Mechanical arm multi-station accurate alignment method with far and near sight distance guiding function

Abstract

The invention discloses a multi-station accurate alignment method for a mechanical arm with far and near sight distance guidance, which comprises the following steps of: firstly, constructing a two-eye visual configuration with far and near sight distances, and forming an Eye-in-Hand visual feedback system with the mechanical arm; calibrating internal and external parameters of two-eye vision and a hand-eye relation transformation matrix; establishing a task table of each station through an off-line prior local alignment mode; a three-stage alignment strategy is provided, namely, multi-station operation initial pose acquisition, initial positioning of a global camera and fine alignment of a local camera, so that the mechanical arm can achieve accurate alignment of a tail end tool and a target under multiple stations. According to the invention, the sensing capability of the mechanical arm system to the environment is improved, and the alignment precision is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of aerospace, and in particular relates to a multi-station precise alignment method of a mechanical arm with far and near vision distance guidance. Background technique [0002] In the aerospace field, robotic arms are often used for nail feeding and inserting in automatic drilling and riveting systems, assembly of hole and shaft parts, and space on-orbit services. In most cases, the robotic arm can only perform pre-planned actions step by step, and cannot adaptively adjust to changes in the task environment. This working mode lacks flexibility, especially in complex industrial sites, where unknown environmental changes occur from time to time, which will seriously affect the working efficiency and accuracy of the robotic arm. [0003] In order to improve the stability and flexibility of manipulators, vision-based manipulator measurement systems have received extensive attention from researchers. Vision sen...

AI Technical Summary

Problems solved by technology

During the movement of the robot arm from far to near, the camera will be out of focus and out of focus at certain distances, resulting in a decrease in the accuracy of pose measurement, and even the failure of the assembly task

In view of such problems, the application of the zoom camera in the visual guidance of the manipulator is studied. The zoom camera can clearly image the target during the movement of the manipulator. However, the current zoom camera has difficulties in calibration, low measurement accuracy, and poor flexibility. characteristics, which greatly limit its application in industrial field

Aiming at the problem of manipulator assembly of large-sized workpieces, the alignment process of the tool at the end of the manipulator and the target workpiece is divided into two stages: long-distance coarse alignment and short-distance fine alignment, based on the multi-sensor automatic alignment strategy. A variety of sensors are used, which increases the complexity of the system and the difficulty of data processing

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