Precise docking technology in full-automatic quick hitch coupling device

When the full-automatic quick hitch coupling device (full-AQHCD) of the rescue robot wrist automatically locks tightly the attachment interface, i.e., the lower coupling parts (LCP), it must synchronously dock precisely with and switch on the hydraulic pipelines of the LCP automatically, for this reason, the precise docking theory (PDT) based on digital measurement and the PDT based on analog measurement are proposed for guiding the manufacturing at the product stage and the prototype stage respectively. The PDT at product stage is: the full-AQHCD is regarded as a passive target, and the LCP is regarded as an active target; the full-AQHCD is connected with the LCP through 4 coupling points; the position-orientation relationships between the passive target coordinate system (X₁O₁Y₁), the active target coordinate system (X₂O₂Y₂) and the precise docking coordinate system (XOY) are established by measurement; the coordinates of docking points (CDPs) in X₁O₁Y₁ are transformed to the CDPs in XOY, and then transformed to the CDPs in X₂O₂Y₂; the postures of the docking points on the active target are adjusted according to their CDPs in X₂O₂Y₂ to achieve the precise docking with the docking points on the passive target; finally, the docking points on the active target are fixed. The PDT at prototype stage is: the full-AQHCD is regarded as a passive target, and the LCP is regarded as an active target; the oil-lines cabin of the full-AQHCD is not constructed to expose the operation space (like wrench space) of the working cabin of the full-AQHCD; the full-AQHCD is connected with the LCP through 4 coupling points; the additional oil source is supplied for first “docking” hydraulic lines in the operation space, and then “measuring, posture adjusting and finally fixing” hydraulic lines of the active target; the oil-lines cabin of the full-AQHCD is completed. Regarding the above two theories under two conditions, simulation and verification are carried out.