High Precision Automatic Assembly Based on Microscopic Vision and Force Information
An automatic system is developed to realize high precision assembly of two components in the size of mm level with an interference fit in 3 dimensional (3 D) space with 6 degree of freedoms (DOF) which consists of a manipulator, an adjusting platform, a sensing system and a computer. The manipulator is employed to align component B to the component A in position. The adjusting platform aligns the component A to component B in orientations and inserts A into B. The sensing system includes three microscopes and a force sensor. The three microscopes are mounted approximately orthogonal to observe components from different directions in the aligning stage. The force sensor is introduced to detect the contact force in assembly process. In the aligning stage, a pose control method based on image Jacobian matrix is proposed. In the insertion stage, a position control method based on the contact force is proposed. The calibration of image Jacobian matrix is also presented. Experimental results demonstrate the effectiveness of the proposed system and methods.
IEEE Transactions on Automation Science and Engineering