Dynamic simulation and disturbance torque analyzing of motional cable harness based on Kirchhoff rod model

The motional payloads on stabilized platform must be linked by some cable harnesses with other immobile apparatus. During the operation of stabilized platform, these cable harnesses can create spring disturbance torque which is exerted on the stabilized platform and then reduce the stabilizing precision. None of current studies can deal with the spring disturbance torque problem. To analyze the spring disturbance toque, a dynamic thin rod model is presented for simulating the motional cable harness which is based on the Kirchhoff rod theorem and can consider the geometrically non-linear effects. The internal bending and torsion restoring torques are simulated and then a predictive analysis of the disturbance torque can be performed in motional cable routing design. This model is solved with differential quadrature method (DQM). By using zeros of the Chebyshev polynomial as the grid points, the arc-coordinate is discretized to obtain a set of ordinary differential equations in time domain which is solved by implied method to obtain the profile and internal force of cable harness. The accuracy of this model is validated by comparing the simulation results and the experiment results (both the spring force and the deformed profile of the motional cable harness). In the experiment, a special optical measuring instrument based on binocular vision is developed. The comparison of experimental and simulated results shows that the simulation model can represent the real motional cable harness well, and the spring disturbance force simulation results are precise enough for spring disturbance torque analysis. This study will be helpful to obtain an optimized motional cable harness layout design with small spring disturbance torque.