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IJRAET

MODELLING OF AN ROBATIC ARM USING SOLID WORKS

1 P SURENDERNATH, 2 K.NAGARAJA RAO

1 Pg Scholar, Department of MECH, VIVEKANANDA GROUP OF INSTITUTIONS, Ranga Reddy, Telangana, India. 2 Associate Professor (HOD), Department of MECH, VIVEKANANDA GROUP OF INSTITUTIONS, Ranga Reddy,

Telangana, India.

Abstract: Robotics is a combination of mechanical, electrical and computers in which they can perform the operations by programming. Movement of the robots is caused by actuators either hydraulic or pneumatic. Robot arm is a mechanical arm similar to the functions of human arm.

Robots are combinations of manipulators, actuators and shafts. To reduce the human effort in industries and to function in critical areas robots\robot arm is used. it is designed to work in programmable mode in accurate time for different works like gripping, welding, pick and place etc., in major industries in order to reduce the human effort.,

The present work here is to design of robotic arm along with manipulators (for rotational and translation) by using SOLIDWORKS 2014.

Keywords— sensors, actuators, servo motors, degrees of

freedom, design, solid works

INTRODUCTION

Robotics is the branch of mechanical, electrical and computer science engineering .that deals with the design, construction, operation, and application of robots as well as computer systems for their control, sensory feedback, and information processing.

These technologies deal with automated machines that can take the place of humans in dangerous environments or manufacturing processes, today, robotics is a rapidly growing field, as technological advances continue, research, design, and building new robots serve various practical purposes, whether domestically, commercially or military. Many robots do jobs that are hazardous to people such as defusing bombs, mines and exploring shipwrecks.

This paper describes my senior design project that examines both tasks using a robotic manipulator with degrees of freedom.

Degrees of freedom: The number of independent ways by which a dynamic system can move without violating any constraint imposed on it, is called degree of freedom. In other words, the degree of freedom can be defined as the minimum number of independent coordinates that can specify the position of the system completely.

In mechanics the degree of freedom (DOF) of a mechanical is the number of independent parameters that define its configuration. It is the number of parameters that determine the state of a physical system and is important to the analysis of systems of bodies in mechanical engineering, robotics and structural engineering.

The following will demonstrate the degrees of freedom

Using the human arm:

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First Degree: Shoulder Pitch Point your entire arm straight out in front of you. Move your shoulder up and down. The up and down movement of the shoulder is called the shoulder pitch.

Second Degree: Arm Yaw Point your entire arm straight out in front of you. Move your entire arm from side to side. This side to side movement is called the arm yaw.

Third Degree: Shoulder roll Point your entire arm straight out in front of you. Now, roll your entire arm from the shoulder, as if you were screwing in a light bulb. This rotating movement is called a shoulder roll.

Fourth Degree: Elbow Pitch Point your entire arm straight out in front of you. Hold your arm still, then bend only your elbow. Your elbow can move up and down. This up and down movement of the shoulder is called the shoulder pitch.

Fifth Degree: Wrist Pitch Point your entire arm straight out in front of you. Without moving your shoulder or elbow, flex your wrist up and down. This up and down movement of the wrist is called the wrist pitch.

Sixth Degree: Wrist Yaw Point your entire arm straight out in front of you. Without moving your shoulder or elbow, flex your wrist from side to side. The side to side movement is called the wrist yaw.

Six degrees of freedom: Six degrees of freedom (6DoF) refers to the freedom of movement of a rigid body in three-dimensional space. Specifically, the body is free to move forward/backward, up/down, left/right (translation in three perpendicular axes) combined with rotation about three perpendicular axes, often termed pitch and roll.

An example of six degree of freedom movement is the motion of a ship at sea. It is described as

Translation:

Moving up and down (heaving);

Moving left and right (swaying);

Moving forward and backward (surging);

Rotation:

Tilting forward and backward(pitching)

Turning left and right (yawing)

Tilting side to side (rolling)

Seventh Degree: Wrist Roll Point your entire arm straight out in front of you. Without moving your shoulder or elbow, rotate your wrist, as if you were turning a doorknob. The rotation of the wrist is called the wrist roll.

Cartesian coordinate frame: The most used and familiar coordinate system is the Cartesian coordinate system. Most will be familiar with this as the X, Y; axis is at 90° to each other. A point can be located on a plane by locating the distance of a point from its origin(0, 0) along each axis. This is a 2 dimensional representation, hence the two axis X & Y. To find a point in space it is necessary to add a third axis (Z).This third axis will form a 3 dimensional grid that matches a set of coordinates to a single point in space.

The axes of machines are always defined by what is known as the right-hand rule. If we take the thumb as pointing in the direction of the positive X-Axis then the second finger is pointing towards the positive Y-Axis and the middle finger towards the positive Z-Axis. The Z axis is always in the direction of the spindle or grab arm as shown in the ‘Cartesian Robot’ below.

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The description of robot motion:

The main function of robot control software (e.g. Robot Ware) is the motion control of a robot. The motion of robot’s manipulator joints, the tool or the gripper can be described in different coordinate systems. These coordinate systems are used for the realization of several control functions, including off-line programming, program adjustment, coordination of the motion of several robots or a robot and additional servo drives, jogging motion, copy of programs from one robot to another, etc. The main coordinate systems used to describe the motion of a robot are shown because different types of grippers and tools have different dimensions, a special point, not depending on the type of the tool and called tool centre point (TCP) is selected. This point is the origin point of the tool coordinate system. A similar point can be used to describe the gripper or the wrist coordinate system. The mutual connections of a tool, a wrist and other coordinate systems are shown in Fig

The position of the robot and its movements are always related to the tool centre point (TCP). This point is normally defined as being somewhere on the tool, e.g. on top of the welding electrode or at the centre of a gripper. When a position is recorded, it is the position of the TCP that is recorded. This is also the point that moves along a given path at a given velocity. 7If the robot holding a work

object and is working on a stationary tool, a stationary TCP is used. If that tool is active, the programmed path and speed are related to the work object.

Tool coordinate system: The orientation of a tool at a programmed position is given by the orientation of the tool coordinate system. The tool coordinate system refers to the wrist coordinate system, defined at the mounting flange on the wrist of the robot. The tool mounted on the mounting flange of the robot often requires its own coordinate system to enable the definition of its TCP, which is the origin of the tool coordinate system Fig The tool coordinate system can also be used to get appropriate motion directions when jogging the robot. If a tool is damaged or replaced, the tool coordinate system must be redefined.

Wrist coordinate system: In a simple application, the wrist coordinate system can be used to define the orientation of the tool; here the z-axis is coincident with axis 6 of the robot Fig The wrist coordinate system cannot be changed and is always the same as the mounting flange of the robot in the following respects: The origin is situated at the centre of the mounting flange (on the mounting surface). The x-axis points in the opposite direction, towards the control hole of the mounting flange. The z-axis points outwards, at right angles to the mounting flange.

Base coordinate system is linked to the mounting base and stationary base of a robot. In a simple application, programming can be done in the base coordinate system; here the z-axis is coincident with axis 1 of the robot

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In this case:

- The origin is situated at the intersection of axis 1 and the base mounting surface. --The x and y plane is the same as the base mounting surface.

-The x-axis points forwards.

- The y-axis points to the left (from the perspective of the robot).

- The z-axis points upwards.

For example, floor-mounted robot can be easily programmed in the base coordinate system. If, however, the robot is mounted upside down (suspended), programming in the base coordinate system is more difficult because the directions of the axes are not the same as the principal directions in the working space. In such cases, it is useful to define a world coordinate system.

World coordinate system: will be coincident with the base coordinate system if it is not specifically defined. If several robots work within the same working space at a plant, a common world coordinate system is used to enable the robot programs to communicate with one another. It can also be advantageous to use this type of a system when the positions are to be related to a fixed point in the work shop as shown in fig

The user coordinate system: is related to the essential points of the technological process. A robot can work with different fixtures or working surfaces having different positions and orientations. A user coordinate system can be defined for each fixture. If all positions are stored in object coordinates, you will not need to reprogram if a fixture must be moved or turned. By moving (translating or turning) the user coordinate system as much as the fixture has been translated or turned, all programmed positions will follow the fixture and no reprogramming will be required. The user coordinate system is defined based on the world coordinate system

Object coordinate system: is a coordinate system targeted to an object. Normally the user coordinate system is used to get different coordinate systems for different fixtures or working surfaces. A fixture, however, may include several work objects that are to be processed or handled by the robot. Thus, it often helps to define ac coordinate system for each object in order to make it easier to adjust the program if the object is moved or if a new object, the same as the previous one, is to be programmed at a different location. This coordinate system is also very well suited for off-line programming since the positions specified can usually be taken directly from a drawing of the work object. The object coordinate system can also be used when jogging the robot. The object coordinate system is defined based on the user coordinate system. The object coordinate system can be programmed by the numerical definition of characteristic points or by a

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manual jogging manipulator via characteristic points and automatic storage of these coordinate values in memory.

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The programmed positions are always defined relative to an object coordinate system. If a fixture is moved or turned, it can be compensated for by moving or turning the user coordinate system. Neither the programmed positions nor the defined object coordinate systems need to be changed. If the work object is moved or turned, it can be compensated for by moving or turning the object coordinate system.

If the user coordinate system is movable, i.e. coordinated external axes are used, and then the object coordinate system moves with the user coordinate system. This makes it possible to move the robot in relation to the object even when the workbench is being manipulated .Sometimes the same path is to be performed at several places on the same object. To avoid having to re-program all positions each time, a displacement coordinate system can be defined. This coordinate system can also be used in conjunction with searches to compensate for differences in the positions of the individual parts. The displacement coordinate system defined based on the object

coordinate system.

Programmed motion of a robot

A robot has the following types of programmed movements:

Joint motion (joint interpolation) is the independent movements of joints to the destination position. Reaching the position happens at the same time moment.

Linear motion (linear interpolation). The TCP is moving along a straight line.

-Circle motion (circular interpolation). The tool centre point is moving along a circle.

Joint interpolation: When the accuracy of the path is not too important, this type of motion is used to move the tool quickly from one position to another. Joint interpolation also allows an axis to move from any location to another within its working space in a single movement. All axes move from the start point to the destination point at constant axis velocity. The velocity of the tool centre point is expressed in mm/s (in the object coordinate system).As interpolation takes place axis-by-axis, the velocity will not be exactly the programmed value. During interpolation, the velocity of the limiting axis, i.e. the axis that travels fastest relative to its maximum velocity in order to carry out the movement, is determined. Then the velocities of the remaining axes are calculated so that all axes reach the destination point at the same time. All axes are coordinated in order to obtain a path that is independent of the Velocity. Acceleration is automatically optimized to the max performance of the robot.

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Linear interpolation: During linear interpolation, the TCP travels along a straight line between the start and destination points. To obtain a linear path in the object coordinate system, the robot axes must follow a non-linear path in the axis space. The more non-linear the configuration of the robot is, the more accelerations and decelerations are required to make the tool move in a straight line and to obtain the desired tool orientation. If the configuration is extremely non-linear (e.g. in the proximity of wrist and arm singularities), one or more of the axes will require more torque than the motors can give. In this case, the velocity of all axes will automatically be reduced. The orientation of the tool remains constant during the entire movement unless a reorientation has been programmed. If the tool is re-orientated, it is rotated at constant velocity. A maximum rotational velocity (in degrees per second) can be specified when rotating the tool. If this is set to a low value, reorientation will be smooth, irrespective of the velocity defined for the tool centre point. If it is a high value, the reorientation velocity is only limited by the maximum motor speeds. As long as no motor exceeds the limit for the torque, the defined velocity will be maintained. If, on the other hand, one of the motors exceeds the current limit, the velocity of the entire movement (with respect to both the position and the orientation) will be reduced. All axes are coordinated in order to obtain a path that is independent of the velocity. Acceleration is optimized automatically.

Circular interpolation: The trajectory circular interpolation is used for tool motion as well as for interpolation near the intermediate via points of nonlinear trajectory. A circular path is defined using three programmed positions that define a circle segment. The first point to be programmed is the start of the circle segment. The next point is a support point (circle point) used to define the curvature of the circle, and the third point denotes the end of the circle. The three programmed points should be dispersed at regular intervals along the arc of the circle to make this as accurate as possible. The orientation defined for the support point is used to select between the short and the long twist for the orientation from the start to the destination point. If the programmed orientation is the same relative to the circle at the start and the destination points, and the orientation at the support is close to the

same orientation relative to the circle, the orientation of the tool will remain constant relative to the path.

Classification of robots: Now a day, robots do a lot of different tasks in many fields and the number of jobs entrusted to robots is growing steadily. That's why in my opinion one of the best ways how to divide robots into types is a division by their application. Robots can be classified in various ways, depending on their components, configuration, and use. Three common methods of classifying robots are by the types of control system used, the type of actuator drive used, and the shape of the work envelope

There are:

1. Cortisone robots

2. Cylindrical robots

3. Spherical or polar robots

1. Cartesian robots: Cartesian robots are used for pick and place work, application of sealant, assembly operations, handling machine tools and arc welding. It’s a robot whose arm has three prismatic joints, whose axes are coincidental with the Cartesian coordinators.

Applications of Cartesian robots:

This robot is being used to apply adhesive to a pane of glass. This robot is capable of handling large sized work pieces.

This orientation of a Cartesian robot transfers Integrated Circuits (ICs) from a pallet and transfers the part to a specific place.

Companies need to monitor their products to ensure that they are of a high quality. Cameras mounted on the Cartesian robot above monitor the passing components for in accuracy. Due to its construction the robot can move along with the moving conveyor and focus on a product at once. Owing to its linear movement the Cartesian robot is ideal for the transfer and stacking of

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sheet metal or timber sheets. It can feed sheets into processing machines or draw them away as finished products.

2. Cylindrical robots: Cylinder robots are used in assembly operations, handling of machine tools, spot welding and handling at die cast machines. They also have many uses in medical testing. The example below has two prismatic joints and one rotary joint. A Cylindrical robot is able to rotate along its main axes forming a cylindrical shape.

Applications of cylindrical robots:

The medical robot is used in numerous medical applications, for DNA screening, forensic science, drug development and toxicology. These robots are suitable in medical research where hundreds of samples must be tested and the same repetitive tasks performed many times. The robot eliminates human error providing more repeatable yields and consistent results A typical example of its duties would be to pull out a drawer to access a test plates, lift out a sample plate, close the drawer and finally take the sample to another instrument to be tested.

3.Spherical or Polar Robots:

Spherical or Polar Robots combine rotational movements with single linear movements of the arm. The polar robot is sometimes referred to as the gun turret configuration. They are generally used in many welding applications mainly spot, gas and arc. Polar robots are extremely suitable for reaching into horizontal or inclined tunnels

Applications of polar robot: The main application for these types of robots is welding. They can be quite large and weigh over a 1000kg. Polar Robots are used widely in the car manufacturing industries.

Industrial robots: Industrial robots are robots used in an industrial manufacturing environment. An industrial robot is defined by as an automatically controlled, re programmable multipurpose manipulator program. The field of robotics may be more practically defined as the study, design and use of robot systems for manufacturing (a top-level definition relying on the prior definition of robot).Usually these are articulated arms specifically developed for such applications as welding, material handling, painting and others. If we judge purely by application this type could also include some automated guided vehicles and other robots.

Domestic or household robots: Robots used at home. This type of robots includes many quite different devices such as robotic vacuum cleaners, robotic pool cleaners, sweepers, gutter cleaners and other robots that can do different chores. Also, some surveillance and teal presence robots could be regarded as household robots if used in that environment.

Types of industrial robots are:

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1. Sacra robots

2. Six axis robots

3. dual-arm robot

4. Welding robot

5 .material handling robot

6. Paint robot

7. Assembly robot

Scare robots: Scare robots are robots that can do 3 translations plus a rotation around a vertical axis. This configuration was developed to meet the needs of modern assembly work where fast movement with light payloads is required. The rapid placement of electronic components on PCB’s is an obvious application The Scare robot is a combination of two horizontal rotational axes and one linear that moves vertically.

The SCARA robot is based on a 4-axis design. It is ideal for high-speed assembly, kitting, packaging, and other material-handling applications.

Applications:

The Scare robot is testing a newly made calculator to ensure it is operational prior to packaging. The camera observes the screen to see if the operation performed by the robot is achieving the desired result.

The Scare design can quickly remove components from an assembly line and accurately stack them.

The Scare robot is excellent for precision positioning and makes it very suitable for the assembly of components.

The picture above shows the robot taking parts from the supply unit and assembling them. The robot can pivot around to the left and change its gripping hand to a screw or drilling head. These different heads for the robot are known as end effectors.

Revolute robot:

The revolute robot or Puma as it is also known most resembles the human arm with three main rotational degrees of freedom. The manipulator rotates on the base much like the human waist. The other two rotational axes resemble the shoulder and the elbow. The additional wrist action adds two more degrees of freedom, movement up and down (pitch) and rotation (roll). A final movement is Yaw which is the movement of the wrist from side to side

Applications of revolute robot:

This kind of robot is ideal for spray painting where it can be taught the human movements required to paint an object.

Due to their manufacture based on the human hand the Revolute robot is suitable for numerous application. These include welding, pick and place operations, component assembly and electrical soldering.

Humanoid robots: The development of robots resembling the human body over the last number of years has been

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for more entertainment value than that of practicality. However this trend is changing with much research being carried out on how these robots could blend into our lives and perform human chores. The film industry has released films like ET, Transformers, AI and I robot that have all toyed with the idea of robots as humans with feelings and emotions. This type of robots are used in defense, space shuttles etc.,

Medical robots: Robots used in medicine and medical institutions. First and foremost - surgery robots. Also, some automated guided vehicles and may befitting aides. Service robots: Robots that don’t fall into other types by usage. These could be different data gathering robots, robots made to show off technologies, robots used for research, etc. Military robots: Robots used in military. This type of robots includes bomb disposal robots, different transportation robots, reconnaissance drones. Often robots initially created for military purposes can be used in law enforcement, search and rescue and other related fields. Space robots: out robots used in space as a separate type. This type would include robots used on the International Space Station, Canada that was used in Shuttles, as well as Mars rovers and other robots used in space.

Hobby and competition robots: Robots that you create. Line followers, sumo-bots, robots made just for fun and robots made for competition.

Now, as you can see there are examples that fit into more than one of these types. For example, there can be a deep sea exploration robot that can gather some valuable information that can be used for military purposes.

Forces and Moments:

For an efficient and successful robot it is necessary to look at the various forces that both inhibit and help the operations of a robot. It is important to select the right servo motor for a specific joint as over loading can cause the life of the servo to be cut short. Firstly the torque

required of the servo will be defined by the force (moment) acting about it.

Moment = Force (Newton’s) x Distance (Meters).

The force the arm will exert on the servo will be determined by a number of factors. The main consideration is the weight that the arm is required to lift. Secondly the weight and length of the arm are two important factors. The weight of the arm and the weight of the load must be added together. The length of the arm is also important as it determines the distance of the load from the fulcrum (pivot point).

Moment = Force x Distance,

the moment acting around the servo will be greater the longer the arm.

To calculate the total moments about the servo you would add the moments of the arm and the load together.

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To calculate the total moments about the servo you would add the moments of the arm and the load together.

Moment = (Load weight x arm length) + (arm weight * ½ arm length)

Notice that for the arm length we only use half the value. This is because the weight of the arm is acting over the entire arm and not at the very end of it. The centre of gravity of the arm is where the arm would balance perfectly if suspended from a string. In this example we can estimate the centre of gravity of the arm is the centre of the arm. Once this calculation has been complete the answer is the actual torque being applied. This is the minimum torque required from a motor. To allow for simple overloading and smooth operation a motor of a higher torque value should be used; this is known as a factor of safety. It is recommended that if a motor of 100Nm is needed then look for a motor with 20% higher torque

Actuators:

Motors are the most common way to control the movements of robots and are known as actuators. They can be connected to gears and wheels and are a perfect way of adding mobility. There are a number of different types of motors that can be used, dc, stepper and servo motors.

DC Motors

These are the most common motors available, connected to a power supply by two wires. The direction of a DC motor can be changed by reversing the polarity of the motor supply voltage. DC motors draw a large amount of current and as a result cannot be wired straight from a control system such as PIC. DC motors do not offer accurate, controlled rotation.

Stepper Motors:

Stepper motors work in a similar way to dc motors, however where a dc motor has just one electromagnet, the stepper has many. The stepper is controlled by the sequential turning on and off of these coils. Each time a

new coil is energized the motor rotates another couple of degrees. The number of degrees that a motor turns with each pulse is called the step angle. Repeating the sequence causes it to move a few more degrees, this continues until a full rotation is achieved. The diagram below shows how a basic motor works. The magnet in the middle is joined to the motor shaft. The four magnets on the outside represent each coil of the tipper motor. As the coils are energized the centre magnet is attracted in different directions, therefore the correct sequence of pulses will achieve motor rotation.

The common stepper motors that are used in projects operate on the same principle as the simple examples above. The main benefit of the stepper motor is controlled movement. The above motors have step angles of 90°. This large angle will not make for smooth movements. This is over come using of a gear shaped toothed steel disc that replaces the rotating magnet in the centre.

The top electromagnet (1) is turned on, attracting the nearest teeth of the disc. When the teeth are aligned to the top electromagnet they are slightly out of line with electromagnet (2).

Continuing the sequence the electromagnet (3) is powered and another step occurs

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The last electromagnet (4) is activated pulling the rotor another 3.6°. When the first electromagnet is energized again the teeth in the sprocket will have rotated by one tooth. As there are 25 teeth on the disc it will take 100 steps to complete one rotation. 25teeth x 4steps per tooth = 100 steps.

Stepper motors convert electrical pulses into discrete mechanical rotational movements. They offer very good holding torque, speed regulation and accurate movement. The wearing parts in a stepper motor are limited, unlike the DC motor they do not contain brushed which can wear and lead to malfunction. Steppers are used in printer control, conveyor belt drives, photo or film processing machine and also in scanners.

Stepper motors require a controller to operate them. Legislator caters for stepper control once the correct sequencing table for the specific motor is available. The motor has six wires that will connect to the PIC board. Two are used for constant 0v & 5v, the four others are direct outputs from the PIC.

Servo Motors: Of the three motors, the servo motor offers the smoothest and greatest control. They can be told to rotate to a specific point, making them ideal for applications that require precise movement. The rotation of a servo is limited; most rotate from 90° to 180° though some can complete a full rotation. They cannot rotate continually due to their structure so are unsuitable for driving wheels, but their torque and control make them suitable for powering robotic arms and such. Servos have three wires connected to them.

As with the stepper motor two of the wires are for the power supply- 0v & 5v. The third cable feeds straight from the PIC output pin and cannot be received via a transistor

chip, this is to ensure that it is a frequency that the servo receives, not a straight current. The potentiometer is connected to the motor through a gear train. A signal is given to the motor to rotate to a given position, as the motor turns it also moves the potentiometer causing its resistance to change. This resistance is monitored by the control circuit ensuring Servos have three wires connected to them.

Servos are positioned using a technique called Pulse Width Modulation. Servos generally require a pulse width of 0.75ms to 2.25ms every 20ms.This pulse width must be constantly repeated every 20ms, if the pulse is lost the servo will loosen its position. Pulse widths of 0.75ms to 2.25ms take the servo from 0° to 150°, any pulse widths between these can be selected to achieve the required position. It is the pulse width that controls the position of the servo, not the number of times it is repeated each second.

End Effectors: In the robotic world it is generally understood that the end of the wrist is the end of the robot. The robot has the capability of moving to various positions within the limits of its work envelope. The robot is not yet prepared for the operation that it has to carry out; it does not have the correct “Hand”. The end effect is the correct name for the attachment that can be mounted to a bolting plate fitted to the wrist. These attachments can be for grasping, lifting, welding, painting and many more. This means that the standard robot can be carry out a vast range of different applications depending on the end effectors that is fitted to it.

Mechanical grippers: There are two types of end effectors- grippers and tools. Tools are used where an operations such as welding, painting or drilling need to be performed. Their shapes and types are numerous and varied.

Drilling and end effectors with bush attached: There are three basic categories of grippers- mechanical, magnetic and pneumatic.

Mechanical gripper: The most common type of gripper is the two finger type as seen in the picture previously. There are multiple finger types capable of more Complex.

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The mechanics of a gripper is that the gripper fingers close against the object with sufficient mechanical force to hold the object firmly against gravity and movement forces. The force should not however be too severe and cause damage to the component. The grippers may be powered by servos, pneumatic or hydraulic power. Mechanical grippers may not always be suitable for handling some components due to their size or delicacy. Magnetic or pneumatic grippers offer alternative solutions to managing components.

Multiple finger grippers

Magnetic grippers: These grippers are use to handle ferrous material. The grippers will be electromagnetic or permanent magnets. The electromagnetic can pick and release it component by switching on and off the magnet. Using a permanent means that the component cannot be simply dropped from the magnet, it must be slid off using a pneumatic piston. This may seem pointless when an electromagnet can be used. There is reduced risk of sparking because no electrical power is used, makes these types more suited in certain hazardous environments.

Pneumatic or Vacuum Grippers: Circular vacuum or suction cups made from plastic or rubber form pneumatic grippers. The cups press against the material to be lifted and the air drawn out by means of a pump, creating a plunger effect. This suction force allows the component to be lifted. The weight and centre of gravity of the components determines the number of suction cups used.

To allow for an effective suction the object to be lifted must have a relatively smooth flat and clean surface. Releasing of the part once it reaches its destination simply means neutralizing the vacuum and allowing air into the suction pads.

Safety precisions in robots:

1. Use protective cover to prevent workers from being in contact with the robots in operation or working area.

2. Robots should be equipped with safety precautions like alarms, flashes and shields, etc.

3. Understand the tensile strength of the robot and avoid overloading.

4. Take measures to avoid bug or failure of the software, for instance, robots equipped with several processors; auto disconnection when computer cannot be connected with the robots for a long time; two computers working simultaneously to check the data, etc.

5. Always test and maintain to avoid the malfunction of robots. For instance, addition of sensors to test and track information of voltage, pressure, temperature, velocity and acceleration etc. Backup hardware should be added to prevent malfunction, for instance, when carrying load, more operating machines should be used, so as to avoid accidents when one of them fails to function properly and drops the heavy load.

SOLIDWORKS

Solid Works is mechanical design automation software that takes advantage of the familiar Microsoft Windows graphical user interface.

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It is an easy-to-learn tool which makes it possible for mechanical designers to quickly sketch ideas, experiment with features and dimensions, and produce models and detailed drawings.

A Solid Works model consists of parts, assemblies, and drawings.

Typically, we begin with a sketch, create a base feature, and then add more features to the model. (One can also begin with an imported surface or solid geometry).

We are free to refine our design by adding, changing, or reordering features.

Associatively between parts, assemblies, and drawings assures that changes made to one view are automatically made to all other views.

We can generate drawings or assemblies at any time in the design process.

The Solid Works software lets us customize functionality to suit our needs.

INTRODUCTION TO SOLIDWORKS

Solid works mechanical design automation software is a feature-based, parametric solid modeling design tool which advantage of the easy to learn windows TM graphical user interface. We can create fully associate 3-D solid models with or without while utilizing automatic or user defined relations to capture design intent.

Parameters refer to constraints whose values determine the shape or geometry of the model or assembly. Parameters can be either numeric parameters, such as line lengths or circle diameters, or geometric parameters, such as tangent, parallel, concentric, horizontal or vertical, etc. Numeric parameters can be associated with each other through the use of relations, which allow them to capture design intent.

Design intent is how the creator of the part wants it to respond to changes and updates. For example, you would

want the hole at the top of a beverage can to stay at the top surface, regardless of the height or size of the can. Solid Works allows you to specify that the hole is a feature on the top surface, and will then honor your design intent no matter what the height you later gave to the can. several factors contribute to how we capture design intent are Automatic relations, Equations, added relations and dimensioning.

Features refer to the building blocks of the part. They are the shapes and operations that construct the part. Shape-based features typically begin with a 2D or 3D sketch of shapes such as bosses, holes, slots, etc. This shape is then extruded or cut to add or remove material from the part. Operation-based features are not sketch-based, and include features such as fillets, chamfers, shells, applying draft to the faces of a part, etc.

Building a model in Solid Works usually starts with a 2D sketch (although 3D sketches are available for power users). The sketch consists of geometry such as points, lines, arcs, conics (except the hyperbola), and splices. Dimensions are added to the sketch to define the size and location of the geometry. Relations are used to define attributes such as tangency, parallelism, perpendicularity, and concentricity. The parametric nature of Solid Works means that the dimensions and relations drive the geometry, not the other way around. The dimensions in the sketch can be controlled independently, or by relationships to other parameters inside or outside of the sketch.

Several ways a part can be builded like

1. Layer-cake approach :The layer-cake approach builds the part one piece at a time, adding each layer, or feature, onto the previous one.

2. Potter’s wheel approach :The potter’s wheel approach builds the part as a single revolved feature. As a single sketch representing the cross section includes all the information and dimensions necessary to make the part as one feature.

3. Manufacturing approach :The manufacturing approach to modeling mimics the way the part would be manufactured. For example, if the

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stepped shaft was turned a lathe ,we would start with a piece of bar stock and remove material using a series of cuts.In an assembly, the analogue to sketch relations is mates. Just as sketch relations define conditions such as tangency, parallelism, and concentricity with respect to sketch geometry, assembly mates define equivalent relations with respect to the individual parts or components, allowing the easy construction of assemblies. Solid Works also includes additional advanced mating features such as gear and cam follower mates, which allow modelled gear assemblies to accurately reproduce the rotational movement of an actual gear train.

Finally, drawings can be created either from parts or assemblies. Views are automatically generated from the solid model, and notes, dimensions and tolerances can then be easily added to the drawing as needed. The drawing module includes most paper sizes and standards.

A Solid Works model consists of parts, assemblies, and drawings.

(1) Part: Individual components are drawn in the form of part drawings.

(2) Assembly: The individual parts are assembled in this region.

(3) Drawings: This contains detailed information of the assembly.

HISTORY OF SOLIDWORKS

Solid Works Corporation was founded in December 1993 by Massachusetts Institute of Technology graduate Jon Hirsch tick ; Hirsch tick used $1 million he had made while a member of the MIT Blackjack Team to set up the company. Initially based in Waltham, Massachusetts, USA, Hirsch tick recruited a team of engineers with the goal of building 3D CAD software that was easy-to-use, affordable, and available on the Windows desktop. Operating later from Concord, Massachusetts, Solid

Works released its first product Solid Works 95, in 1995. In 1997 Desalt, best known for its CATIA CAD software, acquired Solid Works for $310 million in stock.

Solid Works currently markets several versions of the Solid Works CAD software in addition to e Drawings, a collaboration tool, and Draft Sight, a 2D CAD product.

Solid Works was headed by John McLane from 2001 to July 2007 and Jeff Ray from 2007 to January 2011. The current CEO is Bertrand Sicot.

Solid works versions:

Name/Version Version History Value

Release Date

Solid Works 95 44 1995

Solid Works 96 243 1996

Solid Works 97 483 1996

SolidWorks 97Plus 629 1997

Solid Works 98 817 1997

SolidWorks 98Plus 1008 1998

Solid Works 99 1137 1998

Solid Works 2000 1500 1999

Solid Works 2001 1750 2000

SolidWorks2001Plus 1950 2001

Solid Works 2003 2200 2002

Solid Works 2004 2500 2003

Solid Works 2005 2800 2004

Solid Works 2006 3100 2005

Solid Works 2007 3400 2006

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Solid Works 2008 3800 July 1, 2007

Solid Works 2009 4100 January 28, 2008

Solid Works 2010 4400 December 9, 2009

Solid Works 2011 4700 June 17, 2010

Solid Works 2012 5000 September, 2011

Solid Works 2013 6000 September, 2012

Solid Works 2014 7000 October, 7, 2013

SOLIDWORKS 3-D MECHANICAL DESIGN APPLICATIONS:

Solid Works Standard

Solid Works Professional

Solid Works Premium: provides a suite of product development tools mechanical design, design verification, data management, and communication tools. Solid Works Premium includes all of the capabilities of Solid Works Professional as well as routing and analysis tools, including Solid Works Routing, Solid Works Simulation, and Solid Works Motion.

Solid Works Education Edition: provides the same design functionality but is configured and packaged for engineering and industrial design students.

DESIGN VALIDATION TOOLS:

Solid Works Simulation is a design validation tool that shows engineers how their designs will behave as physical objects.

Solid Works Motion is a virtual prototyping tool that provides motion simulation capabilities to ensure designs function properly.

Solid Works Flow Simulation is a tool that tests internal and external fluid-flow simulation and thermal analysis so designers can conduct tests on virtual prototypes.

Solid Works Simulation Premium is a Finite Element Analysis (FEA) design validation tool that can handle some multi physics simulations as well as nonlinear materials.

PRODUCT DATA MANAGEMENT TOOLS :

Solid Works Workgroup PDM is a PDM tool that allows Solid Works users operating in teams of 10 members or less to work on designs concurrently. With Solid Works PDM Workgroup, designers can search, revise, and vault CAD data while maintaining an accurate design history.

Solid Works Enterprise PDM is a PDM tool that allows Solid Works users operating in teams at various separate facilities to work on designs concurrently. With Solid Works Enterprise PDM, designers can search, revise, and vault CAD data while maintaining an accurate design history. Enterprise PDM maintains an audit trail, is compatible with a variety of CAE packages (Auto Desk, Siemens, PTC, Catia, etc.) to maintain interfile relations, and will manage the revisions of any document saved in the vault. Enterprise PDM also uses a workflow diagram to automatically notify team members when a project moves from one stage to the next, as well as tracking comments. Enterprise PDM is capable of interfacing with various MRP/ERP systems and can be used online to interface with customers and the supply chain.

DESIGN COMMUNICATION AND COLLABORATION TOOLS:

eDrawings Professional :An e-mail-enabled communication tool for reviewing 2D and 3D product design data across the extended product development team. eDrawings generates accurate representations of DWG gateway is a free data translation tool that enables any AutoCAD software user to open and edit any DWG file, regardless of the version of AutoCAD it was made in.

Mobile e Drawings

Solid Works Viewer: is a free plug-in for viewing Solid Works parts, assemblies, and drawings.

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'3DVIA Composer', now known as 'Solid Works Composer', is a technical communications software that allows 3D views of models to be integrated into documents such as work instructions, internal or external manuals, marketing materials, or web applications. The 3D views can be updated automatically when the design updates, reducing the workload of the employee creating the technical document, as editing for changes is not as severe.

CAD PRODUCTIVITY TOOLS:

Solid Works Toolbox is a library of parts that uses "Smart Part" Technology to automatically select fasteners and assemble them in the desired sequence.

Solid Works Utilities is software that lets designers find differences between two versions of the same part, or locate, modify, and suppress features within a model.

Feature Works is feature recognition software that lets designers make changes to static geometric data, increasing the value of translated files. With Feature Works, designers can preserve or introduce new design intent when bringing 3D models created in other software into the Solid Works environment.

Design of robotic parts:

1.Base 2.Actuator 3.wrest 4.arm the robot 5.shoulder swivel 6.assembly of shoulder swivel and arm robot 7.assembly of robot arm

Base of a robot:

Actuator of a robot:

Wrest of robot arm:

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Arm of the robot:

Robot arm shoulder swivel:

Assembly of shoulder swivel and arm:

Assembly of robot arm:

Conclusion:

Pick and place of six degrees freedom arm MOTO MEN ES 165D-100 robot is designed by using SOLID WORKS PREMIUM 2014.

The design concept is to said the robotic arm mechanism to load and unload the object, with the entire design concept, continue the next level that is analysis based on the design concepts.

Analysis included weight consideration, material consideration and size consideration.

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The purpose of analysis is to get result with slightly affected the performance of the robotic arm.

After completing all the process, fabrication process will takes place

REFERENCES:

[1] Chun Htoo Aung, Khin Thandar Lwin, and Yin Mon Myint, Modeling Motion Control System for Motorized Robot arm using MATLAB, World Academy of Science, Engineering and Technology 42 2008.

[2] Ahmad A. Mahfouz ,Mohammed M. K., Farhan A. Salem, Modeling, Simulation and Dynamics Analysis Issues of Electric Motor, for Mechatronics Applications, Using Different Approaches and Verification by MATLAB/Simulink (I). IJISA Vol. 5, No. 5, 39-57 April 2013 .

[3] Norman S. Nise, Control system engineering, sixth edition, John Wiley & Sons, Inc, 2011.

[4] Farhan A. Salem, Modeling controller selection and design of electric DC motor for Mechatronics applications, using different control strategies and verification using MATLAB/Simulink, Submitted to European Scientific Journal, 2013

[5] M.P.Kazmierkowski, H.Tunia "Automatic Control of Converter-Fed Drives", Warszawa 1994.

[6] R.D. Doncker, D.W.J. Pulle, and A. Veltman. Advanced Electri-cal Drives: Analysis, Modeling, Control. Springer, 2011.

[7] Grzegorz SIEKLUCKI,Analysis of the TransferFunction Models of Electric Drives with Controlled Voltage Source PRZEGL ˛ AD ELEKTROTECHNICZNY (Electrical Review), ISSN 0033-2097, R.88NR7a/2012.

[8] An educational MATLAB m.file applied to PMDC motor controllers design comparison, selection and analysis Ahmad A. Mahfouz, Farhan A. Salem

[9] B. Shah, Field Oriented Control of Step Motors, MSc. Thesis, SVMITB haruch, India, Dec. 2004. Modeling, Simulation and Control Issues for a Robot ARM; Education and Research (III) 39 Copyright © 2014 MECS I.J. Intelligent Systems and Applications, 2014, 04, 26-39

[10] Jamal A. Mohammed, Modeling, Analysis and Speed Control Design Methods of a DC Motor Eng. & Tech. Journal, Vol. 29, No. 1, 2011

[11] R.C. Dorf and R.H. Bishop, Modern Control Systems,10th Edition, Prentice Hall, 2008