Prof. Dr.-Ing. Ludger Overmeyer

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

Publications

Abstract: For factory planning projects the layout capturing and layout processing process need a huge amount of effort, because they are typically done by hand. These processes could be accelerated and optimized by using a drone and automated analysis algorithms. Furthermore, this article shows a way to raise the digitization level for industrial processes. The key aspect lies on the usage of a drone in indoor environment and the processing of three-dimensional point cloud models for factory planning processes.

drone, factory planning, 3D-factory layout, object recognition

In this paper, the validation of an inductive sensor for an energy self-sufficient sensor for condition monitoring of wet-running steel disc clutches in marine gearboxes is presented. For a reliable operation of these a permanent monitoring of their state is advisable. As part of condition-based maintenance, more and more sensors are being installed in machines. Reliability becomes even more important when people are endangered by possible failure of the machines. In shipping, it is essential that, for example, the powertrain and thus the transmission are in perfect condition. In case of long distance traveling, wear or even damage of important components has to be known so that maintenance can be carried out proactively. To address this need an energy self-sufficient and wireless sensor network is developed. Miniaturized sensor nodes monitor torque, rotational speeds, temperatures as well as the wear condition of the torque transmitting components. The energy needed to operate these sensors is obtained from the surrounding environment. Thus, the system operates wirelessly and without an external energy supply, whereby the installation and maintenance costs decrease significantly. In addition to the concept of sensor integration in the transmission, the energy harvesting concept is also described in more detail. Finally, measurements are taken in a gear-like environment and the behavior of a magnetoinductive sensor in a not constantly supplied situation has been examined.

ship, gearbox, wear, sensor, torque

This paper describes the development and prototypical implementation of an energy self-sufficient sensor for condition monitoring of wet-running steel disc clutches in marine gearboxes. For the precise control of an automated system and the monitoring of its performance, the knowledge about the possible wear is an essential prerequisite. In addition, the storage of sensor data over the life of the system offers the possibility of long-term condition monitoring. The combination with various other technological components creates a solution that enables cost-effective condition monitoring of marine gearboxes. Compared to existing systems, for example, the costs for installation and maintenance are significantly reduced. Both the methodology from the morphological box to the fine concept as well as the first measurements of the sensors are presented.

automated system, condition monitoring, metrology, clutch, gearbox

Structured factory planning is a key to ensure the competitiveness concerning to the increasing pressure from globalization and the high market dynamic. Companies though avoid to do factory planning projects, because of the high effort. For this reason, the processes of factory layout capture and factory layout assessment are in need of improvement in order to increase the efficiency, which will be achieved through new technologies and a semi automation of the processes.

factory planning, drone, photgrammetry, laserscan, image data processing

Black marking as micrometer scaled binary coding applied on shafts by ultrashort pulsed lasers with high contrast and without ablation as a non-contact sensor system for combined measurement of angular position and torque.

laser materials processing, sensors, absorption, image analysis

The measurement of the absolute rotational angle and torque via sensors forms the basis for many industrial sectors. Until now, combined sensors have not been available, so that a lot of installation space is occupied by sensor setups. In addition, the sensor setups get expensive quickly. Therefore, an optical and non-contact measurement method to detect the absolute angle of rotation and torque was developed. This paper presents the validation methodology, the setup of the test bench and the validation results. With an angular resolution of 0.001 degree and an accuracy of more than 0.05 percent, the results are promising. However, for industrial application further investigations on determining torque and miniaturizing the optical setup are required.

absolute angular position, angle difference, sensor, torque

This paper describes the production process of serially arranged hybrid steel parts, produced by combining a laser welding process with a subsequent cross wedge rolling process. The presented results are only a first approach in order to get first insights in the forming behaviour of laser welded and cross wedge rolled parts. The investigated material combination is C22 (1.0402) and 20MnCr5 (1.7147). This innovative process chain enables the production of hybrid parts. To evaluate the developed process chain, the weld and the joining zone is analysed before and after cross wedge rolling. Main results are that the joining process using laser welding enables a strong bonding between the two materials with a higher hardness in the joining zone than for the individual materials. After the forming process, the bonding of the joining zone is still present, while the hardness decreased but remains higher than of the materials themselves.

tailored forming, laser welding, hybrid parts, cross wedge rolling

An essential component of belt conveyor systems are the support idlers. Particularly in bulk material handling systems, which are used in demanding terrain with numerous gradients as well as under extreme environmental conditions in tropical and arctic regions, they are exposed to considerable stress. The steadily growing flow rates mean higher loads and speeds for the support idlers. This trend is countered by new drive concepts. For example, belt-driven conveyor systems with internally installed motors are used.

Within a research project, the IPH is developing a dual measuring system that can be used to test both conventional bearing rollers and driven bearing rollers.

driven idlers, test rig, efficiency of conveying systems

The measurement of torque via sensors as well as the generation of torque form the basis of many industrial sectors. Within a research project an optical and non-contact measurement method to detect the absolute rotation angle and torque was developed. For comparison with the current state of the art torque sensors a test stand was built and compared to a reference torque sensor. The results of this validation are presented in the present paper.

torque, rotation angle, optical, validation

In order to improve the overall efficiency of production facilities through the use of automated guided vehicle systems (AGVs), the availability of the AGVs has to be high. Failures of AGVs have to be minimized. However, if a failure occurs, a successful disturbance management is crucial. Especially for producing companies, economic losses can occur, if material is not at the right place at the right time. Delays can be a hazard to the adherence to delivery dates. In this research project, a support system is developed that automatically generates strategies for the handling of disturbances.

AGV, expert system, automated guided vehicles, case-based reasoning, CBR

A combined measurement method for the optical determination of the absolute rotational angle and torque was realized. Absolute codings of the angle as well as proper production technologies for the production of suitable markings on the shaft were investigated and successfully implemented.

The absolute rotational angle could be measured with a resolution of about 0.001° at an accuracy of better than 0.2° (corresponds to 0.05% f. s.). Torque was determined with an accuracy of about 3% f. s..

The conclusion is that the overall aim was achieved.

optical measurement, torque, absolute angle of rotation

This paper proposes a method for the automated generation of roadmaps for AGVs. So far the roadmaps are mostly generated manually, which leads to long and laborious planning phases. The presented method incorporates both mathematical roadmap algorithms as well as human knowledge in the form of a fuzzy inference system. The results of the expert system are evaluated in comparisons to the A* algorithm and to manually generated roadmaps on a real production layout. In both cases the expert system performs better.

fuzzy logic, expert system, AGV, roadmap

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