The servo system occupies a relatively important position in the electronic control system of the whole rapier loom, which is reflected in the two aspects of servo function and price. Electronic let-off and electronic take-up used to be optional parts (especially electronic take-up), specified by the user. The machine has been configured as a standard part. The electronic let-off and electronic curling are done by the servo system. The EDB series servo system developed and manufactured by Nanjing Estun Company has successfully completed the electronic let-off and electronic crimping of rapier looms for several well-known rapier loom manufacturers after market tempering and improvement in recent years. Servo applications provide a suitable choice for manufacturers to reduce costs and increase efficiency. The following will introduce the application of Estun EDB servo system on the rapier loom produced by a manufacturer in East China.

The interweaving of warp and weft yarns on a rapier loom can only be accomplished by the organic coordination of the five major movements of browning, weft insertion, weft beating, warp let-off, and winding, as well as the coordination of other auxiliary movements. In addition, there are auxiliary movements controlled by auxiliary mechanisms, such as warp breakage automatic stop, weft lack automatic stop, weft yarn replenishment (shuttle change) and other auxiliary movements. The control of the whole operation process is complicated. It is necessary to realize the basic functions such as start, stop, warp stop, weft stop and automatic weft searching of the loom. The relevant mechanism adjusts the speed of the let-off motor and the take-up motor respectively through the servo controller to maintain the required weft density of the fabric and ensure the constant tension. The following figure is the block diagram of the control system of the rapier loom

The control circuit takes PLC as the core, or replaces it with single-chip microcomputer. The following mainly introduces the electronic let-off and electronic winding mechanism closely related to the servo system. The electronic let-off mechanism consists of three parts: the tension signal acquisition system, the signal processing and control system, and the weaving shaft drive device. The pressure sensor installed on the double rear beam detects the warp surface tension, the PLC detects the tension feedback signal when it is flat brown, and the signal is processed by the PLC to control our servo system. , so as to realize the automatic control of constant tension and ensure the uniform tension in the process of the weaving shaft changing from large to small