The Movement Analysis and Research of 3R Parallelogram Linkage Manipulator
This paper studies three degrees of freedom used in multi-joint robot kinematics in the process of loading and unloading problems, through the homogeneous coordinate transformation method to describe the spatial relationship between two adjacent connecting rod, thus derived the equivalent homogeneous transformation matrix between "gripper coordinate system" and "reference frame", establishing a movement equation for the operation arm, then worked out all joints variable with the known position vector of the last connecting rod.
K. Tao and S. L. Fan, "The Movement Analysis and Research of 3R Parallelogram Linkage Manipulator", Advanced Materials Research, Vols. 588-589, pp. 1636-1639, 2012