Dynamic simulation of auto-centralizer for horizontal well traction robot based on ADAMS

Traction robot conveying technology is efficient in horizontal well logging. Auto-centralizer is an assistant support to bear the weight of robot and center the robot in casing while logging. The mechanical model for an auto-centralizer with four pair of bias arms was built based on spring-lever mechanism. ADAMS (Automatic Dynamic Analysis of Mechanical Systems) was applied to analyze the sensitiveness coefficient of structural parameters and spring force, thus optimizing the structural parameters. Consequently, a simulation model was built based on the optimization result, and a simulation study was carried out on the mechanical properties and dynamic performance with the ADAMS mechanics system modeling and simulation module. The results implied that the original structure had a disadvantage while traversing obstacles. Further studies indicated that the coupling between the pair arms adopted hinge joint, which couldnʹt form a closed triangle of force while traversing obstacles. We have employed an improved structure by adding a connecting lever to eliminate the constraint between the arms. Contrast experiments show that the new structure avoids bearing the load with one side and has less shock while traversing obstacles, thus improving smoothness of movement for the traction robot.