Optimal control of a novel cutter head driving system for tunnel boring machine

The cutter head of a tunnel boring machine may be trapped in extremely adverse geological environments, which requires a large enough driving torque to get rid of the trapped condition. In this paper, a novel driving scheme is proposed to improve the driving performance of the tunnel boring machine cutter head without increasing the installation power. First, the hydro-viscous clutch is introduced to achieve the soft start of the cutter head by the flexible effect of viscous oil film. Then, the flywheel is employed as the energy storage element to provide sufficient torque during the hydro-viscous clutch engagement, which assists the cutter head to get rid of the trapped condition. Moreover, an optimal state feedback control law based on a linear quadratic regulator is designed by compromising system impact and hydro-viscous clutch friction loss to optimize the hydro-viscous clutch engagement process and achieve favorable driving performance of the cutter head. Finally, numerical simulations are conducted to validate the effectiveness of the proposed driving technology.