The tension fluctuation of the shuttleless loom is caused by factors such as the shedding, beating-up, and the change of winding and unwinding radius of the beam(the loom rotation rate).
The periodic high-frequency tension fluctuation caused by the opening height and beating up can be solved by mechanical design.
The tension fluctuations during the winding and unwinding process of the beam can be balanced and compensated by adjusting the warp let-off amount.
To ensure weft density precisioness and constant warp tension during operation, maximumly avoid starting marks and obtain high-quality fabrics, it is necessary to ensure that the warp let-off motion and the take-up motion are synchronized.
However, with the weaving process progresses, the diameter of the warp beam with warp wire is gradually becoming smaller, and the diameter of the winding roller with mesh is gradually becoming larger, plus the shrinkage rate factor, traditional machines are hard to operate and response.
Lanying CNC let-off and take-up systems are precise and easily to achieve synchronization.
The let-off controller receives the pulse signal of the main shaft encoder and the sensor signal of the back roller, then feedbacks to system to calculate internally. Fuzzy PID will work and output pulse to control warp let-off motor to ensure the warp tension is constant while keeping synchronization with winding roller according to the warp beam diameter changing and the reduction ratio of the warp beam, and the received signal.
In the weaving process, the warp tension is a periodic change process. Warp tension control is a process that the controller continuously detects the warp tension value, and adopts an appropriate control method to control the running speed of the let-off motor, so that the warp tension maintains a dynamic and stable process near the set value.
In the warp tension control system of the traditional PID control algorithm, because the calculation of dynamic torque is complicated and highly dependent on mathematical model which is difficult to guarantee, it often fails to meet requirements in practical applications.
The idea of fuzzy control is to use the error and error change rate to control, and its control law is derived from human experience, that is, without knowing the control object model of the system, to use the known error and error change rate to effectively control the system.
On this basis, the Lanying CNC wire mesh weaving machine adopts the fuzzy control method in the intelligent control system combined with the PID control method.
The fuzzy PID control algorithm has the advantages of fast response speed, good robustness and high precision, which can effectively ensure the warp tension is stable, the response speed of the system is fast, and the control precision is high, which improves the automation level of the wire mesh weaving machine.
The unique calculation method, fuzzy control method and professional tension control unit in the CNC system independently developed by Hebei Lanying Technology Co., Ltd. realize the precise control of the mesh surface tension. The mesh surface tension is displayed and automatically adjusted in real time.