Types of Industrial Robots: How Many Are There and What Are Their Uses?

Industrial robots have become the backbone of modern manufacturing and numerous other industries, driving efficiency, precision, and safety to unprecedented levels. These automated marvels, far from being the futuristic fantasies of yesteryear, are now indispensable tools that perform a wide array of tasks, from intricate assembly to heavy lifting. But the world of industrial robots is not monolithic. It is a diverse ecosystem of machines, each designed with specific configurations and capabilities to address particular needs. Understanding the different types of industrial robots is crucial for businesses looking to leverage automation effectively.

As futurist Ray Kurzweil aptly stated:

“Technology is moving so fast that it is creating whole new paradigms, and the very notion of what is possible is constantly being redefined.”

This statement rings particularly true when we consider the rapid evolution and expanding applications of industrial robots. From their initial deployment in automotive manufacturing to their current use in sectors ranging from pharmaceuticals to food processing, industrial robots have continuously adapted and diversified. This article will delve into the primary types of industrial robots, exploring their distinct designs and the specific uses that make them invaluable in today’s industries.

Classifying the Robotic Workforce

Industrial robots can be categorized in several ways, including by their:

• Mechanical structure or configuration: This is the most common classification and focuses on the robot’s arm geometry and movement capabilities.
• Application: Robots can be categorized by the tasks they perform, such as welding robots, painting robots, or assembly robots.
• Motion control system: This refers to the type of control employed, like point-to-point control or continuous path control.
• Degree of automation: From fully autonomous robots to those requiring significant human programming and intervention.

For this article, we will focus primarily on the classification based on mechanical structure, as it directly dictates the robot’s capabilities and suitability for different tasks. Let’s explore the most prominent types:

1. Articulated Robots

Articulated robots, often resembling a human arm, are perhaps the most versatile and recognizable type of industrial robot. Their key characteristic is their rotary joints, which allow for a wide range of motion and flexibility. Typically, they have anywhere from two to ten or more rotary joints (axes), with six-axis robots being the most common. These axes allow the robot to move in complex patterns and reach around obstacles, mimicking the flexibility of a human arm and wrist.

Key Features and Uses:

• High Dexterity: The multiple joints provide exceptional dexterity, enabling them to perform intricate tasks in confined spaces and at various angles.
• Versatility: Articulated robots are highly adaptable and can be configured for a broad spectrum of applications, making them a workhorse in many industries.

Common Applications:

• Welding: Especially arc welding, where precise and complex weld paths are often required.
• Painting and Coating: Achieving even coverage on complex shapes.
• Assembly: Assembling intricate products, from electronics to machinery components.
• Material Handling: Picking, placing, and transferring parts with varying orientations.
• Machine Tending: Loading and unloading parts from CNC machines and other equipment.
• Deburring and Grinding: Using tools to finish surfaces effectively.

Industries: Automotive, aerospace, manufacturing, electronics, and metal fabrication are just a few industries that heavily rely on articulated robots.

2. SCARA Robots (Selective Compliance Articulated Robot Arm)

SCARA robots are specifically designed for high-speed, high-precision assembly and pick-and-place operations where vertical movement is limited. They are characterized by their selective compliance, which means they are stiff in the vertical direction but compliant in the horizontal plane. This compliance allows them to insert parts into tight tolerances without jamming. SCARAs typically have 3 or 4 axes of motion.

Key Features and Uses:

• High Speed and Precision: Optimized for rapid, repetitive tasks with great accuracy.
• Vertical Stiffness, Horizontal Compliance: Excellent for insertion tasks and handling delicate components.
• Cost-Effective: Often more affordable than articulated robots for specific applications.

Common Applications:

• Assembly: Ideal for assembling electronic components, small mechanical parts, and consumer products.
• Pick and Place: Rapidly transferring parts from one location to another.
• Packaging: Orienting and placing products into packaging.
• Machine Loading/Unloading: Especially for smaller parts in automated lines.

Industries: Electronics assembly, pharmaceutical packaging, food processing, and light manufacturing are prime users of SCARA robots.

3. Delta Robots (Parallel Robots or Spider Robots)

Delta robots, also known as parallel robots or spider robots, are uniquely designed for high-speed pick-and-place and light assembly applications. They are characterized by their parallel linkage mechanism, where the actuators are located at the base, and the end effector is suspended from three or more arms that move in parallel. This configuration results in very fast acceleration and precise movements.

Key Features and Uses:

• Extremely High Speeds: Capable of very rapid movements, making them ideal for high-throughput operations.
• High Precision: Maintains accuracy even at high speeds.
• Light Payload Capacity: Typically used for handling lighter objects.

Common Applications:

• Pick and Place: Sorting, orienting, and transferring small, lightweight items at very high speeds.
• Food and Beverage Industry: Picking and packaging food items like cookies, candies, and fruits.
• Pharmaceutical Packaging: Handling and packaging pills and vials.
• Electronics Assembly: Placing small electronic components.

Industries: Food and beverage, pharmaceutical, electronics, and consumer goods manufacturing benefit significantly from the speed and precision of delta robots.

4. Cartesian Robots (Gantry Robots or Linear Robots)

Cartesian robots, also known as gantry robots or linear robots, move along three linear axes (X, Y, Z). Their structure resembles a rectangular coordinate system, and they are often built as overhead gantries. This design offers simplicity, rigidity, and the ability to handle heavy payloads over large workspaces.

Key Features and Uses:

• Large Workspace: Can cover extensive areas, making them suitable for handling large or multiple parts.
• High Payload Capacity: Capable of lifting and manipulating heavy loads.
• Simplicity and Accuracy: Easy to program and offer precise linear motion.

Common Applications:

• Material Handling (Heavy): Moving large and heavy objects, such as car bodies or steel beams.
• Palletizing and Depalletizing: Stacking and unstacking boxes or materials on pallets.
• Machine Tending (Large Parts): Loading and unloading large workpieces from machines.
• Waterjet Cutting and Laser Cutting: Providing precise motion for cutting large sheets of material.
• 3D Printing and Additive Manufacturing: Building large-scale objects layer by layer.

Industries: Manufacturing with heavy components, warehousing and logistics, construction, and large-scale fabrication operations commonly employ Cartesian robots.

5. Cylindrical Robots

Cylindrical robots have one rotary joint at the base and at least one prismatic joint to connect the links. Their workspace is cylindrical, hence their name. While less common in extremely advanced applications compared to articulated or SCARA robots, they still find niche uses.

Key Features and Uses:

• Simpler Design: Generally less complex and potentially more robust for specific tasks.
• Vertical Reach: The prismatic joint allows for vertical movement, while the rotary base facilitates horizontal reach.

Common Applications:

• Pick and Place: In simpler automation setups.
• Machine Tending: Loading and unloading parts in specific configurations.
• Assembly: For tasks that require movements within a cylindrical workspace.

Industries: Found in older automation systems, and still used in specific applications within machine shops and some manufacturing lines where the cylindrical workspace is advantageous.

6. Collaborative Robots (Cobots)

Collaborative robots, or cobots, represent a significant shift in industrial robotics. They are designed to work safely alongside humans in a shared workspace, without the need for traditional safety barriers like cages. Cobots are equipped with advanced sensors and safety features that allow them to detect and respond to human presence, preventing collisions and ensuring operator safety. They are generally easier to program and deploy compared to traditional industrial robots.

Key Features and Uses:

• Safety: Designed for safe human-robot collaboration with force and torque sensors, and safety-rated software.
• Ease of Programming: Often programmed through intuitive interfaces, like hand-guiding or drag-and-drop software.
• Flexibility and Adaptability: Easily redeployed for different tasks and processes.
• Cost-Effective for Specific Tasks: This can be more accessible for smaller businesses and for automating tasks that were previously considered too complex or costly to automate.

Common Applications:

• Assembly (Collaborative): Working alongside humans in assembly lines, handling tasks that require both human dexterity and robotic precision.
• Machine Tending (Collaborative): Assisting human operators in loading and unloading machines.
• Quality Inspection: Performing visual or sensor-based inspections alongside human quality control personnel.
• Packaging and Palletizing (Collaborative): Working in conjunction with human packers and palletizers.

Industries: A wide range of industries, particularly those emphasizing human-robot collaboration, such as small to medium-sized enterprises, electronics, consumer goods, and industries with flexible manufacturing needs.

7. Mobile Robots (Autonomous Mobile Robots – AMRs and Automated Guided Vehicles – AGVs)

Mobile robots are a rapidly evolving category, adding mobility to industrial automation. They can be broadly classified into Automated Guided Vehicles (AGVs) and Autonomous Mobile Robots (AMRs). AGVs typically follow predefined paths using wires, magnetic tape, or sensors, while AMRs use advanced sensors, mapping, and navigation software to move autonomously and dynamically within an environment, adapting to obstacles and changes.

Key Features and Uses:

• Mobility and Navigation: Can move freely or semi-autonomously throughout a facility, transporting materials, and tools, or performing tasks at different locations.
• Flexibility in Layout: AMRs, in particular, offer greater flexibility in factory layout and process flow compared to fixed automation.
• Integration with Other Robots: Mobile robots can work in conjunction with stationary industrial robots, creating more complex and automated workflows.

Common Applications:

• Material Transportation: Moving materials, parts, and products within warehouses, factories, and distribution centers.
• Intralogistics: Automating internal logistics and material flow within facilities.
• Warehouse Automation: Supporting order fulfillment, inventory management, and other warehouse tasks.
• Inspection and Monitoring (Mobile): Equipping mobile robots with sensors to conduct inspections or monitor environmental conditions as they move.

Industries: Warehousing and logistics, manufacturing, e-commerce fulfillment, healthcare (transporting materials in hospitals), and increasingly in retail and hospitality.

The Ever-Expanding Horizon of Industrial Robots

The types of industrial robots discussed above represent the major categories currently deployed. However, the field of robotics is continuously evolving, with ongoing research and development leading to new robot designs, capabilities, and applications. We are seeing advancements in:

• Robot dexterity and sensitivity: Enhanced sensors and control systems make robots more capable of handling delicate and complex tasks.
• Artificial intelligence and machine learning: Integrating AI and ML leads to smarter robots that can learn, adapt, and make decisions more autonomously.
• Human-Robot collaboration advancements: Cobots are becoming more sophisticated and easier to integrate into human-centric workplaces.
• Mobile robotics innovation: AMRs are becoming more intelligent, robust, and capable of navigating increasingly complex environments.

In conclusion, understanding the different types of industrial robots is essential for businesses looking to harness the power of automation effectively. Each type offers unique strengths and is suited to specific tasks and industries. By carefully considering the needs and capabilities of each robot type, businesses can make informed decisions to optimize their operations, enhance productivity, and remain competitive in an increasingly automated world. The future of industrial robotics is bright, with continuous advancements promising even more sophisticated and versatile machines that will continue to reshape industries across the globe.