An approach to engineering and engineering design which integrates mechanical, electrical and electronic, and software engineering together with information technology within a wide range of products and processes. But there are really as many definitions of mechatronics as there are workers in the field.

There are a number of overviews on the Web, e.g. http://www.engineeringzones.com/mechtron.htm (from which I stole the above figure), and http://www.memagazine.org/backissues/may97/features/mechtron/mechtron.html

A quote from the latter: "Classically trained mechanical engineers will run the risk of being left out of the interesting work" carried on by multidisciplinary product design teams, according to John F. Elter, vice president of strategic programs at Xerox Corp. in Webster, N.Y. "At Xerox, we need designers who understand the control theory well enough to synthesize a better design. These people will have much more of a chance to lead." Elter added that "the mechanical engineers who know some computer science are far more valuable than the computer scientists who know some mechanical engineering. The mechanical engineers have a better feel for the overall system and do a better job of making the crucial trade-offs. One possibility is that the mechatronics practitioner will prototype the whole design, then the specialists in the various disciplines will take over the detail design."

For Web searching on this or any other engineering topic, please see http://www.eng.yale.edu/ee-labs/WebInfoTalk/ , but first visit our library and its physical and electronic resources, and our expert librarian, Andy Shimp.

• Origins

• term coined in Japan in late 1960s.
• Microelectronics and mechatronics were vigorously embraced by Japanese manufacturers from then on, especially after the 1973 oil crisis.

• Examples

• automotive systems are richly mechatronic (as many as 30 such subsystems in modern cars). Of these the most prominent are

• electronic ignition and other aspects of engine control (emission control standards made them indispensable)
• transmission and cruise control
• anti-lock brakes
• control of 'bodily functions' (windows, power-lock, automatic wipers, climate control, seat adjustments)
• security (keyless entry) and safety (airbags)
• in the automotive example the systems context extends almost seamlessly to larger scales. I.e. increasingly intelligent vehicles become part of larger transportation system coordination, e.g. see http://www.computer.org/intelligent/articles/intelligent_vehicles.htm
• "Fly-by-wire" aircraft (e.g. Boeing 777)

• Cameras, both film and electronic. All residual mechanical functions (focus, iris and film advance are electronically controlled.

• "Intelligent" Materials and Structures, e.g. automatic vibration damping, even preventing buckling.

• Hard drives (and other computer peripherals) read/write heads are controlled by a very high performance positioning 'servo', a term going back to WWII. (We are making such a mechanism part of the new EE229Lb lab.)

• really almost any modern technological product is to varying degrees mechatronic.

- Courses at Yale that use mechatronic themes:

- EE 227La "Introduction to Electrical Engineering Lab I" provides exposure in miniature to mechatronic themes. Uses mobile robot platform

- EE 350b "Autonomous Systems" will make more advanced use of autonomous controllers in a fleet of smaller more agile mobile robots (intended to play tag, etc.)

• Mechatronic System Ingredients (electronics is suffused through all of them)

• Sensors, and associated signal conditioning electronics. Solid state (integrated circuit) sensors have greatly expanded the scope of sensor deployment
• Analog signal processing and control components (e.g. op amps)
• Data converters (analog-to-digital, digital -to-analog)
• Microcontrollers (e.g. PIC series from MicroChip) and associated software development environment, digital signal processing, control theory
• Actuators, and associated driver electronics
• Power sources (batteries, power supplies)

• Features & Tools

• Failure of mechatronic systems is typically more abrupt and total than with older electromechanical systems unless redundancy is used.

• Mechatronics is inherently interdisciplinary, requiring a range of knowledge usually beyond that of a single person, except in simple systems. Thus mechatronics is inherently systems oriented and a team effort.

• Educationally an important topic for ME students (see quote at beginning). Because of its interdisciplinary nature, some advocate teaching it along the lines of tactical exercises in the military. E.g. see http://www.lgu.ac.uk/deliberations/Subjects/eng/newacad3.html

• The ability of mechatronics design tools to communicate across disciplinary boundaries becomes very important. Most CAE tools (e.g. Pspice, Electronic Workbench) don't do this well, or at all. "Mixed-signal" simulation is needed. On an educationally suitable scale, MATLAB and Simulink http://www.mathworks.com/products/simulink/ could be considered.

• The Saber® simulation package from http://www.analogy.com is an industry-standard "mixed-signal" simulator now used to communicate mechatronic design and analysis tasks between GM, Ford and Daimler-Chrysler and their auto sub-systems suppliers. It provides a common tool for exploring trade-offs and "what-if" scenarios.
• It is difficult to learn mechatronic design, except "on the job." It is a great area for a senior Special Project – come see me if you need a co-advisor.

• Some particular problems for electronics integration:

• Electrical noise is a common problem, generated by the arcing of contact closures, of dc motor brushes, by high-power electronics (e.g. actuator drivers "rattling" the supply voltage for low-power control portions.
  • Remedies: separate power and signal/control wiring, "bypass capacitors", filters, voltage regulators and other power conditioning
• Supply voltage spikes can be severe, e.g. in automotive systems
• Elevated temperatures due to actuator power dissipation and/or high ambient temperatures (e.g. a car's under-hood environment is a high-stress example, can exceed the 125 deg.C upper limit of the military temperature range. )
• Thermal cycling can in its cumulative effects be more destructive than prolonged elevated temperatures.
• The safe overload margin of mechanical or hydraulic systems is usually larger than that of sensors attached to them (e.g. bending or pressure). This can damage or miscalibrate sensors.

• Some references:

Journal:

• Transactions on Mechatronics, published jointly by IEEE and ASME, accessible from Yale full-text via our library system http://www.library.yale.edu/eas/ieeexplore.html , specifically http://ieeexplore.ieee.org/lpdocs/epic03/RecentIssues.htm?punumber=3516

• Mechatronics - Electronic Control Systems in Mechanical Engineering, W. Bolton, Addison Wesley Longman Ltd, 1995
• Understanding Electro-Mechanical Engineering, L. J. Kamm, IEEE Press, 1995
• Mechatronics - Electromechanics and Contromechanics, D. K. Miu, Springer, 1993
• Mechatronics System Design, D. Shetty and R. A. Kolk, PWS, 1997
• Mechatronics - Mechanical System Interfacing, D. M. Auslander and C. J. Kempf, Prentice Hall, 1996
• Mechatronics Engineering, D. Tomkinson and J. Horne, McGraw-Hill, 1995
• Mechatronics - Perception, Cognition and Execution, edited by G. Rzevski, Butterworth-Heinemann Ltd, 1995
• Mechatronics - Concepts in Artificial Intelligence, J. Johnson and P. Picton, Butterworth-Heinemann Ltd, 1995
• Mechatronics - Electronic Control Systems in Mechanical Engineering, W. Bolton, Addison-Wesley, 1996.
• Electromechanical Product Design (Handbook of), P. L. Hurricks, Longman, 1994
• Mechatronik, Komponenten - Methoden - Beispiele, B. Heimann, W. Gerth and K. Popp, Hanser Lehrbuch, Fachbuchverlag Leipzig, ISBN 3-446-18719-7, 1998 (in German).