Trajectory Control of Tunnel Boring Machine Based on Adaptive Rectification Trajectory Planning and Multi-cylinders Coordinated Control

Trajectory control of tunnel boring machine (TBM) has important implications for excavation efficiency and tunnel quality. A novel rectification trajectory planning method is proposed for TBM with adaptively designed direction and curvature against different attitude deviations and target path, and is comparatively studied with traditional method via numerical simulations. TBM could be fully-actuated by decoupling thrust and torque cylinders in horizontal and vertical planes, respectively. After the tropology analysis of the 4-SPS/PS structure, the real-time expected motions of torque cylinders in vertical plane are derived via reverse kinematics together with synchronous thrust cylinders; so does cylinders in horizontal plane. The proportional direction valves of torque and gripper cylinders are compensated with fixed pressure drop. A compound displacement tracking controller could be established, including flow-speed feed-forward with dead-band compensation and displacement feedback by fuzzy proportional–integral (PI) controller with separated integration. Synchronous controller of integral separated PI structure is also proposed. Experiment results on a Φ 2.5 m scaled TBM indicate that, the displacement tracking performance of cylinders under the compound controller against unbalanced load, which is ± 0.9 mm for high-speed thrust cylinders and ± 0.13 mm for low-speed gripper and torque cylinders, could meet the tolerance of trajectory planning and realize accurate attitude correction.