Analysis Of Key Problems And Model Experimental Research On A Long-span Wire Driven Parallel Robot

Based on the solution of the unstressed length of the cable, the direct and inverse kinematics models for the cable-cabin system of a Large Radio Telescope (LT) are solved. Thus the unlooped control of movement of the cabin is realized by adjusting the transformative lengths of the cables, which lays the theoretic foundation for the fine control of the LT500m prototype. The label of the home pose, the measurements of static error and dynamic error of the cabin and so on experiments are finished, which is the experimental groundwork for the model experiments of the amendatory structure for LT.The reachable workspace of a long-span Wire Driven Parallel Robot (WDPR) and its estimation rule of the stiffness characteristics are advanced. The workspace and the stiffness capability for LT50m are determined respectively. The analytic expression of the stiffness matrix of WDPR is deduced. The variation law of stiffness with tower heights and cable tensions is founded, and the conclusions will be used as good reference for the stiffness amelioration, vibration control, and control bandwidth determination. What's more, in view of the weak torsional stiffness and movability of the cabin for WDPR, the better amelioration structure is determined by experiments and simulation.The structure parameters of two amelioration structures, cabin with add-on vessel and cabin with inactive cables, are optimized. That the two constructions can control pseudo-drag cable and wind induced vibration is verified. The results will be used for the structure type and design for LT500m prototype.The approach of kinematics parameter demarcation for WDPR based on static demarcation is designed. The convergence of the static demarcation is validated by simulation on LT5m model experiments, showing that the geometry parameters have a dominating effect on the position and orientation of the moving platform for LT5m model. To realize dynamic parameter demarcation for WDPR, flexible demarcation based on Artificial Neural Networks (ANN) is brought forward. The simulation of flexible demarcation shows its validity so as to provide a new demarcation for LT500m prototype system.The inverse dynamic model for a long-span WDPR is founded, and the rationality of the dynamic model is verified by numerical analysis. The higher precision of the control for WDPR is obtained.The similar empirical formulas of the cable tension and the structural natural frequency for LT are established. The corresponding forecasted coefficients of aberrant model for LT versus LT prototype are deduced. The predictions of the cable tension and the structural natural frequency for LT500m are realized. Similar degree for WDPR system is defined on the fuzzy mathematical method, and the similar degrees of the cable tensions and the natural frequencies between LT model and LT prototype are confirmed by simulation. The rationalization of the similar degree definition is proved. Similar degree applies the scale guideline to aberrance grade between LT model and LT prototype.