How Does a Robotic Arm Work? Your Complete Guide

Have you ever wondered how those precise, tireless mechanical arms in factories accomplish their tasks? We’re talking about the robotic arm! Designed for heavy, dangerous, and repetitive tasks, robotic arms boost productivity and cut costs. In this article, we’ll delve into the inner workings of a robotic arm, from its fundamental components to its practical applications.

What Is a Robotic Arm?

A robotic arm is a key part of an industrial robot – a mechanical arm that can be programmed to perform various tasks. It’s built from several connected sections, often called “axes” or “joints.” Each of these sections has a stepper or servo motor that allows it to move in a specific way.

The more joints or axes a robotic arm has, the more flexibly it can move and the wider its reach. These motorized axes help the robot make incredibly precise movements, ensuring high accuracy in its work.

An industrial robot is positioned so its robotic arm can reach the workpieces it needs to handle. For instance, a six-axis robotic arm can move in six different directions, offering maximum versatility.

The space where each robotic arm can operate is known as its “work envelope.” The robotic arm also controls its “end-effector” – the tool attached at its tip. During operation, the robotic arm positions itself to access the workpiece, then uses the end-effector to complete the task.

To perform manufacturing jobs, robotic arms need to be programmed. This is usually done using a controller and a teaching pendant. Some robotic arms can even be programmed by manually moving them into position.

A Closer Look at How the Robotic Arm Works

A robotic arm is typically made of metal, usually with 4 to 6 joints, and is used in various manufacturing applications. They often resemble a human arm, complete with a wrist, forearm, elbow, and shoulder. These different joints give them the necessary “degrees of freedom” for movement.

Industrial robotic arms are built from steel or cast iron, from the base up to the wrist. A robot controller powers the motor connected to each joint. For larger arms designed to lift heavy loads, hydraulic or pneumatic systems might be used for power.

The arm’s main job is to move the end-effector, which can be used to pick up, place, move, or weld a component, or even an entire product. Depending on the manufacturer’s needs, these robotic arms can be programmed to perform a single task or a variety of different jobs.

Beyond heavy lifting, palletizing goods, or welding entire cars, these robotic arms are also used for incredibly delicate tasks. They can assemble the smallest motherboards or microprocessors with astounding precision and accuracy.

These mechanical marvels will continue to play a vital role in manufacturing for many years to come.

The Importance of Joints in Robotic Arms

Because robotic arms are inspired by the human arm, you’ll typically see them with multiple joints, allowing for free and flexible movement. A “joint” is simply any movable part of the robotic arm.

Each joint operates independently while also working seamlessly with the others for maximum performance. This is why a robotic arm can move up and down while rotating simultaneously. In short, a robotic arm cannot function without joints, and an industrial robotic arm must have at least two joints.

The more joints a robotic arm has, the greater its maneuverability. These joints – often called “axes” – are crucial in defining how a robotic arm will function. Joints provide freedom of movement, making a robot incredibly versatile.

Joints also offer a structure that simplifies maintenance and repair. If a failure occurs, it’s easy to pinpoint the problem to a specific joint rather than guessing.

Flexible joints allow robotic arms to twist, turn, and move up and down with ease.

Different Configurations of Robotic Arms

When choosing an industrial robot, many factors come into play, including its purpose, required speed, precision level, and whether it will operate in a collaborative environment. All these factors determine the best industrial robot for a job. The robot’s configuration is a key element that dictates how an industrial robot moves and defines its workspace. There are six main types of robot configurations: Cartesian, Cylindrical, Spherical, SCARA, Articulated, and Delta.

1. Cartesian Robots

• Explanation: These robots move along each of the Cartesian coordinates in a straight line (x, y, z). This setup creates a box-shaped work envelope.
• Common Uses: Many 3D printers use a Cartesian configuration for their print nozzles.

2. Cylindrical Robots

• Explanation: This configuration allows the robot’s tool to rotate along a central axis. The tool can also move up and down this central axis, as well as inward and outward. This creates a cylinder-shaped work volume.
• Common Uses: Often used for spot welding, handling die-cast machines and machine tools, and assembly tasks.

3. Spherical Robots

• Explanation: This setup allows the tool to sweep out a sphere-like workspace. It enables the tool to rotate around a primary axis and a second axis positioned at a 90-degree angle to the main axis. The tool can also pivot around an axis.
• Common Uses: Frequently employed in material handling, welding, and die casting.

4. SCARA (Selective Compliance Articulated Robot Arm)

• Explanation: SCARA robots use pivot points to enable their tool to move in both cylindrical and Cartesian motions. This allows the tool to move more swiftly and easily for specific motions, like an arc.
• Common Uses: SCARA robots are utilized in biomedical applications, assembly, and palletizing.

5. Articulated Robots

• Explanation: This is the most common image that comes to mind when we think of an industrial robot. It must have a wrist joint, an elbow joint, and at least one shoulder joint. Many configurations can include both major and minor axes.
• Common Uses: Common uses for articulated robots include packaging, arc welding, material handling, and machine tending. The VEX V5 Workcell is an example of an articulated setup.

An Example of Articulated Robots – 6-Axis Cobots from Universal Robots:

In the articulated robot segment, Universal Robots is a well-known name, especially in the world of collaborative robots, or cobots. Their cobots have 6-axis articulated arms, which help them move like a human arm, smooth and precise in many directions. What makes them special is that they are designed to safely work next to people, without needing safety fences.

This feature has made Universal Robots a global leader in cobots. Models like the UR5e or UR10e are great examples of 6-axis cobots. They can be programmed easily to do many jobs, such as assembling small parts, polishing surfaces, feeding materials into CNC machines, or checking product quality. These cobots help improve productivity and reduce boring, repetitive tasks for workers.

By combining the smart movement of jointed robot arms with the safety of cobots, Universal Robots has helped bring a new level of automation to modern factories.

6. Delta (Parallel) Robots

• Explanation: Delta robots are the fastest type of robot configuration in terms of tool movement. They use parallel connections to enable their tool to quickly sweep out its workspace.
• Common Uses: Delta robots excel at various tasks, including rapid and nimble pick-and-place operations in sorting activities.

What Is a Robotic Arm’s Work Envelope?

The work envelope is a geometrically shaped area where the robotic arm (manipulator) can operate. It depends on factors like the number of degrees of freedom, size, type, and range of the robot’s end-effector, as well as any parts of the robot that might interact with the environment (e.g., a gripper). The number of linear or angular actuators determines the shape of this envelope.

The work envelope is crucial for determining the ideal use for a robot. When selecting or designing a robot for a task, the size and shape of its work envelope at the operating site must be specified. To prevent accidents, the envelope may sometimes need to be limited by sensors that alert the controller.

How Do Robotic Arms Control End-Effectors?

An end-effector, also known as “end-of-arm tooling,” is a tool attached to the end of a robotic arm to manipulate objects. It only becomes active when a user triggers it using the corresponding software.

In simpler terms, the end-effector is what performs tasks like picking and placing items, assembling product components, stacking cartons and packages, and so on. A robotic arm is essential to automate and improve a process, but it’s the end-effector that truly allows the robot to work. Different end-effectors are suitable for various purposes, and the choice depends on the task at hand.

How Robotic Arms Perform Manufacturing Applications

One of the main advantages of industrial robotic arms is their flexibility to handle a wide range of applications, from the simplest to the most complex tasks, in the safest or harshest conditions. Besides removing human workers from potentially dangerous situations, automating these operations frees up personnel to perform higher-value duties like client interaction. Here are some of the most widespread applications for robotic arms in manufacturing today:

Palletizing

Robotic arms can automate the process of loading items or products onto pallets. Automating palletizing makes it more precise, economical, and predictable. Robotic arms free human employees from hazardous jobs that could result in physical harm.

Material Handling

By ensuring that products and materials are properly stored, accessible, or delivered correctly, robotic arms for material handling can help create a secure and efficient warehouse. Automating these procedures can boost a facility’s productivity, speed up product delivery to consumers, and reduce worker injuries.

Welding

Robots are highly capable of welding in high-tech industrial settings, such as automotive production. Welding is an excellent application for sophisticated robots, demonstrating why vision and AI augmentation have a crucial influence on product quality.

Inspection

Identifying manufacturing quality problems often takes longer when quality inspection is completed only after the production line. Businesses can benefit from real-time inspection by augmenting robots with vision and AI systems, which helps cut down on waste and downtime.

Pick and Place

Pick-and-place robots are frequently used in logistics and modern production. To accelerate the manufacturing and distribution of goods, they are equipped with cutting-edge machine vision systems that can quickly and efficiently identify an object, grasp it, and transport it from one place to another.

Conclusion

Robotic arms are incredibly useful for various industrial and manufacturing purposes that demand speed, precision, and repetition. Today, robotic arms are used to generate faster returns on investment and improve productivity across multiple industries and sectors. They provide a high degree of accuracy and eliminate humans from hazardous tasks. Best of all, they’ve become much more economical and are often sold with various attachments for assigned duties. So, what are you waiting for? Get a robotic arm today to meet your industry targets!

About Servo Dynamics Engineering – Preferred Distributor of Universal Robot in Vietnam

Are you looking for an optimal robotic arm solution for your business in Vietnam? Servo Dynamics Engineering is proud to be the preferred distributor of Universal Robots – a world-leading brand of collaborative robots (cobots). With extensive experience and expertise in automation, we are committed to providing advanced robot solutions that help businesses optimize production processes, enhance efficiency, and reduce costs. Our team of engineers is always ready to offer dedicated consultation, installation, and technical support, ensuring your robot system operates smoothly and efficiently to meet all your stringent requirements.