| With the continuous development of new energy vehicles and digital products,the portable charging equipment and the large capacity rechargeable battery have become the future development trend.The lithium-ion battery has the characteristics of high energy storage density and long service life,which has become the mainstream in the cell.The processing technology of lithium-ion battery is mainly divided into three kinds: winding technology,lamination technology,slicing technology.The study found that the production efficiency of lithium battery in winding process is high,but the performance of the batteries are generally;The processing technology of the lithium battery in laminated is complex,resulting the production efficiency is not high,but the performance of the battery is very good;The performance of the slicing lithium battery and the laminated lithium battery are basically the same,but the processing technology is much more complex than the laminated lithium battery,so it is rarely used.With the development of automation technology,the lamination lithium battery will become the mainstream of the lithium battery.Tension control is the key technology in the process of lithium battery lamination,it is easy to deform or break of the isolation membrane when the tension is too large.It is easy to fold and retraction of the isolation membrane when tension is too small,lead to the separation of membrane stack is not neat.It is easy to explode in the process of using when the lithium battery is not qualified.In this paper,we studied a new active continuous unwinding technique and a master-slave synchronization control technology to control the tension,compared with the previous passive unwinding,high speed continuous active unwinding is achieved,at the same time,the tension of the lithium battery lamination machine is stable in the process of the intermittent reciprocating lamination of the lamination machine.The mathematical model of the isolation film tension control of the lithium battery lamination machine is established based on the working principle of the lithium battery lamination machine,design the control strategy of the tension control system and the deviation rectification control system,the mathematical model of linear motor dynamics and the mathematical model of rotary motor dynamics are established,we use the least square parameter identification method to identify the mathematical model of linear motor and rotary motor,at the same time,the trajectory of linear motor is simulated and analyzed by the method of non-symmetrical S curve trajectory planning.In solving the problem of the separation membrane rectification of the lithium battery lamination machine system,we give up the common rectifying device of market to use the project of control guide plate before and after motion to achieve rapid correction,and the adaptive fuzzy control algorithm is developed to reduce the error of deviation.Combined with the mathematical model,control strategy and control algorithm for Matlab/simulation,the simulation results show that the design of the system is feasible.To build the experimental platform,combined with the classic PID control algorithm to achieve the transmission of active isolation film unwinding,at the beginning of the experiment,the following error of linear motor is large,which leads to the mathematical model of the system is not accurate.Therefore,the feed forward control algorithm and predictive control algorithm are introduced,and good experimental results are achieved.In this study,the cycle of lithium battery lamination machine is increased to 0.55s/pec from 1.1s/pec,and the tension is very stable.The alignment of isolation membrane's reached ±0.15 mm,CPK index reached 2.936,far exceeding the existing technical level.The final experimental results show that the design of the tension control system and the deviation of the control system of the lithium battery lamination machine are feasible,and the alignment of isolation membrane's also fully meet the market demand. |
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