Algorithm of getting and applying target let-off value of loom

At present,many looms use conventional PID control in China,which can′t get a good control result.Due to defects of conventional PID control,the concept of target let-off value is defined,and an algorithm to get the target let-off value of loom is designed.An application example is introduced.The algorithm can tell complicated patterns weaving apart from the whole weaving process through warp voigt model,fit the warp tension curve with least square method,and then get the target let-off value in the end.The simulated results indicate that the target let-off value is exact enough,and the control effect and dynamic performance of two examples are obviously superior to those of conventional PID contro1.