Multi-motor Virtual-like Total Axis Control Based On Sliding Mode Observer

With the continuous development of modern industrial technology,the operation mode of single motor system can not meet the needs of a variety of production.In many industrial production in our country,many areas need more than two motors running,such as paper making,printing and other industries.In the papermaking,textile,printing and other industries,the mechanical shaft driving way is replaced by large quantities of multi-motor synchronous driving mode.At present,the common control strategies of multi-motor synchronous driving mode are parallel control,master-slave control,cross-coupling control,deviation coupling control and electronic virtual line-shafting.Among them,electronic virtual line-shafting control strategy has been successfully applied to the paper machine and other equipment with the advantages of flexible configuration,easy adjustment and so on.In the process of load disturbance,the traditional electronic virtual line-shafting control strategy had a great error in the speed and position of motors due to the time lag of the virtual elastic torque feedback.Aiming at this problem,this paper proposes an improved electronic virtual line-shafting control strategy.In this strategy,the sliding mode observer is designed to load torque,the observed load torque feedback to the virtual machine and feedforward compensation in real-time;at the same time,in order to solve the contradiction between the speediness and the buffeting degree of the traditional sliding mode algorithm design observer,the novel exponential reaching law is proposed to design the load observer.Finally,a multi-permanent magnet synchronous motor driven paper transport experimental platform is set up,and the traditional electronic virtual line-shafting strategy and improved electronic virtual line-shafting strategy are experimentally analyzed.The experimental results show that the improved electronic virtual line-shafting can improve the ability of the system to deal with the load change,and effectively reduce the speed and position synchronization error of motors.