Kinematic Analysis and Virtual Prototype Simulation of the Thrust Mechanism for Shield Machine

The hydraulic thrust system of the shield machine is used for driving forward and pose adjustment. It is of great significance to figure out the thrust mechanism and motion characteristics of the shield machine to ensure the safety of tunnel excavation. This study aims to develop a model to explore the influence of thrust cylinder advancement on the motions of the shield machine. Firstly, the study carried out mechanism analysis of the thrust mechanism for the shield machine and established a method to describe the position and attitude of the shield machine during the tunneling process by the homogeneous transformation matrix. Then, a new inverse kinematic model was proposed to quantify the relationship between the telescoping movements of cylinders and shield machine motions, and the Jacobian matrix was derived to solve the instantaneous kinematics analysis. Furthermore, a virtual prototype model was developed to simulate the kinematic behavior of the shield machine and validate the accuracy of the kinematic model. The model provides the basic constraint relations for the practical position control system and lays a strong foundation for the dynamic model and automatic trajectory tracking control of shield machines for future studies. Based on the proposed model, the displacement, velocity, and acceleration of cylinders that drive the shield machine to the target motions can be solved exactly. It can provide a reference for the pose control of the shield machine during the practical shield tunneling.