END OF CHAPTER 1

Functions and operational principle of mechatronic devices

Principle of mechatronic devices

The term mechatronics was introduced to the technical terminology by the Japanese company Yaskawa Elektric Corporation (a company founded in 1915) and since 1971 it has been protected as a trade name.

More specifically, it refers to a multidisciplinary approach to product and manufacturing system design. It represents the next generation machines, robots and smart mechanisms for carrying out work in a variety of environments-predominantly factory automation, office automation and home automation .

Mechatronics in the initial period was understood as the design and construction activities involving the inclusion of electronic components and systems to the functional structure of various precision mechanisms.

In 1982, Yaskawa Elektric Co.. resigned from the patent protection of its trademark and from now on we can all use this term. Today it means mechatronics engineering activities including designing, testing and operation of machinery and equipment, in which there is a high level of functional integration of mechanical systems with electronics and computer control.

Mechatronics is an interdisciplinary field, combining in a synergistic manner the classical knowledge of mechanical engineering, hydraulics, pneumatics, electronics, optics and computer science.

As a discipline, mechatronic encompasses electronics enhancing mechanics ( to provide high levels of precision and reliability) and electronics replacing mechanics (to provide new functions and capabilities). Some examples where mechanics has been enhanced by electronics are numerically controlled machines tools which cut metal automatically, industrial robots and automatic bank tellers. The products where electronics replaces mechanics include digital watches, calculator or others.

The aim of mechatronics is to improve the functionality of technical systems and the creation of new concepts of machinery and equipment with built-in 'artificial intelligence'. In various literature sources several definitions of mechatronics can be found, almost all of them put the emphasis on the functional integration of mechanical actuators with electronics and computer control, eg:

mechatronics includes programmable electronic devices and electromechanical systems for embedded, distributed structure of the sensors, processing signals, actuators and communications.

Isermann [1] defines mechatronics as a combination of knowledge from three disciplines - mechanics, electronics and computer science.

Mechatronics was formed in the engineery environment of automation and robotics, where the 'mechanical' way of solving the design was not adequate to the expectations and opportunities that provide other areas of technology,

particularly electronics, optoelectronics, materials engineering, especially computer science [2].

Mechatronics engineering may be regarded as a modern approach to automation techniques for the broadly defined needs of engineering and education. It can be assumed that mechatronics is an interdisciplinary field of science and technology, dealing with general problems of mechanics, electronics and informatics.

However, it contains too many related mechatronic areas that form the foundation of mechatronics and cover many well-known disciplines such as electrical engineering, power electronics, digital technology, microprocessor technology, and other techniques.

Mechatronics engineering provides an opportunity, not only humanization of machines, but also it changes the mindset and the approach to technological issues and most importantly teaching new technologies and ways of acquiring knowledge and skills. The most important feature of mechatronic devices is the ability to process and communicate information accurately in a form of different types of signals (mechanical, electrical, hydraulic, pneumatic, optical, chemical, biological), with high level of automation of these devices.

The basic assumption for the design of mechatronic devices is the acquisition by the device itself which is responsible for the lower levels of the process (task) to allow the user to focus on higher-order functions.

Mechatronic device structure can be considered at two levels: abstract, consisting of the conjunction of partial functions of the main function device and the specific plane, consisting of the combined structural parts and assemblies, which are natural carriers of various functions involved.

The integration of mechatronic device structure is a result of links among 'smart' teams which communicate and cooperate.

The linking mechanical structure, sensors, actuators and information processing occur as a result of mass flow of streams, of energy and information.

Mechatronics is a multidisciplinary engineering field which involves a synergistic integration of several areassuch as mechanical engineering, electrical and electronic engineering, control engineering, and computerengineering.

In this chapter the field of mechatronics is introduced, the technology needs for such systemsare indicated, and some important issues in the design and development of a mechatronic product or systemare highlighted.

Technologies of sensing, actuation, signal conditioning, interfacing, communication, andcontrol are particularly important for mechatronic systems.

Intelligent mechatronic systems require further technologies for representation and processing of knowledge and intelligence, and particularly those tech-nologies that impart intelligent characteristics to the system.

The design and development of a mechatronicsystem will require an integrated and concurrent approach to deal with the subsystems and subprocessesof a multidomain (mixed) system.

The subsystems of a mechatronic system should not be designed ordeveloped independently without addressing the system integration, subsystem interactions and matching,and the intended operation of the overall system.

Such an integrated and concurrent approach will makea mechatronic design more optimal than a conventional design. In this chapter, some important issues inthe design and development of a mechatronic product or system are highlighted

An intelligent mechatronic device.

A mechatronic system generally has some degree of “intelligence” built into it.

An intelligent mechatronicsystem (IMS) is a system that can exhibit one or more intelligent characteristics of a human.

As muchas neurons themselves in a brain are not intelligent but certain behaviors that are effected by those neuronsare, the basic physical elements of a mechatronic system are not necessarily intelligent but the systemcan be programmed to behave in an intelligent manner . An intelligent mechatronic device embodies machine intelligence.

An IMS, however, may take a broader meaning than an intelligent computer.

Theterm may be used to represent any electromechanical process, plant, system, device, or machinery thatpossesses machine intelligence. Sensors, actuators, and controllers will be integral components of sucha system and will work cooperatively in making the behavior of the system intelligent.

Sensing whileunderstanding, or “feeling” what is sensed, is known as sensory perception, and this is very importantfor intelligent behavior. Humans use vision, smell, hearing, and touch (tactile sensing) in the context of their intelligent behavior. Intelligent mechatronic systems too should possess some degree of sensory perception.

The “mind” of an IMS is represented by machine intelligence. For proper functioning of anIMS, it should have effective communication links between various components.

An IMS may consist of an electromechanical structure for carrying out the intended functions of the system.

Computers thatcan be programmed to perform “intelligent” tasks such as playing chess or understanding a naturallanguage are known to employ

artificial intelligence (AI) techniques for those purposes, and may beclassified as intelligent computers.

When integrated with a dynamic electromechanical structure such asrobotic hands and visual, sonic, chemical, and tactile interfaces, they may be considered as intelligent mechatronic systems.

Taking these various requirements into consideration, a general-purpose structure intelligent mechatronic devices .

In broad terms, an IMS may be viewed to contain a knowledge system and a structural system. Theknowledge system effects and manages intelligent behavior of the system, loosely analogous to the brain,and consists of various knowledge sources and reasoning strategies.

The structural system consists of physical hardware and devices that are necessary to perform the system objectives yet do not necessarily need a knowledge system for their individual functions.

Sensors, actuators, controllers (nonintelligent),communication interfaces, mechanical devices, and other physical components fall into this category.

The broad division of the structure of an IMS, as mentioned previously, is primarily functional ratherthan physical. In particular, the knowledge system may be distributed throughout the system, andindividual components by themselves may be interpreted as being “intelligent” as well (for example,intelligent sensors, intelligent controllers, intelligent multiagent systems).

It needs to be emphasized thatan actual implementation of an IMS will be domain specific, and much more detail than what is alluded to may have to be incorporated into the system structure.

Even from the viewpoint of system efficiency, domain-specific and special-purpose implementations are preferred over general-purposemechatronic systems.

Advances in digital electronics, technologies of semiconductor processing, andmicro-electromechanical systems (MEMS) have set the stage for the integration of intelligence intosensors, actuators, and controllers.

The physical segregation between these devices may well be lost indue time as it becomes possible to perform diversified functionalities such as sensing, actuation, condi-tioning (filtering, amplification, processing, modification, etc.), transmission of signals, and intelligentcontrol, all within the same physical device.

Due to the absence of adequate analytical models, sensingassumes an increased importance in the operation and control of intelligent mechatronic systems.

The associated technologies are important in the field of mechatronics.

Smart mechatronic devices will exhibit an increased presence and significance in a wide variety of applications.

The trend in the applications has been towards mechatronic technologies where intelligenceis embedded at the component level, particularly in sensors and actuators, and distributed throughoutthe system.

Application areas such as industrial automation, service sector, and mass transportation havea significant potential for using intelligent mechatronics, and incorporating advanced sensor technology and intelligent control.

Tasks involved may include handling, cleaning, machining, joining, assembly,inspection, repair, packaging, product dispensing, automated transit, ride quality control, and vehicleentraining. In industrial plants, for example, many tasks are still not automated, and use human labor.

It is important that intelligent mechatronic systems perform their tasks with minimal intervention of humans, maintain consistency and repeatability of

operation, and cope with disturbances and unexpectedvariations in the machine, its operating environment, and performance objectives.

In essence, these systems should be autonomous and should have the capability to accommodate rapid reconfigurationand adaptation.

For example, a production machine should be able to quickly cope with variation sranging from design changes for an existing product to the introduction of an entirely new product line.

The required flexibility and autonomous operation translate into a need for a higher degree of intelligencein the supporting devices.

This will require proper integration of such devices as sensors, actuators, andcontrollers, which themselves may have to be “intelligent” and, furthermore, appropriately distributedthroughout the system.

Design, development, production, and operation of intelligent mechatronicsystems, which integrate technologies of sensing, actuation, signal conditioning, interfacing, communi-cation, and intelligent control, have been possible today through ongoing research and development inthe field of intelligent mechatronic systems

Functions of mechatronic devices

In this module, this will discuss a several types of mechatronic devices which is in used by working design. The types of mechatronic devices is used such as switches, relay, solenoid, power diode, power transistor, thyristor, gate controller switch, rectifier , chopper, transducer and others. These types of devices will be discussed in this module by unit in this module.