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Advance in mechatronics

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Advance in mechatronics

  1. 1. Advance in Mechatronics Muzammil Nakadey, Shaikh Moinuddin, Merchant Bilal 1 Kalsekar Polytechnic Address Mechanical Department, 2nd year (inst.code-1608) 1 bmerchant96@yahoo.in Abstract— Mechatronics does not have a definite definition; However, Mechatronics could roughly be defined as an interdisciplinary engineering with a synergistic combination of mechanical engineering. The portmanteau "Mechatronics" was first coined by Mr. Tetsuro Mori, a senior engineer of the Japanese company Yaskawa, in 1969.The major advantages of Mechatronics Systems are that they are simpler, economical, reliable and versatile systems when integrated than being operated as individual systems. Due to these major advantages, its field of application is very vast like Automotives, Defence, Medical, Smart consumer products, Manufacturing, etc. Cars, CD players, washing machines, railways are all examples of mechatronic systems. The main characteristic (and driving force) of recent advances is the progressively tighter coupling of mechanic and electronic components with software. In this paper we survey current developments and discuss future trends in mechatronics, the future of mechatronics will specifically see a move towards a high degree of adaptability and self-organization. Keywords— Mechatronics, Actuators, Automation, Miniaturization, Modularization, etc. I. INTRODUCTION Mechatronics is “the application of microelectronics in mechanical engineering” (the original definition suggested by MITI of Japan). Previously, mechatronics just meant complementing mechanical parts with some electrical units, a typical representant being a photo camera. Today, mechatronics is an area combining a large number of advanced techniques from engineering, in particular sensor and actuator technology, with computer science methods. Figure 1 depicts the three areas of mechatronics and their overlap. Typical examples of mechatronic systems are automotive applications, e.g. advanced braking systems, fly/steer-by wire or active suspension, but also DVD-players or washing machines. Mechatronic systems are characterized by a combination of basic mechanical devices with a processing unit monitoring and controlling it via a number of actuators and sensors. The introduction of mechatronics is a tight integration of mechanical, electrical and information-driven units. Fig. 1 Areas of Mechatronics II. CHANGES IN THE NATURE OF TECHNOLOGICAL PROCESSORS AND PRODUCTS In the era prior to the invention of the electromagnetic induction dynamo (1830-40) by Michael Faraday, all “machines” (technological processes and products) were mechanical (M) in nature, i.e., composed essentially of mechanical units. Since mechanical units exhibit large inertia, machines of this era tended to be large, cumbersome, slow, “uni-functional” and “non-user friendly (difficult to control and maintain)”. However, it sufficed for the innovators of such machines to be well versed in mechanical sciences and arts. By the late 19th century, since electrical (E1) energy can be transmitted and transformed much more easily than mechanical energy, the energy
  2. 2. receiving and manipulating units within machines (technological processes and products) started to be replaced by functionally comparable electric units. As a result, machines became more compact, controllable and user-friendly. A technological transformation occurred with the advent of analog electronic (E2) valves in the earlier half of the last century. This transformation accelerated after the 1950s owing to the development of transistors, digital electronics and power electronics (E3). Wherever possible, electrical functional units were replaced by such electronic units so as to attain several orders superior performance in terms of size, controllability and user-friendliness. The synergistic combination of E1, E2, and E3 technologies may be collectively referred to as E technologies (electrical/electronic technologies). The second half of the last century saw dramatic changes in technological processes and products owing to the rapid extension of earlier successes in electronic technologies towards the development of a bewildering array of digital computational units (computers): general purpose integrated chips (IC), application specific ICs (ASIC), microprocessors (µp), etc. These functional units are now so small in size (miniaturized) that they can be embedded within the functional units. III. STATE OF ART Modeling & Tools: In a certain sense, modeling and even model driven development, i.e. the generation of executable code from a model, has long been existing in the mechatronic world to improve software quality based on model analysis. Code Generation: Based on such a specification, model based development ideally requires the generation of code which meets all real time constraints. This requires the code generator to know about all platform specific constraints like speed and number of processors or available memory. Only a very few research oriented approaches exist to support a uniform modeling of the behavior of all system components including the specification of real time constraints and a corresponding code generation. Processes: The above description focused on modeling the software part of mechatronic systems. One of the most prominent problems in current industrial development and even research approaches is however the lack of integration between the different disciplines, namely mechanical and electrical engineering and computer science or software engineering more specifically. Usually, the mechanical engineer starts with designing the shape and mechanical parts, then the electrical engineer plans the wiring and finally the software engineer has to write the code. This approach leads to a lot of design errors and costly rework when it is finally noticed that some parts do not fit together or the simple layout of processors and memory make certain software solutions impossible. Analysis & Tools: A rather large percentage of mechatronic systems are deployed in safety critical areas (e.g. the automotive or rail domain). This makes analysis of mechatronic systems (or first of all, their models) one of the main areas of work for software engineers employed in the design of such systems. Since its invention in the late 80’s model checking has become a standard technique for verification, in particular for hardware systems. The main advantage of model checking which makes it interesting for mechatronic systems is its (almost) full automation, providing tool support for analysis. Notwithstanding recent advances and success stories, the main challenge is still the so- called state explosion problem: model checking techniques (most often) rely on a search of the whole state space, and this can grow to arbitrarily large dimensions. For Example: SAT solvers are combined with decision procedures (giving so- called SMT-solvers), model checking with specific AI search methods, bounded model checking is parallelized or model checking combined with static analysis methods. Mechatronic systems present a further challenge for verification as they belong to the area of hybrid systems, characterized by a combination of discrete and continuous parts. The software constitutes the discrete part, while the continuous dynamics corresponds to the physical system with its sensors and actuators. Verification of hybrid systems today is still in its infancy. System models in this class are written as timed automata, and a number of tools support verification of timed automata with respect
  3. 3. to reachability or even temporal logic specified properties. Automation can still only partially be achieved; the algorithms employed in the model checking are not guaranteed to terminate anymore. In order to make the actual system fit into the required subclass, approximations of the real system are used. Fig. 2 Composition of Mechatronics system IV.FUTURE DEVELOPMENTS AND CHALLENGES We believe that future mechatronic systems will consist of several autonomously acting agents capable of monitoring their own physical environment as well exchanging information with other agents. Constructing the software of advanced systems requires a number of significant changes of current software engineering techniques. In particular, the following issues have to be addressed to build the next generation systems properly. A. Current software design processes are tailored towards a particular domain rather than spanning over all involved domains. B. Modeling formalisms allow for a description of static systems but not for their volatility. Model transformations are meant for transforming models towards a particular use on a platform but not for describing the change in that model. C. Analysis techniques mainly rely on the knowledge about a global state space and cannot cope with properties only emerging due to the volatility of systems. D. Secure exchange of information is usually based on a central unit and cannot manage decentralized highly distributed systems of agents dynamically building as well as resolving clusters. The integration of mechanical, electrical and software parts poses challenges which so far have only partly been addressed. For the analysis of today’s mechatronic systems we can identify the following shortcomings:  Precise hybrid modeling: No hybrid modeling techniques exist today which are able to describe the diverse parts of a mechatronic system in a uniform and precise way. Current formalisms try to simply combine some of the existing modeling language from the three areas but most often without giving a meaning to the mixed use of diagrams.  Integrated hybrid analysis: The three disciplines involved in the construction of mechatronic systems all have analysis techniques on their own. Instead of applying these in isolation, an integrated analysis framework is needed in which a particular type of analysis in one area supports & relies on analysis in another area. Fig. 3 Example of Miniaturization Verification Systems with discrete and continuous parts are intrinsically difficult to verify. Model checking of hybrid systems and the transfer of known verification techniques to the domain of hybrid systems remains a challenge. Volatility Evolution according to new data from the environment will be one main characteristic of future advanced mechatronic systems. The behavior of such systems will thus not be completely fixed during design, but is allowed to adapt to environmental changes. The permitted degree of change might partially be laid down by model transformations being part of the model itself. Verification thus has to show that the system remains safe under all possible influences from the environment. V. FUTURE TRENDS IN MECHATRONICS ENGINEERING By definition, automation is the replacement of human labour. And technology is (just) a bag of tools that come in the form of hardware and/or software. A tool is something that assists in performing existing tasks better or enables new
  4. 4. tasks to be performed. In other words, it somehow replaces human labour, i.e., automates the task. Thus progress in technology (through mechatronics, or otherwise) is synonymous to automation. Human activity can be broadly divided into two categories: individual or collective (social). Individual activities may be purely mental or combined with physical activity. Irrespective of whether it is reflexive or reflective, any human physical act requires effort at five levels: i. Setting the goal (a purely mental activity). ii. Sensing the environment through the five sensory organs: eyes, ears, skin, tongue, and nose. iii. Communicating the sensory signals to the central neural processor called the brain. iv. Fusing the signals to recognize patterns of interest and output the command signals to human limbs. v. Performing the physical task using limbs (actuators). A remarkable human ability is to learn from the results obtained from past acts so as to perform better when executing similar tasks in the future. This learning ability provides human beings with the ability to act as autonomous units. A further ability lies in communicating with other human beings so as to undertake collective tasks. The above description of human abilities provides a basis for understanding trends in mechatronics. A. Sensing and sensor fusion (task ii) will be the next capability to be acquired by mechatronic systems. Already, many mechatronic units possess rudimentary sensing abilities. For instance, modern air conditioning units are able to sense air temperature and humidity through separate sensors and fuse the signals through fuzzy logic reasoning. Likewise, sensors in the form of transducers have long been used to enable feedback control in machines. However, there is still a long way to go. Sensors produce copious amounts of data that need to be digested to discover patterns of interest before control can be effected through the “actuators”. Advances in high-speed microcomputers and signal processing algorithms have now opened the door for the exploitation of sensors exploiting a wide range of physical, chemical and, even, biological phenomena. While actuators are limited in variety, the variety of possible sensors is almost unlimited. For instance cutting forces in CNC machining (Figure 4) and its consequences (e.g., tool fracture) can today be monitored and controlled using commercially available devices capable of sensing machining noise, machine vibrations, acoustic emission, drive motor current, etc. Future mechatronic engineers will have to possess deeper understanding of natural sciences so as to cope with the growing variety of sensors. Fig. 4 CNC Machine B. Machine learning: Intelligence means adapting to the environment and improving performance over time. Within the domain of mechatronic engineering, “there has been considerable interest in learning through the use of ANN and fuzzy logic for applications in control and robotics, autonomous guided vehicles (AGV), etc., that require mainly reflective intelligence when performed by human operators and tasks, such as machine diagnostics, requiring combinations of reflexive intelligence and low level reflective intelligence.” This interest will continue well into the future. Fig. 5 Example of sensing and sensor fusion: Robots C. Autonomization refers to the development of the ability to survive and perform robustly while the external environment changes. With progress in sensor and learning technologies, tomorrow’s mechatronic devices can be expected to become progressively more autonomous. They will be able to reset their local goals autonomously under changing external environments so as to meet the broad system-level goals set by human beings.
  5. 5. D. Modularization will be a consequence of autonomization. Mechatronic sub-units will come in modular form, i.e., with all the abilities required for local goal setting, control, and learning encapsulated within the sub-unit. Thus, in time, every mechatronic sub-unit will be self-contained and intelligent. E. Miniaturization refers to the trend towards mechatronic units of significantly smaller size (Figure 3). Progress in precision engineering, newer materials (composites, diamond coatings, etc.), and nano-technologies will contribute to this development. F. Links to the Internet: The Internet will become ubiquitous within the mechatronic world. Every autonomous mechatronic unit will be connected via broadband and satellite networks to the rest of the world. Each mechatronic device will be able to access the information and knowledge base available on the Internet so as to optimize its own performance. At the same time, it will be able to communicate its operational status to remote monitors. G. Societies of devices: The metaphor of society is very similar to that used by Minsky in his book “The Society of Mind”. He says: “[M]ind is made up of many smaller processes. These we’ll call agents. Each mental agent by itself can only do simple things that need no mind or thought at all. Yet when we join these agents and societies in certain special ways this leads to true intelligence.” Once a mechatronic device has become autonomous, locally intelligent, and able to communicate extensively via the Internet, it can join “societies” of devices with a common purpose or interest. VI.CONCLUSIONS In this article, we have sketched current, future trends and advancement in the development of mechatronic systems. In particular, we have discussed the challenges involved in the construction of future advanced systems. Summarizing, these can be roughly divided into two categories: the challenges arising from the collaboration of several different disciplines (which is already an issue today), and those due to the aspect of self-coordination which seems to be a main characteristic distinguishing current from future mechatronic systems. These are challenges to all involved disciplines, but in particular to software engineering. Key to a success in mastering them is the joint effort and collaboration of disciplines, within computer science and engineering. ACKNOWLEDGMENT Healthy thanks to Prof. Aamir Siwani and Prof. Rashid for their proper guidance and co-operation. REFERENCES [1] Nitaigour Premchand Mahalik, Mechatronics, McGraw- Hill International Edition, 2012 [2] www.advancemechatronics.com [3] www.sciencedirect.com [4] wiki.answers.com [5] seminarprojects.com [6] www.powershow.com [7] link.springer.com [8] www.designnews.com [9] mechatronics-net.de [10] www.scribd.com