Design of warp knitting electronic shogging system based on mixed-velocity planning curve

Abstract

To realize high-speed running of a warp knitting machine, the shogging motion should not only meet the requirement of high dynamic response but should also satisfy high positioning accuracy. Due to the large location disturbance and the dynamic response delay in the interpolation method or the single velocity planning curve method, an electronic shogging system for a warp knitting machine based on the mixed-velocity planning curve is proposed in the present study. Through the analysis of the shogging motion combined with the knitted structure, the optimal resolution of the instruction signal is calculated, which is 725 pulses for one needle step, and the velocity loop bandwidth of the servo driver is optimized. In addition, the motor with a load inertia ratio close to 1 is also selected. Analysis of the shogging motion vibration curve confirms that the shogging motion has advantages of high positioning accuracy and high dynamic response under the mixed-velocity planning curve. The response performance with the mixed curve is 12.5% higher than that with the quintic polynomial, and the positioning accuracy of the mixed curve is 26% higher than that with uniform acceleration–deceleration curve.