What is a robotic arm?
A robotic arm, also known as an articulated robot, is a mechanical arm that performs a variety of repetitive tasks.
It has multiple segments connected by joints, kind of like a human arm. The joints allow the arm to bend and rotate to perform complex movements.
Robotic arms are powered by electric motors and can have anywhere from three to ten or more joints.
As a rule of thumb, the more joints, the more flexible and skillful the arm can be.
Robotic arms are often used in manufacturing for repetitive, dangerous tasks like:
- Picking and placing: They’re excellent for quickly moving light objects from one location to another with extremely high precision. They’re used extensively in packaging and assembly lines.
- Welding: Robotic arms can handle welding guns and torches to join metal parts with a tremendously high degree of speed, accuracy, and repeatability.
- Painting: Automated painting is a popular application for articulated robots. They can paint large objects or many small parts very efficiently and uniformly.
Top 5 types of robotic arms and what they do best
Articulated robotic arms: The most versatile option
Articulated robotic arms, also known as six-axis robots, are the most common and flexible type of robot arm. These arms have a shoulder, elbow, and wrist joint that provide a human-like level of motion.
- Extremely high level of dexterity: The multiple joints allow these arms to execute complex tasks with an enormous degree of precision and agility.
- Very versatile: Used across various industries for tasks requiring precision, such as welding, painting, and assembly, their adaptability makes them a great fit for handling intricate components in electronics and automotive manufacturing, as well as for loading and unloading a tremendous variety of objects.
- Complex: Despite their versatility, these arms typically come with higher costs and complexity.
Additionally, the complexity in programming due to multiple axes of motion might make alternatives like SCARA or delta robots more suitable for repetitive, high-volume tasks.
But that’s typically not too much of a problem with newer models, which have simpler programming frameworks.
Cartesian robotic arms: Precision and speed
Cartesian robotic arms move along three linear axes: X, Y, and Z.
The big deal? This allows for quick, precise movement, which is a match made in heaven for high-speed assembly and pick-and-place tasks. Cartesian bots' simple but robust design also makes them extremely durable and low-maintenance.
- Precision on the production line: Cartesian robots shine in environments like electronic, automotive, and consumer goods assembly lines, where their accuracy and speed guarantee a high-volume, error-free production.
- Placement experts: These robots are the go-to for tasks requiring extreme precision, such as positioning computer chips on circuit boards, neatly organizing cookies in packages, or methodically loading bottles into crates.
- Specialized but limited: Despite their capacity for repetitive, precise tasks, Cartesian arms don't match the versatility of their articulated counterparts. Mainly because they’re limited to movement along three straight axes and often present challenges in navigating complex paths or handling varied orientations.
- Compact but efficient: While they have a smaller work area compared to other robot types, if your operations involve quick, precise linear movements or assembly tasks, the Cartesian robot arm is a perfectly fine choice.
Collaborative robotic arms: Reliable shop floor partners
Collaborative robotic arms, or “cobots,” are designed to work side by side with humans on the production line without safety barriers.
That’s why cobots are lightweight, flexible, and equipped with sensors that detect contact forces and immediately stop their movement before an ugly injury happens.
- Safe, streamlined collaboration with humans: Unlike traditional industrial robots, cobots feature rounded contours and padded surfaces to minimize the risk of injury from accidental contact.
- All-around workhorses: Cobots are perfect for repetitive tasks such as CNC machine tending, assembly, and packaging, but they can do a lot more.
- Automation without breaking the bank: Manufacturers are adopting cobots as a cost-efficient method to automate production, offering simple programming and flexibility in deployment.
- Easy integration: Cobots provide an accessible entry point into automation, improving productivity without the need to overhaul your existing workforce or processes, making them an excellent choice for SMEs that would like to dip their toes into the automation waters.
SCARA robotic arms: Ultra-precise
SCARA (Selective Compliance Assembly Robot Arm) robots have two parallel rotary joints that provide compliance in a selected plane.
They’re very fast, precise, and rigid. SCARA robots are ideal for high-speed assembly applications where dexterity and flexibility are important.
- Precision is the name of the game: SCARA robots are distinguished by their two parallel rotary joints, which enable exceptional agility and accuracy within a specific plane.
- Specialized in assembly and packaging: These robots are fantastic at tasks that need precision, such as packaging, palletizing, assembly, and material transfer, making them valuable assets in automotive and electronics production lines.
- High productivity with limitations: While SCARA robots are huge assets when it comes to productivity and precision in their designated tasks, they do have restrictions in motion, range, and payload capacity compared to their articulated cousins.
- Fixed positioning: SCARA robots operate from a stationary base (typically anchored on the floor), which might limit their utility in scenarios requiring mobility or the ability to maneuver around obstacles. For handling heavier loads or overcoming physical barriers, articulated robots might be a better fit.
Parallel/Delta robotic arms: Best for high-speed tasks
Parallel robotics, also known as delta robots, are some of the fastest and most skillful robot types.
They consist of three arms connected to a common base, with an end-effector (such as a gripper) at the end of each arm. The arms move the end-effector in a coordinated motion to achieve quick pick-and-place and high-speed assembly tasks.
- Efficient even when things get fast: Delta robots are unmatched in high-speed tasks such as pick-and-place, sorting, and assembly, with cycle times up to three times faster than those of articulated robot arms.
- Industry favorites: Particularly favored in food processing, pharmaceuticals, and electronics manufacturing, delta robots meet the demands for high throughput and strict cleanliness, also proving invaluable in semiconductor production for handling small, high-volume parts.
- Some limitations, though: Their movement is more restricted, limiting their use in jobs needing a wide work area or precise path navigation.
- Precision with programming challenges: With second-to-none speed and acceleration, delta robots have a narrower motion range and carry lighter loads than their articulated counterparts, and their sophisticated design necessitates a bit more complex programming for precise arm coordination.
