What Is an Articulated Robot?
An articulated robot is a type of industrial robot that can move like a human hand.
Compared to robots with fewer axes to drive, vertically articulated robots have a higher degree of freedom and can efficiently perform tasks that used to be performed by human hands or by robots with a lower degree of freedom, which can take a long time to perform. Vertical articulated robots have a wide range of motion, so they are good at performing precise work repeatedly. By introducing them to production sites where their characteristics can be utilized, they are expected to improve operational efficiency.
Uses of Vertical Articulated Robots
Vertical articulated robots are used in a wide range of fields, including automobiles, home appliances, and food products. In production lines, they are used in the following processes:
1. Welding
Welding is the process of joining automobile bodies and other components with metal parts. By having robots perform this work, accurate welding with little variation is possible and quality improvement can be expected.
2. Conveyance
This work involves arranging products and parts at high speed with equal spacing and the movement of heavy loads.
3. Assembly
This work involves assembling parts that have been grabbed onto other parts, tightening screws, etc. Vertical articulated robots can also handle tasks that are performed by human hands, enabling them to accurately reproduce the skills of skilled craftspeople.
4. Painting
Painting is the process of applying color to automobile bodies and other parts using a spray gun attached to the end of an articulated robot.
5. Inspection
This is a process in which a part is brought within the measurement range of an inspection camera or sensor to determine whether the appearance and quality (OK/NG, etc.) of the part is good or bad.
Principle of Vertical Articulated Robots
Vertical articulated robots consist of a manipulator, a controller, and a teaching pendant.
1. Manipulator
The manipulator is the main part of a robot arm. Various movements can be performed by servo motors attached to the joints. The following tools are attached to the tip of the manipulator to enable vertically articulated robots to perform their tasks:
- Welding machine;
- Screwdrivers;
- Camera for inspection;
- Spray gun for painting;
- Robot hand and
- Cleaning equipment.
2. Controller
A controller is a device used to control manipulators and has the following functions:
- Determination of the next movement of the robot in response to commands from a higher-level device such as a PLC
- Calculates and commands motor movements to ensure that the robot performs precise movements
- Stops the robot when it detects an abnormality in its motion.
In recent years, many products have been equipped with AI. Some robots can determine how to move next without teaching.
3. Teaching Pendant
Teaching pendants are devices that allow humans to operate vertically articulated robots. It is used for teaching the robot to memorize its movements using a keyboard or touch panel, and for checking alarms when an abnormality occurs in the robot.
Other Information for Vertical Articulated Robots
1. Difference Between Vertical Articulated Robots and Horizontal Articulated Robots
The difference between vertical articulated robots and horizontal articulated robots lies in the complexity of the movements that can be performed.
Vertical Articulated Robots
Vertically articulated robots generally have six axes, and by rotating each axis, they can perform movements that allow them to move freely in three-dimensional space. In other words, in addition to horizontal and vertical movements such as X, Y, and Z, rotational movements such as Rx, Ry, and Rz can also be performed.
Horizontal Articulated Robot
Horizontal articulated robots consist of four axes, with three axes for horizontal motion and one for vertical motion. In other words, three axes are used to move freely in the horizontal direction (X and Y if expressed in the three-dimensional direction), while the remaining axis is used to move vertically (Z if expressed in the three-dimensional direction). Because of this structure, a horizontally articulated robot cannot perform rotational movements (Rx, Ry, Rz) in 3D space.
2. Advantages of Introducing an Articulated Robot
The introduction of vertically articulated robots and the replacement of tasks previously performed by human operators with robots will have the following advantages:
Increased Factory Productivity
Robots are good at precision work or monotonous repetitive tasks (e.g., pick-and-place of products). Having vertically articulated robots perform these tasks allows workers to focus on other important value-added tasks. This can increase factory productivity.
Quality of the Process Where Robots Are Introduced Will Increase
Unlike humans, robots are less prone to variation when repeating the same task, which can be expected to improve quality. By introducing vertically articulated robots, it is possible to achieve a repetitive variation of ±0.1 mm or apply the correct amount each time.