Mechanical arms are just a structural branch of industrial robots. The family of industrial robots is very large. To put it bluntly, the structure of industrial robots is like a house, with villas, large flat floors, residential areas, apartments, and even container houses. These houses can all accommodate people, but the difference lies in the design of the room type. Industrial robots are the same, although they have different structures; their essence is to be applied in industrial manufacturing, as long as they can be used.
Let's get straight to the topic, because industrial robots are a very large family, including serial robots, parallel robots, cylindrical coordinate robots, spherical coordinate robots... It may sound confusing, so this article will not introduce the structure of robots; instead, it will primarily focus on practical applications, list the most common industrial robots on the market, and then discuss the production lines for which they are suitable.
1. The most common-Multi-Joint serial robot
This is the most common robot, which we often see in promotional videos. Multi-joint serial robots are composed of rigid links connected by multiple joints (usually rotating or sliding joints) in sequence, forming a structure similar to a "humanoid arm". This design endows it with high flexibility and complex mobility. For example, a six-degree-of-freedom serial robot (such as Braun's Universal US series) can achieve precise control of any spatial position and posture, suitable for tasks such as welding, spraying, and assembly.
Generally speaking, the most commonly used multi joint serial robots are four axis robots and six axis robots. What we often refer to as the seventh or eighth axis actually means adding an additional axis to them.
Multi joint serial robots are widely used in key links of manufacturing industry,
include:
Automatic assembly: such as precision assembly of automotive components.
Welding and spraying: Welding robots need to accurately control the position of the welding gun in three-dimensional space.
Handling and transportation: For example, stable operation is achieved through joint coordination when handling heavy objects.
In summary, this type of robot is at the model worker level and can be used in various industrial scenarios. When using this industrial robot, it is important to consider the robot's arm span and load, which determine the robot's workspace and work quality.
2. The most popular - collaborative robots
Collaborative robots are a type of multi-joint serial robots, but their biggest feature is flexible operation, which allows them to work perfectly with humans without considering the safety space of the robot.
Its existence is designed for direct interaction with humans, with built-in high-sensitivity sensors (such as force sensors, collision detectors) and real-time response mechanisms that can automatically slow down or stop when human proximity is detected, without the need for physical isolation (such as safety fences).
Collaborative robots, as lightweight and highly flexible entities, are generally applied to these production lines:
Assembly and Welding: Collaborative robots undertake critical tasks in automotive manufacturing, such as component assembly, welding, and spraying. For example, Braun's xz series robots achieve efficient handling and assembly in automotive electronics factories.
Handling and loading/unloading: In traditional manufacturing, collaborative robots replace manual labor to complete tasks such as material handling. For example, collaborative robots can be installed in machine tool operations to perform complex part cutting, ensuring accuracy and quality.
Flexible production: Collaborative robots support small batch customized production in unstructured environments, adapting to the needs of multiple varieties and small batches. For example, GGII data shows that in 2022, the proportion of handling/loading/unloading, assembly, and screw locking scenarios exceeded 50%.
3. The most low-key - Cartesian coordinate robot
Cartesian coordinate robots should belong to the first generation of "internet celebrities". They were once kings and almost dominated the automation of the entire injection molding industry. However, as more and more new models were developed, this big brother became much more low-key.
Structurally speaking, a Cartesian robot consists of three mutually perpendicular linear moving axes (X, Y, Z axes), forming a framework similar to a three-dimensional coordinate system. The position of its hand is determined by three independent degrees of freedom, and the action space is a rectangular prism. The structure includes vertical columns and horizontal beams, and the end effector is precisely positioned through a control system.
Cartesian robots are most commonly used in the injection molding industry, mainly in the automation of parts picking, handling, loading and unloading, and auxiliary production processes, including mold picking and handling. Cartesian robots use linear motion of X, Y, and Z axes to quickly extract finished products or nozzles from the mold and transport them to the material box or conveyor belt.
4. The most peculiar - parallel robots
A parallel robot looks like a "big spider" and is an industrial robot with a closed-loop structure. Its core feature is the connection between the moving platform and the fixed platform through multiple independent motion chains, which significantly differs from traditional serial robots in structural design and performance.
A parallel robot consists of a moving platform (end effector) and a fixed platform connected by at least two independent motion chains, forming a closed-loop structure. Its typical structure includes multiple parallel arms or branches, each arm moving independently and working together. This structure makes it outstanding in terms of high stiffness and strong load-bearing capacity, without the cumulative error problem of serial robots.
This robot is typically used in:
Sorting and Handling: Used for fast and accurate sorting, handling, and boxing operations in industries such as food, electronics, chemicals, and packaging. For example, tasks such as installing car lights and luggage racks in automobile factories, or assembling and handling electronic components.
Metal processing: applied to the loading and unloading, part handling, and precision assembly of equipment such as milling machines, grinders, drilling machines, and spot welding machines.
Automated production line: replacing manual assembly, testing, labeling and other processes to improve production efficiency.
5. The simplest SCARA horizontal robot
This type of robot belongs to cylindrical coordinate robots, usually having 4 degrees of freedom, including 3 rotation joints (for planar positioning) and 1 movement joint (for controlling Z-axis vertical motion). Its biggest feature is that it can make the robot move on a horizontal plane, and in addition, an additional sliding joint is used for vertical movement. SCARA robots are commonly used in assembly operations, with fast speed and accurate positioning accuracy, designed specifically for precision assembly. Activities include handling, dispensing, locking screws, packaging, and encapsulation.
6. The most capable of handling - AGV robot
AGV robots are actually more cross industry robots. They are not only used in industry, but also have a wide range of applications, including logistics and warehousing, manufacturing, and some special industries.
AGV robots use electromagnetic, optical, laser, or visual guidance devices to accurately move along predetermined paths under computer monitoring, completing tasks such as cargo transportation, handling, or picking. Its core function is to replace manual handling and achieve logistics automation, suitable for fields such as factory workshops, warehousing logistics, and automobile manufacturing.
The above six types of robots are currently the most common industrial robots on the market. As the saying goes, there is no good or bad robot, and the one that can adapt to its own production line is the best robot.