Industrial robot is a highly automated multi-joint mechanical device that can perform various manufacturing and processing tasks in various industrial environments. These robots can be programmed to perform various tasks and have high precision and efficiency. They are widely used in many industrial fields such as electronics, logistics, and chemicals.
So, what are the specific components of a complete industrial robot? Next, we will analyze in detail the various components of industrial robots to help you understand this important technology more deeply.
Under normal circumstances, industrial robots are composed of four main parts and six subsystems.
These four parts include: the drive system, the actuator, the sensing system, and the control system.
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1.Execution mechanism
The execution mechanism is a crucial part of a robot, typically consisting of a series of links, joints, or other types of motion pairs. Based on its functions, it can be divided into parts such as the hand, wrist, arm, waist, and base.
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2.The drive system
The drive system of industrial robots is responsible for providing power to the components of the execution system, consisting of two parts: the drive and the transmission mechanism, which are usually closely connected to the actuator. The drive can use electric, hydraulic, pneumatic devices, or a combination of them. Common transmission mechanisms include harmonic drive, screw drive, chain drive, belt drive, and various gear drives.
3.The control system
The control system of industrial robots is mainly responsible for manipulating the robot's actuators through the robot's operating instruction program and signals received from sensors, so that it can implement predetermined movements and functions. According to whether the system has feedback functionality, the control system can be divided into open-loop control systems and closed-loop control systems. The former refers to industrial robots without feedback functionality, while the latter has this feature.
The control system of industrial robots is mainly composed of two parts: the main control computer and the joint servo controller.
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4.The Sensing systems
Sensing systems play a vital role in robotics and are generally divided into two categories: internal and external sensors, based on the source of the information they acquire. Internal sensors, such as position and speed sensors, are essential for robot motion control and are used to collect information within the robot. They are indispensable basic components. External sensors are responsible for detecting the environment in which the robot is located, the state of external objects, or the relationship between the robot and external objects. Common external sensors include force sensors, tactile sensors, proximity sensors, and visual sensors. In certain specific application areas, such as those requiring perception of temperature, humidity, pressure, slip, and chemical properties, special external sensors may also be required.
Traditional industrial robots mainly rely on internal sensors for precise control of robot motion, position, and attitude. However, by adopting external sensors, robots will have a certain degree of adaptability to the external environment and exhibit some intelligent characteristics.
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Internal Sensors |
Usage |
Precise control of robots |
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Detected information
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Position, angle, velocity, acceleration, attitude, etc. |
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Sensors used |
Microswitches, photoelectric switches, differential transformers, encoders, potentiometers, accelerometers, gyroscopes, inclination sensors, force sensors, etc. |
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External sensors |
Usage |
Understanding the state of the work piece, the environment or the robot in the environment, and flexible and effective manipulation of the work piece |
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Detected information |
Work and environment: shape, position, range, mass, attitude, motion, speed, etc. Robot and environment: position, speed, acceleration, attitude, etc. Manipulation of the workpiece: non-contact, contact (obstacle detection, collision detection), haptics, gripping force, etc. |
Table.1 Classification of robot sensors
The six sub-systems can be divided into mechanical structure system, driving system, Sensory System, robot-environment interaction system, human-robot interaction system and control system.
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1. Mechanical Structure System
The mechanical structure of industrial robots is mainly divided into two types: serial and parallel. The biggest feature of serial robots is that the movement of one axis will affect the origin of another axis, while this will not happen in parallel robots. Early industrial robots mainly used serial structures. Parallel mechanisms are closed-loop mechanisms that connect the moving platform and the fixed platform through at least two independent motion chains, with two or more degrees of freedom. Parallel mechanisms include the wrist and arm, where the arm has a larger range of motion in space, and the wrist is the part that connects the tool and the subject. Compared with serial robots, parallel robots have higher stiffness, stability, carrying capacity, micro-motion precision, and less motion load. In terms of position solving, serial robots have simple forward solutions and difficult inverse solutions, while parallel robots have complex forward solutions and relatively easy inverse solutions.
2. Drive System
The drive system is a device that provides power for the mechanical structure system. According to the power source, the transmission method of the drive system can be divided into hydraulic, pneumatic, electric, and mechanical types. Early industrial robots mainly used hydraulic drive. However, due to problems such as leakage, noise, and low-speed instability in hydraulic systems, as well as higher weight and cost of power units, only large heavy-duty robots, parallel processing robots, and some special application occasions use hydraulic-driven industrial robots. The advantages of pneumatic drive include fast speed, simple system structure, easy maintenance, and low price. However, the operating pressure of pneumatic devices is low, and it is not easy to accurately position, so it is usually only used for driving the end effector of industrial robots. Pneumatic grippers, rotary cylinders, and pneumatic suction cups can be used for medium and small load workpiece gripping and assembly. Electric drive is currently the most commonly used drive method, with the characteristics of convenient power supply, fast response, strong driving force, convenient signal detection, transmission, and processing, as well as various flexible control methods. The drive motor generally uses a stepping motor or a servo motor, but the application of direct drive motors is also widespread, although it has a higher cost and more complex control. The reducer used with the motor generally uses a harmonic reducer, a planetary reducer, or a worm reducer. Due to the large number of linear drive requirements in parallel robots, linear motors have been widely used in parallel robot fields.
3. Sensory System
The robot sensory system is responsible for transforming various internal state information and environmental information from signals into data and information that the robot can understand and apply. In addition to perceiving mechanical quantities related to its own working state, such as displacement, speed, and force, visual perception technology also plays a key role in industrial robot perception. The visual servo system uses visual information as a feedback signal for controlling the robot's position and attitude. In addition, machine vision systems have been widely used in various fields such as quality inspection, workpiece recognition, food sorting and packaging. The sensory system includes internal sensor modules and external sensor modules, and the use of smart sensors improves the mobility, adaptability, and intelligence level of robots.
4. Robot-Environment Interaction System
The robot-environment interaction system is a device that realizes the connection and coordination between the robot and the equipment in the external environment. The robot and the external equipment are integrated into a functional unit, such as a processing and manufacturing unit, welding unit, assembly unit, etc. It can also be a multi-robot integrated into a functional unit to perform complex tasks.
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5. Human-Machine Interaction System
The human-machine interaction system is equipment that allows humans to communicate with and participate in robot control. Examples include: standard computer terminals, instruction consoles, information display panels, danger signal alarms, etc.
6. Control System
The task of the control system is to control the robot's actuators to complete the specified motion and functions according to the robot's operation instructions and the feedback signals from the sensors. If the robot does not have feedback information, it is an open-loop control system; if it has feedback information, it is a closed-loop control system. According to control principles, it can be divided into program control systems, adaptive control systems, and artificial intelligence control systems. According to the form of controlling motion, it can be divided into point-to-point control and continuous trajectory control.
1. Application in the stacking process
In various production environments, highly automated robots are widely used in stacking operations. Compared with manual stacking, robots can bear greater pressure and have higher work efficiency. Handling robots can classify and transport goods according to their characteristics, and move them to the specified position, making the material handling, container handling, and other processes on the production line more efficient.
2. Application in the welding process
Welding robots are mainly used in welding operations, and the welding needs vary across different industries. Therefore, there are different types of welding robots such as spot welding robots, arc welding robots, and laser robots. Among them, the automotive manufacturing industry is the most widely used industry for welding robots. The welding difficulty, welding quantity, and welding quality of robotic welding have overwhelming advantages over manual welding.
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3. Application in the assembly process
In industrial production, part assembly is a labor-intensive task that requires a large number of workers. With the development of technology, assembly robots have gradually replaced human assembly. Assembly robots combine various technologies such as communication technology, automatic control, optical principles, and microelectronics. By writing a suitable program, assembly robots can be applied to specific assembly work. Their biggest features are high installation precision, flexibility, and durability, especially suitable for the installation of electronic components and car precision parts.
4. Application in the inspection process
Robots also have various additional functions and can replace humans in special positions. For example, in high-risk areas such as nuclear pollution zones, toxic zones, or unknown high-risk areas for exploration. In addition, places where humans cannot reach, such as intra-body exploration in patients, industrial flaw detection, and life detection in earthquake disaster relief sites, robots have outstanding performances.
1. Human-robot collaboration
With the development of robots from working away from humans to naturally interacting and collaborating with humans, the maturity of drag teaching and manual teaching technology has made programming simpler and more user-friendly, reducing the professional requirements for operators, making it easier for skilled workers' process experience to be passed on.
2. Autonomy
Currently, robots are developing from pre-programmed, teach-in control, direct control, and remote control operation modes to self-learning and autonomous operation. Intelligent robots can automatically set and optimize trajectory paths according to work conditions or environmental requirements, automatically avoid singular points, predict interference and collision, and avoid obstacles.
3. Intelligent, information-based, and networked
More and more 3D vision and force sensors will be applied to robots, making them smarter. With the advancement of sensing and identification systems and artificial intelligence technologies, robots are evolving from being unidirectionally controlled to storing and applying data on their own, gradually realizing information-based. With the advancement of multi-robot collaboration, control, and communication technologies, robots are evolving from individual entities to interconnected and collaborative cooperation.
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