5 Types of Industrial Robots
Learning more about industrial robots will help make automation easier for any manufacturer.
It’s estimated that nearly 45% of production can be automated with robots.
There’s a variety of industrial robots available to suit nearly every need. In order to choose which type of robot is best, it’s paramount to start from the paradigm of “form follows function”. In other words, the choice of robot form factor should be dependent on its purpose.
Because there’s a wide variety of tasks that can be accomplished with industrial robots, consequently, there’s a number of robot varieties available that are suited to different types of tasks.
Learn more about the advantages of each type of industrial robot below!
What is an industrial robot?
A widely accepted definition for an industrial robot by ISO 8373:2012 is “an automatically controlled, reprogrammable, multipurpose manipulator, programmable in three or more axes, which can either be fixed or mobile for use in industrial automation applications.”
Though industrial robots are available in various form factors depending on the task, the most common industrial robots are automated arms. These robots can be classified into a few different categories based on movement, application, architecture, and brand.
Types of industrial robots
The most common type of industrial robot is a stationary robot--meaning robots that are bolted to a surface such as a floor, ceiling, or walls. There are five main types of stationary robots (or “robotic arms”) available today that can accomplish tasks such as sorting, welding, and finishing. According to the International Federations of Robots, the five main types of industrial robots includes SCARA, Articulated, Cartesian, Delta, and Polar.
ARTICULATED ROBOT
Advantages: Joints allow flexibility of movement. As a result, a broad range of tasks may be performed.
Disadvantages: Articulated robots are more costly compared with other robot arms, and require more sophisticated control systems.
The most common industrial robot structure is the articulated arm, which accounts for 60% of installations worldwide, according to the International Federation of Robots. These robots resemble a human arm and have structures analogous to a shoulder, elbow, and wrist.
Articulated robots have between two to 10 joints which allows them a flexible range of motion to accomplish dynamic tasks. As the number of joints increases, the more “smooth” the robot’s motions become.
Typically, articulated arms can pivot six degrees of freedom. Although this is less than that of the human arm which can rotate seven degrees of freedom, the range of motion is sufficient for almost any task.
The robotic arm may be attached to a gripper, which is analogous to a hand. The gripper may be as simple as suction cups or as complex as hand-like structures with fingers that can grip and pick up objects.
Similar to robot type, the type of gripper is dependent on the task. Alternatively, grippers may be drill bits, sanders, lasers, and almost any type of specialized tool.
Because of their flexible range of motion allowed by joints, articulated robots have many applications. They are used most often for printing, packaging, welding, machine tending, material handling, and metalwork.
SCARA ROBOTS
Advantages: Cost-effective, accurate, and proficient in a variety of assembly approaches.
Disadvantages: Limited range of motion and less efficient than Delta robots
SCARA is an acronym for Selective Compliance Articulated Robot Arm and describes robots with two parallel rotary joints. While SCARA robots are faster than Cartesian robots, they are less precise. Though they are able to move along all three axes, these robots specialize in lateral movements.
SCARA robots revolutionized small electronic manufacturing because of their small footprint, simplicity, and low cost. They are particularly well-suited for assembly applications. The “C” in SCARA stands for “compliance” and refers to the small amount of “give” in its horizontal plane. However, SCARA robots are rigid in their vertical plane, hence the naming structure of “selective compliance”.
SCARA robot’s selective compliance is helpful for inserting parts into single-planes like circuit boards. Fitting a part into a hole requires some rigidity that is not possible with other types of robotic arms. However, SCARA robots have lower weight limits and fewer degrees of freedom due to this design.
CARTESIAN (RECTANGULAR) ROBOTS
Advantages: Can be more cost-effective and have simpler controls, with greater accuracy.
Disadvantages: Can only move linearly in three dimensions.
Cartesian robots operate on three linear axes (forwards and backward, up and down, and side to side). They get their namesake because they operate on the Cartesian Coordinate system (X,Y, and Z). In other words, they move horizontally and vertically in each ninety-degree plane.
Cartesian robots are frequently utilized for material handling, 3D printing, packaging, drilling, and storage or retrieval. Because Cartesian robots only operate linearly in three dimensions, their actions are more accurate. Additionally, they are more cost-effective and have simpler controls.
Advantages: Quick and accurate motions.
Disadvantages: Weight and range of motion restrictions.
Delta robots are popular in the manufacturing of food, pharmaceuticals, and electronics. Delta robots are frequently described as “spider-like” because they are crafted from jointed parallelograms connected to a base and are typically mounted above a workspace.
The Delta robot has sweet origins--it was originally created to pick up pieces of chocolate and place them in a box. Because of its light design, its motions are accurate and very fast.
POLAR (SPHERICAL) ROBOTS
Advantages: Simple control systems, long reach, and fast operations.
Disadvantages: Less flexibility compared with articulated arms and require larger footprints.
Polar robots, also known as ‘spherical robots’, possess an arm attached to two rotary joints and one linear joint. These robots move along polar coordinates, which allows a spherical range of motion.
The first industrial robot ever created was a spherical robot named “Unimate”. Unimate worked on General Motors assembly lines beginning in the 1950s, transporting die castings and welding parts onto auto bodies.
While still in circulation, polar robots are considered slightly obsolete technology that can be replaced by more versatile articulated robot arms. However, polar robots can still be more cost-effective.
When deciding on which type of robot to select, it’s most important to decide on the task or set of tasks it’s required to perform. Additionally, prospective robot owners will need to think about interoperability with existing infrastructure. With a range of options on the market, manufacturers can weigh the costs and benefits to decide on the best model for their needs.
AUTOMATE WITH NRTC
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From decommissioning and tear out to industrial robotic training services to custom flexible work cells, NRTC is the key to integrate your workplace. With personalized training and custom-built designs, NRTC Automation is the destination for all your industrial automation and manufacturing equipment services.
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