6.10 Mechatronic Curriculum Developments

The current mechatronic curriculum leaves much to be desired, and the following strategy, which can be modified and expanded, should be pursued by academia to integrate the mechatronic courses in the undergraduate and graduate curricula:

• commercialize and market mechatronic program;

• expand the mechatronic horizon to conventional and mini-scale mechatronic systems, as well as to MEMS and NEMS which are emerging areas in engineering;

• revise the engineering curriculum. In particular, Electromagnetics, Electromechanical Motion Devices, Power Electronics, Control, Microelectronics, and DSP courses should be offered as the required core courses, and as prerequisites for advanced mechatronic courses;

• emphasize mechatronics as the center of the undergraduate and graduate electromechanical engi-neering curriculum rather than at the periphery;

• cover moderately complex electromechanical systems and case studies in the undergraduate mechatronic courses and relocate highly specialized topics to the graduate program;

• develop an intellectually demanding, progressive, well-balanced mechatronic curriculum and mechatronic courses with laboratories;

• fully integrate computer-aided-design tools and advanced high-performance simulation software;

• extend mechatronics to the undergraduate senior design projects;

• write and publish comprehensive books, textbooks, and handbooks in mechatronics; and

• widely and timely disseminate the results.

Manageable collaboration between engineering disciplines and departments can be achieved within the mechatronic program. The following basic courses sequence can be applied:

• Electromechanical Motion Devices,

• Power Electronics and Microelectronics,

• Microprocessors and Interfacing,

• Digital Signal Processing,

• Electromechanical Systems,

• Introduction to Mechatronics,

• Control Systems Theory and Control of Mechatronic Systems,

• Mechatronic Systems and Smart Structures,

• Microelectromechancial Systems,

• Nanoelectromechanical Systems. Due to the differences in the electrical and computer, mechanical, and aerospace engineering plans of study and the limited number of elective engineering courses counted towards the degree, the mechatronic courses sequence can be different. For example, for electrical engineering students, the coursework plan of study can be designed using fundamental electrical engineering and applied mechanical engineering; for mechanical engineering students, fundamental mechanical engineering and applied electrical engi

neering can be emphasized. The students will have fundamentals in one core area while accomplishing breadth and receiving applied knowledge in the other field.

6.11 Conclusions: Mechatronics Perspectives

Far-reaching fundamental and technological advances in electromechanical motion devices (actuators and sensors), power electronics, solid-state devices, ICs, MEMS and NEMS, materials and packaging, computers and informatics, microprocessors and DSPs, digital signal and optical processing, as well as computer-aided-design tools and simulation software, have brought new challenges to academia,

industry, and government. As a result, many engineering schools have revised their curricula in order to offer the relevant interdisciplinary courses such as Electromechanical Systems and Mechatronics. The basis of mechatronics is fundamental theory and engineering practice. The attempts to introduce mecha-tronics have been only partially successful due to the absence of a long-term strategy. Therefore, coor-dinated efforts are sought. Most engineering curricula provide a single elective course to introduce mechatronics to electrical, computer, mechanical, and aerospace engineering students. Due to the lack of time, it is impossible to comprehensively cover the material and thoroughly emphasize the cross-disciplinary nature of mechatronics in one introductory course. As a result, this undergraduate or dual-level course might not adequately serve the students’ professional needs and goals, and does not satisfy growing academia, industrial, and government demands. A set of core mechatronic courses should be integrated into the engineering curriculum, and laboratory- and project-oriented courses should be developed to teach and demonstrate advanced hardware and software with application to complex electromechanical systems. The relevance of fundamental theory, applied results, and experiments is very important and must be emphasized. The great power and versatility of mechatronics, not to mention the prime importance of the results it approaches in all areas of engineering, make it worthwhile for all engineers to be acquainted with the basic theory and engineering practice. There is no end to the application of mechatronics and to the further contribution to this interdisciplinary concept. We have just skimmed the surface of mechatronics application to advanced electromechanical systems. New trends will be researched and applied in the near future because mechatronics is an engineering–science–technology frontier. For example, novel phenomena and operating principles in NEMS and MEMS can be devised, studied, analyzed, and verified using nanomechatronics and nanoelectromechanics.

References

II

Physical System Modeling

7 Modeling Electromechanical Systems

Introduction • Models for Electromechanical Systems • Rigid Body Models • Basic Equations of Dynamics of Rigid Bodies • Simple Dynamic Models • Elastic System Modeling • Electromagnetic Forces • Dynamic Principles for Electric and Magnetic Circuits • Earnshaw’s Theorem and Electromechanical Stability

8 Structures and Materials

Fundamental Laws of Mechanics • Common Structures in Mechatronic Systems • Vibration and Modal Analysis • Buckling Analysis • Transducers • Future Trends

9 Modeling of Mechanical Systems for Mechatronics Applications

Introduction • Mechanical System Modeling in Mechatronic Systems • Descriptions of Basic Mechanical Model Components • Physical Laws for Model Formulation • Energy Methods for Mechanical System Model Formulation • Rigid Body Multidimensional Dynamics • Lagrange’s Equations

10Fluid Power Systems

Introduction • Hydraulic Fluids • Hydraulic Control Valves • Hydraulic Pumps • Hydraulic Cylinders • Fluid Power Systems Control • Programmable Electrohydraulic Valves

11Electrical Engineering Introduction • Fundamentals of Electric Circuits • Resistive Network Analysis • AC Network Analysis

12Engineering Thermodynamics

Fundamentals • Extensive Property Balances • Property Relations and Data • Vapor and Gas Power Cycles

13Modeling and Simulation for MEMS

Introduction • The Digital Circuit Development Process: Modeling and Simulating Systems with Micro- (or Nano-) Scale Feature Sizes • Analog and Mixed-Signal Circuit Development: Modeling and Simulating Systems with Micro- (or Nano-) Scale Feature Sizes and Mixed Digital (Discrete) and Analog (Continuous) Input, Output, and Signals • Basic Techniques and Available Tools for MEMS Modeling and Simulation • Modeling and Simulating MEMS, i.e., Systems with Micro- (or Nano-) Scale Feature Sizes, Mixed Digital (Discrete) and Analog (Continuous) Input, Output, and Signals, Two- and Three-Dimensional Phenomena, and Inclusion and Interaction of Multiple Domains and Technologies • A “Recipe” for Successful MEMS Simulation • Conclusion: Continuing Progress in MEMS Modeling and Simulation

14 Rotational and Translational Microelectromechanical Systems: MEMS Synthesis, Microfabrication, Analysis, and Optimization

Introduction • MEMS Motion Microdevice Classifier and Structural Synthesis • MEMS Fabrication • MEMS Electromagnetic Fundamentals and Modeling • MEMS Mathematical Models • Control of MEMS • Conclusions

15The Physical Basis of Analogies in Physical System Models

Introduction • History • The Force-Current Analogy: Across and Through Variables • Maxwell’s Force-Voltage Analogy: Effort and Flow Variables • A Thermodynamic Basis for Analogies • Graphical Representations • Concluding Remarks

7

Modeling Electro­mechanical Systems

7.1 Introduction

7.2 Models for Electromechanical Systems

7.3 Rigid Body Models Kinematics of Rigid Bodies • Constraints and Generalized Coordinates • Kinematic versus Dynamic Problems

7.4 Basic Equations of Dynamics of Rigid Bodies Newton–Euler Equation • Multibody Dynamics

7.5 Simple Dynamic Models Compound Pendulum • Gyroscopic Motions

7.6 Elastic System Modeling Piezoelastic Beam

7.7 Electromagnetic Forces

7.8 Dynamic Principles for Electric and Magnetic Circuits Lagrange’s Equations of Motion for Electromechanical Systems

7.9 Earnshaw’s Theorem and Electromechanical Stability

7.1 Introduction

Mechatronics describes the integration of mechanical, electromagnetic, and computer elements to pro­duce devices and systems that monitor and control machine and structural systems. Examples include familiar consumer machines such as VCRs, automatic cameras, automobile air bags, and cruise control devices. A distinguishing feature of modern mechatronic devices compared to earlier controlled machines is the miniaturization of electronic information processing equipment. Increasingly computer and elec­tronic sensors and actuators can be embedded in the structures and machines. This has led to the need for integration of mechanical and electrical design. This is true not only for sensing and signal processing but also for actuator design. In human size devices, more powerful magnetic materials and supercon­ductors have led to the replacement of hydraulic and pneumatic actuators with servo motors, linear motors, and other electromagnetic actuators. At the material scale and in microelectromechanical systems (MEMS), electric charge force actuators, piezoelectric actuators, and ferroelectric actuators have made great strides.

While the materials used in electromechanical design are often new, the basic dynamic principles of Newton and Maxwell still apply. In spatially extended systems one must solve continuum problems using the theory of elasticity and the partial differential equations of electromagnetic field theory. For many applications, however, it is sufficient to use lumped parameter modeling based on i) rigid body dynamics

for inertial components, ii) Kirchhoff circuit laws for current-charge components, and iii) magnet circuit laws for magnetic flux devices.

In this chapter we will examine the basic modeling assumptions for inertial, electric, and magnetic circuits, which are typical of mechatronic systems, and will summarize the dynamic principles and interactions between the mechanical motion, circuit, and magnetic state variables. We will also illustrate these principles with a few examples as well as provide some bibliography to more advanced references in electromechanics.

7.2 Models for Electromechanical Systems

The fundamental equations of motion for physical continua are partial differential equations (PDEs), which describe dynamic behavior in both time and space. For example, the motions of strings, elastic beams and plates, fluid flow around and through bodies, as well as magnetic and electric fields require both spatial and temporal information. These equations include those of elasticity, elastodynamics, the Navier–Stokes equations of fluid mechanics, and the Maxwell–Faraday equations of electromagnetics. Electromagnetic field problems may be found in Jackson (1968). Coupled field problems in electric fields and fluids may be found in Melcher (1980) and problems in magnetic fields and elastic structures may be found in the monograph by Moon (1984). This short article will only treat solid systems.

Many practical electromechanical devices can be modeled by lumped physical elements such as mass or inductance. The equations of motion are then integral forms of the basic PDEs and result in coupled ordinary differential equations (ODEs). This methodology will be explored in this chapter. Where physical problems have spatial distributions, one can often separate the problem into spatial and temporal parts called separation of variables. The spatial description is represented by a finite number of spatial or eigenmodes each of which has its modal amplitude. This method again results in a set of ODEs. Often these coupled equations can be understood in the context of simple lumped mechanical masses and electric and magnetic circuits.