Phenomenon of higher transitional loop of tufted carpet and its compensation

As the development of jacquard technology of tufted carpets,the phenomenon of higher transitional loop which seriously influence the effectiveness of multi-level loop jacquard in all kinds of jacquard systems has to be elim inated.The dynam ic characteristic response time of step motor is the fundamental cause lead ing to the phenomenon in the system of step servo jacquard,which is explained through mathematicalmodel of velocity control.For solving this problem,the analytical equation of speed curve was derived from the dynam ic characteristics equation of step motor.The amount of compensation was accurately calculated based on the equation.The compensation program based on index shaped curve was selected through comparing S-shaped curve with index shaped curve.Furthermore,a set of single-chip control program was proposed to solve the problem.The compensation program can improve the flexibility of the step servo to control the jacquard system.