Control Of Medium Wire Cutting Machine Tools
Oct 20, 2024| Open-loop control
Open-loop control system for wire cutting refers to a control system that does not accept feedback, only controls output, and controls without regard to consequences. It is also called a non-feedback control system. In CNC machine tools, it consists of a stepper motor and a stepper motor drive circuit. According to the input command, the CNC device sends a pulse command to the stepper motor drive circuit after calculation, thereby driving the workbench to move a certain distance. This servo system is relatively simple, stable in operation, and easy to master and use, but the improvement of accuracy and speed is limited. Therefore, it is generally only used for some economical CNC machine tools that can ignore external influences, have small inertia, or have low accuracy requirements.
Closed-loop control
The closed-loop control system for wire cutting is an automatic control system that consists of a closed loop consisting of a signal forward path and a feedback path, also known as a feedback control system. In CNC machine tools, it consists of a servo motor, a comparison circuit, a servo amplifier circuit, a speed detector, and a position detector installed on the workbench. This system automatically detects the actual displacement of the workbench and compares it with the command value, and controls it with the difference. This system has high positioning accuracy, but the system is complex, difficult to debug and maintain, and expensive. It is mainly used for high-precision and large CNC machine tools.
Semi-closed loop control
The working principle of the semi-closed loop servo system of wire cutting is similar to that of the closed loop servo system, except that the position detector is not installed on the workbench, but on the shaft of the servo motor. The accuracy, speed and dynamic characteristics that this servo system can achieve are better than those of the open-loop servo system, and its complexity and cost are lower than those of the closed-loop servo system. It is mainly used for most small and medium-sized CNC machine tools.