ME 50052 (IR&A) notes in English

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Course Code : ME 50052 (Same as in MA 50052)
Course Title : INDUSTRIAL ROBOTICS & AUTOMATION

UNIT-I: FUNDAMENTALS OF ROBOTICS

1. Introduction

Robotics is a field of engineering and science that involves the design, construction, operation, and use of robots. Robots are machines designed to perform tasks that can be programmed or controlled automatically. The goal of robotics is to create robots that can assist humans or even replace humans in performing tasks that are dangerous, repetitive, or too complex.

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2. Definition of a Robot

A robot is defined as an automatic device that can perform a variety of tasks or operations. It is programmable and capable of carrying out tasks without direct human intervention. A robot typically performs actions based on pre-programmed instructions or responds to input from sensors or the environment.

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3. Robot Anatomy (Parts) and Its Working

A robot consists of several parts that work together to perform tasks. These parts include:

• Manipulator: The manipulator is the robotic arm or the system of mechanical links that moves and positions the end effector to perform tasks.

• End Effectors: These are devices attached to the end of the manipulator. The end effector interacts with the environment to perform specific tasks like gripping, welding, or painting.

• Base: The robot’s base is the stationary part that holds the entire robot structure. It provides stability and may include wheels or legs for movement.

• Controller: The controller is the "brain" of the robot. It processes instructions and controls the movement of the manipulator and end effector.

• Sensors: Robots use various sensors (e.g., proximity sensors, cameras, force sensors) to interact with and adapt to their surroundings.

• Power Supply: The power supply provides energy to the robot’s actuators and controllers, allowing it to function.

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4. Robot Components

• Manipulator: A manipulator is essentially the robot arm. It is the mechanism responsible for moving and positioning the end effector. The manipulator may consist of multiple links and joints.

• End Effectors: These are tools or devices attached to the end of the manipulator, designed to perform the desired task. Common examples include grippers, welding torches, or painting nozzles.

• Links: Links are the rigid components that connect the joints of the manipulator. Links can vary in length and shape and play a role in determining the robot's reach and dexterity.

• Joints: Joints are the movable parts that connect the links together. They enable the manipulator to move and achieve different positions. Joints are typically classified into two types:

  • Revolute Joints: These joints allow rotational movement.
  • Prismatic Joints: These joints allow linear (sliding) movement.

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5. Construction of Links

Links are constructed using materials such as metals (steel, aluminum) or lightweight alloys, depending on the required strength and weight considerations. The design of the links affects the robot’s overall flexibility, speed, and strength. Links must be designed to withstand the forces and stresses generated during movement.

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6. Types of Joints

There are several types of joints used in robots, allowing different types of movement:

• Revolute Joints: These joints allow rotation about an axis. This is the most common joint type, used for tasks that require circular movement.

• Prismatic Joints: These joints provide linear or sliding motion, allowing movement along a straight line.

• Spherical Joints: These joints allow movement in any direction, similar to how the human shoulder joint functions.

• Cylindrical Joints: These joints allow a combination of rotation and linear movement.

• Universal Joints: These joints allow for rotation in two different axes.

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7. Classification of Robots

Robots can be classified based on several factors:

• By Degrees of Freedom (DOF): This refers to the number of independent movements a robot can make. A robot with more DOF can perform more complex tasks. Common configurations include 2D robots (2 degrees of freedom) or 3D robots (3 degrees of freedom).

• By Type of Control:

  • Manual Robots: Controlled directly by human operators.
  • Autonomous Robots: Operate on their own with minimal human intervention, usually guided by sensors and programmed tasks.

• By Structure:

  • Articulated Robots: These robots have joints that allow them to perform rotational movements. They are often used in manufacturing and assembly.
  • SCARA Robots: Selective Compliance Assembly Robots are designed for high-speed, precise tasks like assembly.
  • Cartesian Robots: These are linear robots that move along X, Y, and Z axes.

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8. Structural Characteristics of Robots

• Mechanical Rigidity: Rigidity refers to the stiffness of the robot's structure. A rigid structure can hold its position accurately but may limit the flexibility of motion. In contrast, a flexible structure allows more movement but may not be as precise.

• Workspace: The workspace of a robot is the area within which it can move and perform tasks. The size and shape of the workspace depend on the robot's configuration, the length of the links, and the type of joints.

• Reachability: The reachability of a robot refers to the maximum distance the end effector can move from its base. This is important when determining the robot’s ability to perform tasks in larger or complex areas.

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9. Mechanical Rigidity

Mechanical rigidity refers to the resistance of the robot structure to deformation under load. A robot’s rigidity affects its ability to maintain precision during movements. Higher rigidity is desirable for tasks that require high accuracy, while lower rigidity may allow for more flexibility but at the cost of precision.

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10. Effects of Structure on Control Work Envelope and Work Volume

• Work Envelope: The work envelope of a robot is the volume or space that the robot can reach and work within. It depends on the robot’s manipulator size, type of joints, and configuration.

• Work Volume: The work volume is closely related to the work envelope. It defines the total area in which the robot can operate effectively and safely. For a robot to perform tasks efficiently, its work volume should cover the area of operation.

The robot's structure determines its range of motion, which influences both its work envelope and the work volume. A well-designed robot structure can maximize the work volume, enabling it to perform a wider variety of tasks.

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11. Robot Work Volumes: Comparison

Robots are designed with varying work volumes based on their intended applications.

• Articulated Robots: These robots generally have a large work envelope because they can rotate and move in multiple directions. This makes them suitable for tasks requiring complex movements, such as welding or painting.

• SCARA Robots: SCARA robots have a limited vertical work volume, but they are highly effective in horizontal plane tasks, making them ideal for assembly operations.

• Cartesian Robots: Cartesian robots typically have a rectangular work envelope, which is good for linear movements but may not be suitable for tasks requiring complex positioning.

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12. Advantages and Disadvantages of Robots

Advantages:

• Consistency and Precision: Robots can perform tasks with high accuracy and repeatability, reducing human error.
• Speed and Efficiency: Robots can work faster than humans, leading to higher productivity.
• Safety: Robots can be used in hazardous environments, reducing the risk to human workers.
• Versatility: Robots can be programmed to perform a wide range of tasks across different industries.

Disadvantages:

• High Initial Cost: The initial investment for a robot can be expensive, making it less accessible for smaller companies.
• Maintenance: Robots require regular maintenance and repair to ensure they continue to function correctly.
• Limited Flexibility: While robots are great for repetitive tasks, they can struggle with tasks that require adaptability or human-like decision-making.
• Job Displacement: Automation through robotics may lead to job losses in certain sectors as tasks become automated.

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Summary

This unit introduces the fundamentals of robotics, including its definition, components (manipulator, end effectors, links, and joints), and classifications. The structural characteristics of robots, including mechanical rigidity, work envelope, and work volume, are crucial factors in determining a robot’s performance. Robotics provides several advantages like improved precision and safety but also poses challenges such as high costs and potential job displacement.

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UNIT-II: ROBOTIC DRIVE SYSTEM AND CONTROLLER

1. Actuators in Robotics

Actuators are components that convert energy into motion. They are the "muscles" of the robot, enabling it to perform various actions like moving, rotating, lifting, or pushing. Actuators are typically driven by hydraulic, pneumatic, or electrical power. Each type of actuator has specific advantages and is used for different robotic applications depending on the required force, speed, and precision.

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2. Types of Actuators

Hydraulic Actuators:

• Hydraulic actuators use pressurized fluids (usually oil) to create motion.
• They are capable of producing large amounts of force with relatively smaller components.
• Applications: Hydraulic actuators are used in heavy-duty robots or tasks requiring high power, such as construction robots, industrial robots, and material handling systems.

Advantages:

• High power-to-weight ratio
• Can lift heavy loads
• Precise control for large forces

Disadvantages:

• Requires a hydraulic pump and fluid, making the system complex
• Potential leakage of fluid

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Pneumatic Actuators:

• Pneumatic actuators use compressed air to generate motion.
• These actuators are commonly used for robots that require lightweight, fast, and simple movements.
• Applications: Pneumatic actuators are used in robots for assembly, packaging, and simple manipulation tasks.

Advantages:

• Simple and cost-effective
• Lightweight
• Easy to control

Disadvantages:

• Lower force compared to hydraulic actuators
• Air leakage can cause a loss in efficiency

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Electrical Actuators:

• Electrical actuators use electric motors to create motion. They are the most common type of actuator in modern robotics.
• Applications: Electrical actuators are used in a wide variety of robots, including industrial robots, mobile robots, and robotic arms.

Advantages:

• High precision
• Easy to control using electrical signals
• Low maintenance compared to hydraulic and pneumatic systems

Disadvantages:

• Limited by torque and speed capabilities
• Less force generation compared to hydraulic actuators

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3. Linear Actuators

A linear actuator generates motion in a straight line, as opposed to the rotational movement that most actuators produce. It can be powered hydraulically, pneumatically, or electrically.

• Applications: Linear actuators are commonly used in robotic arms, lifting devices, or machines that need to perform tasks like pushing, pulling, or lifting in a straight line.

Types:

• Electric Linear Actuators: Use an electric motor to drive a screw or gear system.
• Hydraulic Linear Actuators: Use pressurized fluid to push a piston and create linear motion.
• Pneumatic Linear Actuators: Use compressed air to move a piston.

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4. Rotary Drives

A rotary drive generates rotational motion. This is the most common form of actuator movement used in robots, as it drives the joints of the robot.

• Applications: Rotary drives are used to control the movement of robotic arms and other rotating parts.

Rotary motion is achieved through electric motors, hydraulic systems, or pneumatic actuators that convert energy into rotational force.

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5. Motors Used in Robotic Drive Systems

• AC Servo Motors:
  • AC servo motors are used for precise control of angular position, speed, and acceleration.
  • Applications: AC servo motors are commonly used in high-performance applications like robotics, CNC machines, and automated manufacturing.

Advantages:

• Precise control
• High efficiency
• Faster response times

Disadvantages:

• More complex control systems are required
• Expensive compared to DC motors

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• DC Servo Motors:
  • DC servo motors are commonly used in robots for precise motion control. They use a direct current (DC) power supply and can be easily controlled by varying the voltage and current.
  • Applications: Used in robotic arms, small mobile robots, and automated manufacturing lines.

Advantages:

• Simple control
• High torque at low speeds
• Low cost

Disadvantages:

• Limited speed range
• May require a feedback system for accuracy

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• Stepper Motors:
  • A stepper motor divides a full rotation into multiple steps, allowing precise control over the motor's position. Stepper motors do not require feedback systems since their position is known from the number of steps taken.
  • Applications: Used in robotics for precise positioning, like in 3D printers, CNC machines, and small robotic arms.

Advantages:

• Precise control without feedback
• Cost-effective
• Reliable for open-loop control

Disadvantages:

• Limited torque at high speeds
• Can produce vibration and noise

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6. Conversion Between Linear and Rotary Motion

• Conversion between linear and rotary motion is essential in robotics, as actuators can either provide linear or rotary motion. Several devices are used to convert one type of motion into another:
  • Rack and Pinion: A system where a rotating gear (pinion) moves a linear gear (rack).
  • Lead Screw: A mechanism where the rotary motion of a screw is converted into linear motion along the axis of the screw.

These mechanisms are commonly used in robotic arms, conveyor systems, and other applications where motion needs to be converted from one type to another.

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7. Feedback Devices

Feedback devices are used in robotics to provide information about the position, speed, or torque of actuators, enabling precise control of robot movements. These devices send signals back to the robot controller, which uses this information to adjust the actuators.

• Potentiometers:
  • Potentiometers measure the position of an actuator by varying resistance as the actuator moves. The controller reads this resistance to determine the position.
• Optical Encoders:
  • Optical encoders use light sensors to detect the movement of a rotating disk attached to the motor. These devices can measure the number of rotations or position with high accuracy.
• DC Tachometers:
  • DC tachometers measure the rotational speed of a motor. They convert the rotational speed into a proportional electrical voltage, allowing the controller to monitor and adjust the speed.

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8. Robot Controller

The robot controller is the brain of the robot. It processes the instructions for robot movement, controls the actuators, and monitors the sensors. The controller's role is to interpret the inputs (from sensors, user commands, or programs) and then translate them into commands for the actuators to carry out.

• Types of Controllers:
  • Open-loop Controllers: These controllers do not receive feedback. They send commands to actuators without adjusting based on external data.
  • Closed-loop Controllers: These controllers receive feedback from sensors and adjust commands accordingly to achieve desired accuracy.

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9. Controller Programming

Controller programming refers to the process of creating programs that dictate how a robot will behave. It involves specifying the robot's movements, actions, and responses to environmental conditions.

• Programming Methods:
  • Teach Pendant Programming: In this method, the operator manually moves the robot through the desired path, and the robot records the movement to replicate it later.
  • Lead-through Programming: Similar to teach pendant programming, but the operator moves the robot in a natural way, and the controller records the movement automatically.
  • Offline Programming: This involves programming the robot on a computer without the need for the robot to be physically present.
  • Robot Programming Languages: These include specialized languages like VAL (robot programming language), which provide a way for the robot to interpret commands.

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Summary

• Actuators are the driving force behind robotic motion, with hydraulic, pneumatic, and electrical drives being the most common types.
• Linear and rotary actuators help robots perform different tasks that require straight or rotational motion.
• Motors such as AC and DC servos and stepper motors provide precise movement control for robots.
• Feedback devices like potentiometers, encoders, and tachometers ensure that robots perform tasks accurately by providing real-time position, speed, and torque data.
• The robot controller is responsible for interpreting input and controlling the robot’s movements, and programming the robot is essential for ensuring the robot carries out specific tasks effectively.

By understanding these concepts, you will have a clearer idea of how robots are powered, controlled, and programmed to perform tasks efficiently.

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UNIT-III: SENSORS

In robotics, sensors are essential components that allow robots to interact with their environment. They provide real-time data to the robot’s controller, enabling it to make decisions and perform tasks accurately. Below is a detailed explanation of the various topics under Sensors in robotics.

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1. Requirements of a Sensor Used in Robotics

Sensors are integral in robotics for a robot to perceive and interact with its surroundings. The requirements of sensors used in robotics include:

• Accuracy: Sensors must provide precise data to ensure accurate actions and responses from the robot.
• Range: The sensor should cover the range required for the robot’s task (e.g., the distance a proximity sensor can detect).
• Speed: Sensors must be fast enough to provide real-time feedback for the robot’s actions.
• Durability: Sensors should be robust and resistant to environmental conditions (e.g., temperature, humidity, dust).
• Cost: The sensor should be cost-effective without compromising performance.
• Size: Sensors should be small and lightweight to be integrated into compact robotic designs.
• Power consumption: They should have low power consumption, especially for mobile robots.

Sensors in robotics typically provide input data, which is processed by the robot’s controller to perform actions like detecting obstacles, monitoring force and pressure, and ensuring that tasks are completed accurately.

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2. Proximity Sensing

Proximity sensors detect the presence or absence of an object within a certain range, usually without physical contact. They are commonly used for obstacle detection, navigation, and ensuring safety around robots. These sensors are often used in industrial robots to prevent collisions.

• Types of Proximity Sensors:
  • Inductive Proximity Sensors: Detect metallic objects by creating a magnetic field and measuring changes when a metal object enters this field.
  • Capacitive Proximity Sensors: Detect objects based on changes in capacitance caused by the presence of a material near the sensor.
  • Ultrasonic Sensors: Measure distance by emitting sound waves and detecting the time it takes for the waves to bounce back from an object.
  • Infrared Sensors: Use infrared light to detect nearby objects by measuring the reflection of the emitted light.

Applications:

• Obstacle detection
• Object counting
• Positioning tasks

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3. Force and Torque Sensing

Force sensors measure the amount of force exerted on the robot, while torque sensors measure rotational force (torque) around a joint. These sensors are crucial for tasks like gripping, manipulating objects, and performing assembly operations with precision.

• Force Sensors: They can detect both pushing and pulling forces. These sensors help the robot maintain a delicate balance, ensuring that it doesn’t apply excessive force while handling fragile objects.

  • Applications: Grasping and handling objects, applying a specific amount of pressure during assembly, ensuring no damage during tasks like pick-and-place.

• Torque Sensors: These sensors measure rotational forces or torques applied to a joint or axis. They are often used to monitor and control the movements of robot arms and other rotating components.

  • Applications: Monitoring the rotation of joints, preventing excessive torque that could damage the robotic structure or environment.

Working Principle:

• Force sensors typically use strain gauges, piezoelectric materials, or load cells to detect changes in force.
• Torque sensors use similar principles but are designed to measure rotational force or torque rather than linear force.

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4. Introduction to Machine Vision

Machine Vision is the ability of a robot to interpret visual information and make decisions based on that data. It involves the use of cameras and image processing systems to analyze the visual environment.

• Robot Vision System: A robot vision system typically includes a camera, image processing software, and a robot controller. The system works by scanning and digitizing image data (from cameras), which is then analyzed to make decisions or perform actions.

  • Scanning and Digitizing Image Data: Involves capturing images in digital format, making them easier for computers to process. This process converts the analog visual input (light, color, shapes) into data that a robot can use.

  • Image Processing: The digital data is processed to extract useful information, such as detecting objects, recognizing patterns, measuring dimensions, or determining the position of objects in space.

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5. Image Processing and Analysis

Image processing refers to the manipulation of images to improve their quality or extract useful data. In robotics, image processing allows the robot to "see" and make sense of its surroundings.

• Steps in Image Processing:
  1. Acquisition: Capture the raw image data.
  2. Pre-processing: Improve image quality (e.g., noise reduction, contrast adjustment).
  3. Segmentation: Divide the image into segments to identify objects or regions of interest.
  4. Feature Extraction: Identify specific characteristics (e.g., edges, corners, shapes) in the image.
  5. Recognition: Determine what the extracted features represent (e.g., identifying an object, a person, or a particular scene).
• Image Analysis: After processing, the robot can analyze the data to perform tasks like object identification, navigation, or decision-making based on visual inputs.

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6. Cameras (Acquisition of Images)

Cameras are integral to robot vision systems. They capture images or video of the environment, which is then processed by the robot’s vision system to make decisions.

• Types of Cameras:

  • Standard Cameras: Capture images in the visible spectrum.
  • Depth Cameras: Capture 3D data (such as stereo vision or time-of-flight cameras).
  • Infrared Cameras: Capture images using infrared light, useful in low-light or dark environments.
  • Stereo Vision Cameras: Two cameras that simulate human binocular vision to capture depth information from the environment.

• Working Principle:

  • The camera uses sensors (such as CCD or CMOS) to convert light (photons) into electrical signals that can be processed.
  • The camera's software then digitizes the image, making it possible for the robot to "see" the scene in terms of data.

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7. Videocon Cameras (Working Principle & Construction)

Videocon cameras are a type of camera used for capturing video images that can be analyzed by the robot. They are commonly used in industrial robots for tasks like inspection, object detection, and quality control.

• Working Principle:
  • Videocon cameras capture real-time video using optical sensors. These sensors convert light into electrical signals.
  • The video is transmitted to the robot’s vision system, where it is processed for interpretation and analysis.
• Construction:
  • Optical Lens: Captures light from the environment.
  • Image Sensor (CCD/CMOS): Converts light into electronic signals.
  • Processor: Processes the signals to create a digital image.
  • Output Interface: Sends the digital image to the robot’s controller or vision system for analysis.

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8. Applications of Robot Vision System

Robot vision systems have various applications in industries, and they can be used in tasks such as inspection, identification, navigation, and serving.

• Inspection:
  • Robots with vision systems can inspect products for defects, quality assurance, and verification of proper assembly. Examples include visual inspection in manufacturing or sorting tasks.
• Identification:
  • Vision systems can be used to identify objects, labels, or patterns, allowing robots to distinguish between different items in a warehouse or production line.
• Navigation:
  • Vision systems help robots navigate their environment by identifying obstacles, detecting paths, and avoiding collisions. Autonomous mobile robots, such as those used in warehouses or for delivery, use vision for navigation.
• Serving:
  • Robots with vision systems can serve food or drinks, pick items from shelves, or handle customer inquiries by identifying objects and human interactions. Examples include service robots in restaurants or healthcare settings.

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Summary

• Sensors in robotics are used to detect and measure physical properties like proximity, force, torque, and more. They provide essential data that enables robots to perform tasks such as object detection, manipulation, and environmental interaction.
• Proximity sensors detect objects without contact and are useful in navigation and obstacle avoidance.
• Force and torque sensors allow robots to measure applied forces and rotation, making tasks like gripping and assembling possible.
• Machine Vision enables robots to interpret visual data and make decisions based on it, such as object detection, recognition, and navigation.
• Cameras capture images or video for analysis, and videocon cameras are often used for real-time video capture in industrial robots.
• Applications of vision systems include inspection, identification, navigation, and serving, which are widely used in industrial automation, logistics, and service robots.

By understanding how sensors and machine vision work, robots can be made more effective and capable of performing complex tasks in dynamic environments.

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UNIT-IV: ROBOT KINEMATICS AND ROBOT PROGRAMMING

Robot kinematics and robot programming are critical areas of robotics that allow robots to perform specific tasks with precision. Below is a detailed explanation of Robot Kinematics and Robot Programming.

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1. Forward Kinematics

Forward Kinematics (FK) involves calculating the position and orientation of the robot's end-effector (the tool or hand) based on the given joint parameters, such as angles or displacements. In simple terms, forward kinematics is about determining where the robot's end-effector will be located when the joints are at specific positions.

• Process:
  • The robot’s arm or manipulator is composed of links connected by joints (rotational or prismatic).
  • For each joint, the robot's position is described in terms of joint angles or displacements.
  • Using these joint parameters, the position and orientation of the robot’s end-effector can be calculated using a sequence of transformations (rotation and translation matrices).

Equation: $P_{end-effector} = T_1 \times T_2 \times ... \times T_n$ Where:

• $T$ is the transformation matrix that describes the position and orientation of each link.
• $P_{end-effector}$ is the position of the end-effector in the base frame of the robot.

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2. Inverse Kinematics

Inverse Kinematics (IK) is the process of determining the joint angles or displacements needed to place the robot's end-effector at a desired position and orientation in space. While forward kinematics works from joint angles to end-effector position, inverse kinematics works in the opposite direction.

• Process:
  • Given the desired position and orientation of the end-effector, inverse kinematics computes the joint variables (angles or displacements) required to achieve that configuration.
  • Inverse kinematics is often more complicated than forward kinematics, as there can be multiple solutions, no solution, or infinite solutions for certain robot configurations.

Equation: $P_{desired} = f(\theta_1, \theta_2, ..., \theta_n)$ Where:

• $P_{desired}$ is the desired position of the end-effector.
• $\theta_i$ are the joint angles.

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3. Differences Between Forward and Inverse Kinematics

Parameter	Forward Kinematics (FK)	Inverse Kinematics (IK)
Purpose	Calculate end-effector position from joint angles	Calculate joint angles from end-effector position
Complexity	Relatively simple and straightforward	More complex and often has multiple solutions
Applications	Used to model and control robot movement	Used to determine how to move the robot's joints to a target pose
Uniqueness of Solution	Typically has a unique solution for each joint configuration	May have multiple or no solutions depending on the robot configuration

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4. Forward Kinematics and Inverse Kinematics of Manipulators with Two Degrees of Freedom (in 2D)

• Two Degrees of Freedom (DOF): A 2D manipulator has two joints and two links, typically a simple robot arm with two rotational joints.

  • Forward Kinematics: Given two joint angles, $\theta_1$ and $\theta_2$, the position of the end-effector can be found by applying the transformation matrices for each joint. In the 2D case, the equations would be:

    $$x = L_1 \cos(\theta_1) + L_2 \cos(\theta_1 + \theta_2)$$
    $$y = L_1 \sin(\theta_1) + L_2 \sin(\theta_1 + \theta_2)$$
    

    Where:

    • $L_1$ and $L_2$ are the lengths of the two links.
    • $\theta_1$ and $\theta_2$ are the joint angles.

  • Inverse Kinematics: Given the desired position $(x, y)$ of the end-effector, the joint angles can be determined using trigonometric relationships and inverse solutions. A typical approach is using the law of cosines and sine to solve for the joint angles:

    $$\theta_2 = \arccos\left(\frac{x^2 + y^2 - L_1^2 - L_2^2}{2 L_1 L_2}\right)$$
    $$\theta_1 = \arctan\left(\frac{y}{x}\right) - \arctan\left(\frac{L_2 \sin(\theta_2)}{L_1 + L_2 \cos(\theta_2)}\right)$$

  • Problems:

    • Multiple Solutions: There may be more than one pair of joint angles that can place the end-effector in the same position.
    • No Solution: If the end-effector's desired position is outside the reach of the manipulator, there will be no solution.
    • Singularities: There can be specific joint configurations (such as when the arm is fully stretched) where the manipulator’s kinematics becomes degenerate, making it hard to compute the inverse kinematics.

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5. Deviations and Problems in Kinematics

• Numerical Instability: Solutions for inverse kinematics may become unstable, especially when joints approach extreme angles or singularities.
• Complexity: The inverse kinematics of complex robots with many degrees of freedom (DOF) can be challenging and computationally expensive.
• Discontinuities: Certain robot configurations may have multiple valid solutions, leading to discontinuous movements or jumps in motion, which can affect smooth control.
• Reachability Issues: If the desired position of the end-effector is beyond the robot's reachable workspace, there will be no solution.

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6. Teach Pendant Programming

Teach Pendant Programming is a method where the operator physically moves the robot arm through its desired path using a hand-held device called a teach pendant. The pendant records the robot's movement and then generates the corresponding program for that motion.

• Advantages:

  • Quick and easy to use.
  • No need for programming knowledge.
  • Suitable for simple or repetitive tasks.

• Disadvantages:

  • Limited to manual movement.
  • Not efficient for complex tasks with many movements.

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7. Lead-through Programming

Lead-through Programming is similar to teach pendant programming but more advanced. In this approach, the operator leads the robot through the desired path by guiding the arm manually while the system records the motion.

• Applications:
  • Teaching robots to follow a specific path, such as during welding, painting, or assembly.
  • Often used when the robot’s task is too complex for traditional programming methods.

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8. Robot Programming Languages

Robot programming languages are specially designed to program robots. These languages provide commands that control robot movements, sensors, end-effectors, and more.

• Examples:
  • VAL: A programming language for early robots, particularly used in PUMA robots.
  • RAPID: ABB's robot programming language.
  • Karel: A high-level language designed for programming robots used by FANUC robots.

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9. VAL Programming

VAL Programming is a language developed for controlling Unimation robots. It is based on structured programming techniques and is used for tasks like motion control, sensor data processing, and robot operations.

• Syntax: VAL programming consists of instructions like MOTION, WAIT, and IF-THEN constructs.

  Example:

  MOVE TO (x, y, z)
  WAIT UNTIL (object_detected)
  PICK UP (object)
  

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10. Motion Commands

Motion Commands are instructions in robot programming that control the movement of the robot's end-effector. These commands specify how the robot should move (linear, rotational, etc.) and the desired position.

• Types of Motion:
  • Linear Motion: Moving the end-effector in a straight line.
  • Joint Motion: Moving the robot’s joints to desired angles.

Example:

MOVE LIN (x1, y1, z1)
MOVE JNT (theta1, theta2)

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11. Sensor Commands

Sensor Commands are used to interact with the robot's sensors (e.g., proximity sensors, force sensors) to gather data or trigger actions.

Example:

IF (force > 10) THEN
    STOP

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12. End-effector Commands

End-effector commands control the robot's tools or manipulators, such as a gripper, welder, or camera.

Example:

OPEN GRIPPER
CLOSE GRIPPER

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13. Simple Programs

A simple robot program could involve moving the robot to a specific position, performing a task (like picking an object), and then returning to its home position.

Example:

MOVE TO (x1, y1, z1)
OPEN GRIPPER
PICK OBJECT
MOVE TO (x2, y2, z2)
CLOSE GRIPPER
RETURN HOME

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Summary

• Forward Kinematics helps calculate the position of the robot's end-effector from joint angles.
• Inverse Kinematics computes the joint angles needed to place the end-effector at a specific position.
• Teach Pendant Programming and Lead-through Programming are methods for teaching robots by manually guiding them through their tasks.
• Robot Programming Languages like VAL are used to program robot actions.
• Motion, Sensor, and End-effector Commands are the building blocks for instructing robots to perform specific actions in various environments.

Mastering these concepts is crucial for both designing robot motions and controlling robotic systems in various industries.

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UNIT-V: AUTOMATION

Automation is the technology used to control and monitor the production and delivery of products and services. It involves using control systems like computers or robots for handling different processes and machinery in an industry. Below is a detailed explanation of each topic in Automation and its Industrial Applications:

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1. Basic Elements of an Automated System

An automated system consists of various components working together to achieve a particular task with minimal human intervention. These basic elements are:

1. Sensors: Devices that detect changes in the environment (e.g., temperature, pressure, proximity) and provide input to the system.

   • Examples: Temperature sensors, proximity sensors, photoelectric sensors.

2. Actuators: Devices that perform actions based on the commands received from the controller. They are the "muscles" of the system, converting electrical signals into mechanical motion.

   • Examples: Motors, hydraulic cylinders, pneumatic actuators.

3. Controller: The "brain" of the automation system. It processes input from sensors and sends commands to actuators to perform specific actions.

   • Examples: Programmable Logic Controllers (PLC), microcontrollers.

4. Human-Machine Interface (HMI): A user interface that allows human operators to interact with the automated system for control, monitoring, and feedback.

   • Examples: Touchscreen panels, button interfaces, computers.

5. Communication Networks: These are the connections (wired or wireless) that facilitate data transfer between the components of the automated system. Communication protocols ensure the transfer of control signals, feedback data, and status information.

   • Examples: Ethernet, Modbus, Fieldbus.

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2. Advanced Automation Functions

Advanced automation functions go beyond basic tasks to optimize the system’s performance, improve precision, reduce human intervention, and allow for flexible and adaptive operations. These functions include:

1. Adaptive Control: Adjusting the process in real-time based on feedback from sensors to optimize performance (e.g., adjusting speed or force in a robotic system).

2. Fault Detection and Diagnosis: Identifying and diagnosing faults in the system to maintain productivity and reduce downtime. This helps in predictive maintenance.

3. Process Control: Regulating continuous or batch processes, such as in chemical manufacturing, where parameters like temperature and pressure must be kept within specific limits.

4. Robotics: The use of robots to automate repetitive, dangerous, or high-precision tasks, such as assembly, welding, or painting.

5. Artificial Intelligence (AI) and Machine Learning (ML): Implementing algorithms that allow systems to improve over time by learning from past actions, optimizing processes, or detecting patterns in data.

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3. Levels of Automation

Automation levels refer to the extent to which human intervention is required in the system. These levels range from full human control to fully autonomous systems. The common levels of automation are:

1. Manual Operation (Level 0):

   • Human directly controls all aspects of the system.
   • Example: Traditional machines operated manually by workers.

2. Assisted Operation (Level 1):

   • Automation provides basic assistance, but humans still have significant control.
   • Example: Machines with operator intervention for certain tasks like turning on/off or speed adjustments.

3. Partial Automation (Level 2):

   • Some tasks are automated, but the human operator is responsible for oversight and decision-making.
   • Example: CNC machines with limited automatic functions (e.g., setting tool paths) but require human input for other aspects.

4. Conditional Automation (Level 3):

   • The system performs most tasks autonomously, but humans can intervene when necessary.
   • Example: Advanced robotics in assembly lines where robots do most work but can be overridden by humans if there is a malfunction.

5. High-Level Automation (Level 4):

   • The system can handle all tasks autonomously, but human supervision might be required in exceptional cases.
   • Example: Automated manufacturing plants with minimal human presence.

6. Full Automation (Level 5):

   • No human intervention is required. The system is fully autonomous, capable of monitoring, decision-making, and executing tasks without human input.
   • Example: Fully automated assembly lines or autonomous vehicles.

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4. Industrial Applications of Robots

Robots are widely used in various industries for tasks that require precision, speed, and consistency. Below are some common industrial applications of robots:

A. Application of Robots in Machining

In machining operations, robots are used to handle parts and tools, perform high-precision tasks, and improve production efficiency. Some key applications include:

1. Loading and Unloading:

   • Robots can load raw materials into machines (like CNC machines) and unload finished products.

2. Tool Changing:

   • Robots equipped with tool changers can automatically switch between tools in CNC machines, improving flexibility.

3. Inspection:

   • Robots equipped with sensors and cameras can inspect parts for quality, ensuring that only defect-free parts are produced.

4. Polishing and Grinding:

   • Robots can be used to polish or grind surfaces with high accuracy and consistency, making them ideal for industries that require a high level of finish.

B. Application of Robots in Welding

Robots in welding applications improve speed, precision, and quality. Welding robots are used in industries like automotive and construction. Some uses include:

1. Arc Welding:

   • Robots are commonly used for MIG (Metal Inert Gas) and TIG (Tungsten Inert Gas) welding, where high precision is required.

2. Spot Welding:

   • Robotic arms can carry out spot welding in high-volume production lines, especially in the automotive industry, where the assembly of body parts requires high-speed and consistent welding.

3. Laser Welding:

   • Robots can handle laser welding machines that require precise beam positioning for small, high-strength welds.

C. Application of Robots in Assembly

Robots in assembly lines perform tasks that require precision, repetitive actions, and flexibility. Some tasks include:

1. Part Handling:

   • Robots are used to pick and place parts into assembly stations, ensuring uniformity and preventing human errors.

2. Screw Driving and Fastening:

   • Robots can automatically place screws or fasteners in the correct locations with exact torque and positioning, improving consistency.

3. Packaging:

   • Robots can be used in packaging lines to arrange products into boxes, pallets, or containers efficiently.

4. Quality Inspection:

   • Robots equipped with sensors or cameras inspect assembly processes, checking for errors in assembly, misalignment, or damaged parts.

D. Application of Robots in Material Handling

Material handling refers to the movement, protection, storage, and control of materials throughout the manufacturing process. Robots help in:

1. Palletizing and Depalletizing:

   • Robots are used to stack or unstack goods on pallets. They can handle a variety of products and arrangements, improving efficiency in warehouses.

2. Transporting Materials:

   • Autonomous robots (AGVs) are used to transport materials between workstations, minimizing human involvement and improving safety.

3. Sorting:

   • Robots can automatically sort materials based on size, shape, color, or weight, reducing human effort in material handling.

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Summary

• Basic Elements of an Automated System: Includes sensors, actuators, controllers, HMI, and communication networks that interact with each other to automate processes.
• Advanced Automation Functions: Involves adaptive control, fault detection, process control, robotics, and AI to improve system efficiency and performance.
• Levels of Automation: Range from manual operation (Level 0) to full automation (Level 5), where human intervention decreases as automation increases.
• Industrial Applications of Robots: Robots are used in various industries like machining, welding, assembly, and material handling to increase efficiency, quality, and safety.

Automation is transforming industries by increasing precision, reducing costs, enhancing flexibility, and ensuring faster production cycles. Understanding these concepts is crucial for anyone involved in manufacturing, robotics, and automation systems.