Prof. Dr.-Ing. Ludger Overmeyer

Function:
Managing partner & Spokesperson of Management
Phone:
+49 (0)511 279 76-119
E-Mail:
info@iph-hannover.de
vCard:
vCard
ResearchGate:
http://www.researchgate.net/profile/Ludger_Overmeyer

Publications

Automated guided vehicle systems (AGVS) have become indispensable in advanced production facilities. Due to significant progress in the field of automated guided vehicles (AGVs) and the increased automation within production plants, the potential applications for AGVs increase. The design of the roadmap for automated guided vehicle systems is a time-consuming process which is currently performed manually for the most part. Because of the AGVs increasing degree of complexity a manual design of the roadmap becomes more and more difficult and challenging. In the course of the research project “Automatic design of the roadmap for automated guided vehicle systems” (IG 18007) a software demonstrator was developed which allows the automated generation of the roadmaps for AGVS. The software demonstrator was applied to real reference scenarios and it was proven that the automatically generated roadmaps are as reliable as the manually generated ones and in some cases even more efficient.

fuzzy logic, expert system, AGV, roadmap

In this article, image processing of a binary single track code for determining torque is presented. The aim of the research is to determine the absolute angular position of a shaft and the applied torque. For capturing an image of the binary code two independent imaging modules are used, both allowing for measuring the angular position and rotational speed. Combining both imaging modules, torque can be determined. Position markings are directly applied on the shaft using a laser to ensure a simple integration of the system into any application. The selected technological approach is based on a contactless measurement method using angle differences. The concept of image processing as well as first research results are presented for determining the angular position twice and, thus, the torque applied to the shaft.

image processing, single track code, torque

Regarding the handling of complaints by customers, 8D reports are used for analysis and correction of errors that occur in the production process. However, the quality of these reports is often inadequate and leads to longer processing time and errors. Due to time and capacity restrictions in most cases, 8D reports undergo inadequate internal quality testing. Consequently, the aim of optimizing internal processing fails and poor 8D reports with insufficient solutions are sent to the customer. In this paper, we describe problems with faulty 8D reports in detail, and then present a system that automates quality checking of 8D reports based on these facts. This paper focusses on the basic structure of the developed system and how it improves the quality level of 8D reports within the complaint handling process.

complaint, quality management, 8D method, 8D report

In this article, a combined contactless measurement method is presented which is based on angle differences. The aim is the development of a combined, optical measurement system to determine the angular position of a shaft and the applied torque on it as well as an appropriate production technology to apply markings. Two independent modules are used which separately allow the measurement of angular position and rotational speed and if combined can measure torque. To ensure a simple integration of the system into any application, position markings are directly applied on the shaft using a laser. The selected technological approach is based on a contactless measurement method using angle differences. The concept as well as first research results are presented.

absolute angular position, angle difference, contactless combined measurement, sensor, torque

Automated guided vehicles (AGVs) with autonomous behavior and decentralized human-machine interaction (HMI) are suitable for use in logistics. To facilitate natural interaction, HMI may involve both speech and gesture control. This paper presents a new cognitive approach based on electroencephalography (EEG) for multimodal HMI combining speech and gesture control for AGVs used in logistics. The results indicate that implicit EEG-based measures such as alertness and relaxation significantly affect speech control performance. Consequently, monitoring the user's cognitive workload during logistic operations may lead to a substantial improvement in work performance.

logistics, cognitive robotics, electroencephalography

In multistage hot forging processes, the preform shape is the parameter mainly influencing the final forging result. Nevertheless, the design of multistage hot forging processes is still a trial and error process and therefore time-consuming. The quality of developed forging sequences strongly depends on the engineer's experience. To overcome these obstacles, this paper presents an algorithm for solving the multi-objective optimization problem when designing preforms. Cross wedge rolled (CWR) preforms were chosen as subject of investigation. An evolutionary algorithm is introduced to optimize the preform shape taking into account the mass distribution of the final part, the preform volume and the shape complexity. The developed algorithm is tested using a connecting rod as a demonstration part. Based on finite element analysis, the implemented fitness function is evaluated, and thus the progressive optimization can be traced.

preforming optimization, hot forging, evolutionary algorithms, cross wedge rolling

In today's production and logistics systems automated guided vehicle systems (AGVS) play a central role for the Realization of a powerful internal material transport. Through the use of cognitive technologies industiral trucks should be enabled, similar to humans, to respond flexibly to changes in physical environment and organizational changes in the workflow. This creates interactive AGV, which are superior to currently available conventional AGV because they can adapt their behavior independently and flexibly to changing production environments and requirements. As part of this the current high implementation effort for AGVS can be reduced at the same time.

AGVS, gesture control, voice control

Automated guided vehicle systems (AGVS) are an example of high-performance production systems in intralogistics and in many areas of internal material transportation. The essential function of an AGVS is the automatic control of automated guided vehicles (AGVs) which can be equipped with application-specific load handling devices ( e. g., telescopic forks or lift tables). Therefore an AGV is used in different application fields such as pallet transport, installation or commissioning. In this project, a speech and gesture control and autonomous navigation for AGV are implemented.

AGV, speech control, gesture control, autonoumous navigation

Automated guided vehicles (AGVs) with autonomous behavior and decentralized human-machine interaction (HMI) are suitable for use in logistics. To facilitate natural interaction, HMI may involve both speech and gesture control. This paper presents a new cognitive approach based on electroencephalography (EEG) for multimodal HMI combining speech and gesture control for AGVs used in logistics. The results indicate that implicit EEG-based measures such as alertness and relaxation significantly affect speech control performance. Consequently, monitoring the user's cognitive workload during logistic operations may lead to a substantial improvement in work performance.

logistics, cognitive robotics, electroencephalography

Within the research project "Situational behavior control for interactive, automated guided vehicles" a voice and gesture-based control concept was developed and implemented on an automated forklift truck. Based on an industrial application the economic value of this system is to be reviewed in the context of a material flow simulation.

gesture control, speech control, automated guided vehicles

Within this article a decentrally controlled, intelligent material flow system is presented. The novel product routing is based on a decentralized intelligence and conducts the route planning of the individual materials. The decentralized intelligence permits an expansion or adaption of the production line at any time without significant configuration. In addition, the networked decentralized intelligence allows a parallel flow of material and information, and an identification of the layout of the entire conveyor system. Another core element is the decision-making cognitive conveyor, which is composed of small-scale conveyor modules. In addition to transporting, injecting and ejecting a variety of intralogistics functions can be solved with the cooperation of these conveyor modules. For this cognitive conveyor a drive solution is presented that meets the requirements in terms of functionality and compactness.

Decentralized Intelligence, Material Flow, Cognitive Conveyor, ProductionML, Routing

In this article a small scale, cyber-physical conveyor system using the example of a cognitive conveyor is presented. This cognitive conveyor is modularly assembled of individual conveyor modules that are smaller than the transported units. Furthermore the cognitive conveyor is in the position to handle different intralogistical functions such as transport unit's transporting, rotating, buffering and sequencing. Parallel to the route of the physical transport unit, a data shadow is moved: Hereby all data describing the transport operation are available at any time of transport. Cognitive conveyor's control is decentralized and distributed. Hereinafter both the hardware setup of the conveyor modules and the necessary control algorithms are described. The control algorithms are on the one hand used to move the physical transport unit on the surface of the cognitive conveyor. On the other hand it is utilized to align the data shadow with physical transport unit's information.

cyber-physical conveyor technology, decentralized control, material flow, ProductionML

The condition-based maintenance of a marine gearbox poses special challenges because of the inaccessibility to the hull of the ship and harsh environment in the form of higher temperatures, continuous vibrations and salty sea air, which can lead to corrosion. In this article, the integration of a wireless sensor network with a marine gearbox is shown. The integration consists of sensor nodes that record characteristic measurement data, send them actively to a receiving unit and harvest energy from the environment for electrical supply after a one-time installation expenditure. The developed sensor node has a thermoelectric power supply that allows measurement intervals of less than 20 minutes. The recorded vibration data from the gearbox surface are sent via ZigBee wireless technology. By evaluating the envelope spectrum of the measured vibration data, the current rotational speed of the input drive shaft could be identified.

energy harvesting, thermoelectric generator, wireless sensor network, condition monitoring

This article shows how the known human capabilities for flexibility and adaptation to changing environmental conditions, which are reflected in the cognitive characteristics of people, can be transferred to forklift trucks in intralogistics. As examples for the implementation of Industry 4.0 in intralogistics, technologies are introduced that allow forklift trucks to recognize their surroundings, to communicate information, to conclude and therefore act autonomously, to make decisions, to learn or to plan. These capabilities are realized by an optical positioning system, a camera-based storage and retrieval support system, tire integrated sensors and new interaction concepts for forklift trucks in the form of speech and gesture.

forklift truck, gesture control, speech control, 3D-camera, optical positioning system

Many companies can or must reduce energy consumption in their production. The Institut für Integrierte Produktion Hannover (IPH) has developed procedures and a formula with which companies can improve the energy balance. At the same time the quality of products can be increased by this approach.

process management software, quality costs, reliability engineering

Automated guided vehicles (AGV) are very common in modern production environments nowadays. The planning of roadmaps for the vehicles is still a very time consuming task that includes different optimization goals (e.g. shortest path, collision avoidance, maximizing of the free space). Depending on the scenario different optimization goals have different priorities. The weighting of the goals depends on the experience and judgement of the experts. Automated approaches in form of path planning algorithms give results that are mathematically correct but aren’t applicable in reality. This paper presents an expert system that automatically generates roadmaps for AGVs. The aim is to generate road maps that are both efficient and applicable. For this purpose common path planning algorithms (Lee and A*), that are able to generate mathematical efficient road maps, are combined with expert knowledge in the form of fuzzy logic. The results of the expert system are evaluated using real layouts and are compared to manual generated road maps.

Road map, automated guided vehicles, A*, path planning

In the presented article, the initial situation, which leads to the development of a small-scaled cyber physical material handling system, is presented first. Therefore, apart from the general requirements of material handling systems, the reasons for a determination of new requirements are presented as well. Since the developed system consists of multiple decentralized controlled conveyor elements, the data transmission principle inside the system will be described.

cyber physical material handling system, data transmission, decentralized controlled, conveyor

This paper is concerned to technology trends in logistics and shows a user interface which is focused on voice commands for using it with automated guided vehicles (AGV). Furthermore a multimodal human-machine interaction (HMI) will be presented, which gives the user the possibility to communicate and control an AGV due to information from a speech recognition system and an electroencephalograph (EEG). It will be shown which potentials based on the merging between the acoustical voice signals and the non-invasive recording of the brainwaves from the EEG-Headset are available. By the detection of the cognitive and emotional state of the user from the signal curves by the EEG like attention or mental effort, an intelligent HMI should be realized. As a result, dialogues between humans and machines could be used more efficient and wrong inputs, like for example the request for a reconfirmation if an inattention is detected, could be reduced. First perceptions will be shown in this paper. In conclusion there will be a prospect of upcoming studies in the future.

driverless transport systems, driverless transport vehicles, voice control, eeg

This article presents a solution for the thermoelectric power supply of wireless sensor nodes for condition monitoring of marine gearboxes. Among the different ambient energy sources in marine gearboxes, frictional heat has been identified to be appropriate to thermally power a thermoelectric generator (TEG). The such generated electricity may power wireless sensor nodes for detecting temperature, vibration, torque and rotational speed. Requirements for a corresponding energy supply are formulated, constructive solutions are presented and thermal simulations and practical experiments are reviewed. The results are evaluated and a solution is selected for further implementation, which provides for an actively cooled TEG in the area of the ship gearbox’s heat exchanger. This can provide continuous electrical power of up to 14 mW, thus supplying the planned sensor nodes. The disadvantage of this solution is that a comparatively extensive mechanical modification, for example, to the oil and cooling water pipelines is required.

energy harvesting, thermoelectric generator, wireless sensor nodes, thermal simulation, condition mo

The method of injection molding is one of the most important processes in the processing of plastics. Thus moldings can be produced economically in large quantities and with a high reproducibility. Besides quality the energy consumption in the production is an important part because of the energy transition and the rising energy prices. In particular, small and medium enterprises from the plastics processing industry in Germany with about 3,000 companies are, therefore, forced to optimize their processes and production equipment energetically.

injection molding, plastics processing, energy optimization, parameter optimization, energy model