the interaction between the part, dynamic system, control system, and changing mechanical behavior with all its consequences for the optimization process, a simulation of the complete mechatronic system is integrated into the optimization process within the research work presented in this paper. A hybrid multibody system (MBS) simulation, that is a MBS containing flexible bodies, in conjunction with a cosimulation of the control system represented by tools of the computer aided control engineering, is integrated into the optimization process. By an inner optimization loop the controller parameters are adopted new in each of the iterations of the topology optimization in order to provide realistic load cases. The benefits will be illustrated by an example in conjunction with the humanoid robot ARMAR III of the Collaborative Research Centre 588 “Humanoid Robots-Learning and Cooperating Multimodal Robots” in Karlsruhe Germany. It will be shown how the new approach for the optimization of parts “within” their surrounding mechatronic system allows an efficient optimization of such structures.

Methods for lightweight design of mechanical components in humanoid robots

With the development of humanoid robots, lightweight construction and energy efficiency play an important role as these mobile, dynamic systems have to work self-sufficiently. The application of computer-aided (CAE) methods in the development process is one possibility to achieve the required weight reduction. On the basis of a classical topology optimization carried out on the robot ARMAR III, an extended system-based method for dynamic, mechatronic systems is presented. Different analysis domains, namely hybrid multibody system dynamics (MBS), finite element analysis (FEA), control system simulation and topology optimization are integrated into a straightforward, automatic way. For the use of fiber reinforced composite materials in such parts, a FE-based method for the determination of ply orientations and thickness relations is presented.

Design of Modules and Components for Humanoid Robots

The development of a humanoid robot in the collaborative research centre 588 has the objective of creating a machine that closely cooperates with humans. The collaborative research centre 588 (SFB588) “Humanoid Robots – learning and cooperating multi-modal robots” was established by the German Research Foundation (DFG) in Karlsruhe in May 2000. The SFB588 is a cooperation of the University of Karlsruhe, the Forschungszentrum Karlsruhe (FZK), the Research Center for Information Technologies (FZI) and the Fraunhofer Institute for Information and Data Processing (IITB) in Karlsruhe. In this project, scientists from different academic fields develop concepts, methods and concrete mechatronic components and integrate them into a humanoid robot that can share its working space with humans. The long-term target is the interactive cooperation of robots and humans in complex environments and situations. For communication with the robot, humans should be able to use natural communication channels like speech, touch or gestures. The demonstration scenario chosen in this project is a household robot for various tasks in the kitchen. Humanoid robots are still a young technology with many research challenges. Only few humanoid robots are currently commercially available, often at high costs. Physical prototypes of robots are needed to investigate the complex interactions between robots and humans and to integrate and validate research results from the different research fields involved in humanoid robotics. The development of a humanoid robot platform according to a special target system at the beginning of a research project is often considered a time consuming hindrance. In this article a process for the efficient design of humanoid robot systems is presented. The goal of this process is to minimize the development time for new humanoid robot platforms by including the experience and knowledge gained in the development of humanoid robot components in the collaborative research centre 588. Weight and stiffness of robot components have a significant influence on energy efficiency, operating time, safety for users and the dynamic behaviour of the system in general. The finite element based method of topology optimization gives designers the possibility to develop structural components efficiently according to specified loads and boundary conditions without having to rely on coarse calculations, experience or

Integrated structural and controller optimization for lightweight robot design

With the development of humanoid robots, lightweight construction and energy efficiency play an important role. In state-of-the-art processes and methods concerning structural optimization it is assumed that there exists a set of external loads or load functions acting on the part. But humanoid robots are very complex mechatronic systems. The fact that the systems dynamic properties and its overall behavior may change due to geometric modifications of a part caused by an optimization process is typically neglected. In order to take into account the interaction between the part, dynamic system, control system and the changing mechanical behavior with all its consequences for the optimization process, a simulation of the complete mechatronic system is integrated into the optimization process within the research work presented in this paper. A hybrid multibody system (MBS) simulation, that is, a MBS containing flexible bodies, in conjunction with a co-simulation of the control system represented by tools of the Computer Aided Control Engineering (CACE) is integrated into the optimization process. By an inner optimization loop the controller parameter are adopted new in each iteration of the topology optimization in order to provide realistic load cases. The research work presented in this paper is a contribution towards the integration of existing CAE methods into a continuous process for structural optimization. The benefits will be illustrated by an optimization of parts of the humanoid robot ARMAR of the collaborative research centre for “Humanoid Robots”. The new process allows an efficient optimization of structures “within” their surrounding mechatronic system.

Stability maintenance of a humanoid robot under disturbance with fictitious zero-moment point (FZMP)

The goal of the project SFB588 supported by the Deutsche Forschungs-gemeinschaft (DFG) is to generate concepts, methods and a concrete prototype of a humanoid robot. The intended application area is, for instance, a generic kitchen, where the robot is planed to perform actions autonomously at the users request. In this paper, a model of stable analysis of a humanoid robot is given, in which the different environments are considered. By introducing a concept of fictitious zero-moment (FZMP), a method to maintain the whole body stability of robot under disturbance is presented. The support polygon and the rotation edge in the case of losing balance are determined by means of simulation. In order to maintain stability in different environments a new control strategy is presented including the adjustment of the support polygon, the push or pull support of hand with environment, the movement of upper robot body. The relative position between FZMP and support polygon is specially emphasized. The feasibility of the proposed method is demonstrated through the simulation.

Development of a new wrist for the next generation of the humanoid robot ARMAR

The development of a humanoid robot within the scope of the collaborative research centre 588 has the objective of creating a machine that can closely cooperate with humans. This development area presents new challenges for designers. In contrast to industrial robots - for which mechanical rigidity, precision and high velocities are primary requirements - the key aspects here are prevention of hazards to users, a motion space that corresponds to that of human beings, and a lightweight design. In order to meet these requirements, the robot must have humanlike appearance, motion space, and dexterity. Additionally, its kinematics should be familiar to the user, and its motions predictable, so as to encourage inexperienced persons to interact with the machine. This article gives insight into the design of a new wrist for the next generation of the humanoid robot ARMAR. The goals of the development project are both to improve the motion space and to achieve a humanlike appearance. The new mechanical design is described in detail completed by a study of a first prototype.

System based topology optimization as development tools for lightweight components in humanoid robots

With the development of humanoid robots, lightweight construction and energy efficiency play an important role as these mobile, dynamic systems have to work self-sufficiently. In state-of-the-art processes and methods concerning structural optimization it is assumed that there exists a set of external loads or load functions acting on the part. But humanoid robots are very complex mechatronic systems. The fact that the systempsilas dynamic properties and its overall behavior may change due to geometric modifications of a part caused by an optimization process is typically neglected. In order to take into account the interaction between the part, dynamic system, control system and the changing mechanical behavior with all its consequences for the optimization process, a simulation of the complete mechatronic system is integrated into the optimization process within the research work presented in this paper. A hybrid multibody system (MBS) simulation, that is, a MBS containing flexible bodies, in conjunction with a co-simulation of the control system represented by tools of the computer aided control engineering (CACE) is integrated into the optimization process. The benefits will be illustrated by an optimization of parts of the humanoid robot ARMAR of the collaborative research centre for ldquoHumanoid Robotsrdquo. Especially the optimization of two parts at a time within one optimization loop allows an efficient optimization of structures ldquowithinrdquo their surrounding mechatronic system.

Academic Engineering Design Education in a Realistic Environment

The objective of academic education for mechanical design engineers is to convey qualifications which are necessary for product development in an industrial environment. The goal of the work described here is to improve engineering design education and to provide a more active learning experience. Design students should be familiarized with modern methods and technologies which they will most likely encounter during their future career. Design cannot be taught sufficiently in lectures alone [1, 2] and requirements on graduates in product development are continuously increasing. Not only professional skills but also social skills as well as proficiency with new technologies and methodologies become increasingly important [3]. For meeting these requirements the Karlsruhe Education Model for Product Development (KaLeP) [4] was developed at the Institute of Product Development (IPEK) at the University of Karlsruhe in Germany. In this contribution we present KaLeP, the role of modern design tools like CAD/PDM and wikis in education, the course projects for Machine Design and Integrated Product Development including training concept as well as the technical and organizational environment in which these courses take place.Copyright

Managing complex simulation processes: the generalised contact and channel model

Today, usage of simulation tools is a common practice in many fields of product development. Performance and complexity of modern simulation tools and methods increased steadily throughout the past years. Concurrently, the selection of an appropriate simulation process became more and more challenging. As this task is of main importance for a successful application in product development, the Contact and Channel Model (C&CM) is extended towards a more generalised approach now including also processes and their interfaces. For the first time, the C&CM has been implemented in a standardised software solution that may be used within modern product development.