Regional coupling based synchronization control of multi-motor driving TBM cutterhead system

Tunnel boring machine (TBM) is widely used in long deep tunnel construction with its advantages of high efficiency, safety and low manpower. Cutterhead driving system provides power for excavating rocks and is an important component of TBM. Since the cutterhead system is driven by multiple induction motors, the synchronization control of multi-motor is critical important for high efficient excavating. The driving motors have to bear different excavating loads due to the uneven distribution of soils acting on the cutterhead surface. In this paper, all the driving motors are divided into two regions and a regional coupling based synchronization control strategy is proposed for the TBM cutterhead system. The dynamical induction motor model for vector control is established through coordinate transformation. The synchronous control of motors in each region is achieved by designing a master-slave motor control strategy. To deal with the torque difference between two regions, a fuzzy logic PID coordination controller is proposed for the master motors. Then, the synchronous control of driving motors is achieved by the presented regional coupling control strategy. The proposed synchronization control strategy is validated by simulating on multi-motor driving TBM cutterhead system for constant load torque and varying load torques, respectively. Compared with the single master-slave control, the proposed regional coupling control can achieve quicker dynamic response and better synchronization performance.