The tension control system in the printing industry is a critical component that ensures the quality and efficiency of material handling during winding and unwinding processes. This system, based on the STM32L151CCU6 microcontroller, implements a closed-loop control mechanism that guarantees high precision, fast response, and ease of operation. By integrating PID control algorithms, the system adapts to various materials and maintains consistent tension throughout the process. Additionally, it calculates the diameter of the material roll, ensuring a more accurate and stable tension control.
Tension control is essential in the printing industry, especially when dealing with flexible materials. During the winding process, maintaining the right tension is crucial to avoid issues like deformation or loosening of the material. If the tension is too high, the material may stretch or break; if too low, it might not be compact enough for transport. Therefore, the system measures the roll diameter in real-time and adjusts the tension accordingly, optimizing the entire winding process.
As the printing industry becomes more structured, the demand for precise tension control has increased. There are three main types of tension control systems: indirect, direct, and composite. While indirect methods reduce costs by eliminating the need for tension sensors, they lack the accuracy required for high-performance applications. Direct methods, though more expensive, offer higher precision and faster response times. The system described here uses the STM32F103RCT6 as the main controller, featuring a 72 MHz clock speed, integrated peripherals, and a 3.3 V operating voltage, making it ideal for complex control tasks.
The system operates by setting a desired tension value and using feedback from a tension sensor to adjust the actuator—typically a magnetic powder brake or clutch. The control algorithm continuously compares the actual tension with the setpoint, adjusting the output to maintain stability. This ensures smooth operation during unwinding, guiding, and winding phases.
For measurement, the system employs a tension sensor positioned at a 120-degree wrap angle on a roller. The force detected includes both the material tension and the roller’s weight, which is then filtered out to obtain an accurate reading. The signal is amplified using an instrumentation amplifier, such as the AD620AN, to ensure high accuracy and minimal noise.
In terms of hardware design, the system uses a combination of buttons and encoders for user input, along with an LCD display for real-time monitoring of tension values and output percentages. The magnetic powder actuators, either a clutch or brake, are controlled via a PWM signal, which is amplified to supply the necessary current. This setup allows for precise and responsive control, enhancing the overall performance of the tension control system.
Overall, this advanced tension control system provides reliable, efficient, and adaptable performance, meeting the growing demands of modern printing and material handling industries.
Shanghai Janetec Electric Co., Ltd. , https://www.janetecelectric.com