The Science and Education of Mechatronics Engineering
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Both photos: ©2000 Artville, LLC. Emphasizing Team Building in a Problem- and Project-Based Curriculum to Meet the Challenges of the Interdisciplinary Nature of this Field o far there is no common and widely accepted under- N Hewit in [3] states: A precise definition of mechatronics is standing of what mechatronics really is. Many different not possible, nor is it particularly desirable, because the notions similar to or including mechatronics have been field is new and expanding rapidly; too rigid a definition used in various contexts; micromechatronics, opto- would be constraining and limiting, and that is pre- mechatronics, supermechatronics, mecanoin- cisely what is not wanted at present. Sformatics, contromechanics and megatronics are Mechatronics as an interdisciplinary subject some of these, each coined to put forward a tends to attract contributions from all related specific aspect or application of mech- fields without really putting forward the atronics. Examples of attempts to describe opportunities and challenges arising spe- mechatronics include the following. cifically due to the interdisciplinary inter- N Mechatronics encompasses the actions. An example of this is that many knowledge and the technologies mechatronics conferences have been required for the flexible genera- unfocused and thereby have not at- tion of controlled motions [1]. tracted the most adequate contributions, N Mechatronics is the synergistic which definitely exist. This is a disadvan- combination of mechanical and tage in that it hampers the development of electrical engineering, computer sci- mechatronics as an engineering science. Sci- ence, and information technology, entific publications in mechatronics, to help in which includes control systems as well as nu- making the subject more focused, are still quite rare. merical methods used to design products with One of the earlier publications is Mechatronics—an Interna- built-in intelligence [2]. tional Journal published by Elsevier Science, first published in 1991. 20 IEEE Robotics & Automation Magazine 1070-9932/01/$10.00©2001IEEE JUNE 2001 The IEEE/ASME Transactions on Mechatronics, a more recent the subsystem-based approach is likewise totally predomi- publication, began in 1996. nant, but with a too limited coverage of the development This article is not just another attempt to describe the re- process and corresponding team building. Typically, books search community’s definition of the term mechatronics. of this literature devote the first chapter to defining or ex- Rather, we try to get to the heart of multidisciplinary engi- plaining what mechatronics is, and then the remaining neering, of which mechatronics is an excellent example, and chapters each cover a subject (modeling, sensors, actuators, point out how the integration of disciplines leads to new de- control, computer hardware, interfaces, communication, grees of freedom in design and corresponding research direc- etc.) in a traditional but short-form way (see, e.g., [2, 5]). tions that otherwise would not have been investigated. This is Successful mechatronics engineering can hardly be based the major contribution achieved by a multidisciplinary ap- solely on such literature. proach to engineering science; it leads to a new important research field and at the same time helps to push research The subsystem-based approach to in related fields into new fruitful directions. mechatronics is still a drastic improvement from the early days The Importance of Interdisciplinarity A general discussion on interdisciplinarity in research, its when the mechanical engineers first claimed lack in academia, and its tremendous importance designed the mechanical system. for the next century is presented by Mayer-Krahmer in [4]. Large studies are referred to in which it is concluded The subsystem-based approach to mechatronics is still a that the technology at the beginning of the next century can- drastic improvement from the early days when the mechanical not be partitioned according to conventional disciplines and engineers first designed the mechanical system, which was further that important innovations often stem from the inter- then handed over to the control engineers doing a control de- action of several previously unconnected streams of scientific sign. Concurrently, a computer system was designed by the and technological activity. Further, the full potential of electrical engineers and finally programmers were given the interdisciplinarity includes bridging the gap between real ap- impossible task of designing and implementing a complex plications, including research, and the scientific disciplines. controller due to an odd mechanical design, on a too slow This is also discussed in [4] and referred to as the dynamics of computer system. research and technology; a science-push cycle is followed by a demand-pull cycle, a process that is nonlinear and that requires An Approach for Next-Generation efficient feedback and interaction. Mechatronic Systems The advances in digital electronics have enabled the possibility The Traditional Mechatronics Approach to invent, create, or improve systems that rely on mechanical Engineering of mechatronic systems and products is well es- components to perform their intended dynamic actions. The tablished in a substantial number of industrial branches like au- key disciplines to be mastered concurrently and in an inte- tomotive, manufacturing systems, aircraft control, grated manner are mechanical engineering, software engi- construction equipment, etc. Such engineering typically ap- neering, control engineering, and computer engineering. The plies a subsystem-based approach to mechatronics. By subsys- major paradigm shift enabled by mechatronics is that of shift- tem based we refer to a product development strategy by which ing the implementation of functionality from mechanical integrated systems are built from technology homogeneous hardware to computer software, but still and most importantly subsystems (mechanics, electronics, control and software). the end-effecting components are mechanical. Notably, we The subsystems are developed in a concurrent manner with an consider software, rather than microelectronics or micropro- important focus on subsystem interfaces. Once the interfaces cessors, as being the major new paradigm as it is the software are designed, each subsystem is designed in a fairly traditional that provides the new and extensive flexibility and freedom in way. This means that the focus has been on team building to design. However, in many cases the actual software design is improve communication and multidisciplinary understanding implemented in electronic hardware (hardware/software between engineers of different expertise such that the inter- co-design), but in both cases there is a software design level. faces can be properly defined. Some figures from a world leader in industrial robot design In the subsystem-based approach there is no real demand and manufacturing show clearly the trend of moving function- on development of a certain technology as a result of its ality from mechanics to software. About 12 years ago develop- closer integration with other technologies; e.g., the close ment engineers were split between mechanics, electronics, and integration of automatic control and computer science. software in roughly estimated shares of 60, 25, and 15, respec- The performance of the mechatronic system is instead tively, whereas in 1998 the shares were 30, 15, and 55, respec- merely a result of a sound integration of existing technol- tively. Similar figures have been presented for many embedded ogy. In the existing engineering literature on mechatronics, control system applications related to mechatronics. Still, there JUNE 2001 IEEE Robotics & Automation Magazine 21 are situations in which passive mechanical components are ucation is also a question of either integration of new courses added in order to cope with certain functional requirements within an existing program or tailored development of a that cannot readily be solved in control software. An example is completely new program. What is discussed here falls in the a passive compliant element added to facilitate the integration of former category. The students are first given a solid base in force and position control. The important message in terms of mechanical engineering and then the advantage of receiving mechatronics here is that an integrated and concurrent design specific project and problem-oriented interdisciplinary train- approach is essential to find an “optimal” combination of the ing on top of this base. best from several engineering domains. As mechatronics is a holistic, synergistic, and interdisciplin- A fundamental aspect of mechatronics is that theories and ary subject, it is not an easy task to integrate it into an engi- neering curriculum while still fulfilling the learning objectives. As a background for formu- We claim that mechatronics as an lating the aims and objectives for a specific engineering science should focus on the course, one should consider the balance between: interdisciplinary interactions, and N technology and methodology; N theoretical science and practical engineer- based on these identify, formulate, ing skills; and conduct new research. N working in teams and the assessment of the individual student learning performance. The following discussion regarding mecha- concepts for mechanical design that have evolved over centu- tronic course organization should be seen with