Comparative analysis of design concepts of mechatronics systems with a CAD tool for system architecting

In mechatronics systems design, designers need to deal with complexity derived from the integration of subsystems with various engineering disciplines. In particular, while developing product architecture for the next generation systematically, the present generation systems in the market should be reviewed in terms of their functional overview as well as module structure. This paper proposes a method for developing product architecture by a comparative analysis of the functional overview as well as physical decomposition of existing mechatronics systems. The method employs function–behaviour–state modelling and a computer-aided design (CAD) system for system architecting (SA-CAD) as a modelling scheme and modelling environment, respectively. The paper describes the application of the proposed method in the development of product architecture of autonomous vacuum cleaning robots.     

Design of command shapers for residual vibration suppression in Duffing nonlinear systems

Residual vibrations generated from rest-to-rest maneuvers are crucial for applications in precision engineering, active structural control, space engineering, and other mechatronics applications. In certain applications, the structures to be controlled could be highly nonlinear yet lightly damped. Although the traditional input shaping techniques, which utilize destructive interference, work well for linear and weakly nonlinear systems, they show little effects on systems with strong nonlinearity. In this paper, a general input shaper design methodology for single-degree-of-freedom systems with Duffing nonlinearity is developed by an energy approach. Following this approach, two-step and three-step shapers, as well as their design procedures, are developed, which in the linear limit reduce to the traditional zero-vibration and zero-vibration-and-derivative shapers, respectively. The robustness of these nonlinear shapers is investigated numerically through case studies. The results show that the three-step shapers are sufficiently robust to resist certain level of parameter variations (from their designed values) without exciting significant residual vibrations. The two-step shapers, however, are less robust in comparison. Meanwhile, it is also found that the presence of damping effectively disturbs the energy flow and thus induces residual vibrations. For the less robust two-step shapers, an effective ‘online tuning’ scheme is also proposed here to further improve its performance in a damped nonlinear system. These shaping schemes, as well as their practical adjustment routing, could be applied to the particular structural or mechatronics systems with Duffing or other nonlinearities for vibration suppression to enhance the performance of mechatronics systems.     

Teaching control system design through mechatronics: academic and industrial perspectives

The present approach to teaching control system design as a stand-alone course offered late in the undergraduate curriculum, with little discussion of hardware, implementation, or integration through design, is ineffective in preparing students for engineering practice. Control systems must be integrated into the design from the beginning and not be simply after-thought add-ons. Based on the authors' extensive experience teaching mechatronics to university students and professional engineers, an integrated mechatronic approach to teaching controls is proposed. This approach will seriously address the deficiencies in the present-day skills of working professionals, as observed by the authors in teaching professional engineering workshops. These deficiencies are a direct result of how we presently teach controls and related topics.     

The role of bond graph modeling and simulation in mechatronics systems: An integrated software tool: CAMP-G, MATLAB–SIMULINK

One of the main and most challenging steps in the design and analysis of a mechatronics system is to generate a computer model. This paper explores the fundamental theory, the methodology and the process from conceptual ideas to practical realization. Using a multienergetic approach that allows the modeling of interdisciplinary models, it explores the theory and method to automate the process of the generation of the differential equations and how to automate the derivation of transfer functions. The approach is discussed for linear and non-linear systems. The generation of a computer model takes new dimensions when that model contains mixed energy domains such as electromechanical, electrohydraulic, thermo-fluid, and electronic control systems all together. These are typical of mechatronics applications. This paper explores the bond graph technique as a modeling tool to generate state space models or non-linear models together with software tools. CAMP-G (Computer Aided Modeling Program with Graphical input) has been developed in order to generate computer models automatically and have them integrated with MATLAB–SIMULINK as simulation tools. Several aspects of mechatronics systems design have been investigated in order to focus on which areas the bond graph modeling technique can help engineers in the process of creating mechatronics systems from scratch. Towards this end, the paper deals with computer-generated models of sensors, actuators, and multidisciplinary complex physical systems.     

Can agile methods enhance mechatronics design education?

This paper presents a study of the integration of agile methods into mechatronics design education, as performed at KTH Royal Institute of Technology. The chosen method, Scrum, and the context of the studied capstone course are presented.With the integration of Scrum into the capstone projects, an educational favorable alternative is identified, to previously used design methodologies such as more traditional stage-gate methods as the Waterfall or method or the V-model. This is due to the emphasis on early prototyping, quick feedback and incremental development. It still might not be the favorable method for use in large scale industrial development projects where formal procedures might still be preferred, but the pedagogical advantages in mechatronics education are valuable. Incremental development and rapid prototyping for example gives many opportunities for students to reflect and improve. The Scrum focus on self-organizing teams also provides a platform to practice project organization, by empowering students to take responsibility for the product development process.Among the results of this study, it is shown that it is possible and favorable to integrate Scrum in a mechatronics capstone course and that this can enhance student preparation for a future career as mechatronics designers or product developers. It is also shown that this prepares the students with a larger flexibility to handle the increased complexity in mechatronics product development and thereby enabling the project teams to deliver results faster, more reliable and with higher quality.     

A mechatronics control engineering class at Beihang University,China: Practicing and exploring

Due to the synergistic nature of mechanical engineering, electronic control and systematical thinking [1], the mechatronics education is regarded as a complicated and more demanding course characterized by the need of highly integrated ability with theoretical knowledge and hands-on experiment to solve proposed problems, and thus has drawn great attention worldwide. As one of the typical and innovative teaching modes in mechatronics in China, mechatronics teaching in Beihang University has formed a “One main line, Two links, Three practical points” mode and methodology, which emphasizes on the links and mapping relationships between theoretical teaching and practical teaching. After 6-year practicing and exploring, the course has made fundamental and systematic innovation achievements in the field with respect to class materials, teaching mode, teaching system. Several typical mechatronics projects proposed and achieved by students have verified the effect and innovation of the project based teaching mode and methodology.     

Mechatronics-an industrial perspective

The term "mechatronics" is defined to provide a framework for technical and practical considerations. Within this framework, the importance of "intimate and organic" integration in mechatronics product designs is raised. Several issues pertaining to attaining this ideal integration of mechanical, electronic controls, and system engineering in mechatronics product designs are cited. To further advance the current mechatronics products, areas of improvement are also presented.     

A mechatronics educational laboratory – Programmable logic controllers and material handling experiments

The integration of robotics, conveyors, sensors, and programmable logic controllers into manufacturing and material handling processes requires engineers with technical skills and expertise in these systems. The coordination of assembly operations and supervisory control demands familiarity with mechanical and electrical design, instrumentation, actuators, and computer programming for successful system development. This paper presents an educational mechatronics laboratory that encourages multi-disciplinary hands-on engineering discovery within team settings. Three focused progressive experiments are reviewed that allow students to program and operate a programmable logic controller, a traditional conveyor system, and a distributed servo-motor based conveyor. The students also program and implement two robotic arms for material handling applications. The equipment, learning objectives, and experimental methodology for each laboratory are discussed to offer insight. A collaborative design project case study is presented in which student teams create a smart material handling system. Overall, engineering graduates have generally been required to learn material handling and other multi-disciplinary concepts in the field, and therefore, a well-rounded engineering curriculum should incorporate mechatronics in both the classroom and laboratory.     

Physical design of testable CMOS digital integrated circuits

A methodology for physical testability assessment and enhancement, implemented with a set of test tools, is presented. The methodology, which can improve the physical design of testable CMOS digital ICs, is supported in realistic fault-list generation and classification. Two measures of physical testability, weighted class fault coverage and fault incidence, and one measure of fault hardness are introduced. The testability is evaluated prior to fault simulation; difficult-to-detect faults are located on the layout and correlated with the physical defects which originate them; and suggestions for layout reconfiguration are provided. Several design examples are described, ascertaining the usefulness of the proposed methodology. The proposed methodology demonstrated that stuck-at test sets only partially cover the realistic faults in digital CMOS designs. Moreover, it is shown that classical fault models of arbitrary faults are insufficient to describe the realistic fault set. Simulation results have shown that the fault set strongly depends on the technology and on the layout style     

Loop-based interconnect modeling and optimization approach for multigigahertz clock network design

A highly efficient loop-based interconnect modeling methodology is proposed for multigigahertz clock network design and optimization. Closed-form loop resistance and inductance models are proposed for fully shielded global clock interconnect structures, which capture high-frequency effects including inductance and proximity effects. The models are validated through comparisons with electromagnetic simulations and measured data taken from a Power4 chip. This modeling methodology greatly improves the clock interconnect simulation efficiency and enables fast physical design exploration. Examples of interconnect performance optimization are demonstrated and design guidelines are proposed.     

An intelligent-agent framework for concurrent product design andplanning

This paper proposes a multi-agent framework to develop product design and planning using the concurrent engineering approach. The ideas in the framework draw on design-team behavior in many domains. The goal is to provide information that will help teams of designers, engineers and managers from various functional areas improve initial designs so that they satisfy a wider variety of concerns. Our model provides support to bring together constraints from the different team members in the development cycle. By integrating downstream constraints into the design phase, we reduce the need for redesign (due to design mistakes) later in the product development cycle. Our framework integrates a blackboard architecture with an intelligent agent (IA) network. Our methodology uses conflict-resolution (CR) techniques and design-improvement suggestions to refine the initial product design, and process plan generation and simulation to verify the manufacturability of the design. The contributions of the paper are threefold. First, our framework provides a more realistic way of modeling design teams by providing a way to model an individual team member's perspective as a segment of a continuum of task knowledge. Second, we identify the essential components of concurrent engineering needs, and develop a framework for integrating these components so as to ensure adequate coordination among the processes involved. Third, our methodology uniquely meshes together design constraints with factory resource considerations, so that the final product design is ensured to be feasible and manufacturable     

Using mechatronics in early design

This paper presents the results of integrating mechatronics into a large second year design course. Issues related to course objectives, implementation, costs and results from a curriculum perspective are presented. The systems developed for this course are the result of three years of system design and modification. The results of this paper demonstrate that for realistic costs and efforts, mechatronics can be integrated into a sophomore level design class that services approximately 300 students per year. Furthermore, results from the senior level capstone design course indicate that the use of mechatronics permeates throughout the students' career.     

Combining aspects and object-orientation in model-driven engineering for distributed industrial mechatronics systems

Recent advances in technology enable the creation of complex industrial systems comprising mechanical, electrical, and logical – software – components. It is clear that new project techniques are demanded to support the design of such systems. At design phase, it is extremely important to raise abstraction level in earlier stages of product development in order to deal with such a complexity in an efficient way. This paper discusses Model Driven Engineering (MDE) applied to design industrial mechatronics systems. An aspect-oriented MDE approach is presented by means of a real-world case study, comprising requirements engineering up to code generation. An assessment of two well-known high-level paradigms, namely Aspect- and Object-Oriented paradigms, is deeply presented. Their concepts are applied at every design step of an embedded and real-time mechatronics system, specifically for controlling a product assembler industrial cell. The handling of functional and non-functional requirements (at modeling level) using aspects and objects is further emphasized. Both designs are compared using a set of software engineering metrics, which were adapted to be applied at modeling level. Particularly, the achieved results show the suitability of each paradigm for the system specification in terms of reusability quality of model elements. Focused on the generated code for each case study, statistics depicted an improvement in number of lines using aspects.     

Tracking the consequences of design decisions in mechatronic Systems Engineering

The design of mechatronic systems involves several technical and scientific disciplines. It is often difficult to anticipate, at the outset, the consequences of design decisions on the ultimate effectiveness of such complex systems, in which case the evaluation process is required to support the designers each time engineering choices must be made or justified. Since designers may belong to different technical and scientific cultures however, their understanding of both the design stakes and the evaluation process is too often biased. Moreover, design choices take place in an uncertain context and according to multiple criteria, some of which may be contradictory. In order to track the consequences of design decisions, we are proposing a conceptual data model to perform evaluations within the MBSE framework of Systems Engineering. We then proceed by relying on the relationships demonstrated by such a model to identify the potential impacts of design choices on future product performance. Since data available during the conceptual phase of the design are typically uncertain or imprecise, an original research protocol is extended to a qualitative impact analysis for the purpose of highlighting the most promising alternative system design solutions (ASDS). An example in the mechatronics field serves to illustrate our proposals.     

Curriculum,equipment and student project outcomes for mechatronics education in the core mechanical engineering program at Kettering University

Following an NSF grant in 1997 to develop undergraduate mechatronics laboratories and courses, two senior-level elective courses were introduced in the mechanical engineering curriculum at Kettering University. The student popularity of the subject, and relevance to graduating mechanical engineers soon made it clear that mechatronics education belonged to the core curriculum at Kettering. To integrate mechatronics into the mechanical engineering core, two existing sophomore-level courses were redesigned to include significant educational experiences in mechatronics design and prototype fabrication. Introduction to Design (ME-203) previously featured a 6-week student project in which teams of students would design and build an electromechanical device to accomplish functionality defined in design constraints provided by the professor. However, these devices were not mechatronic in nature. In the revised course, the objective is to evolve these designs to utilize embedded microcontrollers, sensors and actuators and achieve much more sophisticated functionality. To accommodate the anticipated increase in time required to complete such projects, the existing sophomore course Instrumentation (ME-204) was revised to incorporate learning objectives from the senior-level mechatronics elective courses. Further, 6 weeks of laboratory time from Instrumentation could then be dedicated to the aforementioned mechatronic projects. As such, both ME-203 and ME-204 have been integrated to form an eight-credit “Introduction to Mechatronics Design” course. This paper details the scope of this course, the specialized equipment developed for it and student project outcomes.     

Electrical design inspection: a methodology for using circuitsimulation in the design and development of electronic power supplies

The authors present an electrical design inspection (EDI) methodology that combines advanced power circuit simulation techniques and RISC (reduced instruction set computing) workstation hardware to use simulation in the day-to-day design of electronic power supplies. This methodology makes use of circuit simulation to detect design faults in electronic power supplies and prevent them from propagating further in the product realization process. A hierarchy of inspections which form the basis of EDI methodology, is introduced. The methodology has been embedded in a prototype electrical design inspection system which has been tested on a Sun Sparcserver 4/490 dedicated to circuit simulation. The power of this methodology has been illustrated by its application to a self-oscillating variable-frequency DC-DC power converter with peak current control. It is demonstrated that EDIS can automatically execute inspections requiring an accurate determination of the steady-state solution of the circuit, and process these results. The steady-state accelerator capability within the SIMPLIS circuit simulator has made it possible to achieve this in an unprecedentedly short CPU time     

Engineering education for mechatronics

This paper defines mechatronics, explains mechatronics philosophy, and describes characteristics of mechatronics products and systems. It reviews aspects of education and training for mechatronics and compares the two different approaches to engineering education: generalist engineering versus specialist engineering. It also examines the Japanese approach to product development strategies and mechatronics education and training. It also gives an overview of mechatronics education in higher education institutions across the world with a specific reference to a typical mechatronics engineering degree program. Finally it concludes that there will be an increasing need in the future for discipline-based mechatronics engineers     

Integrating topology optimization in precision motion system design for optimal closed-loop control performance

In pursuit of better accuracy, higher speed and larger scale, manufacturers of high-performance devices increasingly rely on components which have been designed with a multidisciplinary approach from the outset. In the context of motion systems, this means that for instance structural mechanics, control engineering and thermal analysis are considered early in the design. In addition, the prospect of producing freeform device components using additive manufacturing at full scale allows designers to even further refine components to a specific purpose, or even integrate multiple functions into a single component. The design freedom offered by additive manufacturing is far greater than that offered by traditional techniques. To exploit this freedom a topology optimization framework is proposed that allows to determine the optimal material quantity and distribution within a design volume. In particular, this article focuses on the closed-loop control performance of a motion system component, while simultaneously ensuring that mechanical requirements are met. Based on an example, it is demonstrated that this leads to nontrivial and non-intuitive designs which provide improved performance at lower structural mass compared to eigenfrequency designs. The framework allows rapid development of prototype designs, which may eliminate some of the costly design iterations which are currently made in industrial practice.