Showing papers on "Mechatronics published in 2001"

On a new generation of torque controlled light-weight robots

Abstract: The paper describes the recent design and development efforts in DLR Robotics Lab towards the second generation of light-weight robots The design of the light weight mechanics, integrated sensors and electronics is outlined The fully sensory joint, with motor and link position sensors as well as joint torque sensors enables the implementation of effective vibration damping and advanced control strategies for compliant manipulation The mechatronic approach incorporates a tight collaboration between mechanics, electronics and controller design The authors hope that important steps towards a new generation of service and personal robots have been achieved

Design for control-a concurrent engineering approach for mechatronic systems design

Abstract: The well-accepted basis for developing a mechatronic system is a synergetic concurrent design process that integrates different engineering disciplines. In this paper, a general model is derived to mathematically describe the concurrent design of a mechatronic system. Based on this model, a concurrent engineering approach, called design for control (DFC), is formally presented for mechatronic systems design. Compared to other mechatronic design methodologies, DFC emphasizes obtaining a simple dynamic model of the mechanical structure by a judicious structure design and a careful selection of mechanical parameters. Once the simple dynamic model is available, in spite of the complexity of the mechanical structure, the controller design can be facilitated and better control performance can be achieved. Four design scenarios in application of DFC are addressed. A case study is implemented to demonstrate the effectiveness of DFC through the design and control of a programmable four-bar linkage.

Composable Models for Simulation-Based Design

Abstract: This article introduces the concept of combining both form (CAD models) and behavior (simulation models) of mechatronic system components into component objects. By connecting these component objects to each other through their ports, designers can create both a system-level design description and a virtual prototype of the system. This virtual prototype, in turn, can provide immediate feedback about design decisions by evaluating whether the functional requirements are met in simulation. To achieve the composition of behavioral models, we introduce a port-based modeling paradigm. The port-based models are reconfigurable, so that the same physical component can be simulated at multiple levels of detail without having to modify the system-level model description. This allows the virtual prototype to evolve during the design process, and to achieve the accuracy required for the simulation experiments at each design stage. To maintain the consistency between the form and behavior of component objects, we introduce parametric relations between these two descriptions. In addition, we develop algorithms that determine the type and parameter values of the lower pair interaction models; these models depend on the form of both components that are interacting. This article presents the initial results of our approach. The discussion is limited to high-level system models consisting of components and lumped component interactions described by differential algebraic equations. Expanding these concepts to finite element models and distributed interactions is left for future research. Our composable simulation and design environment has been implemented as a distributed system in Java and C11, enabling multiple users to collaborate on the design of a single system. Our current implementation has been applied to a variety of systems ranging from consumer electronics to electrical train systems. We illustrate its functionality and use with a design scenario.

Towards a mechatronic compiler

Abstract: A simultaneous engineering framework for designing optimal mechatronic systems is presented. In the first part of this paper, a method, based on genetic algorithms, for optimizing the geometric configuration of three-axis machine tools in the conceptual design stage is presented. The second part describes a method, based on component mode synthesis, to derive a low-order control model from a finite-element description of the mechanical and drive structures of the mechatronic system. In the third part, motion controllers are derived that are robust against configuration changes of the mechatronic system to be controlled.

Engineering of Intelligent Systems

Abstract: Ant colony optimisation is a relatively new meta-heuristic search technique for solving optimisation problems. To date, much research has concentrated on solving standard benchmark problems such as the travelling salesman problem, quadratic assignment problem and the job sequencing problem. In this paper, we investigate the application of ant colony optimisation to practical telecommunication design and synthesis problems having real-world constraints. We consider a modelling approach suitable for ant colony optimisation implementation and compare the results to the simulated annealing meta-heuristic.

The science and education of mechatronics engineering

Abstract: We try to get to the heart of multidisciplinary engineering, of which mechatronics is an excellent example, and point out how the integration of disciplines leads to new degrees of freedom in design and corresponding research directions that otherwise would not have been investigated. This is the major contribution achieved by a multidisciplinary approach to engineering science; it leads to a new important research field and at the same time helps to push research in related fields into new fruitful directions. We point to a number of areas that have benefited from the interdisciplinary perspective and a focus on interactions between disciplines including: engineering curriculum; mechatronics research; control of nonlinear mechanical systems; real time control systems modelling; and time varying control systems.

Generalization of the cascade principle in view of a structured form of mechatronic systems

Abstract: With the steady increase in microcontroller performance, mechatronic systems have become more and more complex. This requires new organizational structures both in system design and in controller structure. For system design, a practical way of structuring mechanical systems vertically and horizontally has already been presented in a number of papers. This structure has to be reflected in the controller as well. The aim of this paper is to adapt and combine well-known controller design techniques to make up a new and well-structured way of controller design tailored to the organizational structure of mechatronic design. After a brief overview of the mechatronic design structure, this new controller design technique will be presented on the basis of the cascade structure of SISO controllers and the centralized controllers with state-vector feedback. For an example, the controller of a new modular railway system is presented, with special emphasis on the active suspension/tilt system.

Grasping the interdisciplinarity of mechatronics

Abstract: The two technical universities of Switzerland, the Swiss Federal Institute of Technology of Lausanne (EPTL) and Zurich (ETHZ), have a long tradition in mechatronics education One successful part of this education at ETHZ is a lecture called Smart Product Design with a main emphasis on hands-on experience Apart from providing the basics of mechatronics, the students work on a real mobile robot system during the course Each student team receives a mobile robot kit, based on a Motorola 68332 microcontroller Each year's course ends with a competition between the fully autonomous robots of the interdisciplinary student teams In the recent years' competitions the students had to build robots to autonomously construct towers, to play golf or soccer, or to collect Lego students to bring them to school The article briefly discusses the important aspects of mechatronics education and then focuses on the Smart Product Design course at ETHZ, discussing the lecture, the laboratory work, and the experience gained during the last eight years

High Performance Computing in Science and Engineering 2000

Abstract: Using large scale computer simulations we have investigated the interplay between single chain dynamics and the kinetics of phase separation in a symmetric binary polymer blend. In the framework of a coarse grained lattice model the bond fluctuation model on a three dimensional lattice we monitor the growth of concentration fluctuations after a quench from the one phase region into the miscibility gap. Chains of 64 effective segments are simulated in a cell of linear dimension L = 160, i.e., each simulation box contains 256 000 particles. The growth rate of composition fluctuations is averaged over 64 realizations of the temperature quench. The simulation results are compared to dynamic mean field theory without any adjustable parameter. Two theoretical approaches have been investigated: dynamical self--consistent field theory and external potential dynamics. The quantitative comparison between simulation and theory reveals the pronounced influence of the single chain dynamics on the dynamics of collective variables. A Rouse-like single chain dynamics can be incorporated into the dynamical self--consistent field theory via a non-local Onsager coefficient. The external potential dynamics results in Rouse-like dynamics without the need of a non-local Onsager coefficient. Moreover, the latter method is about an order of magnitude computationally faster than the dynamic self--consistent field theory.

Is anything really new in mechatronics education

Abstract: Yes, there is something new in the way mechanical engineers are expected to design and in the way professors must now teach design. To illustrate how one institution is helping mechanical engineers to become mechatronics engineers, the article describes the undergraduate program in mechatronics at Rensselaer Polytechnic Institute, and in particular, the integration of the theory covered in lectures with the laboratory exercises. The hardware systems used in both courses are described. Also discussed are observations from conducting professional training in mechatronics both in industry and for the ASME Professional Development Program.

What is Mechatronics? : Proposing a Didactical Approach to Mechatronics

Abstract: The academic subject of mechatronics has been definedpreviously in numerous publications. This study aims atanalyzing mechatronics by using categories developed within theeducational science of Didactics. The result of the analysis,that relies on data from mechatronics education at KTH andother universities, shows that the identity of mechatronics canbe described as thematic, and the legitimacy as functional,which gives implications for the questions of communication andselection: what should be taught, and how. This is combinedwith a study of the evolution of the subject of mechatronics,where it is possible to see the gradually changing identity,from a combination of a number of disciplinary subjects to onethematic subject. The first part of the thesis concludes that mechatronics isautonomous, thematic and functional. Teaching and learningmechatronics according to the identity and legitimacy of thesubject benefits from collaborative, experimental andinternational settings. The functional legitimacy todayrequires the collaborative and the international setting,meaning that the mechatronics employer requires these skillswhen employing a mechatronic engineer. Further, an exemplifyingselection requires the experimental setting, in particular whencomparing a representative selection with the reproduction ofknowledge, and an exemplifying selection with the creation ofknowledge. To conclude, there are a number of important aspects to takeinto account when teaching and learning mechatronics. Three ofthese aspects, collaborative, experimental and internationalare suggested as important, and also a direct consequence ofthe identity of mechatronics. This thesis shows that thesethree aspects are indeed possible to integrate intomechatronics education, which will benefit greatly fromthis.

A solution to holonic control systems

Abstract: New revolutionary manufacturing paradigms, which take advantage of the latest emerging mechatronics, information and communication technologies and integrate them in a highly dynamic and agile economic, technical and organisational manufacturing environment, are being researched and developed in the last decade This new generation of manufacturing systems is referred to as intelligent manufacturing systems, and both the "holonic manufacturing system" and the "agent-oriented manufacturing system" paradigms have been presented in recent years as the basis for making such systems a reality In this paper, the main specifications of the implementation of an intelligent manufacturing system at industrial level with agent-based control software technology are presented as a practical solution to the holonic control paradigm

An integrated method for managing complex engineering projects using the design structure matrix and advanced simulation

Abstract: This thesis proposes an integrated project management framework for complex engineering projects such as the development of an automobile. The integrated method streamlines project planning and control using three modules: structuring, modeling, and scheduling. In the structuring module, the design structure matrix (DSM) method is used to structure the information flows among tasks and capture the iteration loops. By classifying various types of information dependencies, a critical dependency path is identified and redundant constraints are removed for the modeling and scheduling analyses. In the modeling module, a generalized process model predicts complex behaviors of iterative processes using advanced simulation techniques such as the Latin Hypercube Sampling and parallel discrete event simulation. The model computes the probability distribution of lead time and identifies critical paths in a resource-constrained, iterative project. Using the results of analyses from the structuring and modeling modules, a network-based schedule in the form of a PERT or Gantt chart is developed in the scheduling module. The schedule is used as the basis for monitoring and control of the project. The primary goal of this work is to develop an integrated method that guides project management efforts by improving the effectiveness and predictability of complex processes. The method can also be used for identifying leverage points for process improvements and evaluating alternative planning and execution strategies. Better project management will ultimately result in a better quality product with timely delivery to customers. Two case studies are performed to illustrate the utility of the method. Thesis Advisor: Steven D. Eppinger, General Motors LFM Professor of Management

8.5.3 A Framework for a Systems Engineering Body of Knowledge

Abstract: At this time, systems engineering has no recognized body of knowledge. Without such a body of knowledge, systems engineers have difficulty agreeing on exactly what systems engineering should be and academia has difficulty in teaching it. This paper first summarizes a number of models of systems engineering and proposes a framework for a systems engineering body of knowledge (SEBOK) based on a combination of two of the models. The paper then proposes a road map for the development of the SEBOK, a way to offer a world class postgraduate degree and closes with some perspectives on systems engineering that become visible when system engineering is viewed within the framework.

Remote laboratory for a brushless DC motor

Abstract: The objective of this study is to investigate remote-learning methods in the context of mechatronics education, and in particular, for the study of brushless DC motors, which are extensively employed in robots, information devices, home appliances and other areas. While hypermedia-based courseware and computer-assisted instruction are widely used in conventional desk-type learning, very few examples exist of remote learning that involve experiments. The authors therefore developed a prototype client-server system for remotely conducting experiments on brushless DC motors, including Web-based courseware and other software. The server computer is connected to the motor laboratory, and the visual image and sounds of the experiment are transmitted to the client computer in real time. The remotely located user can operate the motors and conduct experiments through the client computer. Through demonstrations to a class, the authors conclude that the remote lab combined with a simulation of the motor's dynamic behavior can be a quite effective teaching aid for the study of precision motors.

Application of fuzzy logic in engineering problems

Abstract: In today's fast paced world of increasing and innovative new technology, fuzzy logic is a practical mathematical addition to classic Boolean logic. We can see its applications in many fields of science and engineering. This paper gives a general overview with a large bibliography, on many such applications to target tracking, pattern recognition, robotics, power systems, controller design, chemical engineering, biomedical engineering, vehicular technology, economy management as well as decision making, communications and networking, electronic engineering, civil engineering, sensor technology, and industry.

Conceptual design of mechatronic systems supported by semi-formal specification

Abstract: Mechatronics - the synergetic integration of different engineering domains can create new products and stimulate innovative solutions. In order to yield this potential experts from different engineering domains need a common method to specify results during the early stage of product conceptualization. The article presents an integrated method for the conceptual design of mechatronic products. It comprises a new semi-formal specification language for the modelling of functions. This language is closely related to the semi-formal modelling of principle solutions. The systematic approach of product conceptualization is exemplified by vehicle convoy driving systems.

The Mechatronics Control Kit for education and research

Abstract: We discuss the use of the Mechatronics Control Kit from Mechatronic Systems, Inc. for control education and research. The Mechatronics Control Kit can be configured with several distinct plants, including a simple DC motor, an inertia wheel pendulum and a Pendubot. The digital electronics are fully integrated and include a Texas Instruments DSP development system, the TMS320C6711 DSK Board (a DSP board with parallel port interface), a PWM output/optical encoder input data acquisition daughter board, a PWM amplifier, and power supplies. We discuss the hardware and software interface and outline a set of experiments that can be performed using this system.

Mechatronic systems, communication, and control in precision agriculture

Abstract: Site specific agriculture requires the application of field machinery capable of precise, repeatable operations based on models of systems processes. Such equipment requires a host of high-precision sensors and actuators. In the mechatronic design process outlined, the efficiency of the design process and the performance of the mechanisms can be improved considerably or even be optimized through concurrent, integrated development of the mechanisms, control systems, and advanced information systems. Such advanced sensing systems with modern feedback controllers can generate significant demands for data processing and require substantial communications bandwidth. Standardized agricultural bus systems form the backbone for the high-variability and high-bandwidth data streams. In this article, three example mechatronic designs of mobile agricultural machinery are discussed, and the requisite communication system for these machines is presented.

Optimal Design of CAPAMAN (Cassino Parallel Manipulator) with Prescribed Workspace

Abstract: CaPaMan (Cassino Parallel Manipulator) is a 3-Degree Of Freedom spatial parallel manipulator that has been designed at the Laboratory of Robotics and Mechatronics, in Cassino. In this paper we present a formulation for an optimum design for CaPaMan architecture when the workspace is suitably prescribed.

A Complex Mechatronic System: from Design to Application

Abstract: Progress in mobile robotics requires the researchers to access and improve all modules that compose the robot, from low-level mechanical components to high-level reasoning systems. This paper presents the development process of the robots built at the Autonomous Systems Lab, EPFL Lausanne, Switzerland. Starting from the mechanical and electrical design up to the application, we show the challenges that needed to be faced as well as the solutions that have been devised. The description covers aspects like the operating system and framework, because of its role in the overall safety and dependability of the whole software system, the research as a precondition for innovative products, and the man-machine interface, which is indispensable for conveying information to the user as well as allowing the user to interact with the robot. The issues that have been faced stem from the hierarchical, layered construction of a complex mechatronic product, where the operation of the machine depends on the smooth cooperation of each layer; In the same way, the overall safety is undermined by the least reliable piece building the system.

Mechatronics/process control remote laboratory

Abstract: Under an NSF—DUE sponsored laboratory development program, we have developed a multidisciplinary mechatronics/process control remote laboratory (MPCRL) consisting of an array of experiments, which expose students to elements of aerospace, mechanical, electrical, civil, and chemical engineering. A new laboratory curriculum and manual have been developed to introduce students to PC-based data acquisition, rapid control prototyping, and control of a multitude of multidisciplinary experimental test-beds. In addition, in summer 2000, we developed the MPCRL web site to facilitate remote access to our laboratory test-beds via the world-wide-web. The MPCRL web site features online-experiments, information/navigation/ resource centers, prerecorded videos of experiments, live video stream of online-experiments, and a chat window. The MPCRL supports undergraduate and graduate control courses including the capstone design projects. Finally, its outreach efforts have included summer workshops for graduate and high school students.

Rough-terrain mobile robot planning and control with application to planetary exploration

Abstract: Future planetary exploration missions will require mobile robots to perform difficult tasks in highly challenging terrain, with limited human supervision. Current motion planning and control algorithms are not well suited to rough-terrain mobility, since they generally do not consider the physical characteristics of the rover and its environment. Failure to understand these characteristics could lead to rover entrapment and mission failure. In this thesis, methods are presented for improved rough-terrain mobile robot mobility, which exploit fundamental physical models of the rover and terrain. Wheel-terrain interaction has been shown to be critical to rough terrain mobility. A wheel-terrain interaction model is presented, and a method for on-line estimation of important model parameters is proposed. The local terrain profile also strongly influences robot mobility. A method for on-line estimation of wheel-terrain contact angles is presented. Simulation and experimental results show that wheel-terrain model parameters and contact angles can be estimated on-line with good accuracy. Two rough-terrain planning algorithms are introduced. First, a motion planning algorithm is presented that is computationally efficient and considers uncertainty in rover sensing and localization. Next, an algorithm for geometrically reconfiguring the rover kinematic structure to optimize tipover stability margin is presented. Both methods utilize models developed earlier in the thesis. Simulation and experimental results on the Jet Propulsion Laboratory Sample Return Rover show that the algorithms allow highly stable, semi-autonomous mobility in rough terrain. Finally, a rough-terrain control algorithm is presented that exploits the actuator redundancy found in multi-wheeled mobile robots to improve ground traction and reduce power consumption. The algorithm uses models developed earlier in the thesis. Simulation and experimental results show that the algorithm leads to improved wheel thrust and thus increased mobility in rough terrain. Thesis Supervisor: Steven Dubowsky Professor of Mechanical Engineering

Integrated mechatronics solution to maximise tractability and efficiency of wheeled vehicles

Abstract: The objective of this work is to apply mechatronics to increase the stability, tractability and efficiency of wheeled vehicles operating on steep slopes. The essential feature of this work is that both of the two basic methods of steering a vehicle are used so that they both tend to produce the same centre of curvature for the path of the vehicle. This deliberate redundancy means that the inevitable failure of one steering system is prevented by both systems acting in unison. This "steer and drive by wire" system was made feasible due the smart on-board wheel angles and wheel speed control system presented in this paper.

Advanced mechatronics in ESA's space robotics developments

Abstract: Space robots are driven by requirements for high performance and versatility under extreme constraints of low mass, low energy consumption, and few interaction possibilities with supervising humans. This necessitates high degrees of miniaturisation and autonomy. The paper gives an overview of advanced mechatronic solutions for novel space robot systems in a variety of applications: small robot arms for operation on a Space Station or on planets; various concepts of mobility on the Moon, Mars, or Mercury; penetrating or drilling systems for subsurface investigations; micro satellites circling a Space Station and flying robots exploring extreme topologies on Mars.

Open system real time architecture and software design for robot control

Abstract: Robotics equipment used in research studies or industrial prototyping often require reconfiguration of some hardware/software architectures and algorithms for new experiments and trials. Such requirements highlight the interest in new "open" control system architectures, interacting with suitable applications for software development in order to reduce and simplify the project cycle. This paper shows an application based on one of these systems, the OpenDSP, which allows an easy reconfiguration of a DSP-based hardware for different applications. An interesting feature of the developed system is given by its full integration with the Matlab environment. OpenDSP is developed by the Mechatronics Laboratory of Politecnico di Torino, Italy.

Mechatronics design for a programmable closed-loop mechanism

Abstract: As the demand increases for machines with high accuracy, high speed and high stiffness, programmable closed-loop linkages (PCLL) emerge. This paper presents further results obtained from a study of the mechatronics design approach to PCLL systems proposed by the authors elsewhere. In this approach, the system performances such as motion tracking and torque fluctuation are further improved after a suitable design of mass redistribution. In the present paper it is shown that a scheme called negative mass redistribution, which follows the principle of shaking force/shaking moment balancing, can achieve an excellent improvement in system performance. Furthermore, simultaneous variation in the length of the link and the gain of the PD controller is studied, which shows promise for further improvement in system performance. In general, these studies have shown that complex control algorithms may not achieve a better result than that achieved by a simple PD controller combined with a mass redistribution ...