The function of a robot control system is to receive detection signals from sensors and drive the various motors in the robotic arm according to the requirements of the operational task. Just as human activity relies on our senses, robot motion control is inseparable from sensors. Robots need sensors to detect various states. Internal sensor signals are used to reflect the actual motion state of the robotic arm joints, while external sensor signals are used to detect changes in the working environment.
Robot control system classification (by control method)
1. Centralized Control System
Using a single computer to perform all control functions is simple in structure and low in cost, but it has poor real-time performance and is difficult to expand. This structure was often used in early robots.
Its advantages include: lower hardware cost, easier information collection and analysis, easier to achieve optimal system control, better overall integrity and coordination, and more convenient PC-based system hardware expansion.
The disadvantages are: the system control lacks flexibility, control risks are easily concentrated, and once a failure occurs, the impact is wide and the consequences are serious; because industrial robots have high real-time requirements, when the system performs a large amount of data calculation, it will reduce the system's real-time performance, and the system's ability to respond to multiple tasks will also conflict with the system's real-time performance; in addition, the system wiring is complex, which will reduce the system's reliability.
2. Master-Slave Control System
The system employs a master-slave two-tier processor architecture to implement all control functions. The master CPU handles management, coordinate transformation, trajectory generation, and system self-diagnosis; the slave CPU controls the motion of all joints. This master-slave control method offers good real-time performance and is suitable for high-precision, high-speed control, but it suffers from poor system scalability and maintenance difficulties.
3. Distributed Control System
The system control is divided into several modules according to the nature and method of the system. Each module has different control tasks and control strategies. The modules can be in a master-slave relationship or an equal relationship. This approach has good real-time performance, is easy to implement high-speed and high-precision control, is easy to expand, and can realize intelligent control. It is currently a popular approach.
Basic functions of robot control system
1. Control the movement position of the robotic arm's end effector (i.e., control the points the end effector passes through and the path it moves along);
2. Control the movement posture of the robotic arm (i.e., control the relative position of two adjacent moving parts);
3. Control the motion speed (i.e., control the change in the position of the end effector over time);
4. Control the motion acceleration (i.e., control the speed change of the end effector during the motion process);
5. Control the output torque of each power joint in the robotic arm: (i.e., control the force applied to the manipulated object);
6. It has user-friendly human-computer interaction functions, and the robot completes the prescribed tasks by memorizing and reproducing information;
7. Enable robots to detect and sense their external environment. Industrial robots are equipped with vision, force, and tactile sensors to measure, identify, and judge changes in working conditions.
