## 5 Self-Insulation Performance Simulation Analysis

Table 2: Material selection comparison. of 2.5-4.5 GPa ensures sufficient rigidity while avoiding the brittleness problem that may be caused by polyimide (3.0-5.0 GPa), and its density of 1.1-1.4 g/cm\({}^{3}\) is also better than polyimide (1.4-1.6 g/cm\({}^{3}\)), which is more conducive to lightweight design. In terms of insulation performance, the dielectric strength of epoxy resin of 15-22 kV/mm fully meets the working requirements of the charged environment. Although it is slightly lower than that of polyimide (20-30 kV/mm), considering the significantly higher cost of polyimide, epoxy resin has obvious advantages in terms of cost performance. For the selection of drive rope materials, polyester resin is an ideal choice with its moderate mechanical properties (40-90 MPa tensile strength, 180-400 MPa bending strength) and elastic modulus of 2.0-3.5 GPa. Compared with silicone (1.0-2.0 GPa elastic modulus), polyester resin has better dimensional stability and can transmit driving force more accurately; compared with phenolic resin, polyester resin has better flexibility. Although polyimide is superior in performance, its high cost makes it unsuitable as a rope material that needs to be used in large quantities. Although the dielectric strength of polyester resin of 10-15 kV/mm is not as good as that of epoxy resin and polyimide, it has fully met the insulation requirements of ropes, and its cost advantage is obvious. Considering the performance requirements and economic benefits, the combination of epoxy resin and polyester resin has achieved the best balance in mechanical properties, control accuracy and insulation safety, and is the most suitable material solution for rope-driven manipulators in live environments. Overall, the high strength, high rigidity, and lightweight properties of epoxy resin make it an ideal choice for the main body of the robotic arm, while the moderate elasticity and bending properties of polyester resin make it more suitable as a drive rope material. The combination of the two achieves the best balance in ensuring mechanical properties, control accuracy, and insulation safety. Five planes are selected to calculate the electric field (Figure 13). The field values are calculated along the diameter of the plane. Plane 1 is the moving platform of the wrist joint. Plane 2 is the fixed platform of the wrist joint. Plane 3 is the elbow joint. Plane 4 is the moving platform of the shoulder joint. Plane 5 is the fixed platform of the shoulder joint. The specific simulation environment details are shown in Table 3.  
Figure 13: Components of the finite element model of the system. The HV contact electrode at the end-effector of the moving platform engages with a 220 kV cylindrical charged body to simulate contact with exposed cables. The electrode on the fixed platform is set to ground potential. The simulated potential and electric field intensity distributions are shown in Figure 14. Potential distribution and electric field intensity profiles were obtained by sampling surfaces of both moving and fixed platforms in the simulation model. In this simulation, five measurement planes were selected to measure the specific distribution of the electric potential. The selected measurement positions are shown in Figure 13. The measurement results at the different positions are shown in Figures 15 and 16. The potential results in Figure 15 indicate that the potential distribution reduces nonlinearly with the distance between the mechanical arm and the cable. The potential gradient across the insulator surface exhibits smooth monotonic decay without abrupt discontinuities, indicating no localized breakdown risk. The simulation results reveal distinct potential distributions across various sampling planes. At position 1, located in close proximity to the charged conductor, the measured potentials reach a maximum of approximately 138.4 kV with a minimum of 135.2 kV, resulting in a potential differential within 3.2 kV.