Alexander Verl

A generic energy consumption model for decision making and energy efficiency optimisation in manufacturing

Today, energy efficiency in production systems has partially been achieved on the component level, but methods are missing for the energy optimal operation of plants, machines and components. We therefore, propose a novel generic method to model the energy consumption behaviour of machines and plants based on a statistical discrete event formulation. It is lean, integrative and scalable and can be used directly in planning processes to make predictions of the energy consumption of different configurations in different scenarios based on any amount of available information. Using the modelling framework, we introduce applications in real-time, tactical and strategic decision making processes that make it possible to exploit the potential for energy consumption minimisation of any given machine or production system while obeying conflicting general conditions.

Care-O-bot ® 3 - creating a product vision for service robot applications by integrating design and technology

This paper introduces Care-O-bot® 3, a highly integrated and compact service robot with manipulation, navigation and vision capabilities. In particular, Care-O-bot® 3 combines the best of available technology including a 7 DOF light-weight arm, an omnidirectional platform and many high-end sensors along with a sustainable, end user oriented design concept enabling many interaction possibilities.

The Bionic Handling Assistant: a success story of additive manufacturing

Purpose – This review will describe the development of the Bionic Handling Assistant as well as the additive manufacturing (AM) process of robot grippers and its possibilities.Design/methodology/approach – AM offers the chance to use the additive processes to produce highly flexible automation parts and systems as the Bionic Handling Assistant in small and medium quantities that can utilize a lot of design advantages provided by the process.Findings – A lot of products of today and especially tomorrow could be produced by rapid manufacturing. New categories of products, such as the Bionic Handling Assistant, will occur.Originality/value – In the paper, aspects of a visionary scenario for future productions are shown and demonstrated on the Bionic Handling Assistant.

IPAnema: A family of Cable-Driven Parallel Robots for Industrial Applications

Nowadays there are very little robot systems in operation in the field of medium to large-scale handling and assembly mostly due to lack of repetitive processes or shortcomings in programming and configuring such robots. In this paper we introduce a family of cable-driven parallel robot called IPAnema that are designed for industrial processes. We address the system architecture, key components such as winches and controller, as well as design tools. Furthermore, some experimental data from the evaluation are presented to illustrate the performance of cable robots.

Making existing production systems Industry 4.0-ready

AbstractThis paper presents an approach to how existing production systems that are not Industry 4.0-ready can be expanded to participate in an Industry 4.0 factory. Within this paper, a concept is presented how production systems can be discovered and included into an Industry 4.0 (I4.0) environment, even though they did not have I4.0-interfaces when they have been manufactured. The concept is based on a communication gateway and an information server. Besides the concept itself, this paper presents a validation that demonstrates applicability of the developed concept.

Energy consumption modeling and optimization for production machines

In order to facilitate the process of replacing existing energy sources with sustainable alternatives and to minimize the environmental impact, the energy efficiency not only in consumer and building technology, but also in manufacturing has to be improved. At present, no suitable techniques are available to model and optimize the energy consumption behavior of production machines that take into account how the machines are used. To overcome this limitation, we introduce a lean, scalable modeling formalism that allows making predictions about the energy efficiency depending on design and operation. We present examples for modeling and optimization of a milling machine.

Architecture for Multilevel Monitoring and Control of Energy Consumption

Guaranteeing energy efficient operation of production systems through a-priori optimization is an extremely complex task. We therefore propose an alternative approach where controls can decide locally if an energy reduction is possible and set components to energy-optimal states. In this paper we present results from the research group ECOMATION describing the information flow that generates energy control loops on different levels based on model information and an appropriate communication and control infrastructure. The communication mechanisms and control structures in production systems and machines are presented which allow using models automatically and coherently on all required levels of detail and abstraction.

Expedient modeling of ball screw feed drives

Ball screw feed drives are the most commonly used mechanism to provide linear motion in high speed machine tools. Position accuracy and the achievable closed loop bandwidth of such drive systems are usually limited by the structural vibration modes of the mechanical components. Higher order plant models allow for a better understanding of the system dynamics, improve the design process of feed drives and are essential for the development of sophisticated control strategies. The ball screw shaft, describing a complex flexible structure, is probably the most significant component concerning structural vibration modes of a feed drive. In this paper, the behavior of the shaft and its dominant influence at different operating and coupling conditions is particularly addressed. Using a hybrid modeling technique, the main characteristics of the shaft are derived and projected onto a clearly arranged and versatile lumped mass model. Simulative and experimental examinations are conducted and a parameter analysis is performed. The presented model proofs to be accurate for a great range of parameters and in addition allows for a physical interpretation of the dominant structural vibration modes of a feed drive.

A rotation invariant feature descriptor O-DAISY and its FPGA implementation

State-of-the-art local feature descriptors like SIFT or SURF require a significant amount of computational power which prevents their usage in applications with real time constraints. Despite recent efforts to simplify the calculation of feature descriptors, a faster computation comes often to the disadvantage of weakening the invariance to rotation or scale. Recently, Tola et al. introduced DAISY, a new local feature descriptor for wide-baseline matching across stereo image pairs. It is shown that DAISY outperforms SIFT in terms of matching accuracy while being computed significantly faster. This paper takes on the idea of DAISY by proposing a rotational invariant extension of the descriptor, called O-DAISY, and outlining its implementation on FPGA to achieve real time performance. The results are benchmarked against its original version and against the widely used descriptors BRIEF and SURF on a standardized image set.

Control of an pseudo-omnidirectional, non-holonomic, mobile robot based on an ICM representation in spherical coordinates

For mobile platforms with steerable standard wheels it is necessary to precisely coordinate rotation and steering angle of their wheels. Especially for redundantly actuated platforms the misalignments of a single wheel directly leads to invalid configurations which may cause degraded motion of the platform and high internal forces. An established approach to deal with this problem is to represent the current state of motion in form of the instantaneous centre of motion (ICM) and to derive a valid trajectory for this point. However, this representation bears severe numerical drawbacks. To remedy those numerical problems an alternative ICM representation based on spherical coordinates is proposed in this work. Furthermore, the relations between ICM and generalized robot velocities are addressed. It is shown, that one receives a basis of a subspace within the kinematical constraints¿ nullspace by decomposing the generalized velocity vector in spherical coordinates. Finally the proposed ICM-based control is particularized and simulative analyzed w.r.t. the Care-O-bot 3 demonstrator.