FAST Tension-controlled

In the winding process of the torque-controlled center winders, on which this technology module is based, indirect tension control takes place via the variable motor drive torque.

Tension control - Torque controlled method

For tension-controlled winders, the drive is switched to the "torque-controlled method" and receives the setpoint torque, which is determined by the resulting feedforward control value. The feedforward control consists of the tensile force setpoint, the friction compensation and the acceleration compensation. Since no tension controller is active, no measured values from the web tension measurement are required. This means that expensive and complex sensor technology for web tension measurement can be dispensed with.

Typical applications are found in low-cost winders of insensitive materials with low elasticity and medium line speeds such as:

• Coil winders in the metal-processing industry
• Cable winders
• Margin winding units

• Unwinders in the packaging industry

Tension control (M) - Torque controlled method

This method has a tension controller in addition to 1. The tension controller is dependent on the measurement of the actual tensile force value. The actual tensile force value is measured by a sensor in the material web and is controlled by the tension controller. The feedforward controlconsists of the tension setpoint, the friction compensation and the acceleration compensation.

Typical applications are the winding of insensitive materials with low elasticity and medium line speeds such as:

• Films
• Composite materials
• Paper

• Label materials

Tension control (n) - Speed controlled method

For tension-controlled winders, the drive is switched to the "speed-controlled method". The drive is operated via the set speed, which is composed of the speed feedforward controland the correcting variable of the tension controller. The traction force controller necessarily requires a traction force measurement. The actual tensile force value is recorded by a sensor in the material web and is controlled by the tensile force controller. The speed feedforward controlis determined from the line speed. The torque feedforward controlconsists of the tensile force setpoint and the acceleration compensation.

The tension control (n) in the speed-controlled method offers a decisive advantage: There is no direct influence by friction and therefore the influence of acceleration is significantly lower.

The disadvantage of this method is that the mass inertia ratio must be observed for stable speed control.

It is also recommended to use a diameter sensor for the correct start diameter if there is no clear start diameter after a roll change.

The tension control (n) is used if there are high demands on tensile force quality and tensile force characteristic or if not determinable disturbance variables like friction act on the winder.

Typical applications are the winding of insensitive materials with low to high elasticity and medium line speeds such as:

• Films
• Composite materials
• Paper
• Label materials

The Winder Tension-Controlled module from Lenze is specifically designed for controlling tension during material winding and unwinding. This module is suitable for a wide range of industrial applications where precise tension and speed control are critical for processing quality. Tension control can be either open-loop or closed-loop, and the module enables smooth control with acceleration and friction compensation. This article details the individual functions and technical aspects of the module.

Module Versions

The module is available in three different versions: Base, State, and High. Each of these versions has its own features and capabilities, offering various levels of control and customization for different applications.

• Base Version: The basic version offers open tension control with acceleration compensation and linear friction compensation. This version allows simple tension control settings using a linear characteristic and calculates the winding material diameter based on line speed.
• State Version: The advanced version provides three different characteristics for tension control: linear tension profile, linear torque profile, and a user-definable profile. This version also supports a PI controller for closed-loop tension control and allows for friction identification, helping to control the material more precisely and compensate for friction losses.

• High Version: The most advanced version of the module allows for the identification of the winder's axis inertia, which is then included in the module's parameters. This feature is useful for adjusting control during varying material diameters throughout the process. Additionally, the High version enables gain adaptation of the speed controller during operation.

Tension Control

In the process of winding or unwinding material, precise tension control is crucial to maintaining material quality and proper tension. Tension is directly controlled by the motor torque on the winding axis, with the winding speed indirectly proportional to the material diameter. The module uses open tension control with acceleration and friction compensation, with the coil diameter being a key parameter for proper control.

• Open Tension Control: In the basic version, tension is controlled through a simple linear characteristic, with the coil diameter taken into account. The module monitors the line speed and adjusts the tension accordingly to maintain constant force on the material. Acceleration and friction compensation help maintain stable tension even during speed changes.
• Closed Tension Control: In the State and High versions, closed-loop tension control using a PI controller is available. This controller monitors the actual force on the material and automatically adjusts the motor torque to keep the tension within the desired limits.

Automatic Winding Direction Detection

The module supports automatic detection of the winding or unwinding direction of the material, simplifying control and ensuring consistent tension when changing directions. Detection is based on the line speed and the defined material direction.

If the line speed is zero, the winding direction cannot be automatically identified. In this case, the direction must be manually set via the xWindingDirectionStandstill parameter, specifying whether the material should be wound or unwound.

Acceleration and Friction Compensation Changes in line speed or winding speed can cause irregular tension on the material, potentially leading to material damage. Therefore, the module incorporates acceleration and friction compensation.

• Acceleration Compensation: The module monitors speed changes and automatically adjusts the motor torque to balance the acceleration or deceleration of the line, ensuring constant tension even during speed changes.
• Friction Identification: Friction in the winder mechanism can cause irregularities in material movement. The module allows for friction identification, particularly when the winder is empty, which helps determine the exact torque needed to compensate for friction during operation. The identified friction values are stored and used during operation.

Material Length Counter

The module provides a material length counting function, which is important for monitoring the amount of processed material. Users can choose different sources for length counting, such as:

• lrSetLineVel: The length is calculated based on line speed, where speed is integrated into material length.
• MaterialCounterAxis: This method uses a reference axis (e.g., a rotational sensor) for precise material length measurement. This method is suitable, especially for uneven signals where integrating speed could lead to errors.

Tension Control via Characteristic Function

One of the key features of the module is the ability to control tension via a characteristic function. Users can define how the tension should change with the increasing coil diameter:

• Linear Tension Profile: The tension can be controlled linearly, meaning that as the coil diameter increases, the tension decreases to prevent material damage.
• User-Definable Characteristic: The module allows users to define custom tension characteristics using up to 64 points, enabling precise control customization for specific needs.

Inertia Identification

In the High version, the module can identify the winder’s inertia. This process is essential, especially when winding or unwinding material with varying diameters. Inertia affects the drive behavior, and identifying this parameter allows the module to adjust control parameters for optimal control.

Conclusion

The Winder Tension-Controlled module from Lenze offers a wide range of features for tension and speed control during winding and unwinding. Whether it’s basic tension control or advanced functions like inertia identification, the module provides flexibility for various applications. If you are interested in more technical details or specific settings, the attached document provides extensive instructions for operation and configuration.

If you are interested in more technical details or specific configurations, the attached document provides extensive instructions for operation and configuration.

The Lenze Winder Tension-Controlled module is a key to effective winding operations. Technological advancements in industrial control systems allow for more precise and reliable control of winding and unwinding processes. The Lenze Winder Tension-Controlled module is a high-performance solution for controlling tension during the winding or unwinding of a wide range of materials such as films, textiles, plastics, paper, or metal strips. This module provides a solution for processes where constant and precisely controlled material tension is crucial, reducing the risk of material damage and improving production efficiency.

Features and Principles of Operation

The Lenze Winder Tension-Controlled module offers two main methods of tension control:

• Open-Loop Control: This mode is used in applications where precise tension measurement and control using sensors are not required. The tension is controlled based on a preset torque, which depends on the coil diameter. This method is more economical and less demanding to implement but offers lower accuracy. It is suitable for less sensitive materials, such as metals or cables.
• Closed-Loop Control: For more demanding applications, closed-loop control continuously monitors tension using force sensors. The module automatically adjusts motor torque according to the measured values, ensuring stable and precise tension. This mode is ideal for sensitive materials, such as thin films, paper, or textiles, where precise tension control is critical to the quality of the final product.

Application Areas

The Lenze Winder Tension-Controlled module is widely used in various industries. Depending on specific needs and material types, different control methods can be used:

• Torque-Controlled Method: This method is used in applications where tension measurement is not required. The tension is controlled through predictive control based on set pulling force, friction, and acceleration compensation. Typical applications include winding metal coils, cables, or unwinding in the packaging industry.
• Speed-Controlled Method: This method includes tension measurement and is suitable for applications where high tension precision is required. Predictive control is supplemented by corrections based on actual tension force measurement. Applications include processing films, composite materials, paper, and labels.

Technical Aspects and Key Features

Speed and Tension Control: One of the key functions of the module is controlling speed and tension based on the winding diameter. The motor speed and torque dynamically adapt based on the current diameter measurement, ensuring constant material tension throughout the process. For winders requiring precise tension control, the system offers closed-loop control using a tension sensor.

• Friction and Acceleration Compensation: Friction and acceleration can affect tension stability during winding. The Lenze module offers automatic friction identification and compensation, improving system stability, especially during rapid speed changes or when working with materials sensitive to tension changes. Friction identification is critical in applications with complex mechanical systems, such as oil gearboxes, where friction depends on temperature.
• Diameter Measurement and Material Counter: The module provides automatic coil diameter measurement and material counter functions, which are essential for tracking the length of material that has been wound or unwound. This function is important in processes requiring precise monitoring of the amount of processed material. The coil diameter is automatically calculated based on line speed and winding speed.
• Real-World Applications: The Lenze Winder Tension-Controlled module is used in various industries, from metalworking to the production of flexible packaging and textiles. In the metalworking industry, the module is used for controlling the winding of metal strips and cables, where maintaining constant tension throughout the process is crucial. In the printing industry and flexible packaging production, the module is used for precise tension control of films and foils, ensuring high product quality.

Conclusion

The Lenze Winder Tension-Controlled module is a reliable and flexible solution for industrial winding and unwinding processes. It offers a wide range of features for tension control, diameter measurement, and friction compensation, making it an ideal tool for applications where precision and efficiency are critical. The module offers customization options based on specific needs, helping to optimize the production process and ensure the quality of processed materials.

If you are interested in more technical details or specific configurations, the attached document provides extensive instructions for operation and configuration.

The main differences between versions V1 and V2 of the FAST Technology module Winder Tension-Controlled are as follows:

Additional Features and Improvements

• V2 includes additional features compared to V1, such as Quick Stop, which allows for faster and safer stopping of the winding process. This feature is not mentioned in V1.
• V2 also adds a function for terminating the winding process and includes the ability to monitor web breaks, ensuring better quality control.

Support for Different Axis Control Versions

• V2 includes support for L_MC1P_AxisBasicControlV2, which is a newer version of the axis control function block, while V1 uses an older version of this block.

Speed Controller Gain Adaptation

• In V2, the speed controller gain adaptation has been improved, allowing for more precise and smoother speed regulation during winding, depending on the inertia of the winder. This feature was not as detailed in V1.

Support for Virtual Axes and Simulation

• V1 did not support simulation in the "PLC Designer" and lacked support for virtual axes. V2 changed this, adding support for Modulo traversing range for more precise positioning during winding.

Improved Tension Control

• Closed-loop tension control in V2 is improved to better compensate for friction and acceleration. This improvement ensures more constant tension on the material during winding, which was not as well developed in V1.

Speed Control

• V2 includes the possibility of speed limitation during the winding process, helping to prevent unwanted accelerations and decelerations. This feature is not mentioned in the older version (V1).

In summary, V2 offers greater flexibility, improved precision, and better integration with newer technology solutions for tension and speed control during material winding processes.