Cooperative Hoisting with Dual Crawler Cranes: Modeling, Motion Planning, and Control under Constraints

With the rapid development of large scale infrastructure construction and industrial assembly such as wind turbine installation, bridge segment erection, and modular plant construction dual crawler cranes (DCCs) have become essential equipment for handling oversized and heavy loads. Their cooperative hoisting capability enables the manipulation of massive structures beyond the lifting capacity of a single crane. However, due to the cooperative hoisting of DCCs represents a complex nonlinear control problem characterized by strong coupling, underactua-tion, and multiple motion constraints. Ensuring safe, efficient, and precise load manipulation in such systems poses significant challenges, particularly when considering the bounded nature of rope velocities and the closed chain geometric configuration formed by the cranes and the suspended load. This thesis investigates the modeling, trajectory design, and control of DCCs cooperative hoisting systems with two types of suspended loads: a point-mass load and a rigid-rod load. For the point-mass case, a comprehensive kinematic model is developed to describe the motion under cable velocity constraints. To achieve time optimal lifting while respecting the rope-velocity bounds, an optimal control method is proposed to minimize the total hoisting duration under physical constraints. Building upon this, an adaptive velocity shaping technique is introduced, which dynamically adjusts the motion speed based on the instantaneous position of the load and the cable dynamic factors. This adaptive mechanism guarantees con-straint satisfaction while maintaining high motion efficiency and smooth deceleration as the load approaches the target position, thereby further reducing the total lifting time. For the rigid-rod load system, a complete nonlinear dynamic model is established without linearization assumptions. Through systematic constraint reduction, the original fifth order dynamic model is reduced to a simplified third order representation that retains essential nonlinear behaviors. This formulation provides an accurate yet tractable foundation for controller designand serves as a reference for similar closed chain mechanical systems. Stability of the closed loop system is analytically verified through both linearized and energy based approaches. A constraint consistent trajectory generation method is then proposed, in which reference trajectories are directly designed in the cable length domain. By determining the equilibrium configuration at each instant through the system’s balance equations, the approach ensures that all reference trajectories inherently satisfy static equilibrium and geometric feasibility. On this basis, a PID-based coupled error compensation control scheme is developed to coordinate the motions of the two cranes while suppressing load sway. The controller integrates synchronization and attitude error compensation to achieve cooperative stability and high precision tracking. Extensive simulation studies are conducted in MATLAB to validate the effectiveness of the proposed models and control strategies. The results demonstrate that the developed methods ensure precise trajectory tracking, strong robustness to system asymmetry, and significant improvements in lifting efficiency and vibration suppression.