Industrial robots are multi - joint manipulators or multi - degree - of - freedom machine devices widely used in the industrial field. They have a certain degree of autonomy and can achieve various industrial processing and manufacturing functions relying on their own power sources and control capabilities. Industrial robots are widely used in various industrial fields such as electronics, logistics, and chemicals.

Generally speaking, an industrial robot consists of three major parts and six subsystems.

The three major parts are the mechanical part, the sensing part, and the control part.

The six subsystems can be divided into the mechanical structure system, the drive system, the perception system, the robot - environment interaction system, the human - machine interaction system, and the control system.

1. Mechanical structure system

From a mechanical structure perspective, industrial robots are generally divided into serial robots and parallel robots. The characteristic of a serial robot is that the movement of one axis will change the coordinate origin of another axis, while the movement of one axis in a parallel robot will not change the coordinate origin of another axis. Early industrial robots all adopted serial mechanisms. A parallel mechanism is defined as a closed - loop mechanism in which the moving platform and the fixed platform are connected through at least two independent kinematic chains. The mechanism has two or more degrees of freedom and is driven in a parallel manner. A parallel mechanism has two components, namely the wrist and the arm. The movement area of the arm has a great influence on the working space, and the wrist is the connecting part between the tool and the main body. Compared with serial robots, parallel robots have the advantages of high stiffness, stable structure, large load - carrying capacity, high micro - motion accuracy, and small motion load. In terms of position solution, the forward solution of a serial robot is easy, but the inverse solution is very difficult; on the contrary, for a parallel robot, the forward solution is difficult, but the inverse solution is very easy.

2. Drive system

The drive system is a device that provides power to the mechanical structure system. According to different power sources, the transmission modes of the drive system are divided into four types: hydraulic, pneumatic, electric, and mechanical. Early industrial robots used hydraulic drives. Due to problems such as leakage, noise, and low - speed instability in hydraulic systems, as well as the bulkiness and high cost of power units, currently only large - scale heavy - load robots, parallel processing robots, and some special application scenarios use industrial robots with hydraulic drives. Pneumatic drives have the advantages of fast speed, simple system structure, convenient maintenance, and low cost. However, the working pressure of pneumatic devices is low, and it is not easy to achieve precise positioning. Generally, it is only used to drive the end - effectors of industrial robots. Pneumatic grippers, rotary cylinders, and pneumatic suction cups as end - effectors can be used for workpiece grasping and assembly of medium and small loads. Electric drive is currently the most widely used drive method. Its characteristics are convenient power supply, fast response, large driving force, convenient signal detection, transmission, and processing, and it can adopt a variety of flexible control methods. The drive motors generally use stepper motors or servo motors. Currently, there are also direct - drive motors, but they are more expensive and the control is more complex. The reducers matched with the motors generally use harmonic reducers, cycloidal pin - wheel reducers, or planetary gear reducers. Due to the large number of linear drive requirements in parallel robots, linear motors have been widely used in the field of parallel robots.