Computer-aided design (CAD) is the use of computer technology to aid in the design and especially the drafting (technical drawing and engineering drawing) of a part or product, including entire buildings. It is both a visual (or drawing) and symbol-based method of communication whose conventions are particular to a specific technical field.
technical drawing:-"art and practice of creating accurate representations of objects for technical, architectural and engineering needs."
Drafting can be done in two dimensions ("2D") and three dimensions ("3D").
Drafting is the integral communication of technical or engineering drawings and is the industrial arts sub-discipline that underlies all involved technical endeavors. In representing complex, three-dimensional objects in two-dimensional drawings, these objects have traditionally been represented by three projected views at right angles.
Current CAD software packages range from 2D vector-based drafting systems to 3D solid and surface modellers. Modern CAD packages can also frequently allow rotations in three dimensions, allowing viewing of a designed object from any desired angle, even from the inside looking out. Some CAD software is capable of dynamic mathematic modeling, in which case it may be marketed as CADD — computer-aided design and drafting.
CAD is used in the design of tools and machinery used in the manufacture of components, and in the drafting and design of all types of buildings, from small residential types (houses) to the largest commercial and industrial structures (hospitals and factories).
CAD is mainly used for detailed engineering of 3D models and/or 2D drawings of physical components, but it is also used throughout the engineering process from conceptual design and layout of products, through strength and dynamic analysis of assemblies to definition of manufacturing methods of components.
CAD has become an especially important technology within the scope of computer-aided technologies, with benefits such as lower product development costs and a greatly shortened design cycle. CAD enables designers to lay out and develop work on screen, print it out and save it for future editing, saving time on their drawings.
AutoCAD is a CAD software application for 2D and 3D design and drafting, developed and sold by Autodesk[Autodesk, Inc. is an American software and services company for the manufacturing, infrastructure, building, media and entertainment, and wireless data services fields]. AutoCAD was one of the first CAD programs to run on personal computers, and notably the IBM PC.
Monday, August 4, 2008
Tuesday, June 24, 2008
Robotics
Robotics is the science and technology of robots, their design, manufacture, and application.Robotics requires a working knowledge of electronics, mechanics and software, and is usually accompanied by a large working knowledge of many subjects.A person working in the field is a roboticist.
The structure of a robot is usually mostly mechanical and can be called a kinematic chain (its functionality being similar to the skeleton of the human body). The chain is formed of links (its bones), actuators (its muscles) and joints which can allow one or more degrees of freedom. Most contemporary robots use open serial chains in which each link connects the one before to the one after it. These robots are called serial robots and often resemble the human arm. Some robots, such as the Stewart platform, use closed parallel kinematic chains. Other structures, such as those that mimic the mechanical structure of humans, various animals and insects, are comparatively rare. However, the development and use of such structures in robots is an active area of research (e.g. biomechanics). Robots used as manipulators have an end effector mounted on the last link. This end effector can be anything from a welding device to a mechanical hand used to manipulate the environment. ISO 10248 defines a robotic application on the industrial field.
Walking is a difficult and dynamic problem to solve. Several robots have been made which can walk reliably on two legs, however none have yet been made which are as robust as a human. Typically, these robots can walk well on flat floors, and can occasionally walk up stairs. None can walk over rocky, uneven terrain.
iCub robot, designed by the RobotCub Consortium.
A robot leg, powered by Air Muscles.
The structure of a robot is usually mostly mechanical and can be called a kinematic chain (its functionality being similar to the skeleton of the human body). The chain is formed of links (its bones), actuators (its muscles) and joints which can allow one or more degrees of freedom. Most contemporary robots use open serial chains in which each link connects the one before to the one after it. These robots are called serial robots and often resemble the human arm. Some robots, such as the Stewart platform, use closed parallel kinematic chains. Other structures, such as those that mimic the mechanical structure of humans, various animals and insects, are comparatively rare. However, the development and use of such structures in robots is an active area of research (e.g. biomechanics). Robots used as manipulators have an end effector mounted on the last link. This end effector can be anything from a welding device to a mechanical hand used to manipulate the environment. ISO 10248 defines a robotic application on the industrial field.
Walking Robots:
iCub robot, designed by the RobotCub Consortium.
Flying:
A modern passenger airliner is essentially a flying robot, with two humans to attend it. The autopilot can control the plane for each stage of the journey, including takeoff, normal flight and even landing. Other flying robots are completely automated, and are known as Unmanned Aerial Vehicles (UAVs). They can be smaller and lighter without a human pilot, and fly into dangerous territory for military surveillance missions. Some can even fire on targets under command. UAVs are also being developed which can fire on targets automatically, without the need for a command from a human. Other flying robots include cruise missiles, the Entomopter and the Epson micro helicopter robot.
Kismet (robot) : can produce a range of Facial expressions,
kismet now resides at the MIT Museum in Cambridge, Massachusetts.
kismet now resides at the MIT Museum in Cambridge, Massachusetts.
Snaking:
Several snake robots have been successfully developed. Mimicking the way real snakes move, these robots can navigate very confined spaces, meaning they may one day be used to search for people trapped in collapsed buildings.The Japanese ACM-R5 snake robot can even navigate both on land and in water.
Two robot snakes. Left one has 32 motors, the right one 10.
Two robot snakes. Left one has 32 motors, the right one 10.
A robot leg, powered by Air Muscles.
Mechatronics
Mechatronics (or Mechanical and Electronics Engineering) is the combination of mechanical engineering, electronic engineering and software engineering. The purpose of this interdisciplinary engineering field is the study of automata from an engineering perspective and serves the purposes of controlling advanced hybrid systems. The word itself is a portmanteau of 'Mechanics' and 'Electronics'.
THERMODYNAMICS
Thermodynamics is a branch of physics and of chemistry that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analysing the collective motion of their particles using statistics. Roughly, heat means "energy in transit" and dynamics relates to "movement"; thus, in essence thermodynamics studies the movement of energy and how energy instills movement. Historically, thermodynamics developed out of need to increase the efficiency of early steam engines.
The laws of thermodynamics:
Zeroth law of thermodynamics (stating that thermodynamic equilibrium is an equivalence relation):
If two thermodynamic systems are separately in thermal equilibrium with a third, they are also in thermal equilibrium with each other.
First law of thermodynamics (about the conservation of energy ):
The change in the internal energy of a closed thermodynamic system is equal to the sum of the amount of heat energy supplied to the system and the work done on the system.
Second law of thermodynamics, (about entropy) :
The total entropy of any isolated thermodynamic system tends to increase over time, approaching a maximum value.
Third law of thermodynamics( about absolute zero temperature):
As a system asymptotically approaches absolute zero of temperature all processes virtually cease and the entropy of the system asymptotically approaches a minimum value; also stated as: "the entropy of all systems and of all states of a system is zero at absolute zero" or equivalently "it is impossible to reach the absolute zero of temperature by any finite number of processes".
Onsager reciprocal relations (sometimes called the Fourth Law of Thermodynamics) :
Express the equality of certain relations between flows and forces in thermodynamic systems out of equilibrium, but where a notion of local equilibrium exists.
The laws of thermodynamics:
Zeroth law of thermodynamics (stating that thermodynamic equilibrium is an equivalence relation):
If two thermodynamic systems are separately in thermal equilibrium with a third, they are also in thermal equilibrium with each other.
First law of thermodynamics (about the conservation of energy ):
The change in the internal energy of a closed thermodynamic system is equal to the sum of the amount of heat energy supplied to the system and the work done on the system.
Second law of thermodynamics, (about entropy) :
The total entropy of any isolated thermodynamic system tends to increase over time, approaching a maximum value.
Third law of thermodynamics( about absolute zero temperature):
As a system asymptotically approaches absolute zero of temperature all processes virtually cease and the entropy of the system asymptotically approaches a minimum value; also stated as: "the entropy of all systems and of all states of a system is zero at absolute zero" or equivalently "it is impossible to reach the absolute zero of temperature by any finite number of processes".
Onsager reciprocal relations (sometimes called the Fourth Law of Thermodynamics) :
Express the equality of certain relations between flows and forces in thermodynamic systems out of equilibrium, but where a notion of local equilibrium exists.
Typical thermodynamic system, showing input from a heat source (boiler) on the left and output to a heat sink (condenser) on the right. Work is extracted, in this case by a series of pistons.
In thermodynamics, a thermodynamic system, originally called a working substance, is defined as that part of the universe that is under consideration. A real or imaginary boundary separates the system from the rest of the universe, which is referred to as the environment or surroundings(sometimes called a reservoir). A useful classification of thermodynamic systems is based on the nature of the boundary and the quantities flowing through it, such as matter, energy, work, heat, and entropy. A system can be anything, for example a piston, a solution in a test tube, a living organism, a planet, etc.
THERMODYNAMIC SYSTEM
MACHINE
The scientific definition of a "machine" is any device that is not a computer that transmits or modifies energy.In common usage, the meaning is that of devices having parts that perform or assist in performing any type of work .Machines normally require some energy and always accomplish some sort of work. Devices with no rigid moving parts can be considered tools.
A machine is anything that makes work easier.
The mechanical advantage of a simple machine is the ratio between the force it exerts on the load and the input force applied. This does not entirely describe the machine's performance, as force is required to overcome friction as well. The mechanical efficiency of a machine is the ratio of the actual mechanical advantage(AMA) to the ideal mechanical advantage(IMA). Functioning physical machines are always less than 100% efficient.
Modern power tools, automated machine tools, and human-operated power machinery are tools that are also machines. Machines used to transform heator other energy into mechanical energy are known as engines.
Compound machines are composed of more elementary machines called simple machines, such as the wedge and the pulley. Machines are considered simple machines if they perform their action in one movement. These devices may also be used to support industrial applications, although devices entirely lacking rigid moving parts are not commonly considered machines. Hydraulics are widely used in heavy equipment industries, automobile industries, marine industries, aeronautical industries, construction equipment industries, and earthmoving equipment industries.
A machine is anything that makes work easier.
The mechanical advantage of a simple machine is the ratio between the force it exerts on the load and the input force applied. This does not entirely describe the machine's performance, as force is required to overcome friction as well. The mechanical efficiency of a machine is the ratio of the actual mechanical advantage(AMA) to the ideal mechanical advantage(IMA). Functioning physical machines are always less than 100% efficient.
Modern power tools, automated machine tools, and human-operated power machinery are tools that are also machines. Machines used to transform heator other energy into mechanical energy are known as engines.
Compound machines are composed of more elementary machines called simple machines, such as the wedge and the pulley. Machines are considered simple machines if they perform their action in one movement. These devices may also be used to support industrial applications, although devices entirely lacking rigid moving parts are not commonly considered machines. Hydraulics are widely used in heavy equipment industries, automobile industries, marine industries, aeronautical industries, construction equipment industries, and earthmoving equipment industries.
mechyz!!!
Mechanical engineering is an engineering discipline that involves the application of principles of physics for analysis,design,manufacturing, and maintenance of mechanical systems. It requires a solid understanding of core concepts including mechanics,kinematics,thermodynamics and energy. Mechanical engineers use the core principles as well as other knowledge in the field to design and analyze motor vehicles,aircraft,heating and cooling systems,watercraft,manufacturing plants, industrial equipment and machinery,robotics,medical devices and more.
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