Modeling and observer-based robust controllers for telescopic truck cranes

Strict underactuation, complex structure, shape variation, and elasticity of machine elements cause many challenges in control of telescopic truck cranes. We develop a dynamic model of telescopic boom cranes considering flexibility and damping of load-carrying rope, viscoelasticity of boom-luff cylinder and extension cylinder. Modeling and control are constituted for the complex operation in which three motors including payload hoist, boom elevation, and boom expansion are simultaneously activated. We provide two observer-based robust controllers entitled second-order and fast-terminal sliding mode controls. These controllers work well even when the crane faces parametric variation and disturbance. The control system halves its sensors because of the performance of observer. We analyze and verify the effectiveness of modeling and controllers by applying to a Grove-TMS500 truck crane. Simulation results show the asymptotical convergence of actuated outputs and the stabilization of unactuated ones. The crane responses hold the robustness against winds and parametric uncertainties. The oscillations of crane outputs are due to elastic components such as handling ropes, two hydraulic cylinders for luffing and expanding the boom. The controllers well eliminate these undesirable oscillations.

Automated summary

This study focuses on the complex control problem of telescopic truck cranes. A dynamic model and controllers are developed, and their effectiveness is validated through simulation results on a Grove-TMS500 truck crane. The controllers effectively eliminate oscillations caused by elastic components and provide robustness against wind and parameter uncertainties.