Product Realization Paradigm ( المنتج تحقيق (نموذج

Product realization is the term used to describe the work that the organization goes through to develop, manufacture, and deliver the finished goods or services. An effective Quality Management System (QMS) includes a comprehensive approach to getting from the product concept to the finished product.

Engineered products frequently involve components from more than one discipline

Traditional product realization

– Discipline ( ) specific sequential process (design then manufacture)

– Drawback: cost overruns due to redesign/re-tooling

A feature that renders something less acceptable; a disadvantage or problem.

A better but still deficient approach

– Discipline specific concurrent (متزامن) process (design for manufacturing)

– Bottleneck: sub-optimal integration

Mechatronics based product realization exploits

– Integrated process founded upon interdisciplinary synergy ( متعدد تآزر(التخصصات

Disciplinary Foundations of Mechatronics

Multi-/Cross-/Inter-Disciplinary

Products and processes requiring inputs from more than one discipline can be realized through following types of interactions.

Multi-disciplinary: This is an additive process of bringing multiple disciplines together to bear on a problem.

Cross-disciplinary: In this process, one discipline is examined from the perspective of another discipline.

Inter-disciplinary: This is an integrative process involving two or more disciplines simultaneously to bear on a problem.

Sequential/Concurrent Product Realization

Sequential and discipline specific concurrent design processes for product realization are at best multi-disciplinary calling upon discipline specialists to “design by discipline.”

Design mechanical system “plant.” Select sensors and actuators and mount on plant. Design signal conditioning and power electronics. Design and implement control algorithm using electrical, electronics,

microprocessor, microcontroller, or microcomputer based hardware.

Mechatronics-based Product Realization

Systems engineering allows design, analysis, and synthesis of products and processes involving components from multiple disciplines.

Mechatronics exploits systems engineering to guide the product realization process from design, model, simulate, analyze, refine, prototype, validate, and deployment cycle.

In mechatronics-based product realization: mechanical, electrical, and computer engineering and information systems are integrated throughout the design process so that the final products can be better than the sum of its parts.

Mechatronics system is not:

simply a multi-disciplinary system simply an electromechanical system just a control system

Fault tolerance:

The ability of a system to respond gracefully to an unexpected hardware or software failure. There are many levels of fault tolerance. Fault tolerance is the property that enables a system to continue operating properly in the event of the failure of some of its components (or one or more faults within).

For example, a motor vehicle designed so it will continue to be drivable if one of the tires is punctured. A structure is able to retain its integrity in the presence of damage due to causes such as fatigue, corrosion, manufacturing flaws, or impact.

Fault-tolerant computer system

Fault-tolerant describes a computer system or component designed so that, in the event that a component fails, a backup component or procedure can immediately take its place with no loss of service. Fault tolerance can be provided with software, or embedded in hardware, or provided by some combination.

In the software implementation, the operating system provides an interface that allows a programmer to "checkpoint" critical data at pre-determined points within a transaction. In the hardware implementation (for example, with Stratus and its VOS operating system), the programmer does not need to be aware of the fault-tolerant capabilities of the machine.

At a hardware level, fault tolerance is achieved by duplexing each hardware component. Disks are mirrored. Multiple processors are "lock-stepped" together and their outputs are compared for correctness. When an anomaly occurs, the faulty component is determined and taken out of service, but the machine continues to function as usual.

the lowest being the ability to continue operation in the event of a power failure. Many fault-tolerant computer systems mirror all operations -- that is, every operation is performed on two or more duplicate systems, so if one fails the other can take over.

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Evolution of Mechatronics as a Contemporary Design Paradigm

Technological advances in design, manufacturing, and operation of engineered products/devices/processes can be traced through:

Industrial revolution Semiconductor revolution Information revolution

Industrial Revolution

Allowed design of products and processes for energy conversion and transmission thus allowing the use of energy to do useful work.

Engineering designs of this era were largely mechanical

e.g., operations of motion transmission, sensing, actuation, and computation were performed using mechanical components such as cams, gears, levers, and linkages).

Purely mechanical systems suffer from

Power amplification inability. Energy losses due to tolerances, inertia, and friction.

Semiconductor Revolution

Led to the creation of integrated circuit (IC) technology.

Effective, miniaturized, power electronics could amplify and deliver needed amount of power to actuators.

Signal conditioning electronics could filter and encode sensory data in analog/digital format.

Hard-wired, on-board, discrete analog/digital ICs provided rudimentary computational and decision-making circuits for control of mechanical devices.

Information Revolution

Development of VLSI technology led to the introduction of microprocessor, microcomputer, and microcontroller.

Now computing hardware is ubiquitous, cheap, and small.

As computing hardware can be effortlessly interfaced with real world electromechanical systems, it is now routinely embedded in engineered products/processes for decision-making.

Microcontrollers are replacing precision mechanical components, e.g., precision-machined camshaft that in many applications functions as a timing device.

Programmability of microcontrollers is providing a versatile and flexible alternative to the hard-wired analog/digital computational hardware.

Integrated computer-electrical-mechanical devices are now capable of converting, transmitting, and processing both the physical energy and the virtual energy (information).

Result: Highly efficient products and processes are now being developed by judicious selection and integration of sensors, actuators, signal conditioning, power electronics, decision and control algorithms, and computer hardware and software.

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@Control Software for Mechanical Systems: Object-Oriented Design in a Real-Time World, D.M. Auslander, J.R. Ridgely, J.D. Ringgenberg, 2002 Prentice Hall PTR.

Real-Time Software

The dominant implementation ( السائد medium as well as primary medium of (التطبيقexpression for contemporary (معاصر) mechatronic systems is real-time software. Real-time software is a subdomain of software generally with distinct (مميز) requirements and characteristics. While implementation media are subject to change, software is so dominant now that any design methodologies that are used must allow for the effective implementation of control systems using real-time software.

Real-time software differs from conventional software in that its results must not only be numerically and logically correct; they must also be delivered at the correct time. A design corollary (مستنبط) following from this definition is that real-time software must embody (يجسد) the concept of duration, which is not part of conventional software.

Duration is such an important concept that it will be the focus of the documentation technique used as the heart of a design methodology for producing reliable control system software.

Two terms in common use in this field have overlapping, but not identical meanings. These are rea-time, as used here, and embedded. Embedded refers to computers that are parts of other items and are not explicitly visible to the user. For example, a mobile (cell) phone has one or more embedded computers in it. These computers control the user interaction via the keyboard and display, control the connection between the phone and its nearest base station, filter the incoming signals to remove noise, encrypt and decrypt messages for security purposes, and so on.

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PDA

On the other hand, a pocket size personal digital assistant (PDA) is a computer. Even though the computer in it is of roughly the same capability and performs many of the same functions as the computer in the mobile phone, it is not thought of as embedded.

Embedded computers may -or may not- perform functions that require real-time software. The functions they perform may or may not have time critical components. Real-time software, however, can run on embedded computers or on computers which are doing control functions but are clearly free-standing and not built into the target system.

Thus, many, but not most, embedded computers run real-time software, and many, but not most, real-time software runs on embedded computers.

Master Vs Mater-less cam manufacturing

An example showing the need for on-time delivery of results is the master-less cam grinder shown.

In the master-less cam grinder, the cam which is being ground to shape is rotated while the linear positioner moves back and forth to generate the desired shape for the cam. The rotation of the cam must be precisely coordinated with transverse motion to cut the noncircular cam profile. This is an example of how mechatronics can change the way that problems are approached.

In the mechatronics-based cam grinder, the profile is stored in an array of numbers in software, so the machine's performance is limited only by its inherent mechanical properties. Changing the machinery to make a different cam profile is also much faster since it only requires the loading of new data instead of the installation of new mechanical hardware in the form of the master cam.

In a conventional, mastered cam grinder the motion is controlled by a mechanical system which traces the contour of a master cam. The mechanical tracing mechanism must fill the role of computation (transmission of the desired contour) but also carry enough power to operate the mechanism. This is a limit to performance and can cause a considerable loss of productivity since the time to change the machine from one cam profile to another is considerable. Performance limitations come about because of the dynamics associated with the accelerations of the elements of the mechanism carrying the information from the master to the blank cam, because of friction in that mechanism, and because of other real-world effects. The result is that for high-precision cams, such as those used for automotive engines, the master usually has to be made slightly differently than the actual desired shape of the final product to compensate for these changes. Ironically, given the automotive application, the question may be asked: Why use a cam at all to manipulate the engine valves? In fact, there has been considerable work on electrically actuated valves, but they have not yet been used on mainline production automobiles.