Chapter 3: Classification of Robots

Abstract:

Robots can be classified by their movement, application, or kinematics.

Classification by movement

Articulated robots: Also known as robotic arms, these robots mimic the functions of a human arm.
Rotational motion: Robots have joints that rotate to enable flexible movement.
Coordinate systems: These classify the arm of the robot by its reachable coordinates.

Classification by application

Industrial robots: These robots perform repetitive tasks like picking, moving, and assembling parts.
Domestic robots: These robots help with cleaning tasks and watching over the house.
Entertainment robots: These robots are designed to evoke an emotional response.
Disaster response robots: These robots are rugged and can withstand high temperatures, moisture, dirt, and debris.

Classification by Kinematics

SCARA robots: These robots have two parallel revolute joints and are used for assembly.
Parallel robots: These robots are closed-loop systems that are used for drilling and milling.

Other robot types Autonomous mobile robots (AMRs), Automated guided vehicles (AGVs), Humanoids, Cobots, and Hybrids.

So let's explore the Chapter 3 in detail

3.1 Introduction

Robots are widely used in various fields, from industrial automation to healthcare and space exploration. Their classification is essential to understand their capabilities, design, and applications. Robots can be classified based on different criteria, such as movement, application, kinematics, control mechanisms, and structural configurations. This chapter discusses the classification of robots in detail, providing insights into their functionalities and uses.

3.2 Classification Based on Movement

The movement of a robot determines its mobility and the way it interacts with the environment. Based on movement, robots can be classified as:

3.2.1 Fixed Robots

Fixed robots are stationary and are typically used in industrial automation. They perform repetitive tasks such as welding, painting, and assembly. These robots are usually mounted on a base and have multiple joints for movement.

Examples:

Articulated robots
Cartesian robots
SCARA robots

3.2.2 Mobile Robots

Mobile robots can move freely in their environment using wheels, tracks, or legs. They are designed for applications requiring flexibility and adaptability.

Types of Mobile Robots:

Wheeled Robots: Use wheels for movement (e.g., autonomous vehicles, delivery robots).
Legged Robots: Use legs to navigate rough terrains (e.g., humanoid robots, quadrupeds).
Tracked Robots: Use continuous tracks for movement (e.g., military robots, rescue robots).

3.2.3 Autonomous and Semi-Autonomous Robots

Autonomous Robots: Operate without human intervention using AI and sensors (e.g., self-driving cars, robotic vacuum cleaners).
Semi-Autonomous Robots: Require some level of human control (e.g., teleoperated drones).

3.3 Classification Based on Application

Robots are designed for specific applications across various industries. The major classifications based on application include:

3.3.1 Industrial Robots

Used in manufacturing and automation processes to enhance productivity and precision.

Common Applications:

Assembly lines (e.g., robotic arms in automotive industries)
Welding and painting (e.g., FANUC, KUKA robots)
Packaging and palletizing

3.3.2 Service Robots

Designed to assist humans in non-industrial tasks, such as domestic and healthcare applications.

Types of Service Robots:

Medical Robots: Assist in surgeries, rehabilitation, and patient care (e.g., da Vinci Surgical System).
Household Robots: Used for cleaning, lawn mowing, and security (e.g., Roomba vacuum cleaner).
Logistics Robots: Used in warehouses and distribution centers (e.g., Amazon’s Kiva robots).

3.3.3 Military and Defense Robots

These robots are developed for security, surveillance, and combat operations.

Examples:

Unmanned Aerial Vehicles (UAVs) for reconnaissance
Bomb disposal robots (e.g., TALON EOD)
Autonomous tanks and drones

3.3.4 Space Exploration Robots

Used for planetary exploration, satellite maintenance, and extraterrestrial research.

Examples:

Mars rovers (e.g., Curiosity, Perseverance)
Robotic arms on the International Space Station

3.3.5 Agricultural Robots

Used in farming for precision agriculture, harvesting, and crop monitoring.

Examples:

Autonomous tractors
Drones for pesticide spraying

3.3.6 Entertainment and Companion Robots

Designed for amusement, education, and companionship.

Examples:

Humanoid robots (e.g., Sophia, ASIMO)
Social robots (e.g., Paro therapeutic robot)

3.4 Classification Based on Kinematics

Kinematics deals with the motion of robots without considering forces. Based on kinematics, robots can be classified as:

3.4.1 Cartesian Robots

Have linear movements along the X, Y, and Z axes. They are commonly used in CNC machines and 3D printers.

3.4.2 Cylindrical Robots

Move in cylindrical coordinates with a combination of linear and rotational motion. Suitable for pick-and-place operations.

3.4.3 Spherical Robots

Have two rotational and one linear movement, providing flexibility in reaching different positions.

3.4.4 Articulated Robots

Mimic human arm movements with multiple rotary joints, making them highly flexible (e.g., robotic arms in manufacturing).

3.4.5 SCARA Robots

Selective Compliance Assembly Robot Arm (SCARA) robots are used for fast and precise assembly operations.

3.4.6 Parallel Robots

Use multiple arms working together to manipulate objects with high precision (e.g., Stewart platform).

3.5 Classification Based on Control Mechanism

The way a robot is controlled determines its autonomy and efficiency. Robots can be classified into:

3.5.1 Manual Robots

Controlled entirely by human operators (e.g., remote-controlled bomb disposal robots).

3.5.2 Automated Robots

Operate based on pre-programmed instructions without human intervention (e.g., robotic assembly lines).

3.5.3 AI-Powered Robots

Utilize artificial intelligence, sensors, and machine learning for decision-making and adaptability (e.g., self-driving cars).

3.6 Classification Based on Structural Configuration

The structural design of a robot affects its motion and capabilities.

3.6.1 Humanoid Robots

Designed to resemble and interact like humans, used in research and social applications.

3.6.2 Snake Robots

Mimic the movement of snakes, used for search and rescue operations.

3.6.3 Swarm Robots

A group of small robots working collectively, inspired by nature (e.g., robotic ants for surveillance).

3.6.4 Modular Robots

Consist of interchangeable components, allowing adaptability for different tasks.

3.7 Conclusion

Robots can be classified based on movement, application, kinematics, control mechanisms, and structural configuration. Each classification provides insights into their design, functionality, and potential applications. The continuous advancements in robotics are expanding their scope, leading to innovative solutions in various industries. Understanding these classifications helps in selecting the right robot for specific needs and improving their efficiency in real-world applications.