Definition
Due to different research focuses, there is currently no clear unified standard for the definition of robots internationally. Integrating various definitions, a robot can be understood as: a programmable automatic machine under computer control, which has at least one or more anthropomorphic functions depending on its environment and operational needs. Additionally, it may possess varying degrees of environmental perception capabilities (such as vision, force perception, touch, proximity, etc.), as well as language functions and even logical reasoning and decision-making capabilities, enabling it to perform tasks in the required environment on behalf of humans.
Basic Composition 1. Mechanical Body
The mechanical structure of robots is generally divided into two main categories: one is the operational body mechanism, which resembles a human arm and wrist, and can perform various gripping actions and operational tasks when equipped with various grippers and end effectors. This structure is mainly adopted by industrial robots. The other category is the mobile body structure, which primarily aims to achieve mobility functions, including wheeled, tracked, legged structures, as well as serpentine, peristaltic, and deformable movements. Wall-climbing and underwater propulsion mechanisms also belong to this category.
2. Drive Servo Unit
The movements of the mechanical structure of the robot depend on the joint drives of the robotic joints, and most robots operate based on closed-loop control principles. The role of the servo controller is to drive the joints and move the load in the direction that minimizes deviation. Widely used driving methods include hydraulic servo drives, motor servo drives, and in recent years, pneumatic servo drive technologies have also made certain advancements.
3. Computer Control System
The command values for each joint servo drive are calculated by the main computer and provided at each sampling cycle. The main computer transforms the data into joint command values based on the spatial position, orientation, and speed of the reference coordinates of the teaching points through inverse kinematics calculations. Typically, robots adopt a two-level computer control system consisting of a main computer and a joint drive servo computer. Sometimes, to achieve intelligent control, it is necessary to collect and process various sensor signals, including vision, perform pattern recognition, problem-solving, task planning, and decision-making. In such cases, the spatial teaching points will be generated by a higher-level computer based on sensor signals, forming a three-level computer system.
4. Sensing System
In order for the robot to work normally, it must maintain close contact with the surrounding environment. In addition to the position sensors of the joint servo drive system (referred to as internal sensors), it is also necessary to equip various types of sensors (referred to as external sensors) such as vision, force, touch, and proximity, as well as a sensor signal collection and processing system.
5. Input/Output System Interface
To communicate and respond with surrounding systems and corresponding operations, various communication interfaces and human-machine communication devices are also required. Industrial robots provide an internal PLC, which can connect with external devices to achieve logical and real-time control with external equipment. Generally, there is at least one serial communication interface to complete tasks such as disk data storage, remote control, offline programming, and coordination between dual robots. Some new types of robots also include speech synthesis and recognition technology as well as multimedia systems.