Four Control Modes of Industrial Robot and Intelligent Control Modes

Four Control Modes of Industrial Robot and Intelligent Control Modes

At present, industrial robots are the most widely used robots in the market. They are also the most mature and perfect robots. Industrial robots can be widely used, thanks to their various control modes. According to the different tasks, it can be divided into four control modes: point position control mode, continuous trajectory control mode, force (moment) control mode and intelligent control mode. The main functions of these control modes are described in detail below.

1. Point To Point control (PTP)

This control method only controls the position and posture of the end effector of industrial robot at some specified discrete points in the working space. In control, only industrial robots are required to move quickly and accurately between adjacent points, and there is no requirement for the trajectory of the robot to reach the target point. Position accuracy and speed required for motion are two main technical indicators of this control method. This control method has the characteristics of easy realization and low positioning accuracy requirement. Therefore, it is often used in pick and place, handling, spot welding and inserting components on circuit boards, which require only accurate position and posture of the end effector at the target point. This method is relatively simple, but it is very difficult to achieve the positioning accuracy of 2-3um.

2. Continuous Trajectory Control (CP)

This control method is to continuously control the position and posture of the end-effector of industrial robot in the working space. It is required to move in a certain range of accuracy in strict accordance with the predetermined trajectory and speed. Moreover, the speed is controllable, the trajectory is smooth and the motion is smooth to complete the task. The joint of industrial robot moves continuously and synchronously, and its end effector can form a continuous trajectory. The main technical index of this control method is the trajectory tracking accuracy and stability of the end effector position of industrial robots. This control method is usually used in arc welding, spray painting, edge removal and inspection robots.

3. Force (Torque) Control Mode

When assembling and place the workpieces, etc. In addition to the need for accurate positioning, It also requires that the force used be appropriate. In this case, the Force control(servo) mode must be used. The principle of this control mode is basically the same as that of position servo control, But feedback are not position signals. It's a force signal. So the torque sensor must be used in the system. Sometimes adaptive control is also implemented by using the sensing functions such as proximity and sliding.

4. Intelligent Control Mode

Intelligent control of robots is to acquire knowledge of the surrounding environment through sensors. And make corresponding decisions according to their own internal knowledge base

Using intelligent control technology, the robot has strong environmental adaptability and self-learning ability. The development of intelligent control technology depends on the rapid development of artificial intelligence such as artificial neural network, genetic algorithm, genetic algorithm and expert system in recent years. Maybe this control mode will make industrial robots really have the feeling of artificial intelligence. It is also the most difficult to control well. Besides the algorithm, it also depends heavily on the accuracy of components.

Conclusion

From the point of view of control essence, industrial robots are still in the lower level of space positioning control in most cases. Not too much intelligence. It can be said that it is only a relatively flexible manipulator, which is still a long way from "human".