Abstract:

The lifting capacity parameter is one of key parameters on mobile crane’s safe operation. Aiming at the optimal problem of lifting capacity calculation under multiple parameters constraint, the structural theory research is carried on systematically and synthetically. The relevant algorithms about the telescopic boom strength, rigidity, global stability, local stability, rollover stability and stability of the derricking cylinder are given. The comprehensive assessment system is created that is composed of 13 types of evaluation indicators and four subsystems: boom, super-lift structure, derricking cylinder and rollover performance. Based on these algorithms the optimization model of lifting capacity calculation is established. Different evaluation indices are normalized which forms a normalized index set. Maximizing the set element gets total control performance index. The numerical iterative algorithm of lifting capacity calculation is established based on the Lagrange algorithm. In the process of iteration the algorithm can adjust the weight and amplitude at the same time which is helpful to improve the iterative convergence rate. The calculation results show that the method has fast convergence rate and high calculation accuracy. The study can lay a theoretical foundation for further software development on hoisting capacity calculation of the big tonnage mobile. The relevant algorithms also can provide theory reference for mobile crane’s structure design and product optimization.

Key words: evaluation index, global stability, lifting capacity, normalization, mobile crane