Motion Planning, Finite Element Analysis And Hydraulic System Simulation Of Cable Parallel Manipulator For Multiple Cranes

This thesis was supported by Chinese National Natural Science Foundation, entitled by ―Research on dynamic performance analysis and coordinated control technology of large heavy-duty special cable parallel manipulators for multiple cranes(Project Number: 51275515)‖. Taking the cable parallel manipulator for multiple cranes(CPMMC) as the object, the hoisting trajectory planning and obstacle avoidance path planning are conducted based on the kinematic and dynamic analysis. In addition, the finite element analysis of the CPMMC and the simulation of the hydraulic system are performed. The main research works can be described as follows:1. The basic configuration and working principle of the CPMMC are described. The kinematic equation is derived by use of analytical method. On this basis, the dynamic model of the CPMMC is established with the D’Alembert’s principle. Taking the constraints into consideration, the constant orientation working space of the CPMMC are analyzed and generated through numerical simulation. By a certain engineering case, the kinematic and dynamic models are verified.2. The hoisting trajectory planning of the CPMMC is analyzed. The circle and point-to-point movement of the CPMMC are discussed in non-obstacle working condition. Polynomial interpolation is adopted to eliminate the discontinuity of the accelerations on the luffing system, slewing system and hoisting system, which is the basis of the safety and stability of the CPMMC.3. The obstacle avoidance path planning of the CPMMC is discussed. Considering the original environment of the CPMMC, the model of the working environment is established with MAKLINK method. On this basis, the feasible obstacle avoidance paths are searched rapidly based on Dijkstra algorithm at the first step and then the optimal obstacle avoidance path is determined with ant colony algorithm. The numerical simulation indicated that the adopted method, combining the Dijkstra and ant colony algorithms, has the rapid and accurate path searching capability, which can be applied in the obstacle avoidance tasks of the CPMMC.4. The three-dimensional model of the CPMMC is established. Combined with a hoisting case, the stress and deformation characteristices of the key components are obtained by using the finite element software, and then the weak links of key components are found. Furthermore, the improving suggestions are proposed about the weak links. The results provide the theoretical basis for structure optimization design of the CPMMC.5. The assistance analysis system and simulation model of the hydraulic system for the CPMMC are established, respectively. The co-simulation of the hydraulic system is conducted combining with a certain hoisting case. By simulation, the model of the hydraulic system is verified and some important parameters which influence its dynamic performance are obtained. The simulatio results provide a key basis for practical application of the hydraulic system.