Industrial robots are widely used in industrial manufacturing, such as automobile manufacturing, electrical appliances, food, etc. They can replace repetitive machine-like manipulation work and are a type of machine that can achieve various functions through their own power and control capabilities. They can withstand human command and also operate according to pre-programmed procedures. Today, let’s talk about the basic main components of industrial robots.
1. Main Body
The main mechanical structure refers to the base and the actuating mechanism, including the large arm, small arm, wrist, and hand, forming a multi-degree of freedom mechanical system. Some robots also have a walking mechanism. Industrial robots have up to 6 degrees of freedom or more, and the wrist generally has 1 to 3 degrees of freedom.
2. Drive System
The drive system of industrial robots is divided into three major categories according to the power source: hydraulic, pneumatic, and electric. Depending on the requirements, these three types can also be combined to form a compound drive system. Or through mechanical transmission mechanisms such as synchronous belts, wheel systems, gears, etc., to indirectly drive. The drive system includes power devices and transmission mechanisms, which are used to make the actuating mechanisms produce corresponding actions. These three basic drive systems each have their characteristics, and the mainstream is now the electric drive system.
Due to the widespread acceptance of low-inertia, high-torque AC/DC servo motors and theirCompanion server driver (frequency converters, DC pulse width modulators), this type of system does not require energy conversion, is convenient to use, and has flexible control. Most motors need to be equipped with a precision transmission mechanism behind them: reducers. The gear uses a gear speed converter to reduce the motor’s rotation speed to the desired rotation speed and obtain a larger torque device, thereby reducing the speed and increasing the torque. When the load is large, blindly increasing the power of the servo motor is not cost-effective. A reducer can be used within an appropriate speed range to improve the output torque. Servo motors are prone to heating and low-frequency vibration during low-frequency operation, and long-term and repetitive work is not conducive to ensuring their accurate and reliable operation. The existence of precision reduction motors allows the servo motor to operate at an appropriate speed, enhancing the rigidity of the machine while outputting a larger torque. There are now two mainstream reducers: harmonic reducers and RV reducers.
3. Control System
The robot control system is the brain of the robot and is the main factor determining the functions and capabilities of the robot. The control system issues command signals to the drive system and the actuating mechanism according to the input program and controls it. The main task of industrial robot control technology is to control the range of motion, posture, and trajectory of the industrial robot in the working space, as well as the timing of the actions. It has the characteristics of simple programming, software menu operation, friendly human-computer interaction interface, online operation prompts, and convenient use.
The controller system is the core of the robot, and foreign companies have closely sealed off experiments in our country. In recent years, with the development of microelectronics technology, the performance of microprocessors has become higher and higher, while the price has become cheaper and cheaper. Now, there are already 32-bit microprocessors on the market for 1-2 US dollars. High-performance cost-effective microprocessors have brought new development opportunities for robot controllers, making it possible to develop low-cost, high-performance robot controllers. To make the system have sufficient computing and storage capabilities, robot controllers now mostly use stronger ARM series, DSP series, POWERPC series, Intel series, etc. chips. Because the existing general-purpose chip performance and performance cannot fully meet some robot systems in terms of price, performance, integration, and interface requirements, this has led to the demand for SoC (System on Chip) technology in robot systems, integrating specific processors with the required interfaces together, which can simplify the design of the system’s peripheral circuits, reduce system size, and reduce costs. For example, Actel integrates NEOS or ARM7 processor cores into its FPGA products, forming a complete SoC system. In the field of robot technology controllers, research is mainly concentrated in the United States and Japan, and there are mature products, such as the American DELTATAU company, the Japanese Tomi Corporation, etc. Their motion controllers are based on DSP technology and use an open structure based on PCs.
4. Perception System
It is composed of internal sensor modules and external sensor modules to obtain meaningful information from the internal and external environmental status.
Internal sensors: sensors used to detect the robot’s own status (such as the angle between the arms), mostly sensors for detecting position and angle. Specifically, there are position sensors, position sensors, angle sensors, etc.
External sensors: sensors used to detect the environment in which the robot is located (such as detecting objects, the distance from objects) and the condition (such as detecting whether the grasped object has slipped). Specifically, there are distance sensors, vision sensors, force sensors, etc.
The use of intelligent sensing systems has improved the mobility, practicality, and intelligence standards of robots. The human perception system is agile for robots in external world information, but for some special information, sensors are more effective than human systems.
5. End Effector
The end effector is the part connected to the last joint of the mechanical hand. It is generally used to grasp objects, connect with other mechanisms, and perform the required tasks. In robot manufacturing, the end effector is generally not designed or sold. In most cases, they only provide a simple gripper. The end effector is usually installed on the flange of the robot’s 6th axis to complete tasks in a given environment, such as welding, painting, gluing, and part loading and unloading, which are tasks that need to be completed by robots.
