Background: To the problem that the traditional square laminated machine with passive
unwinding control strategy makes the tape speed periodical changing in reciprocating motion and
not achieve a good tension control, a novel unwinding system and control algorithm are presented
to improve the efficiency and quality of such equipment.
Methods: Compared with the traditional passive unwinding control system, the novel tension control
system adds an active compliance mechanism. After obtaining the motion relationship between
the compliance device and the laminated motion platform through building the complex system
mathematical model, the laminated machine tension control is equivalent to a spatial trajectory
tracking control, and multi-axis synchronous coordinated control algorithm is used to control their
relative motions, and a cross-coupling control in multi-axis coordinated motion is presented to decrease
the synchronous error of the two linear servo motors, which are the compliance device driving
motor and the laminated motion platform driving one. Without tension sensor, however, good
tension control is obtained only by position tracking control.
Results: Based on the proposed approaches and novel unwinding mechanism, the tension control
was examined on an experimental square lithium battery laminated machine and results of the experiments
performed with the experimental setup demonstrated the effectiveness of the proposed
Conclusion: Without a tension sensor, good tension control is obtained only by position tracking
control in the novel unwinding system, and the production quality and efficiency of the lithium battery
laminated machine are improved.