Applied Mechanics and Materials Vol. 840

Abstract: In order to adapt to the mass customization, a new concept of material flow systems that can handle product varieties is needed. Firstly, this paper analyzes the current problems and future requirements of the structure of a new production system. Then, in response to current limitations, the corresponding concept of a decentralized transport system for low payloads with high flexibility is introduced. For this purpose, automated guided vehicles (AGVs) as an effective means of transport are used. The key issues of the autonomous transport system are then researched, and an improvement of the multiple object tracking algorithm is proposed. We demonstrate the performance of our proposed system with a designed workspace. Based on the demonstration and experiment, results show that the proposed concept and the tracking algorithm are appropriate and robust to be implemented in real-time applications.

Abstract: Rising prices and political conditions are increasing the pressure on manufacturers to increase their energy efficiency. While measures for energy intensive processes such as heating or material transformation have been researched in large number in the last year, less effort has been put into the area of robot-based operations. In contrast to that, large potentials can be expected by optimizing the load-to-weight ratio in pick-and-place or assembly tasks. This paper thus researches the energy efficiency potentials of three robot concepts. The standard serial unit is compared to a parallel robot and a hybrid approach between the two, the PARAGRIP. In addition to a review of the current state of the art, a simulation is presented demonstrating saving potentials of more than 40 per cent in an industrial application scenario.

Abstract: Even though modern industrial robots have good repeatabilities, their positioning accuracies are still relatively poor. Moreover, in a complex process chain, involving several handling systems and diverse interdependent tasks, error propagation can make matters worse. In order to achieve the overall desired quality level, intelligent and highly adaptive methods are required to reduce individual errors and remove accuracy couplings as much as possible. This is especially true in high-risk applications, as found in the aviation MRO industry. Because of the difficulty to replicate existing manual MRO accuracy levels, automation in this area is still relatively scarce. For instance the inspection and repair of airplane combustion chamber liners are as yet performed fully manually. In this paper an automated version of the entire liner repair chain is introduced: from robot-guided white light interferometer inspection in a first cell, to part and data transfer to a second robot cell through to the automated repair steps. Particular consideration is given to individual error sources, such as robot and sensor inaccuracies, calibration deviations and the transfer of data between robot cells, as well as error propagation and prevention.

Abstract: To respond to challenges created by an increase of product variants, multi-variant lines are used as today’s assembly systems. In these multi-variant lines different product variants with diverse lot sizes can be efficiently assembled. These assembly systems are characterized by modular structures that allow assembly system adaptation by reconfiguration.The variety of parameters to be considered from the product’s perspective and the correct allocation of different assembly modules increases the complexity when planning these systems. This complexity makes it difficult to successfully plan and implement production processes. Therefore, digital planning tools and models have to be used to schedule new product variants and to verify that the assembly is possible, given by the modules in the assembly line.Due to its ability to reconfigure, the actual assembly system is adaptable to different product variants. But these modifications are performed by the operator on the shop floor and are often neither properly documented nor communicated to the assembly planer. Thus, the configuration status in reality and the virtual model differ from each other. Using the outdated model for planning without taking into account the changes can result in an unrealizable assembly plan.To overcome this problem, the presented paper introduces a method and technical system to identify the actual assembly system configuration before the assembly planning is done. Due to the subsequent update of the virtual model depending on the actual configuration, the assembly planner is supported with the latest version of the assembly system configuration. Furthermore, the assembly planning process is improved, because possible failures are detected in advance in the virtual planning environment.

Abstract: This paper describes the concept and implementation of a hybrid programming method for robots, which absolves working people from the specific expertise that is required for the conventional programming of robots. The method is based on a provided path point, which is presented by laser projection. The projected path points are detected and approached by the robot. By linking the path points and entering the path and transfer parameters on a tablet computer the path is programmed in a simple and easy understandable way. Afterwards the path can be executed and the produced robot program can get exported. In this way, not only the circle of people who can program a robot will be extended, but also the safety of the people improves because nobody has to stay in the immediate vicinity of the robot, while programming it.

Abstract: Actual robot systems are typically used within an industrial environment, where they perform tasks in the areas of manufacturing, assembly, or inspection. Many of these tasks require the definition and execution of sensor-based motions. Such motions are typically defined using a subsymbolic representation like manipulation primitive nets [1] or iTaSC [2]. These representations are only suitable for experts in the domain of robotics because they require the definition of low-level parameters like setpoints, control strategies, or task frames. Since the application domains of robot systems shall be extended to SMEs or private households, existing representations lack in an intuitive interface for users without expert knowledge in the area of robotics. In this work, we describe an intuitive interface for the definition of sensor-based actions. Our approach is based on manipulation primitive nets and consists of a transformation between the subsymbolic manipulation primitive nets and a symbolic user interface, described by a domain specific language.

Abstract: The digital progress monitoring of manual assembly processes at goods with huge dimensions is a challenging task. The paper presents an approach using 3D-image sensors for gesture control and progress recognition. The developed system is able to avoid time and effort consuming walks of workers between assembly objects and computer terminals. Progress recognition of assembly processes is realized by interpreting the movements of the workers’ hands and by detecting the passing of defined coordinates within the assembly and warehouse areas.

Abstract: The assembly of large components is characterized by manual processes and customer-specified products. These are just two of the challenges for the efficient automation of assembly processes. In the field of large component assembly, the goal is to synchronize between the handling system and the moving work piece placed on an unguided transport system. One approach to solve this problem is a direct reference between the product and the assembled work piece. This referencing is done by using a global reference system in which every handling system can be referenced to every work piece throughout the whole production line. This article will show the first results using a global reference to track large components on an unguided conveyor. Moreover, it investigates the question if the metrology system, which was used here, is able to detect even small position deviations on higher frequencies.

Abstract: The production and processing of fiber-reinforced plastics (FRP) is constantly increasing in industry. A commonly used method is resin transfer molding (RTM). FRP components are produced for large series by now. Therefore, the aspect of processing efficiency is becoming more and more important. The semi-finished product can be better exploited, for example, if large preforms were composed of single subpreforms. These subpreforms are easier to drape and can be produced within an automated line. Consequently, the necessary assembly of the subpreforms needs to be automated as well. This way, the process can be made time and resource efficient. The article that follows now will focus more closely on a concept that deals with the handling and subsequent assembling of subpreforms. Furthermore, the variables that can be adjusted for the assembly process are examined and their influence on the resulting connection quality is shown.

Abstract: The utilization of simulation capabilities in the development process of robotic systems is already known as one standard procedure for predicting complex system behavior in a time- and cost efficient manner. eRobotics join multiple process simulation components to build "Virtual Testbeds" to provide a comprehensive tool chain and thus a holistic development. VTB may represent "mental models" of robotic systems and their environment. Therefore, they allow the development of control schemes and directly transfer simulation results for Simulation-based Control for implementing intelligent robot controls. Using Simulation-based Support, the VTBs support the ease of use of robotic systems and also the operators in their decisions. Offering an additional abstraction layer for the user, virtual representations of the robot and its environment are used to intuitively control and maneuver intelligent robotic systems. Thus, Simulation-based Control and Simulation-based Support complement each other and are promising development tools for robotic systems, individual parts thereof as well as systems in their entirety. In our contribution, we present the concepts of SbC and SbS in more detail, by examples of several complex robotic systems such as a Motion Simulator, lightweight robots and a mobile Centaur-like teleoperated robot.