Research On Mechanical Modeling And Simulacation Of Flexible Cable Harness On Spacecrafts Considering Spatial Constraints

Spacecrafts such as satellites are complex and compact which have manyfunction modules. Cables on the satellite in long-term orbit are unorganized andnumerous, they have many functions, including information transmission, powertransmission, structure connection and other functions. Therefore, it gets difficultfor the path planning because of numerous cables. The traditional manual wiringmethods have been eliminated and the computer aided wiring methods are difficultto consider physical characteristics of the cable comprehensively. The authenticityand instantaneity also can not meet the needs of modern industry.In this paper, a mechanical model of the cable is established according to thecharacteristics of large deflection. In this model, any position of the cable isexpressed by pitch angles, deflection angles and antero-posterior diameters; thecable space attitude is expressed by mutual conversions between four coordinates.An equilibrium equation of the cable is established only by considering gravityforce distribution and environment force, a dynamic equation of the cable isestablished according to the motion parameters of the cable. The section, quality,mechanical properties and other physical factors of the cable are considered in thismodel. By establishing the mechanical model of the cable, the change regulation ofcable posture, movement parameters and the internal force along with the changesof cable length and time is expressed. This model provides theoretical basis forwiring in a virtual environment.Usually, the environment of cable wiring is very complex which is filled withmodular units, many functional components and miscellaneous, so the structure iscomplex and the constraints are numerous but these constraints can be classified. Inthis paper, the constraint types of the cable are divided into5categories: theendpoint constraint, the pretightening force constraint, the point or line contactconstraint and partial pressure constraint, the influences of various constraints onthe cable geometry factors, movement factors, stress factors are analysed in thispaper. Then, the new equilibrium equation and kinetic equation are built byconsidering these constraints.There is no clear relationship between the parameters and the length of thecable, the mechanical model and the cable space constraints are calculated by usingthe powerful mathematical calculation functions and data visualization functions ofMATLAB. The space position, movement parameters, internal stress under thecondition of these constraints are showed vividly by the graphics, these simulationanalyses validate the correctness of the cable model.