Rüdiger Hornfeck

Lean Information Management of Manual Assembly Processes: Creating IT-Based Information Systems for Assembly Staff Simultaneous to the Product Engineering Process

T-based work instruction systems help to transfer the diversity of information for workers in an effective manner. In this way, the worker is supported in the comprehension of the task, which leads to such systems receiving increased recognition from manufacturing companies. However, the currently available worker information systems make no statement about how to involve their information processing early in the development process. Because to this, the basic idea of simultaneous engineering could be feasible and a partially automated, timely and cost-effective processing of assembly relevant information could occur. The approach of the development process-oriented, computer integrated documentation and visualisation process for assembly processes (CIV process) consider this problem field and add an innovative contribution.

Worker information system to support during complex and exhausting assembly of high-voltage harness

There are a lot of different kinds of electric drives and each category has a different installation position within a vehicle. A huge number of variants pose a challenge for manual assembly as the varying constellations of high-voltage (HV) cables require individual assembly steps. A worker needs information both about a vehicle and about HV components with their properties. We obtained good results for this on base of a worker information system (WIS). We can visualize parts assembly using three-dimensional (3-D) objects. The results of hazard analysis are shown in text format. But a WIS lacks in representing the physical behavior of parts within assembly. Especially HV cables move in an undetermined way when they are handled. We have an approach to simulate HV cables within assembly simulation. The material properties of HV cables during distortion are calculated in a finite element analysis (FEA). These parameters flow into an assembly simulation containing flexible parts like HV cables and a digital human model. The results of simulation runs can not only be used for assembly planning but also for worker guidance. We present an approach how to qualify simulation results for import to a WIS. In addition, possible application scenarios for such a WIS are explained.

Biomimetic Spider Leg Joints: A Review from Biomechanical Research to Compliant Robotic Actuators

Due to their inherent compliance, soft actuated joints are becoming increasingly important for robotic applications, especially when human-robot-interactions are expected. Several of these flexible actuators are inspired by biological models. One perfect showpiece for biomimetic robots is the spider leg, because it combines lightweight design and graceful movements with powerful and dynamic actuation. Building on this motivation, the review article focuses on compliant robotic joints inspired by the function principle of the spider leg. The mechanism is introduced by an overview of existing biological and biomechanical research. Thereupon a classification of robots that are bio-inspired by spider joints is presented. Based on this, the biomimetic robot applications referring to the spider principle are identified and discussed.

Static modeling of antagonistic pneumatic actuator for robotic applications

The biological of spider legs inspired the development of a biomimetic pneumatic actuator for robotic applications. The concept is to straighten the joint by pressurizing the interior of an exoskeleton to inflate a bellows-like flexible membrane. The flexion is initiated by contraction of a McKibben-type muscle, which is integrated in the exoskeleton chamber. A detailed mathematical model to operate these antagonistic joint actuators is presented. Feasible torque and angle characteristics of the actuator depending on the input pressures are also presented and control strategies are discussed.

Investigating Ergonomics in the Context of Human-Robot Collaboration as a Sociotechnical System

In this publication, we investigate how the term ergonomics could be defined for human-robot collaboration (HRC) as a sociotechnical system (STS). Thus, we compare different definitions of ergonomics and human factors and conclude on a definition suggested for adoption. Moreover, we compile a list of human factors relevant to that context. We conducted this investigation, because HRC is mainly viewed from a technical viewpoint, although the implications of human involvement should not be underestimated. However, ergonomic evaluation of HRC is based on old methods. The main purpose of this publication is therefore to contribute to a foundation for new ergonomic evaluation methods.

Optimized Leg Proportion to Enhance Rough Terrain Mobility of a Biomimetic Walking Robot.

A new approach on the optimization of leg proportions for a biomimetic walking robot is presented in this paper. The main focus is on optimizing robot leg proportions through evaluation of different parameters. These include the workspace volume, circular and spherical radius of movement and the angular variation at the leg endpoint with predefined workspaces of the joints in compliance to biological analogies. Therefore mathematical dependencies are considered separately and finally combined to one value indicating the performance level.